research on degradation of silk fibroin by combination of electron ...

VIETNAM ATOMIC ENERGY INSTITUTE

SCIENCE AND TECHNICS PUBLISHING HOUSE

TheANNUAL REPORT

For 2013


ANNUAL REPORTfo r 2013

Editorial Board:Dr. Tran Chi Thanh, Chief Editor Dr. Cao Dinh Thanh Dr. Nguyen Thi Kim Dung Eng. Nguyen Hoang Anh M.Sc. Nguyen Thi Dinh B.A. Nguyen Thi Phuong Lan

Hanoi, November 2014

The VINATOM Annual Report for 2013 has been prepared as an account of

works carried out at VINATOM for the period 2013. Many results presented in

the report have been obtained in collaboration with scientists from national and

overseas universities and research institutions.

The ANNUAL REPORT for 2013

Edited by

Vietnam Atomic Energy Institute

59 Ly Thuong Kiet, Ha Noi, Vietnam

President: Dr. Tran Chi Thanh

Tel: +84-4-39423434

Fax: +84-4-39424133

This report is available from:

Training and Information Division

Dept. of Planning and R&D Management


59 Ly Thuong Kiet, Ha Noi,Vietnam

Tel: +84-4-39423591

Fax: +84-4-39424133

E-mail: [email protected]

[email protected]

Preface

The research activities of the Vietnam Atomic Energy Institute (VINATOM) during

the period from 1 January to 31 December 2013 are presented in this report. The research activities are focused on the following fields:

1. Nuclear Physics, Reactor Physics;

2. Research Reactor, Nuclear Power Technology, Nuclear Safety, Nuclear Power Economy;

3. Instrumentation, Nuclear Electronics;

4. Industrial Applications;

5. Applications in Ecology, Environment and Geology;

6. Applications in Biology, Agriculture and Medicine;

7. Radiation Protection and Radioactive Waste Management;

8. Radiation Technology;

9. Radiochemistry and Materials Science;

10. Computation and Other Related Topics.

The total number of permanent staff working at the VINATOM as December 31, 2013 is 743 including the clerical service staff. The VINATOM was funded from the Government with the total amount to 172.253 billion VND for FY 2013, an increase of 12.22% compared to the last fiscal year. The international support of 250,000 USD for the VINATOM activities is committed to the operating projects including equipment, staff training and expert services (3 VIE projects, 10 FNCA projects, 18 RAS projects and 11 research contracts with the IAEA).

Main results of fundamental and applied research implemented in the year were presented in 236 scientific articles, reports and contributions published in many journals, proceedings of conferences, etc.

During the time of year 2013, in the VINATOM there were 7 to be graduated in Ph.D. courses; about 155 people have been trained abroad in the fields of nuclear science and technology.

Dr. Tran Chi Thanh

President, VINATOM

9

CONTENTS

Page Preface 5

1. CONTRIBUTIONS 13

1.1- NUCLEAR PHYSICS, REACTOR PHYSICS 15

Investigation for Calculation Methods Used in Analyzing the Physics Characteristics

of Nuclear Power Reactor. 17

Nguyen Tuan Khai, Nguyen Minh Tuan, Tran Quoc Duong, Hoang Van Khanh, Phan Quoc

Vuong, Tran Viet Phu, Tran Vinh Thanh, Nguyen Thi Mai Huong, Nguyen Thi Dung and

Le Tran Chung.

Studying, Surveying the Capabilities of Determining Short-lived Radionuclides of

Instrumental Neutron Activation Analysis Using Pneumatic Transfer System at The

No.13-2 Channel and Thermal Column.

22

Ho Van Doanh, Cao Dong Vu, Tran Quang Thien, Pham Ngoc Son and Nguyen Thi Sy.

Improvement of the DHP Program and Apply for Fission Product Decay Heat

Calculations of 233

U, 235

U, 238

U, 232

Th and 239

Pu. 27

Pham Ngoc Son, Tran Tuan Anh, Nguyen Xuan Hải, Ho Huu Thang and Mai Xuan Trung.

1.2- RESEARCH REACTOR, NUCLEAR POWER TECHNOLOGY, NUCLEAR

SAFETY, NUCLEAR POWER ECONOMY 33

Study on Safety Analysis of PWR Reactor Core in Transient and Severe Accident

Conditions. 35

Le Dai Dien, Hoang Minh Giang, Nguyen Thi Thanh Thuy, Nguyen Thi Tu Oanh, Le Thi

Thu, Pham Tuan Nam, Tran Van Trung, Bui Thi Hoa, Nguyen Huu Tiep and Le Tri Dan.

A Neutronic Feasibility Study of the VVER Assembly Type Design Loaded With Fully

Ceramic Micro-encapsulated Fuel. 43

Hoang Van Khanh, Phan Quoc Vuong, Tran Vinh Thanh.

Calculation of Fuel and Moderator Temperature Coefficients in APR1400 Nuclear

Reactor by MVP Code. 48

Pham Tuan Nam, Le Thi Thu, Nguyen Huu Tiep and Tran Viet Phu.

Establishing Quality Assurance Program for Calculation in Core and Fuel

Management of The Dalat Nuclear Research Reactor Using Low Enriched Fuel. 52

Huynh Ton Nghiem, Luong Ba Vien, Le Vinh Vinh, Nguyen Kien Cuong, Nguyen Manh

Hung, Nguyen Minh Tuan, Pham Quang Huy, Tran Quoc Duong, Vo Doan Hai Đang,

Pham Hong Son, Tran Tri Vien and Tran Thanh Tram.

A SRAC Calculation of The VVER-1000 Core’s Effective Multiplication Factor. 61 Tran Vinh Thanh, Phan Quoc Vuong, Tran Viet Phu, Hoang Van Khanh and Ta Duy Long.

Modeling and Analysis of Thermal Hydraulic Phenomena for VVER-1000 Reactor

when Trip Out of One or Two Main Coolant Pumps by RELAP/SCDAPSIM Code. 69

Le Thi Thu, Pham Tuan Nam, Nguyen Thi Tu Oanh and Nguyen Huu Tiep.

1.3- INSTRUMENTATION, NUCLEAR ELECTRONICS 79

Study the Operation of Sub-system for Cyclotron Kotron13 with the Purpose of

Operation and Maintenance of This Equipment. 81

Nguyen Tien Dung, Pham Minh Duc, Le Viet Phong, Vu Duy Truong and Nguyen Xuan

Truong.

10

Application of Prompt Gamma Neutron Activation Analysis at the N0.2 Horizontal

Channel of the Dalat Nuclear Research Reactor Using a Compton-Suppression

Spectrometer.

84

Tran Tuan Anh, Nguyen Xuan Hai, Nguyen Canh Hai, Pham Ngoc Son, Ho Huu Thang

and Dang Lanh.

Research and Production of Calorimeter for Measuring Irradiation Doses on 10MeV

Electron Beam Accelerator. 90

Cao Van Chung, Nguyen Hoang Hai, Nguyen Anh Tuan and Tran Van Hung.

Researching, Building a Soft-Processor and Ethernet Interface Circuit Using EDK. 95 Tuong Thi Thu Huong, Pham Ngoc Tuan, Truong Van Dat, Dang Lanh and Chau Thi Nhu

Quynh

A Study of Characteristics of Helium-3 (He-3) Proportional Counters in Order to

Design Electronic Circuits for Neutron Detection. 100

Vu Van Tien, Nguyen Van Sy, Nguyen Thi Bao My, Nguyen Thi Thuy Mai and Ho Quang

Tuan.

1.4- INDUSTRIAL APPLICATIONS 107

Corrosion Surveillance in Pipe by Computed Radiography. 109 Nguyen The Man, Dao Duy Dung, Dang Thu Hong, Le Duc Thinh, Ha Hong Thu and

Nguyen Trong Nghia.

Study of Preparation and Survey of Radioisotopes Tracer Applications of Gold

Nanoparticles in the Multi-phase Industrial Processes. 114

Huynh Thai Kim Ngan, Trịnh Cong Son, Duong Thi Bich Chi, Tran Tri Hai, Nguyen Huu

Quang, Bui Trong Duy, Le Trong Nghia and Ngo Duc Tin.

1.5 - APPLICATIONS IN ECOLOGY, ENVIRONMENT AND GEOLOGY 119

Assessing Soil Erosion Rates for a Large Catchment in the Central Highlands of

Vietnam Using Fallout Radionuclides. 121

Phan Son Hai, Nguyen Thanh Binh, Nguyen Minh Dao, Nguyen Thi Huong Lan, Nguyen

Thi Mui, Le Xuan Thang and Phan Quang Trung.

Study on Method for Simulation of Partitioning Tracers in Double Porosity Model of

Fractured Basement Formations. 129

To Ba Cuong, Nguyen Hong Phan, Tran Tri Hai, Le Van Son and Le Van Loc.

Studying the Possibilities of Using The Radium Isotopes to Determine the Mass Ages

and Circulation of the Coastal Water. 138

Nguyen Thi Huong Lan, Phan Son Hai, Nguyen Van Phuc, Phan Quang Trung,

Nguyen Thi Mui and Nguyen Minh Dao.

Studying, Determining the Radionuclide of Tritum in the Water Samples (Rain,

Surface Water) by Using Liquid Scintillation Counting (TRi-carb 3180TR/SL). 142

Nguyen Thi Linh, Nguyen Dinh Tung, Truong Y, Le Nhu Sieu, Nguyen Van Phuc, Nguyen

Van Phu and Nguyen Kim Thanh.

1.6 - APPLICATIONS IN BIOLOGY, AGRICULTURE AND MEDICINE 149

Study on Preparation of 177

Lu, Labeling With Dotatate for Using in Diagnosis and

Treatment Neuroendocrine Tumors. 151

Duong Van Dong, Bui Van Cuong, Pham Ngoc Dien, Chu Van Khoa, Mai Phuoc Tho,

Nguyen Thi Thu and Vo Thi Cam Hoa.

Envisagement of Analytical Process for 13

C/12

C Isotope Ratio (13

C) in Benthic Bivalve

Samples by the Isotope Ratio Mass Spectrometry (EA-IRMS). 162

Ha Lan Anh, Vo Tuong Hanh, Vo Thi Anh and Nguyen Hong Thinh.

11

Techniques for Induction of Premature Chromosome Condensation (PCC) by

Calyculin - A and Micronucleus Assay for Biodosimetry in Vietnam. 167

Pham Ngoc Duy, Tran Que, Hoang Hung Tien, Bui Thi Kim Luyen, Nguyen Thi Kim Anh

and Ha Thi Ngoc Lien.

Field Test of Capability To Prevent Cabbage Clubroot Disease Caused by

Plasmodiophora Brassicae of Silver Nanoparticles Synthesized by Gamma Radiation. 174

Pham Thi Le Ha, Nguyen Tan Man, Nguyen Duy Hang, Le Hai, Tran Thi Tam,

Pham Thi Sam, Le Huu Tu, Tran Thu Hong, Tran Thi Thuy and Nguyen Tuong Ly Lan.

Study on Irradiated Vietnam Java Rambutan Fruit Which Was Postharvested

Treatment to Prolong The Shelflife for Export Purposes. 180

Nguyen Thuy Khanh, Nguyen Thi Ly, Doan Thi The, Cao Van Chung and Nguyen Van

Phong.

Research and Establishment of the Analytical Procedure for/of Sr-90 in Milk Samples. 191 Tran Thi Tuyet Mai, Duong Duc Thang, Nguyen Thi Linh and Bui Thi Anh Duong.

Preliminary Assessment About Genetic Diversity, the Stability of Potential Mutants

From Two Varieties of Chrysanthemum Morifolium Ramat. (Bronze Doa and Purple

Farm) Via Gamma Irradiation.

197

Nguyen Tuong Mien, Le Ngoc Trieu, Le Tien Thanh, Pham Van Nhi and Huynh Thi Trung.

Establishment of Illumination System for Investigation of Monochromatic Lights

Combination Effects on In Vitro Plant Growth. 208

Le Tien Thanh, Le Ngoc Trieu, Nguyen Tuong Mien, Huynh Thi Trung and Phan Quoc

Minh.

Application of In Vitro Flowering Technique on Evaluating of Mutation Capacity and

Color Selection of Torenia Fournieri L. Following Irradiation. 218

Le Van Thuc, Le Thi Thuy Linh, Hoang Hung Tien, Dang Thi Dien, Le Thi Bich Thy and Han

Huynh Dien.

1.7- RADIATION PROTECTION AND RADIOACTIVE WASTE MANAGEMENT 223

Establishing the Stand ard X-ray Beam Qualities for Calibration of Dosimeters Used

in Diagnostic Radiology Following IAEA-TRS457. 225

Duong Van Trieu, Ho Quang Tuan and Bui Duc Ky.

Research on Stabilization of Radioactive Waste by Method of Synrock Ceramic. 232 Nguyen Hoang Lan, Nguyen Ba Tien, Vuong Huu Anh and Nguyen An Thai.

Calculation and Measurement Dose Rate at the Control Area of Electron Beam

Accelerator UELR-10-15S2 at Research and Development Center for Radiation

Technology.

237

Nguyen Anh Tuan, Tran Van Hung, Cao Van Chung and Nguyen Hoang Hai.

1.8 - RADIATION TECHNOLOGY 245

Study on Improving Antioxydant and Antibacterial Activities of Silk Fibroin by

Irradiation Treatment. 247

Tran Bang Diep, Nguyen Van Binh, Hoang Phuong Thao, Pham Duy Duong, Hoang Dang

Sang and Nguyen Thuy Huong Trang.

Study on Preparing Carboxymethyl Starch Hydrogel Radiation-crosslinked on the

Electron Beam Accelerator To Do the Moisturizing Material in Cosmetic. 255

Nguyen Thanh Duoc, Doan Binh, Pham Thi Thu Hong and Nguyen Anh Tuan.

Research on Degradation of Silk Fibroin by Combination of Electron Beam

Irradiation and Hydrothermal Processing. 261

Nguyen Thi Kim Lan, Dang Van Phu, Le Anh Quoc and Nguyen Quoc Hien.

12

Synthesis of Fe3O4-chitosan Magnetic Nanocomposites by Gamma Irradiation for

Absorbing of Heavy Metals in Aqueous Solutions. 269

Tran Minh Quynh, Nguyen Van Binh, Nguyen Quang Long and Hoang Dang Sang.

Studies on Sterilization Process for Some Traditional Products of Herbal Medicine by

Gamma Radiation. 276

Hoang Phuong Thao, Nguyen Van Binh, Tran Bang Diep, Hoang Dang Sang, Nguyen Thuy

Huong Trang, Pham Duy Duong and Tran Minh Quynh.

1.9 - RADIOCHEMISTRY AND MATERIALS SCIENCE 281

Study on Beneficiation Technology of Dong Pao Rare-Earth-Barite-Fluorite with Two

Product Plans About Content and Recovery of Rare-Earth Fine Ores. 283

Duong Van Su, Truong Thi Ai, Bui Ba Duy, Bui Thi Bay, Nguyen Hong Ha, Le Thi Hong

Ha, Doan Thi Mo, Doan Dac Ban and Nguyen Hoang Son.

Improving Technology and Setting-up a Production Line for High Quality Zinc Oxide

(99.5%) With a Capacity of 150 Ton/year by Reduction-Oxidation Process. 297

Pham Minh Tuan, Tran The Dinh, Tran Ngoc Vuong, Tuong Duy Nhan, Tran Trung Son,

Le Huu Thiep, Nguyen Trung Dung, Le Thi Hong, Luong Manh Hung and Bui Huy Cuong.

Determination of Rare Earth and Other Elements in Yen-phu Rare Earth Ore and

Other Intermediate Products From the Floatation And Hydrometallurgical Process on

Portable XRF Si-Pin Detector.

305

Doan Thanh Son, Phung Vu Phong and Nguyen Hanh Phuc.

Studying of Preparation Silver Nano-Particles Using Spinning Disc Reactor. 309 Hoang Van Duc, Nguyen Thanh Chung, Tran Ngoc Ha, Ho Minh Quang and Nguyen Thi

Thuc Phuong.

Research on Technology of Making Rare Earth Alloy Having Rare Earth Content ≥

30% from Ore ( ≥ 40% Reo) Using Aluminum Thermal Technology in Arc Furnace. 314

Ngo Xuan Hung, Ngo Trong Hiep, Tran Duy Hai and Nguyen Huu Phuc.

A Test Study on the Recovery of Zinc Oxide from Bac-Kan Low Grade Zinc Ore. 320 Tran Ngoc Vuong, Pham Minh Tuan, Luong Manh Hung and Bui Huy Cuong.

1.10- COMPUTATION AND OTHER RELATED TOPICS 327

Research to Build The Advanced Training Programs for Nuclear Power Plan. 329 Nguyen Manh Hung, Le Van Hong, Cao Dinh Thanh and Nguyen Ba Tien.

Collect, Analyze and Data Base for Building Up the Investment Reports of the Center

for Nuclear Science and Technology Project. 333

Pham Quang Minh, Tran Chi Thanh, Cao Dinh Thanh, Mai Dinh Trung, Hoang Sy Than,

Nguyen Nhi Dien, Trinh Van Giap, Le Ba Thuan and Vu Tien Ha.

2. IAEA TC PROJECTS AND RESEARCH CONTRACTS 341

2.1 - List of VIE Projects 2013. 343

2.2 - List of FNCA Projects Operating in 2013. 344

2.3 - List of Active Regional/Interregional Projects 2013. 345

2.4 - List of Research Contracts 2013. 347

VINATOM-AR 13--01

The Annual Report for 2013, VINATOM

17

INVESTIGATION FOR CALCULATION METHODS USED IN ANALYZING

THE PHYSICS CHARACTERISTICS OF NUCLEAR POWER REACTOR

Nguyen Tuan Khai1, Nguyen Minh Tuan

2, Tran Quoc Duong

2, Hoang Van Khanh

1,

Phan Quoc Vuong1, Tran Viet Phu

1, Tran Vinh Thanh

1, Nguyen Thi Mai Huong

1,

Nguyen Thi Dung1 and Le Tran Chung

1

1Institute for Nuclear Science and Technology, Vietnam Atomic Energy Institute

179 - Hoang Quoc Viet, Ha Noi

2Nuclear Research Institute, Vietnam Atomic Energy Institute

1- Nguyen Tu Luc, Dalat, Lam Dong

ABSTRACT: The project aims at nuclear human resource development and enhancement in research

capability in reactor physics and kinetics at Nuclear Energy Center (Institute for Nuclear Science and

Technology) and Nuclear Reactor Center (Nuclear Research Institute, Dalat). The main research items of

the project can be summarized as follows: i) Considering possibility on using modern calculation techniques

and methods in investigating neutronic characteristics and neutronics-thermalhydraulics coupling. This item is

proposed to carry out based on international collaboration with Prof. Le Trong Thuy, San Jose University, US.

ii) Carrying out the collaborative activities in research and training between Nuclear Energy Center (Institute

for Nuclear Science and Technology) and Nuclear Reactor Center (Nuclear Research Institute, Dalat). iii)

Opening two-week training course on nuclear reactor engineering (25/Nov. -12/Dec. 2013) in collaboration

with Japan Atomic Energy Agency (JAEA).

1. INTRODUCTION

Development of nuclear human resource and enhancement in research capability in reactor

physics and kinetics including both research and power reactors are one of the priority targets for

research orientations of Vietnam Atomic Energy Institute (VINATOM) in period 2014-2020. This

task is assigned to Nuclear Energy Center, Institute for Nuclear Science and Technology (INST)

and Nuclear Reactor Center, Dalat Nuclear Research Institute (NRI). At present most of the staffs

who are working at Nuclear Energy Center (INST) are young and less experienced. They were

supported by VINATOM to pursue the above mentioned research, including:

- Research project at basis level in 2010 on calculations for some physics and thermal-

hydraulic parameters for VVER-1000 type by Pham Tuan Nam,

- Research project at basis level in 2011 on calculations for some physics parameters for

fuel assembly of VVER-1000 using MCNP4C2 by Nguyen Van Hien,

- Research project at basis level in 2012 on consideration for neutronic characteristics of

PWR 900 MWe of Japanese technology by Phan Quoc Vuong,

Project information:

- Code: 17/2013/HD-NVCB

- Managerial Level: Ministry

- Allocated Fund: 280,000,000 VND

- Implementation time: 12 months (Jan 2013- Dec 2013)

- Contact email: [email protected]

- Paper published in related to the project: (None)

VINATOM-AR 13--01


18

- Research projects at basis level in 2010, 2011 and 2012 on neutronic characteristics of

the OTTO recycling for new generation of reactors by Hoang Van Khanh.

Since 2010 VINATOM has proposed a long-term strategy in nuclear power human resource

development via establishing the qualified research groups at INST. Therefore, the target of this

project is to develop the qualified human resource, gradually enhance research capability on power

reactor physics and kinetics.

2. CONTENTS AND RESULTS

The project has been deployed and carried out based on the research contents written in the

proposal. The obtained results can be summarized as follow:

- Item 1: Investigating possibility of using some modern calculation methods and

techniques in analysis of reactor physics and kinetics characteristics. This is carried out based on

collaboration with Prof. Le Trong Thuy at San Jose University, US through two scientific seminars

on (1) Conventional methods of calculation for light water reactors, and (2) Some orientations for

calculation of reactor core physics characteristics from light water reactor (LWR) to high

temperature gas cool reactor (HTGR) presented by Prof. Thuy. Also we had a detail discussion with

Prof. Thuy on how we can establish a long-term collaboration on research and training, especially

for the goal of research capability enhancement for young people in coming years.

In framework of this research item we have performed scientific reports focusing on the

calculation methods for neutron transport and neutronic characteristics in reactor core, including:

(1) Numerical methods for neutron transport research

(2) Nuclear data edition for reactor physics calculations

(3) Multi-group analysis in reactor core calculations of LWR

(4) Multi-group diffusion theory and harmonic functions

(5) Monte-Carlo simulation method in analysis for neutron transport and diffusion

(6) A calculation program written for neutron transport in reactor core of PWR

These are very fundamental knowledge that the young researchers should be equipped in

order for approaching to high-level research requirements. We have proposed to investigate and

resolve the neutron transport and diffusion in moderator of light water reactor (LWR) as an

illustration for the calculation methods and technique mentioned in the above reports. The obtained

main results were presented in a paper “Simulation for neutron transport in reactor moderator and

proper thickness of light water reflector” which will be published in scientific conference of young

researchers at VINATOM on this October 2014, and also in master thesis written by Phan Quoc

Vuong, a young researcher at Nuclear Energy Center, INST. The thesis is planned for defend in this

August at Institute for Nuclear Technique and Environmental Physics, Hanoi University of

Technology (HUT). The figures 1-3 show the main results of the paper.

VINATOM-AR 13--01


19

Figure 3: Simulation results on neutron backscattering, absorption

and leakage fractions as a function of the reflector thickness.

We have regularly seminars presented by young researcher who are responsible for a given

topics. The reports have been reviewed by the experienced scientists.

- Item 2: Deployment for research collaboration and training activities between Nuclear

Energy Center, INST and Nuclear Reactor Center, Dalat NRI.

In 2013 two young researchers (Le Tran Chung and Ta Duy Long) from Nuclear Energy

Center, INST have been sent to Dalat NRI for 4 months to participate in some oriented research

collaborations such as analysis for neutronic characteristics of HEU and LEU assemblies, and

neutronic-thermal hydraulic coupling calculations.

In framework of this item we have performed 4 scientific reports, including:

(1) Analysis for neutronic characteristics of HEU (36%) and LEU (19.7%) assemblies of

VVR-M2 using MCNP and SRAC codes.

Figure 2: Neutron energy spectrum

at the fuel rod.

Figure 1: Energy decrease of 2 MeV neutrons with

number of collisions in Hydrogen and Oxygen.

VINATOM-AR 13--01


20

(2) Analysis for neutronic-thermal hydraulic characteristics for steady state of PWR

assembly at burnup 0 GWd/ton and 45 GWd/ton using MCNP and COBRA-EN.

(3) Analysis for Main Steam Line Break incident for VVER-1000 (AES92) using RELAP5.

(4) A series of practical assignments with PCTRAN prepared for training course on nuclear

reactor engineering at INST in framework of NUTECH program between VINATOM and JAEA.

This is a good basis for us to prepare a joint-research project on comprehensive neutronic

characteristics of VVER-1000 technology between Nuclear Energy Center, INST and Nuclear

Reactor Center, Dalat NRI.

Item 3: Cooperation in nuclear human resource development with JAEA.

In framework of NUTECH program between VINATOM and JAEA, a training course on

nuclear reactor engineering (Follow-up Training Course-FTC) was held for the first time in

Northern region from 25/Nov. -12/Dec. 2013 at INST, Hanoi. The JAEA has dispatched three

Japanese experts to participate in and give the lectures for the course. We invited eight Vietnamese

lecturers coming from VINATOM and VARANS to give the lectures for the course, three of them

are young researchers at INST who have participated in the instructor training course (ITC) at

IAEA. The course has recruited 20 participants from the organizations and universities concerning

national nuclear power program of the country such as Vietnam Agency for Radiation and Nuclear

Safety (VARANS), Vietnam Atomic Energy Agency (VAEA), VINATOM, Hanoi University of

Technology (HUT), Hanoi University of Science (HUS), Hanoi University of Electricity and

Institute of Energy (IOE).

The course was successfully taken place, where the lectures are well prepared, and the

participants followed fully and actively. The JAEA experts have appreciated the contents and

obtained results of the course, and recommended these FTCs should be continued in next years.

3. CONCLUSION

The project members have fully carried out the registered contents which can be

summarized as follows:

- Investigating the methods of physics and mathematics, and nuclear data update to

resolve the neutron transport and diffusion problem in reactor core. The research content has been

presented in 6 scientific reports and a calculation program on the neutron transport and diffusion.

The obtained main results are written in a paper for the scientific conference of young researchers

on this October 2014, and are scientific content of a master thesis.

- Giving a support for young researchers in research and training collaboration on reactor

physics and safety analysis between Nuclear Energy Center, INST and Nuclear Reactor Center,

Dalat NRI.

- Giving an active contribution in VINATOM-JAEA cooperation on nuclear human

resource development via the training courses on reactor engineering at INST.

In conclusion in development strategy of VINATIOM for the 2014-2020 period, research on

power reactor technology is one of the prioritized orientations. We have prepared a proposal with

the items on (1) the current manpower status, (2) research and training orientation and (3) staff

planning on vision to 2020. We wish that VINATOM kindly consider and support for us in

implementing the scientific and training targets proposed.

VINATOM-AR 13--01


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REFERENCES

[1] John R. Lamarsh, “Introduction to Nuclear Engineering”, Prentice Hall, Upper Saddle River,

New Jersey 07458, 2001.

[2] J. Leppọnen, “Diffusion Code Group Constant Generation Using the Monte Carlo Method”,

In Proc. XII Meeting on Reactor Physics Calculations in the Nordic Countries. Halden,

Norway, May 17-18, 2005.

[3] J. J. Duderstadt and L. J. Hamilton, “Nuclear Reactor Analysis”, John Wiley & Sons, Inc.,

1976.

[4] National Nuclear Data Center, Brookhaven National Laboratory, http://nndc.bnl.gov.

[5] J. Leppọnen, “A new assemply-level Monte-Carlo neutron transportation code for reactor

physics calculation”, In Proc. International Topical Meeting on Mathematics and

Computation, Supercomputing, Reactor Physics and Nuclear and Biological Applications,

M&C 2005. Avignon, France, Sept. 12-15, 2005.

[6] George I. Bell & Samuel Glasstone, “Nuclear reactor theory”, Van Nostrand Reinhold

Company, 450 West 33rd Street, New York, N.Y 10001.

[7] MCNP manual Vol I, II, III-Los Alamos National Laboratory.

[8] Thermal-Hydraulics of Nuclear Reactor-Uchida Masaaki, Tokai Training Center, Nuclear

Technology and Education Center, Japan Atomic Energy Research Institute.

VINATOM-AR 13--02


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STUDYING, SURVEYING THE CAPABILITIES OF DETERMINING

SHORT-LIVED RADIONUCLIDES OF INSTRUMENTAL NEUTRON

ACTIVATION ANALYSIS USING PNEUMATIC TRANSFER SYSTEM

AT THE NO.13-2 CHANNEL AND THERMAL COLUMN

Ho Van Doanh, Cao Dong Vu, Tran Quang Thien, Pham Ngoc Son and Nguyen Thi Sy

Center for Analytical Techniques, Nuclear Research Institute, Vietnam Atomic Energy Institute

ABTRACT: The Nuclear Research Institute (NRI) has recently installed a new automatic pneumatic transfer

system at the Dalat nuclear research reactor for rapid neutron activation analysis based on very short-lived

nuclides. This system can be used to perform short irradiations in seconds either in the vertical channel 13-2 or

in the thermal column of the reactor with thermal neutron flux of 4.2 1012

n.cm-2

.s-1

or 1.2 1011

n.cm-2

.s-

1, respectively. The transferring time of sample from irradiation position to detector position is proximately 3.2

seconds. A loss-free counting system using HPGE detector has been also setup in compacting with the

pneumatic transfer system for measurement of sample’s activity, automatically starting for data acquisition at

irradiated sample’s arrival. Therefore, short-lived nuclides such as 20

F, 77m

Se, 179m

Hf, 46m

Sc, 110

Ag can be used

for INAA at NRI. This report presents the results of detection limit of short-lived nuclides (half-lives < 9,5

min), and the development of a reliable analytical procedure utilizing short-lived radionuclides for INAA:

Procedures for determining Se in biological and geological samples, procedure for determining F in geological

sample. Neutron spectrum parameters at irradiation positions and efficiency of detector were also determined

in order to establish the k0-NAA analytical procedure.

I. INTRODUCTION

Instrumental neutron activation analysis (INAA) has been developed and applied at the 500

kW Dalat research reactor (DNRR) since 1984. Until now, it is capable of analyzing more than 40

elements based on radionuclides with short, medium and long-lived time. For short-lived nuclides

with half-lives from 2 minutes to 2.6 hours, samples are often irradiated at the neutron channel

No.7-1 of Dalat research reactor through a semi-auto pneumatic transfer system (PTS) with valid

irradiation time from 45 seconds to 20 minutes. Measurements are often performed using a gamma

spectrometer coupled with a HPGe (GMX-30190), but with manual manipulation between loading

and counting procedures. Therefore, the shortest-lived nuclides that could be detected are 28

Al (T1/2

= 2.24 min), 52

V (T1/2 = 3.75 min), and 51

Ti (T1/2 = 5.76 min).


- Code: CS/13/01-01

- Managerial Level: Institute




- Paper published in related to the project:

1. H.V. Doanh and and et al. Surveying, installing, calibrating and initial assessing the capabilities of

automatic neutron activation analysis via short-lived nuclides. The proceedings of the conference at a

postgraduate deparment of Dalat University, 10/2013. (in Vietnamese)

2. H.V. Doanh, C.D. Vu, T.Q. Thien, P.N. Son, N.T. Sy, N. Giang and N.N. Dien, “A new rapid neutron

activation analysis system at Dalat nuclear research reactor”, Journal of Nuclear Science and

Technology, 2014.

3. H.V. Doanh and et al., “Determination of selenium in biological standard material by short-time

neutron activation analysis using 77m

Se at Dalat reactor”, Journal of Nuclear Science and Technology,

2014 (being reviewed).

VINATOM-AR 13--02


23

In the recent years, through the IAEA TC Project RER/4/028, a new automatic PTS for

rapid neutron activation analysis (Fig.1) based on short-lived nuclides has been developed. This

PTS system can be used to perform short irradiations in seconds. The return time of sample from

irradiation position to counting position is about 3.2 s. Timing information for both irradiation and

counting will be instantly delivered to the activation analysis workstation computer. The digital

gamma spectrometer is selected and tuned for accurate measurement at high and varying counting

rates, using loss-free counting technology. Accordingly, shorter-lived nuclides (half-life < 1 min)

such as 20

F, 77m

Se, 179m

Hf, 46m

Sc, and 110

Ag can be used for INAA at Dalat reactor, which the former

system can not detect.

The main purpose of this work is to determine detection limit of short-lived nuclides (half-

lives < 9,5 min), and the development of a reliable analytical procedure utilizing short-lived

radionuclides for INAA: Procedures for determining Se in biological and geological samples,

procedure for determining F in geological sample. Neutron spectrum parameters at irradiation

positions and efficiency of detector were also determined in order to establish the k0-NAA

analytical procedure.

Figure1: Diagram of the auto-pneumatic transfer system installed at DNRR.

II. EXPERIMENT

The neutron spectrum parameters including thermal neutron flux th, fast neutron flux f, the

thermal flux to epithermal neutron flux (epi) ratio, the deviation factor of the epithermal neutron

flux from the ideal 1/E law approximated by a 1/E1+

shape and neutron temperature were measured

at sample irradiation positions in channel No.13-2 and thermal column using Au, Zr, Ni and Lu

monitors. Typically monitors with masses of 4 mg for Al-0.1%Au foil (IRMM-530R) and Al-0,1%

Lu foil, 30 mg for pure Ni (wire), 10 mg for Zr (foil) were inserted into a high purity polyethylene

vial and loaded into rabbit (capsule) for irradiation. This monitors were irradiated for 10 min at 13-2

channel and for 2 h at thermal column. After a suitable delay time, the activity measurements were

carried out by a calibrated gamma-ray spectrometer combined with HPGe detector (GMX-30190).

The measured spectra were analyzed by using the k0-IAEA program.

The measurement of efficency of HPGe detector (GMX40-76-PL) were determined by

Monte Carlo code and ETNA software (Efficiency Transfer for Nuclide Activity measurements).

VINATOM-AR 13--02


24

A variety of reference materials (Tuna Fish IAEA-436, Oyster tissue NIST 1566b, Bovine

Liver NIST 1577, Bovine Liver NIST 1577b, Montana Soil NIST 2711a and Obsidian Rock NIST

278) were selected to assess reliability of this system on the short-time activation application. All of

the samples were irradiated at a neutron flux of 4.21012

n.cm-2

.s-1

in the 13-2 channel, and then

counted on the calibrated HPGe gamma-ray spectrometer (GMX40-76-PL).

III. RESULTS AND DISCUSSION

As the results of this study, neutron spectrum parameters (Table 1) at irradiation position of

the thermal column (7/2012, 3/2013 and 4/2013) and the channel No.13-2 (8/2012, 02/2013 and

3/2013) were determined by irradiating Au, Zr, Ni, Lu monitors. In addition, the efficiency curves

(Fig.2) of detector (GMX40-76-PL) for NAA sample at a distance of 5, 10 and 15 cm were

determined by MCNP and ETNA. Analytical procedures for determining Se via 77m

Se in biological

samples and F via 20

F in geological sample were also established.

Table 1: The results of the determination of neutron spectrum parameters

at irradiation facilities of the Dalat research reactor.

Neutron spectrum parameters No.13-2 channel Thermal column

Thermal neutron flux (n/cm2/s) (4.2 0.1) x 10

12 (1.25 0.03) x 10

11

Fast neutron flux (n/cm2/s) (6.6 0.9) x 10

12 (8.4 0.5) x 10

8

The ratio of thermal to epithermal neutron

flux 10.7 6.0 195 11

The deviation factor of the epithermal neutron

flux -0.069 0.008 -0.164 0.186

Neutron temperature (K) 312 12 298 19

MCNP Efficiency of HPGe Det. for NAA Sample

0.000

0.001

0.010

0.100

10 100 1000 10000

E gamma (KeV)

Eff

icie

ncy

MCNP-5cm MCNP-10cm

MCNP-15cm ETNA-5cm

ETNA-10cm ETNA-15cm

Figure 2: Efficiency curves of HPGe detector for NAA sample by MCNP

in comparation with ETNA.

VINATOM-AR 13--02


25

Table 2: The results of concentration (in ppm) analysis

for Se in biological reference materials.

Reference material Certificated value

This work

k-zero method The relative

method

IAEA 463 4.63 0.48 4.55 0.50 4.19 0.46

NIST 1566b 2.06 0.15 2.48 0.57 2.18 0.42

NIST 1577 1.10 0.10 1.24 0.31 1.17 0.22

NIST 1577b 0.73 0.06 0.70 0.11 0.80 0.17

The accuracy for determination of Selenium using the short-lived nuclide 77m

Se was

evaluated by analyzing a number of certified reference materials with different levels of Se (IAEA

436, NIST 1566b, NIST 1577 and NIST 1577b). The agreement between measured and certified

values was generally acceptable, as shown in Table 2.

IV. CONCLUSION

A fast pneumatic sample transfer system for analyzing of extremely short-lived nuclides by

neutron activation analysis has been installed and operated at Dalat nuclear research reactor. In this

study, efficency of detector for NAA sample and neutron spectrum parameters of the thermal

column and channel No.13-2 were determined in order to establish analytical procedures using the

k0-NAA method. The system was applied to determine the concentration of Se in the biological

sample and F in geological sample by using the short-lived nuclide 77m

Se and 20

F. The results

obtained through this research have opened a new possibility on using INAA technique for

measurement of extremely short-lived nuclides at Nuclear Research Institute.

REFERENCES

[1] P. V, Guinn., A. D, Miller., Recent instrument neutron activation analysis studies utilizing

very short-lived activities, Journal of Radioanalytical Chemistry, 1976.

[2] A. D, Becker., Characterization and use of the new NIST rapid pneumatic tube irradiation

facility, Journal of Radioanalytical Chemistry, 1998.

[3] Y.-S. Chung, et al., Characteristics of a new pneumatic transfer system for a neutron

activation analysis at the HANARO research reactor, Nuclear Engineering and Technology,

2009.

[4] S.S. Ismail, A new automated sample transfer system for instrumental neutron activation

analysis, journal of Automated Methods and Management in Chemistry, 2010.

[5] U.M.EL-Ghawi, Determination of Selenium in Libyan Food Items Using Pseudocyclic

Instrumental Neutron Activation Analysis, Journal of Radioanalytical and Nuclear

Chemistry, 2004.

[6] N.C. Hải, P.N. Sơn, Nghiên cứu áp dụng kỹ thuật phân tích kích hoạt neutron lặp vòng dựa

trên các đồng vị sống ngắn để phân tích hàm lượng một số nguyên tố sử dụng hệ chuyển mẫu

tại kênh 13-2 và cột nhiệt của lò phản ứng hạt nhân Đà Lạt, Viện Năng lượng nguyên tử Việt

Nam, 2005.

[7] D.A. Miller, Instrumental neutron activation analysis using short-lived radionuclides,

University of California, Irvine, 1976.

VINATOM-AR 13--02


26

[8] A. D, Miller., P. V, Guinn., Precision high-speed neutron activation nanlysis via very short-

lived activities, Journal of Radioanalytical Chemistry, 1976.

[9] H.M. Dũng, Nghiên cứu phát triển phương pháp k-zero trong phân tích kích hoạt nơtrôn lò

phản ứng hạt nhân cho xác định đa nguyên tố, Luận án tiến sĩ, ĐH KHTN TP.HCM, 2003.

[10] X. Lin, et al., The program "MULTINAA" for various standardization methods in neutron

activation analysis, journal of Radioanalytical and Nuclear Chemistry, 1997.

[11] A. Chhav, et al., Full energy peak efficiency calibration of HPGe detector for point and

extended sources using Monte Carlo code, Journal of Radioanalytical Chemistry, 2011.

[12] D. Radu, et al., Transfer of detector efficiency calibration from a point source to other

geometries using ETNA software, Romanian Reports in Physics, 2010.

[13] M. Blaauw, The Holistic analysis of gamma-ray spectra in instrument analysis, PhD. Thesis,

Interfaculty Reactor Institute, Delft University of Technology, 1993.

[14] Quality aspects of research reactor operations for instrumental neutron activation analysis,

IAEA-TECDOC-1218, 2001.

[15] M.U. Rajput, et al., Characteristic absolute efficiency response curves of a high purity

germanium detector in the energy range 50–1500 keV, Journal of Radioanalytical and

Nuclear Chemistry, 2002.

VINATOM-AR 13--03


27

IMPROVEMENT OF THE DHP PROGRAM AND APPLY

FOR FISSION PRODUCT DECAY HEAT CALCULATIONS

OF 233

U, 235

U, 238

U, 232

Th AND 239

Pu

Pham Ngoc Son, Tran Tuan Anh, Nguyen Xuan Hải,

Ho Huu Thang and Mai Xuan Trung

Department of Nuclear Physics and Electronics, Nuclear Research Institute,


ABTRACT: The program, DHP (Decay Heat Power) for calculation of nuclear decay heat from fission

products has been improved, based on the previous DHP version developed under the MEXT program at

JAEA in 2007. In this improved version, the previous individual calculation functions were combined in to a

complete program, made it easy for user in providing input information by a visualize interface dialog. Based

on the agreement results of comparison between calculation data and experimental valises, the program is

estimated that the calculation functions and the new algorithms applied in this program are properly

implemented. The duration for a calculation with cooling time of 1010

s is about 120s. This program can be

effectively used for decay data, fission yield evaluation and/or products inventory calculations in research

work or training.

I. INTRODUCTION

Gamma and beta decay energy released from the natural decay of the fission products (FP)

contributes approximately 7% to 12% of the total energy generated through the fission process, and

is called “Decay Heat”. After a reactor is shutdown, this source of radioactive decay energy still

remains to maintain a moderate level of heating in the reactor core. The precise data of decay heat

calculations are important need for safety design of a nuclear facility, design of shielding for fuel

discharges, fuel storage and transport flasks, and the management of spent fuel.

In the recent years, with the great efforts of improvement for the evaluation nuclear data

libraries and for new measurements, decay heat calculations are expected to predict the truth data of

decay heat. In this study, an update version of DHP-decay heat calculation program has been

improved for FP decay heat calculations, uncertainty analysis. The method used in the program is

summation calculation, in which the inventories of FP nuclides following a fission process are

calculated by a new numerical algorithm for exactly analysis. Furthermore, the window interface of

the program is designed with optional properties which is easy for users to perform a calculation


- Code: CS/13/01-01






1. Pham Ngoc Son. Calculation of fission product concentrations for time following a fission burst. Asian

Journal of Science and Technology, Vol. 5 pp. 295-298, 2014.

2. Pham Ngoc Son. Decay heat uncertainty analysis. Reported at the Scientific Symposium of Dong Nai

University, P.125 (2014); The 11th

National conference of nuclear science and technology, Aug. 2013

Vung Tau, Vietnam.

3. Pham Ngoc Son. Fission product decay heat calculation of U-235. Accepted to be published in

International Journal of Nuclear Science and Engineering-IJNESE.

VINATOM-AR 13--03


28

process, and the calculated results can be directly displayed in graphical form together with

experimental values, and can be saved as an output data file in tabular form.

II. DEVELOPMENT OF THE DHP PROGRAM

2.1. Development of computational code

The DHP program is developed using the C++ compiler, and the window interface of the

program is designed with optional style. That makes it easy for user to utilize the program, and the

user can choose optionally to calculate FP decay heat after a fission burst or after a period of

irradiation. The input data for the program is loaded from the decay data and fission yield data

libraries with ENDF/B-6 format such as FP Decay data File and fission yield data file from JENDL,

JEFF or other evaluated nuclear data library. In addition, the experimental and recommended values

for comparison are loaded from files in table form. The method used in the program is summation

calculation, in which the inventories of FP nuclides following a fission process are calculated by a

new numerical algorithm for exactly analysis. The window interface of the program is designed

with optional selection of input parameters which is easy for users to perform a calculation process.

The calculated results can be directly displayed in a window interface and can be saved as an output

data file in tabular form. The new update structure of the calculation procedure is presented in

Figure 1. The interface window of program is shown in Figure 2.

Figure 1: Block diagram of the DHP program.

VINATOM-AR 13--03


29

Figure 2: The new window interface of DHP program.

2.2. Test and validation

The program DHP has been improved for some computational function such as update

nuclear decay and fission yield data, new window user interface, update function for uncertainty

analysis, code for fission product concentration inventory and average energy calculations. After

coding, a testing for the program validation was carried out by comparing the results of calculated

average energies for several FP nuclides with data from literatures, Table 1.

The formulas applied for average energy and energy spectra calculation in DHP that given

results in comparison with reference data. From the results shown in Figure 2 and Table 1, the data

calculated by DHP program are good agreement with calculated reference values from [8] and

experimental value reported in [9, 10].

0 1

1

22

2/1 )()1()1()(Q

E

gg

g

dEdEEFEEpEEmcESTE (1)

0 1

1

22

2/1 )()1()()(Q

E

ggg

g

dEdEEFEEpEEQmcESTE (2)

e

l

EQ

E

exceeeexceexcexcee dEECmEEEQEZFESEQEZTEP 2/14222

2/1 )())(,()(),,()(

(3)

where:

Sβ(E): The Beta strength function,

f(Z, Qβ-E): the integrated Fermi function,

VINATOM-AR 13--03


30

Qβ : beta decay energy,

T1/2: beta decay half-life,

E: the excitation energy in the daughter nuclide.

F stands for the Fermi function, and p for the electron momentum.

Eg is related to the excitation energy Ei as Eg = -(Ei -1).

m is electron rest mass, and c is the light velocity.

ξΩ(Z, Ee, Q-Eexc): Shape factor,

Ee: Beta-ray energy,

Eexc: Excitation energy in daughter nuclide,

EL: Maximum level energy experimentally observed in daughter nuclide,

Table 1: The results of calculation for Gamma-ray and Beta average energies in Beta decay

for several fission products, comparison with data from reference [8].

Nuclide Q-value T1/2 <E > (MeV) <E > (MeV)

(MeV) (s) DHP [8] DHP [8]

Rb-89 4.496 909 0.9303 0.9355 2.2313 2.2293

Rb-90 6.587 158 1.9060 1.9162 2.2712 2.2706

Rb-90m 6.696 265 1.0811 1.1180 3.9332 3.8690

Rb-91 5.891 58.4 1.3739 1.3684 2.6876 2.7064

Rb-93 7.462 5.84 2.1544 2.1881 2.5402 2.5765

Sr-93 4.137 445 0.7860 0.7915 2.1724 2.1675

Sr-94 3.508 75.2 0.8309 0.8416 1.4380 1.4192

Sr-95 6.087 23.9 1.8928 1.9013 1.7990 1.7897

Y-94 4.917 1120 1.8111 1.8294 0.7875 0.7570

Y-95 4.453 618 1.3793 1.4147 1.2471 1.1799

Cs-138 5.374 2010 1.2223 1.2250 2.4047 2.4078

Cs-138m 5.457 916 0.2565 0.2250 0.4211 0.4930

Cs-139 4.213 556 1.6487 1.6707 0.3451 0.3050

Cs-140 6.22 63.7 1.8399 1.9102 1.9520 1.8178

III. RESULTS OF CALCULATIONS

The results of calculations for decay heat from fission products of U-233, U-235, are shown

in Figures 3-4. The results of uncertainty analysis are shown in Figure 5.

VINATOM-AR 13--03


31

Figure 3: Result of decay heat calculation for U-233 fast

neutron fission,decay data from JENDL3.3.

Figure 4: Result of decay heat calculation for U-235 thermal

neutron fission, decay data from JENDL3.3.

U-235 Thermal pulse fission

Total Decay Heat

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04

Cooling Time (s)

Decay H

eat

t*f(

t) (

MeV

/fis

sio

n)

JENDL3.3

Uncertainty

Figure 5: The results of total decay heat uncertainty analysis

with JENDL 3.3 data for U-235 thermal neutron fission.

VINATOM-AR 13--03


32

IV. CONCLUSIONS

The DHP application program has been developed and improved for FP decay heat

calculation and its uncertainty analysis. In the present program, the fission product inventory for all

of decay chains and 12 decay modes are taken into account by the internal calculation procedures.

The main advantages of this program are exact calculation, fast and easy to use.

REFERENCES

[1] Fred L. Wilsson: “Fermi’s Theory of Beta Decay”, American Journal of Physics Volume

36, Number 12. December 1968.

[2] G. Rudstam, et al: Atom. Data and Nucl. Data Tables. 45. 239 (1990).

[3] H. V Klapdor: “The shape of the beta strength function and consequences for nuclear

physics and astrophysics”, Prog. Part. Nucl. Phys. 10, 131. 1983.

[4] Kanji TASAKA, Junichi MIWA, Junichi KATAKURA, Tadashi YOSHIDA, Kiyoshi

KAWADE, Toshio KATOH, Takahiro TACHIBANA, Masami YAMADA and Ryuzo

NAKASIMA: “Calculation of Beta-Ray Spectra from Individual and Aggregate Fission

Products”. Journal of Nuclear Science and Technology, 29[4], pp. 303-312. April 1992.

[5] Pham Ngoc Son and Jun-ichi KATAKURA: “Applications of TAGS Data in Beta Decay

Energies and Decay Heat Calculations”. JAEA-Research 2007-068. Octorber 2007.

[6] M. G. Stamatelatos, T. R. England: “Beta-Energy Averaging and Beta Spectra”, UC-34c.

August 1976.

[7] J. Katakura, T. Yoshida, K. Oyamatsu, T. Tachibana, JENDL FP Decay Data File 2000,

JAERI 1343, Japan Atomic Energy Research Institute. 2001.

[8] N. Hagura, T. Yoshida and T. Tachibana, J. Nucl. Sci. Tech., 43, 497 (2006).

[9] M. Akiyama and S. An, “ Measurement of fission products decay heat for fast reactor”,

Proc. of Int. Conf. on Nucl. Data for Science and Techno. , Antwerp Belgium, P.237

(1982).

[10] J. K. Dickens et al., “Fission Products Energy Release for Time following Thermal Neutron

Fission of 235U between 2 and 14000 seconds”, ORNL/NUREG-14 (1977); Nul. Sci. Eng.,

74, 106 (1980).

VINATOM-AR 13--04


35

STUDY ON SAFETY ANALYSIS OF PWR REACTOR CORE

IN TRANSIENT AND SEVERE ACCIDENT CONDITIONS

Le Đai Dien, Hoang Minh Giang, Nguyen Thi Thanh Thuy, Nguyen Thi Tu Oanh,

Le Thi Thu, Pham Tuan Nam, Tran Van Trung, Bui Thi Hoa,

Nguyen Huu Tiep and Le Tri Dan

Nuclear Safety Center, Institute for Nuclear Science and Technology, Vietnam Atomic Energy Institute

Le Van Hong


Vo Thi Huong

University of Science and Technology, Korea

ABSTRACT: The cooperation research project on the “Study on Safety Analysis of PWR Reactor Core in

Transient and Severe Accident Conditions” between Institute for Nuclear Science and Technology (INST),

VINATOM and Korean Atomic Energy Research Institute (KAERI), Korea has been setup to strengthen the

capability of researches in nuclear safety not only in mastering the methods and computer codes, but also in

qualifying of young researchers in the field of nuclear safety analysis. Through the studies on the using of

thermal hydraulics computer codes like RELAP5, COBRA, FLUENT and CFX the thermal hydraulics research

group has made progress in the research including problems for safety analysis of APR1400 nuclear reactor,

PIRT methodologies and sub-channel analysis. The study of severe accidents has been started by using

MELCOR in collaboration with KAERI experts and the training on the fundamental phenomena occurred in

postulated severe accident. For Vietnam side, VVER-1000 nuclear reactor is also intensively studied. The

design of core catcher, reactor containment and severe accident management are the main tasks concerning

VVER technology. The research results are presented in the 9th National Conference on Mechanics, Ha Noi,

December 8-9, 2012, the 10th

National Conference on Nuclear Science and Technology, Vung Tau, August

14-15, 2013, as well as published in the journal of Nuclear Science and Technology, Vietnam Nuclear Society

and other journals. The skills and experience from using computer codes like RELAP5, MELCOR, ANSYS

and COBRA in nuclear safety analysis are improved with the nuclear reactors APR1400, Westinghouse 4 loop

PWR and especially the VVER-1000 chosen for the specific studies. During cooperation research project, man

power and capability of Nuclear Safety center of INST have been strengthen. Three masters were graduated, 2

researchers are engaging in Ph.D course at Hanoi University of Science and Technology and University of

Science and Technology, Korea, respectively.


- Code: 22/2012/HĐ-NĐT

- Managerial Level: Government

- Allocated Fund: 2,995,000,000 VND

- Implementation time: 24 months (Jan 2012-Dec 2013)



1. Le Dai Dien, Nguyen Tu Oanh. Analysis of DVI line break in ATLAS test facility using RELAP5

code. J. Nuclear Science and Technology, No. 4, pp.33-41, VINATOM, 2011.

2. Le Dai Dien, Le Tri Dan. Analysis of Steam Generator Tube Rupture Accident for Korean Reactor

APR1400. J. Nuclear Science and Technology, Vol. 3, No. 2, pp.7-14, VINATOM, 2013.

3. Le Dai Dien, Bui Thi Hoa, Vo Thi Huong. Application of MELCOR code to Westinghouse 4-loop

PWR Severe Accident and Evaluation of RPV Lower Head Performance. . J. Nuclear Science and

Technology, Vol. 4, No.2, VINATOM, 2014

4. Tae Woon Kim, Jinho Song, Vo Thi Huong, Dong Ha Kim, Bo Wook Rhee, Shripad Revankar.

Sensitivity study on severe accident core melt progression for advanced PWR using

MELCOR code. Nuclear Engineering and Design (2013) http:www.elsevier.com/ locate/nucengdes.

VINATOM-AR 13--04


36

1. INTRODUCTION

Safety analysis is one of the requirements for the construction and operation of NPP.

Understanding of physical phenomena - as well as thermal hydraulics computational simulation is

an important tool to confirm safety of NPP in the postulated accidents. The cooperation between

VINATOM and KAERI in the safety analysis of PWR has been established since 2009 and the first

phase has been successful carried out in 2010. In order to strengthen the capability of researchers at

INST, VINATOM the second phase of the project (2012-2013) is supported.

The objectives of the project are as follows:

- Enhancement of capability of implementation of computer codes in the safety analysis

work for NPP including system code and sub-channel code.

- Training of young researchers in safety analysis in thermal hydraulics as well as in

severe accident study.

For the cooperation, the common objectives are the establishments of application system of

thermal hydraulic safety analysis code for PWR, including: Evaluation of system TH code like

RELAP5, MARS and MELCOR for severe accidents. The other important objective is exchange of

human resources between Korea-Vietnam through on the job training (OJT) for Vietnamese code

users and lectures for code technology and safety analysis in the fields of thermal hydraulics and

severe accident.

With the above mentioned targets, the research topics focus on main studies which has been

shown to be effective through research works:

1. To complete basic problems in safety analysis report (SAR) of APR1400 reactor along

with the problems had been done in the first phase (2009-2010) to make a complete safety analysis

problems for APR1400 reactor.

2. To start studing the severe accident in NPP from fundamental phenomena to some key

issues such as skills using MELCOR code, expanding the scope of the research to VVER-1000

reactor, thereby helping staff to participate in the activities that support to Ninh Thuan 1 projects in

future.

3. The study results demonstrated by the thematic research activities, simulations using

computer codes (RELAP5, MELCOR, COBRA, MARS, ANSYS FLUENT, ANSYS CFX) for

some specific problems. There have been some reports in national scientific conferences and the

results demonstrated in Master thesis as well as contribution to doctoral thesis under progress.

The contents of the study are shown systematically in Figure 1. including roadmap for

research towards building expertise in thermal hydraulics safety analysis and severe accident.

Thermal hydraulics phenomena are important in most of accidents in DBA as well as

BDBA. The thermal hydraulic safety concerns with:

- Safety analysis of DBA for evaluating the adequacy of the design to cope with transient

and accident conditions

- Safety analysis of BDBA for evaluating if consequences can be considered as

acceptable

- Safety analysis of Severe accident and Accident management (AM) development to

prevent or mitigate accident consequences

To address these safety concerns, thermal hydraulic codes are studied for simulation of

Korean APR1400 reactor. The main problems in SAR have been studied during the years 2009-

2010 [1] and continued to study in order to make a full set of safety analysis including LOCA,

VINATOM-AR 13--04


37

LOCA and SBO, REA, FWB, LOFA, SGTR, MSLB. Based on these studies, the group of

researchers in thermal hydraulics safety analysis has been set up.

The studies in severe accident have been intensively performed. The training on the basic

phenomena in severe accident with the lectures presented by experts from KAERI was held in

INST.

Figure 1: Implementation strategy of computer codes and research

works for the cooperation.

2. THE MAIN RESULTS AND DISSCUSION

2.1. Improvement of capability of using RELAP5

Three safety analysis problems including LOCA and SBO, SGTR and MSLB have been

performed for APR1400 reactor. Especially in the SGTR analysis, the simulation results has been

compared with the simulated ones by MARS-3D reported by KAERI [2].

Figure 2 shows the primary and secondary system pressures during the simulation for the

SGTR event. When a steam generator tube is ruptured, the reactor coolant system pressure

immediately drops as a tube break and the PRZ backup heater is actuated as designed. After the

ECCS is actuated, water level in PZR increases again. The water levels in PZR and in both steam

generators (intact and broken) are shown in figure 3. It is also noted, that the starting point used in

[2] included steady state (run for 300s) as indicated in the figure. The results simulated by RELAP5

performed by us are in good agreements with the KAERI report [2].

VINATOM-AR 13--04


38

Figure 2: Pressure changes in the primary and secondary loop in SGTR accident

in comparison between calculations by RELAP5 (Right) and MARS-3D(Left)[2].

Figure 3: Collapsed water levels in PZR and narrow range of SG (broken and intact) in SGTR

accident in comparison between calculations by RELAP5 (Right) and MARS-3D(Left)[2].

2.2. Analysis of severe accident in NPP

This study refers to the phenomena and processes occurring in severe accident, the safety

and prevention systems to minimize the accident consequences, the researchers are initially

equipped with the basic knowledge not only in phenomena review but also in study of MELCOR

code by the help of KAERI experts. The modeling of Westinghouse 4-loop PWR was simulated and

SBO with RCP seal leakage is simulated. According to [3], the results reported in WASH-

1400 indicated that breaks of an equivalent diameter in the range of 0.5 to 2 inches in the RCS

pressure boundary are an important events which may lead to core-melt. The overall probability of

core-melt due to SBLOCA could be dominated by events such as RCP seal failures was also

interested.

The water mass in the reactor core and lower plenum decreases and then recovered by water

injection when RCS pressure reaches the set point of accumulators. At about 8h after reactor trip,

the core is uncovered again and collapse in fuel ring 1 occurred. The core center (ring 1) is totally

failed at 9.7h. The sequences are presented in figure 4.

The cladding temperature heat-up and exceeds the melting temperature, the cladding failure

starts to occur from top of ring 1 at 8.16 hours after that it spreads to other areas as shown in figure

4.

VINATOM-AR 13--04


39

The simulations performed in this study are comparable with another simulations by

MELCOR [4].

T = 29400 s (8.17h)

Collapse in ring1 began

T = 31620 (8.78 h)

Debris in Lower Head

T = 36200 s (10.06h)

Collapse of ring 1

T = 36450 s (10.13h)

Failure in ring 2

T = 38200 s (10.6h)

Collapse of ring 2

T = 38230 s (10.62h)

Collapse of ring 3

T = 53050 s (14.7h)

Debris reaches lower

head

T = 63720 s (17.7h)

Melt injected to cavity

T = 90000 s (25h)

Core damage after 25h

Figure 4: Accident sequences in reactor core and lower head.

2.3. Implementation of CFD in reactor T/H

The application of CFD is studied by practice to use ANSYS software (Copyright Research

Academy version) in collaboration with ANSYS staff from Hanoi University for Science and

Technologies (HUST). Based on basic exercises, ANSYS FLUENT and CFX have been used to

simulate PSBT experiments.

VINATOM-AR 13--04


40

Figure 5: Cross view of the void fraction at measurement position.

Simulation of two phase flow in a channel is still hard problem with CFD. For the S1

exercise of the benchmark problem mentioned in this paper there are a lot of study which are

introduced. This study introduces the utilization of two phase flow simulation with additional sub

model of MUSIG which is available in Ansys CFX 14.5. Simulations are presented in figure 5.

The results show that there is a significant improvement of the convergence for the runs

being studied. However, for various case of the two phase flow it is needed to study more

correlations for selection of appropriate key parameters for model simulation.

2.4. Thermal-hydraulic analysis for PWR

Several of important topics related to advanced light water reactor like critical heat flux, two

phase flows, departure from nucleate boiling (DNB) etc. have been studied. The updated knowledge

in thermal hydraulics safety analysis is addressed so that the following studies are intensively

performed:

The APR1400 and VVER-1000/V392 reactors have been simulated using RELAP5 and the

steady state results are given. The nodalization scheme and steady state simulations of APR1400

has been used since 2009 by the authors [1]. Followings are simulated results for VVER-

1000/V392. One nodalization based on OECD benchmark noted as “Simulation #2” and the other

developed by us noted as “Simulation #1”. Both nodalizations and steady state simulations are

satisfactory as indicated in figure 6 and table 1.

VINATOM-AR 13--04


41

560

570

580

590

600

0 200 400 600 800 1000

Nhiệ

t độ (

K)

Thời gian (s)

Figure 6: Water temperature at the inlet and outlet calculated by the RELAP5 using

different nodalizations: “Simulation #1”(left) and “Simulation #2”(right).

The water temperature at the inlet and outlet calculated by the different nodalizations are

presented in Table 1.

Table 1: Thermal hydraulics parameters of RCS of VVER1000/V392

in the normal power operation conditions.

Main parameters Design [7] Calculated #1 Calculated #2

Thermal power, MW 3000 3000 3000

Mass flow rate through the core,

m3/h

86000 ± 2600 86532 86029

Mass flow rate / nhánh, m3/h 21500± 1000 21633 ---

Primary pressure (in PZR), MPa 15.7±0.3 15.73 15.8

Water temperature at inlet, 0C 291 (+2)(-5) 295.3 288.8

Water temperature at outlet, 0C 321±5 324.3 318.8

Pressure drop in core, MPa 0.148 0.177 ---

Pressure drop in RPV, MPa 0.387 0.38 ---

Bypass flow rate, % 3 3.1 ---

Feedwater temperature, oC 220 ± 5 220 220.15

Water level in PZR, m 8.17 8.12 ---

Water level in SG

(secondary side), m

2.7 ± 0.05 2.7 2.63

SG exit steam pressure, MPa 6.27 ± 0.1 6.08 6.27

Steam temperature, oC 278.5 276.7 ---

The steady state calculations are performed by simulations in system codes like RELAP5 for

VVER-1000/V392 in the normal power operation. The thermal hydraulics parameters calculated in

our simulations are generally in good agreements with the design. It is also noted that this

VINATOM-AR 13--04


42

simulations are used not only in verifying the provided design data, but also in safety analysis in

transient and accident conditions.

3. CONCLUSION

Safety Analysis in which T/H studies are very important needs to be addressed not only in

NPP projects going on in Vietnam now, but also in strengthening of our understanding of safety

characteristics of NPP systems. Through joint research project, the APR1400 reactor has been

studied and safety analysis problems were performed. Based on the experience in first phase [1], the

VVER-1000 has been intensively studied, not only in core thermal hydraulics, but also in severe

accident including the containment, core catcher features etc. The severe accident phenomena are

introduced and simulation of PWR using MELCOR code is supported by KAERI. These are highly

appreciated.

The international cooperation is recognized as important factor for HRD in nuclear safety

research. The human resource development in the field of safety analysis now is under the request.

It is not only requirements of the number of researchers, but also higher qualification of researchers

as well as research works.

REFERENCE

[1] Lê Văn Hồng và các cộng sự. Báo cáo tổng kết nhiệm vụ hợp tác theo NĐT 2009-2010

“Hợp tác nghiên cứu phân tích, đánh giá an toàn vùng hoạt lò phản ứng năng lượng nước

nhẹ trong các điều kiện chuyển tiếp và sự cố”. Thư Viện Khoa học Kỹ thuật Trung ương. Hà

Nội, 1/2011.

[2] Chung B.D., et al, “Development and assessment of multi-dimensional flow models in the

thermal-hydraulic system analysis code MARS,” KAERI/TR-3011/2005, KAERI.

[3] Resolution of Generic Safety Issues: Issue 23: Reactor Coolant Pump Seal Failures (Rev. 1)

(NUREG-0933, Main Report with Supplements 1-34 ).

[4] S.G. Ashbaugh et al. “Simulation of Mixed Oxide (MOX) Versus Low Enrichment Uranium

(LEU) Fuel Severe Accident Response Using MELCOR, Sand 2005-4361c.

[5] ANSYS, Inc., Canonsburg, PA 15317, ANSYS CFX-Solver Theory Guide. (Release 14.0,

November 2011).

[6] NEA Nuclear Science Committee, NEA Committee on Safety of Nuclear Installations.

OECD/NRC BENCHMARK BASED ON NUPEC PWR SUBCHANNEL AND BUNDLE

TESTS (PSBT) Volume I: Experimental Database and Final Problem Specifications.

(November 2010).

[7] Training course “Introduction to NPP Technology”. Chapter 5-Reactor Coolant System and

Connected Systems. Risk Engineering Ltd. January 2012.

VINATOM-AR 13--05


43

A NEUTRONIC FEASIBILITY STUDY OF THE VVER ASSEMBLY

TYPE DESIGN LOADED WITH FULLY CERAMIC

MICRO-ENCAPSULATED FUEL

Hoang Van Khanh, Phan Quoc Vuong, Tran Vinh Thanh

Institute for Nuclear Science and Technology, Vietnam Atomic Energy Institute

179 Hoang Quoc Viet, Nghia Do, Ha Noi, Vietnam

ABSTRACT: A neutronic feasibility study is performed to evaluate the utilization of fully ceramic

microencapsulated (FCM) fuel in the VVER fuel type design. The fuel assembly features the same dimensions

as a benchmark VVER-1000 fuel assembly. On the lattice level, the MVP Monte Carlo and the JENDL-3.3

library were used based on the statistical geometry model. This work focus the results of the lattice-level

neutronic study of doubly heterogeneous FCM fuel including effect of packing fraction and TRISO size on the

neutronic characteristics of fuel pin cell and assembly. The results show that TRISO size of 500μm and

packing fraction of 0.45 has the most excellent neutronic characteristics.

Keywords: VVER, FCM, packing fraction, STRISO size.

1. INTRODUCTION

Fully ceramic microencapsulated (FCM) fuels consist of Tristructural Isotropic (TRISO)

fuel particles embedded in a silicon carbide (SiC) matrix. A TRISO particle consists of a spherical

fuel kernel that is coated with successive layers of porous carbon (buffer layer), a dense inner

pyrocarbon (IPyC), SiC, and an outer pyrocarbon (OPyC) layer. In conventional high-temperature

gas-cooled reactor (HTGR) applications, the TRISO particles are dispersed in a graphitic matrix,

producing compacts in the form of pebbles or pellets 00. Under the FCM fuel concept, the graphite

matrix is replaced with a SiC matrix that offers the following potential advantages 0: (i) improved

irradiation stability; (ii) incorporation of yet another effective barrier to fission product release; (iii)

environmental stability under operating (steady state) and transient conditions as well as long-term

storage; (iv) proliferation resistance.

This paper presents the results of the lattice-level neutronic study of doubly heterogeneous

FCM fuel of the VVER fuel type design. The impact of packing fraction and TRISO size on the

neutronic characteristics of fuel pin cell and assembly was considered to carry out their optimal

values for new fuel design.

2. OBJECTIVES

In order to begin assessing the neutronics characteristics of the FCM fuel, unit cell

calculations were performed. These unit cell calculations can provide information about the

neutronic characteristics of a whole core of similar fuel, and also would provide insight into the

influence of these types of cells heterogeneous assemblies containing UO2 pins as well. The main

objective of this work is to:


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VINATOM-AR 13--05


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- Investigate neutronic characteristics of the VVER fuel type design loading FCM fuel.

- Evaluate the effects of varying the kernel size and packing fraction on the neutronic

characteristics. Preliminary evaluation of heterogeneous assemblies containing FCM pins.

- Compare these results to reference UO2 unit cells.

3. METHODOLOGY

Two calculational models, unit pin cell lattice and assembly lattice, were performed using a

Monte Carlo neutron transport MVP code developed by Japan Atomic Energy Agency 0 and the

JENDL-3.3 library 0. The lattice calculations were performed by applying the statistical geometry

model. The fuel pin cells and assembly feature the same dimensions as a benchmark VVER-1000

fuel assembly 0.

4. RESULTS

4.1. Lattice parameters

The specifications chosen for initial analysis approximate the lattice of the VVER-1000.

Initial calculations were performed by assuming that the ordinary UO2 fuel pellets are replaced with

the FCM fuel compacts. FCM fuel is constituted of TRISO fuel particles containing UO2 kernels

embedded within a SiC matrix. Table 1 shows the dimensions and densities (i.e., specific mass) of

the layers of the TRISO particles specified for these initial calculations. The simplifying assumption

was made that the kernel diameter can be varied without changing the layer thicknesses,

notwithstanding the material integrity implications.

Table 1: TRISO fuel particle dimensions and physical properties in FCM fuel.

The fuel assemblies (FA) are hexagonal in shape. They consist of a total of 331 cell

locations in a regular hexagonal array. The 331 elementary hexagonal locations in FA are occupied

by four main types of cells: 312 fuel pin cells, one central water filled instrumentation tube and 18

water filled guide tubes for control insertion. These assemblies are typical of the advanced designs

under active development in Russia for the VVER-1000 reactors 0 as description in Table 2 and

Figure 1.

Table 2: Description of cell types geometry.

VINATOM-AR 13--05


45

Figure 1: Schematic diagram of a uniform LEU fuel assembly.

4.2. Calculation Results

This section presents on the examination of unit pin cell and assembly lattice of UO2. This

section reports on the examination of unit cells of UO2, the effect of packing fraction and TRISO

size on the neutronic characteristics are evaluated.

Figure 2 shows the initial multiplication factor (k∞) of unit pin cells versus packing fraction

(PF). When the PF increases the amount of fuel in the pin cell increases and therefore as the results

the initial k∞ increases.

Figure 2: k∞ versus packing fraction in unit pin cells.

VINATOM-AR 13--05


46

The Figure 2 also implies that the effect of cladding material on k∞ is negligible. Both SiC

and Zr cladding result in similar k∞ value.

Compared to the original design, the infinite multiplication factor (k∞) of FCM design

slowly decreases and get higher values with higher values of packing fraction as shown in Figure 3.

Figure 3: k∞ of pin cell versus burnup with different packing fraction.

For the fuel assembly lattice, its k∞ features the same as of the fuel pin cells. With the

packing fraction of 45%, the k∞ of fuel assembly is closely similar to the one of original design

(Figure 4).

Figure 4: k∞ of fuel assembly versus burnup with different packing fraction.

The values of packing fraction, 45%, will be chosen as the first optimal packing fraction value. To

evaluate the effect of TRISO size on the neutronic characteristics, the TRISO size was increased to

600µm.

Figure 5: k∞ of fuel assembly versus burnup with different TRISO size.

VINATOM-AR 13--05


47

Figure 6: k∞ of fuel assembly versus burnup.

With the increasing of TRISO size, the k∞ of fuel assembly increases. After 500µm, the

change of k∞ in the first burnup step (≤ 60GWd/t) is nearly unchanged. So 500µm was chosen as

the first optimal TRISO size value (Figure 5). Compared to the original design, FCM design can get

longer core life as shown in Figure 6.

5. CONCLUSIONS

A neutronic feasibility study is performed to evaluate the utilization of fully ceramic

microencapsulated (FCM) fuel in the VVER fuel type design. the results of the lattice-level

neutronic study of doubly heterogeneous FCM fuel including effect of packing fraction and TRISO

size on the neutronic characteristics of fuel pin cell and assembly. The results show that TRISO size

of 500μm and packing fraction of 0.45 has the most excellent neutronic characteristics. The effect

of cladding materials is negligible.

REFERENCES

[1] H. Nickel, H. Nabielek, G. Pott, A.W. Mehner, Nucl. Eng. Des. 217. pp. 141–151, 2002

[2] J. Phillips, C. Barnes, J. Hunn, Fabrication and comparison of fuels for advanced gas reactor

irradiation tests, in: Proceedings of HTR 2010, Prague, Czech Republic, paper 236, October

2010,

[3] K.A. Terrani, et al., Fabrication and characterization of fully ceramic microencapsulated

fuels, Journal of Nuc. Mat. 426, pp. 268-276, 2012.

[4] Nagaya, Y., Okumura, K., Mori, T., Nakagawa, M. MVP/GMVP II: general purpose

Monte Carlo codes for neutron and photon transport calculations based oncontinuous

energy and multigroup methods. JAER, I-1348, 2005.

[5] Shibata, K., et al. Japanese evaluated nuclear data library version 3 revision-3:

JENDL-3.3. J. Nucl. Sci. Technol. 39, 1125-1136, 2002.

[6] NEA/NSC/DOC 10, A VVER-1000 LEU and MOX assembly computational benchmark.

Nuclear Energy Agency, Organization for Economic Co-operation and Development, 2002.

VINATOM-AR 13--06


48

CALCULATION OF FUEL AND MODERATOR TEMPERATURE

COEFFICIENTS IN APR1400 NUCLEAR REACTOR BY MVP CODE

Pham Tuan Nam, Le Thi Thu, Nguyen Huu Tiep and Tran Viet Phu


179 - Hoang Quoc Viet, Ha Noi, Vietnam

ABSTRACT: In this project, these fuel and moderator temperature coefficients were calculated in APR1400

nuclear reactor by MVP code. APR1400 is an advanced water pressurized reactor, that was researched and

developed by Korea Experts, it’s electric power is 1400 MW. The neutronics calculations of full core is very

important to analysis and assess a reactor. Results of these calculation is input data for thermal-hydraulics

calculations, such as fuel and moderator temperature coefficients. These factors describe the self-safety

characteristics of nuclear reactor. After obtaining these reactivity parameters, they were used to re-run the

thermal hydraulics calculations in LOCA and RIA accidents. These thermal-hydraulics results were used to

analysis effects of reactor physics parameters to thermal hydraulics situation in nuclear reactors.

I. INTRODUCTION

The Advanced Power Reactor 1400 (APR1400) [1,2,4] is of the pressurized water type

using two reactor coolant loops. This reactor used uranium dioxide fuel, and many characteristics

that were improved from OPR1000 reactor. The simulation and calculation of this new reactor is an

important work that helps to obtain experiences and skills in analysis and assessment NPP

technology.

Fuel temperature coefficient (Doppler effects) and Moderator Temperature Coefficients

(MTC) are two important parameters that have to consider in design and operating of NPP. These

parameters have to be negative in Pressurized Water Reactor (PWR), and also in APR1400. We

carried out these factors to investigate change of reactivity that depend on temperatures of fuel and

moderator. Then these results were used to assess effects of reactor physics factors to TH state in

RIA and LOCA accidents.

II. FUEL AND NUCLEAR DESIGN OF APR1400 REACTOR

APR1400 reactor is the newest water reactor that was result of Korea government project

from 1992. This reactor has lager power, 1400 MWe. And there are many enhancements in fuel and

nuclear design. Figure 1 and table 1 describe the full core of APR1400.


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mailto:[email protected]

VINATOM-AR 13--06


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Figure 1: Reactor Core Cross Section 241 Fuel Assemblies [5].

Table 1: Mechanical Design Parameters [5].

Number of fuel assemblies in core, total 241

Number of CEAs 93

Number of fuel rod locations 56,876

Spacing between fuel assemblies, fuel rod surface to surface

inches (cm)

0.208 (0.528)

Spacing, outer fuel rod surface to core shroud, inches (cm) 0.214 (0.544)

Hydraulic diameter, nominal channel, feet (cm) 0.0393 (1.198)

Total flow area (excluding guide tubes), ft2 (m

2) 60.8 (5.649)

Total core area, ft2 (m

2) 112.3 (10.433)

Core equivalent diameter, inches (cm) 143.6 (3.647)

Core circumscribed diameter, inches (cm) 152.46 (3.872)

Total fuel loading, lb U (kg U) (assuming all rod locations are fuel

rods)

228 x 103 (103.42 x 10

3)

Total fuel weight, lb UO2 (kg UO2) (assuming all rod locations are

fuel rods)

258.6 x 103 (117.3 x 10

3)

Total weight of Zircaloy, lb (kg) 74,950 (33,996.7)

Fuel volume (including dishes), ft3 (m

3) 409.6 (11.6)

This data is adequate for thermal-hydraulics and neutronics calculations in full core of

APR1400 reactor.

III. CALCULATION OF MULTIPLIER FACTOR (K-EFF) AND REACTIVITY

COEFFICIENTS IN FULL CORE OF APR1400 REACTOR

Dopler effect is very important to design and operate a nuclear reactor [6,7,8]. When fuel

temperature changes, cross section of U238

and neutron reaction changes, and reactivity is changed.

In this project, this effect was claculated when fuel temperature changes from 68 F (293 K)-room

temperture to 2500 F (1644 K), that is reached when accident happens.

VINATOM-AR 13--06


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Fiure 2 is result of calculation for change of multiplier factor and reactivity when fuel

average temperature varies.

Figure 2: Dependent of multiplier factor and reactivity

on fuel temperature by MVP code.

Results that were obtained by MVP code, run in personal computer and windows OS, has

0.036% errors. This is fit with results in Safety Analysis Report (SAR) [4].

Moderator Temperature Coefficient (MTC) strongly affects to reactor physics state, too.

When moderator temperature changes, H-2, O-16 and B-10 nuclide densities change, that affects to

neutron flux and reactivity in nuclear reactor. In this project, MTC was calculated in two states, the

first state: hot zero power, 555oF (290.6

oC) water temperature, no control element assemblies

(CEA), clean, 1210 ppm acid boric; and the second state: Hot full power, 588oF (308.9

oC), no

CEAs, clean and 1088 ppm acid boric. The results are -2.19E-04 ∆ρ/oF and -2.63E-04 ∆ρ/

oF ,

corresponding to the first and second states. These results have large different that comparing to

results in SAR, MTC coefficients are -0.11E-04 ∆ρ/oF and -0.51E-04 ∆ρ/

oF.

IV. USING THE NEUTRONICS CALCULATION RESULTS FOR THE THERMAL

HYDRAULICS CALCULATIONS

The thermal hydraulics code - RELAP5 code, was used to carry out the Reactivity Initial

Accident (RIA) and Loss Off Coolant Accident (LOCA) calculation in WINDOW OS [3], on PC.

The calculations used the neutronics calculation results, that showed above. Figure 3 indicated

change of DNBR parameter in control valve - 777 in 6 s after RIA accident. Results obtained from

the new and old input data, are similar. That indicates that MTC and Doppler effects affect to

thermal hydraulics state of reactor very weakly.

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Figure 3: DNBR change in RIA accident.

V. CONCLUSION

In this project, the calculated group completed all of proposed works, described detailed

structure of fuel assembly and full core in APR1400, knew and calculated multiplier factor,

reactivity coefficients, and using nuclear physics results for thermal-hyraulics calculation.

Calculated results are used for nuclear reactor safety analysis, although this data is not high correct

level but it was the first step in full core calculation for APR1400 technology, and understood effect

of and neutronics results to thermal-hydraulics states.

REFERENCES

[1] Design Features, Safety Assessment and Verification of Key Systems, and Economic

Advancements for APR1400, Sung Jae Cho, Eui Jong Lee, Engineering Support Center,

Nuclear Environment Technology Institute, Korea Hydro & Nuclear Power Co., LDT, 103-

16, Munji-Dong, Yuseong-Gu, Daejeon 305-380, Korea.

[2] APR1400 Design Description, Center for Advanced Reactors Development, Nuclear

Environment Technology Institute, 로고 Korea Hydro & Nuclear co., Ltd, 03/2002.

[3] Lê Văn Hồng và các cộng sự. Báo cáo tổng hợp kết quả nghiên cứu khoa học công nghệ nghị

định thư “Hợp tác nghiên cứu phân tích, đánh giá an toàn vùng hoạt lò phản ứng năng lượng

nước nhẹ trong các chuyển tiếp và sự cố, Viện Năng lượng Nguyên tử Việt Nam, Hà Nội,

2011.

[4] Sung-Quun Zee, Modure 2: Reactor Core and Components, Nuclear Power Reactor

Technology, Core Dseign and Analysis Technology Dept., Korea Atomic Energy Research

Institute,

<http://www.kntc.re.kr/openlec/nuc/NPRT/module2/module2_2/module2_2_2/2_2_2.htm#3.

3%20Burnable%20Poisons>

[5] Islamic Azad University. Computation of concentration changes of heavy metals in the fuel

assemblies with 1.6% enrichment by ORIGEN code for VVER-1000, Mohammad

Rahgoshay, Department of Nuclear Engineering, Faculty of Engineering, Science and

Research Branch, , Tehran, Iran, 2006.

[6] K. Okumura, T. Kugo, K. Kaneko, K. Tsuchihashi. SRAC2006: Acomprehensive Neutronics

Canculation Code System, Japan Atomic Enerrgy Angency, 2007.

[7] Y. Nagaya, T. Mori, K. Okumura, M. Nakagawa. MVP/GMVP: General Purpose Monte

Carlo Codes for Neutron and Photon Transport Camculations based on Continuous Energy

and Multigroup Methods Version 2, Japan Atomic Energy Research Institute, 2004.

[8] Lê Đại Diễn. Báo cáo tổng kết đề tài khoa học công nghệ cấp cơ sở “Sử dụng chương trình

MVP tính toán cho mô hình bó nhiên liệu HEU và LEU của lò phản ứng hạt nhân Đà Lạt”,

Hà Nội, 2007.

http://www.kntc.re.kr/openlec/nuc/NPRT/module2/module2_2/module2_2_2/2_2_2.htm#3.3%20Burnable%20Poisons



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ESTABLISHING QUALITY ASSURANCE PROGRAM FOR

CALCULATION IN CORE AND FUEL MANAGEMENT OF THE DALAT

NUCLEAR RESEARCH REACTOR USING LOW ENRICHED FUEL

Huynh Ton Nghiem, Luong Ba Vien, Le Vinh Vinh, Nguyen Kien Cuong, Nguyen Manh Hung,

Nguyen Minh Tuan, Pham Quang Huy, Tran Quoc Duong, Vo Doan Hai Đang, Pham Hong Son,

Tran Tri Vien and Tran Thanh Tram

Reactor Center, Nuclear Research Institute, Vietnam Atomic Energy Institute

ABSTRACT: Quality assurance program for calculation in core and fuel management for research reactor

plays very important role in safety operation and effective utilization of reactor. The main objective of the

program is to ensure the safe, reliable and optimum use of nuclear fuel in the reactor. This project is carried out

to establishing the quality assurance program together with selected, verified and validated computer code

system and data libraries for calculation in core and fuel management of the Dalat Nuclear Research Reactor

(DNRR) using completely low enriched uranium (LEU) fuel assemblies. The selected computer code system,

data libraries and computational models must be fully met requirements for analyzing status and characteristics

of reactor core as well as the requirements for selecting, verifying and evaluating for codes according to the

regulations of the International Atomic Energy Agency (IAEA). When the quality assurance program and

DRRBurn computer code system are applied for calculation in core and fuel management of the DNRR, they

will contribute not only management, safety operation and effective utilization of the DNRR but also building

safety culture and experiences that will be used for other nuclear projects.

INTRODUCTION

After managing and operating of the DNRR during 30 years, staffs of Reactor Physics and

Engineering Department that belongs to Reactor Center have really developed and carried out main

tasks:

- Calculating in core and fuel management of the DNRR using high enriched uranium

(HEU) fuel [1];

- Calculating and performing in partial conversion of the DNRR core to using LEU fuel;

- Design calculation, safety analysis and implementing fully conversion using LEU fuel

of the DNRR [2, 3, 4, 5].

Many computer code systems have been investigated and applied for safety analysis as well

as operation management and utilization of the DNRR. Especially, in full core conversion project,

some selected computer codes have been served for design calculation and safety analysis. Obtained

results from full core conversion project show that calculation tools of Reactor Center were fully

met requirements about in core and fuel management and also in researching, operating

management and utilization of the DNRR.








VINATOM-AR 13--07


53

However, the evaluation of computer code systems and data libraries to apply effectively for

the DNRR was not fully carried out. Procedures of calculation implementation, storage data, etc. are

not still approved and released. So

- Not having consistency in calculation;

- Neutronics calculation depending on experience of performers;

- Not ensure in elimination of errors or mistakes of users;

- Not ensure in inheritance in research.

The calculation in core and fuel management must be organized in a coherent way and in

compliance with safety requirements [15, 16, 17]. This will not only contribute to ensure the safe

operation management and effective exploitation of the reactor but also to establish safety culture

and valuable experience for other nuclear projects. In addition, the establishment and application of

quality assurance program for calculation in core and fuel management will contribute to

consistency in reactor calculations, avoiding errors or mistakes; clearly define responsibilities and

ensuring continuity professional expertise.

I. RESEARCH IN EXPERIMENT AND CALCULATION

I.1. Research in experiment

The research in experiment to reactor’s parameters always is conducted when reactor’s

working configuration is changed to ensure safe operation and effective utilization. The

experimental results are also used to verify computer codes, simulation models and nuclear data

libraries used in the design, operation management and exploitation.

Important parameters of the DNRR were determined by experiments including:

- Neutron distribution (azimuthal distribution in fuel assembly, radial distribution, axial

distribution, symmetric distribution of the reactor core and absolute neutron flux at irradiation

positions);

- Neutron spectra at important positions;

- Control rod worths and integral characteristics;

- Reactivity of fuel assemblies and Beryllium rods;

- Void effect;

- Temperature reactivity feedback coefficient of moderator;

- Xenon poisoning effect;

- Kinetics parameters.

The methods and conditions of experiments in order to reduce errors have been concerned

during implementation such experiments. The experimental results have been synthesized and

established to a set of experimental data used as the basis data for selecting, testing and evaluating

of computer codes and nuclear data libraries as well as to apply in operation management and

exploitation of the reactor.

I.2. Research in theory calculation

The primary objective of the research in theory calculation is to select, evaluate and validate

of computer codes, data libraries and computational models to serve for in core and fuel

management of the DNRR using LEU fuel.

Computer code systems have been researched and used including:

- SRAC system (PIJ, CITATION and COREBN) [11, 12];

VINATOM-AR 13--07


54

- WIMS-ANL and REBUS [7, 9];

- MVP and MVP-Burn [13, 14];

- REBUS-MCNP linkage system [6, 8, 18, 19].

In addition, NJOY code was also used in data processing and created data libraries for other

computer codes like WIMS-D/E and MCNP.

Nuclear evaluated data have been investigated including: ENDF/B7.1 (USA) [20, 21],

JEFF3.1 (Europe) [23] and JENDL4.0 (Japan) [22].

I.2.1. Data library selection

The selection of data libraries have been done basing on three library systems: ENDF/B,

JEFF and JENDL, MCNP5 code was used to calculate for testing. The testing calculations include:

- Infinite multiplication factor for HEU and LEU fuels;

- Neutron spectra and micro cross section of 235

U and 238

U isotopes depending on energy

of HEU and LEU fuels;

- Finite multiplication factor for critical configuration with 72 LEU fuel assemblies and

working configuration with 92 LEU fuel assemblies of the DNRR.

Calculated results of the infinite multiplication factors of fuels show that results from all

three libraries have fairly consistent with each other. The results using ENDF/B7.1 and JEFF3.1 are

closer together than JENDL4.0. The results of neutron spectrum and fission cross sections show that

for HEU fuel spectrum and fission cross section of 235

U of all three libraries have resulted in very

small differences. For the fission cross section of 238

U in the thermal energy, the calculated result

using JEFF3.1 are significantly larger than the other two libraries. The calculated results of two

critical configurations are within acceptable difference.

The calculated results show that the libraries are asymptotic data together. The calculated

results using ENDF library always get in high reliability and closer to experimental values than the

calculated results using the remained two libraries. Therefore data library using for MCNP code is

mainly ENDF/B7.1.

I.2.2. Computer code system selection

A set of data consists of 14 different critical configurations with 25 positions having various

control rod positions that was established during reactor startup was selected to perform the

calculation and obtained results by using current four computer code systems were compared with

each other.

Calculated results from 4 computer code systems show that:

- Regarding to stability, errors of calculated results using MVP and MVP-Burn and

REBUS-MCNP with real geometric models are 0.12% and 0.10% respectively, the SRAC

system and WIMS-ANL, REBUS with lattice cell geometric models are 0.17% and 0.15%

respectively compared with the average value.

- In terms of absolute results, average values of multiplication factor of WIMS-ANL and

REBUS system and REBUS-MCNP system using ENDF/B7 library are 0.9997 and 0.9995

respectively, the SRAC system and MVP and MVP-Burn using ENDF/B6 library are 0.9985 and

0.9981 respectively.

So, computer code systems using real geometric models and new updated libraries give

better stability and more consistent results compared with experimental data.

VINATOM-AR 13--07


55

Table 1 presents main characteristics of the four computer code systems based on the main

features of the method, geometric models and other features.

The calculated results show that all computer code systems can be met requirements in

neutronics calculation of research reactor. So depending on the calculation requirements as well as

the current computer code systems users can select a suitable computer code system. With these

advantages that are presented in Table 1 and the possibility of personal computers nowadays,

REBUS-MCNP was chosen as main calculation tool in the quality assurance program for

calculation in core and fuel management of the DNRR. With complex geometry as the DNRR along

with the presence of beryllium in the core, REBUS-MCNP system can fully satisfy the

computational requirements. Time consuming in calculation was overcome by using PC cluster on

MPI environment.

Table 2: Main characteristics of four computer code systems.

Feature SRAC MVP and

MVP-Burn

WIMS-ANL

and REBUS

REBUS-

MCNP

Solving equation Neutron

diffusion

Neutron

transport

Neutron

diffusion

Neutron

transport

Solving method Finite difference Monte-Carlo Finite difference Monte-Carlo

Geometry Lattice Real Lattice Real

Upgrading ability

- Program None None None Yes

- Data library None None Yes Yes

Beryllium poisoning None None None Yes

Consuming time Short Long Short Long

I.2.3. Comparing calculated results to experimental data

To validate the REBUS-MCNP system with ENDF data library, the system should be

evaluated by performing calculation almost characteristics of the reactor and compared with the

experimental data that were mainly gotten in during reactor startup with LEU fuel. The

implemented calculations include:

- Neutron flux distribution and neutron spectrum;

- Control rod worths;

- Effective reactivity of fuel assemblies and beryllium rods in the core;

- Void effect and temperature reactivity feedback coefficient of moderator;

- Xenon poisoning effect;

- Kinetics parameters.

Calculated and experimental relative thermal neutron flux, the results were normalized to

unit, at highest neutron flux in neutron trap show that.

- In radial direction of the reactor core, discrepancy between calculated results and

experimental data is less than 3%, except cell 6-4 and 12-2 with higher difference about 8%.

VINATOM-AR 13--07


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- In axial direction of fuel centerline, the difference between calculated and experimental

results in range from 15 cm to 65 cm is about 4%, top and bottom of fuel have higher differences

than 10%.

- In axial direction at neutron trap, the difference between calculated and experimental

results is about 4%.

The calculation of the neutron spectrum and absolute neutron flux in the experimental

irradiation positions including neutron trap, channel and two-channel wet dry 1-4 7-1 and 13-2 were

carried out. Table 2 presents experimental and calculated neutron spectrum and neutron flux that

collapsed in three energy groups at neutron trap with highest neutron flux of two configurations

with 104 HEU fuel assemblies and 92 LEU fuel assemblies. The results showed that the difference

between the calculated and experimental within 5%.

Table 2: Integral neutron flux collapsed to three energy groups at neutron trap.

Neutron flux

Mixed-core with 104

HEU fuel assemblies

Working core with 92

LEU fuel assemblies

MCNP5 SANDBP MCNP5 SANDBP

Thermal (n/cm2.s) 2.298.10

13 2.245.10

13 2.317.10

13 2.296.10

13

Epi-thermal (n/cm2.s) 7.027.10

12 7.248.10

12 6.520.10

12 6.224.10

12

Fast (n/cm2.s) 4.031.10

12 4.272.10

12 2.563.10

12 2.641.10

12

The effect of the control rod worths of working configuration with 92 LEU fuel assemblies

were calculated and compared with experimental data in Table 3 Experimental results are lower

than the calculated results in approximately 7%.

Table 3: Effect of control rod worth of working core with 92 LEU fuel assemblies.

Control rod Effective reactivity ($)

Diff. (%) Experiment Calculation

Regulating rod 0.495 0.531 6.73

Shim rod 1 2.966 3.178 6.68

Shim rod 2 3.219 3.422 5.93

Shim rod 3 2.817 2.958 4.76

Shim rod 4 2.531 2.709 6.58

Safety rod 1 2.487 2.604 4.49

Safety rod 2 2.195 2.219 1.10

The calculation of the effective reactivity of fuel assemblies and beryllium rods at different

positions in the reactor core have been conducted in order to determine the effective of reactivity

according to their positions in the reactor core. Calculated and experimental results showed that the

difference is just within 0.05$ (or 5 cent).

Calculated and experimental results also determined negative temperature reactivity

feedback coefficient of working configuration with 92 LEU fuel assemblies shows the inherent

safety of the reactor core using LEU fuel.

VINATOM-AR 13--07


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The calculation of negative reactivity by Xenon poisoning was done by calculating the

present of Xenon in composition of fuel after operating 130 h of the reactor and without Xenon

after cooling. The reactivity value was calculated about 1.30 $ compared with experimental value is

about 1.23 $, the difference between two values is 5.8%.

Table 4 shows the calculated results of kinetics parameters using LEU fuel by VARI3D and

MCNP5 computer codes and experimental data. The difference between calculated and

experimental results of the precursor decay constant and fraction of delayed neutron groups is about

4% and 5% respectively. These data will be used in transient calculation and safety analysis of full

core conversion from HEU to LEU fuel of the DNRR. Prompt neutron life time is determined by

8.925.10-5

s.

The calculated results of characteristic parameters of the reactor core using LEU fuel show

that REBUS-MCNP system fully meets the goal of calculation in core and fuel management of the

DNRR.

Table 4: Calculated and experimental results of precursor decay constant

and fraction of delayed neutron group.

Delayed

neutron

group

Precursor decay constant Delayed neutron fraction

Measured

value

Calculated

value Diff. (%)

Measured

value

Calculated

value Diff. (%)

1 1.358E-02 1.334E-02 1.8 2.648E-04 2.525E-04 4.9

2 3.251E-02 3.273E-02 0.7 1.363E-03 1.421E-03 4.1

3 1.236E-01 1.208E-01 2.3 1.315E-03 1.380E-03 4.7

4 3.141E-01 3.030E-01 3.7 2.902E-03 2.809E-03 3.3

5 8.182E-01 8.503E-01 3.8 1.204E-03 1.213E-03 0.8

6 2.847E+00 2.856E+00 0.3 5.033E-04 5.049E-04 0.3

Sum 7.550E-03 7.580E-03 0.4

II. ESTABLISHING COMPUTER CODE SYSTEM FOR CALCULATION IN CORE

AND FUEL MANAGEMENT

Computer code system for in core and fuel management must comply with the regulation of

core management was specified in the document “Core Management and Fuel Handling for

Research Reactors”, IAEA safety standards [17], which including regulations on: Management

objectives of the reactor core, safety requirements in core management and analysis calculation of

reactor core.

In addition, the computer code system must also suitable to manage the core of the DNRR

and ability to upgrade the system and data libraries to ensure updated when needed.

Each computer code must be evaluated and the can be applied for safety analysis-

particularly for licensing purpose. Each computer code in the system must comply with the

assessment process including the selection rules, testing, evaluation, documentation of the code as

well as the possibility of computer code user specified in the document “Safety analysis for research

reactor,” the IAEA safety report [15,16]. The preparation of input data, establishing calculational

model of the reactor core, edit input files of the codes in the system have to follow test and

evaluation procedures that specified in this document.

VINATOM-AR 13--07


58

The computer code system was selected for in core management of the DNRR include:

- MCNP5 code: Calculate neutron flux and reaction rate;

- REBUS-Win: Burn up calculation and interested materials such as beryllium;

- Two computer codes: NJOY and WIMS-ANL is used to create and update data

libraries;

- DRRBurn code was programmed by Compaq Visual Fortran language on Window

operating system to connect and manage working system and core data management.

DRRBurn code was designed for using easily through the interaction between the user and

the display window on the screen. Calculational model and input files for all the codes in the system

has been built and evaluated. The code will automatically compose input file with core

configuration and composition of fuel material as well as beryllium materials that are updated

basing on information about changing of core configuration and historical reactor operation

supplied by the user to achieve the consistency in the whole process of core and fuel management,

less experienced user can also use the system and avoid possible errors.

The diagram of the DRRBurn computer code system is presented in Figure 1 with functions

including display, computation, management and storage.

The system has been used for core and fuel management of the DNRR from January, 2012

to March, 2014. Difference calculated and experimental excess reactivity following operation time

at maximum nominal power is about 0.08 $ and it shows that the calculated results were quite

suitable.

Figure 1: Diagram of the DRRBurn computer code system.

Update mctal

Calculate neutron

flux and reaction

rate

Composition of fuel

materials and Be in each

depletion time step

Update files MCNPCOMP,

input, a.rebcm, inp

Update multi group cross sections depending on burn

up of fission products and lumped fission product

Update library from evaluated nuclear data

Re-calculte neutron

flux and reaction rate

New depletion step

Update core

confguration: files

FNL, mcnpinpa

Update historical

reactor

operation:LSCL

REBUS_win

Burn up

DRRBurn

Fuel management,

Display

WIMS-ANL

Lattice cell calculation

MCNP5

Calculate neutron

transport

NJOY

Nuclear data processing

Files are updated:

FNL LSCL

MCNPCOMP

Input a.rebcm inp

mctal

Storage at each

depletion time

step MCNPCOMP

Input a.rebcm

inp mctal

VINATOM-AR 13--07


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III. CONCLUSIONS

The experiments were carried out to determine the characteristics parameters of the DNRR

fully using LEU fuel to establish the experimental data in order to operate safely and efficiently

utilization of the reactor. At the same time, the experimental data are applied in evaluating

computer codes to be used in analysis of the reactor.

Conducting theoretical calculations, carried out comparisons with experimental data and

analysis, evaluation to select, test and evaluate computer codes as well as nuclear data library in

order to validate them for putting in analysis and core management for the DNRR.

The linkage DRRBurn computer code was programmed to manage calculations, set up

computational model and input files as well as storage data to ensure compliance with the

requirements of the IAEA in core and fuel management of the DNRR.

Establishing and applying of the quality assurance program in calculation of core and fuel

management of the DNRR. The quality assurance program and DRRBurn system will really not

only contribute to ensure the management, safe operation and efficient utilization of the DNRR but

also to build safety culture and valuable experience for other nuclear projects.

REFERENCES

[1] Ngô Quang Huy và cộng sự. Các đặc trưng vật lý của Lò phản ứng hạt nhân Đà Lạt. Viện

Năng lượng nguyên tử Việt Nam, 1994.

[2] Quy trình khởi động vật lý và khởi động năng lượng để chuyển đổi toàn bộ vùng hoạt lò

phản ứng hạt nhân Đà Lạt sang sử dụng nhiên liệu độ giàu thấp. Viện Nghiên cứu Hạt nhân,

2011.

[3] Nhật ký vận hành lò phản ứng hạt nhân Đà Lạt, 2011-2012.

[4] Báo cáo kết quả khởi động vật lý và khởi động năng lượng để chuyên đôi toan bô vung hoat

Lò Phản ứng h ạt nhân Đà Lạt sang nhiên liệu độ giàu thấp . Viện Nghiên cứu Hạt nhân,

2012.

[5] Báo cáo phân tích an toàn sử dụng cho Lò Phản ứng hạt nhân Đà Lạt 2012, Viện Nghiên cứu

Hạt nhân, 2012.

[6] X-5 Monte Carlo Team, “MCNP - A General Monte Carlo N-Particle Transport Code,

Version 5”, Los Alamos national laboratory, April 2003.

[7] A.P. Olson, “A Users Guide for the REBUS-PC Code, Version 1.4”, Argonne National

Laboratory, Dec. 2001.

[8] John G. Stevens, “The REBUS-MCNP Linkage”, Argonne National Laboratory, April 2008.

[9] J.R. Deen et al., “WIMS-ANL User Manual, Rev. 5,” ANL/TD/TM99-07, Argonne National

Laboratory, Feb. 2003.

[10] Kahler, Albert C. III, MacFarlane, Robert, “The NJOY Nuclear Data Processing System,

Version 2012”, Los Alamos, 2012.

[11] Keisuke OKUMURA, Teruhico KUGO, Kunio KANEKO and Keichiro TSUCHIHASHI,

“SRAC2006: A Comprehensive Neutronics Calculation Systems”, Japan Atomic Energy

Agency, Feb. 2007.

[12] Keisuke OKUMURA, “COREBN: A Core Burn-up Calculation Module for SRAC2006”,

Japan Atomic Energy Agency, Feb. 2007.

[13] Yasunobu NAGAYA, Keisuke OKUMURA, Takamasa MORI and Masayuki

NAKAGAWA, “MVP/GMVP II: General Purpose Monte Carlo Codes for Neutron and

Photon Transport Calculations based on Continuous Energy and Multigroup Methods”,

Japan Atomic Energy Agency, Sep. 2004.

[14] Keisuke OKUMURA, Yasunobu NAGAYA and Takamasa MORI, “MVP-BURN: Burn-up

Calculation Code Using A Continuous-energy Monte Carlo Code MVP”, Japan Atomic

VINATOM-AR 13--07


60

Energy Agency, Jan. 2005.

[15] Safety Analysis for Research Reactors, Safety Reports Series No.55, International Atomic

Energy Agency, 2008.

[16] Safety of Research Reactors, No. NS-R-4 Safety Requirement, International Atomic Energy

Agency, 2005.

[17] Core Management and Fuel Handling for Research Reactors, IAEA Safety Standards,

International Atomic Energy Agency, 2008.

[18] Daniel J. Whalen, David A. Cardon, Jenifer L. Uhle, John S. Hendricks, “ MCNP: Neutron

Benchmark Problems”, Los Alamos National Laboratory, Nov. 1991.

[19] Oscar Cabellos, “ Processing of the JEFF-3.1 Cross Section Library into a Continuous

Energy Monte Carlo Radiation Transport and Criticality Data Library”, OECD-Nuclear

Energy Agency Data Bank, May 2006.

[20] M. B. Chadwick et.al, “ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross

Section, Covariances, Fission Yields and Decay Data”, Nuclear Data Sheet, Elsevier, 2011.

[21] http://t2.lanl.gov/data/endf/

[22] http://wwwndc.jaea.go.jp/ftpnd/jendl/j40p.html

[23] http://www.oecd-nea.org/dbforms/data/eva/evatapes/jeff_31/JEFF312/

http://t2.lanl.gov/data/endf/

http://wwwndc.jaea.go.jp/ftpnd/jendl/j40p.html

http://www.oecd-nea.org/dbforms/data/eva/evatapes/jeff_31/JEFF312/

VINATOM-AR 13--08


61

A SRAC CALCULATION OF THE VVER 1000 CORE’S EFFECTIVE

MULTIPLICATION FACTOR

Tran Vinh Thanh, Phan Quoc Vuong, Tran Viet Phu, Hoang Van Khanh and Ta Duy Long

Nuclear Power Center, Institute for Nuclear Science and Technology,


179 Hoang Quoc Viet, Nghia Do, Cau Giay, Ha Noi

ABSTRACT: Neutronic characteristics for a VVER-1000 were investigated by using SRAC code and nuclear

data library JENDL-3.3 with 107 public energy groups. The elementary lattice modules, PIJ and CITATION,

have been used for modeling of the fuel rods, fuel assemblies and full core. The main Neutronic characteristics

analyzed in this work include infinite multiplication factors (kinf) versus burnup, the distribution of nuclide

concentrations in the pin cells; the pin-wise power distribution in the assembly; the effective multiplication

factors (keff), and the power distribution in the core.

Keywords: SRAC, PIJ, CITATION, effective multiplication factor, power distribution, burnup.

I. INTRODUCTION

Nuclear data libraries provide the data on cross sections and angular distributions of nuclear

reactions with neutron from experimental research and theoretical calculations. The data are used to

simulate neutronic characteristics in nuclear reactor physics. For this reason, the more accurate data

are, the more accurate simulation results become.

This report is based on the OECD benchmark paper: “A VVER-1000 LEU and MOX

Assembly Computational Benchmark. Nuclear Energy Agency, Organization for Economic Co-

operation and Development”[1]. In this report, we present characteristics of the VVER Low

Enriched Uranium (LEU) and Mixed Oxide (MOX) fuel assembly, where the calculations have

been done using 3 libraries: ENDF/B 7.0, JENDL 3.2 and JENDL 3.3. The obtained results are

compared to estimate the accuracy and usability of the data from the libraries with specific

characteristics.

II. CALCULATION SPECIFICATIONS

In this report, we used the SRAC code with PIJ and Burnup modules to modeling LEU and

MOX assemblies. The SRAC code which can be executed in UNIX and LINUX environments was

developed by Japan Atomic Energy Agency (JAEA). The code consists of 107 energy groups with

74 fast groups and 48 thermal groups providing collision probability (PIJ) and resolving neutron

diffusion and transport [2].


- Code: CS/13/04-07



- Implementation Time: 12 months (Jan 2013- Dec 2013)



Tran Vinh Thanh, Phan Quoc Vuong, Nguyen Tuan Khai. Comparative neutronic characteristics

calculations of LEU and MOX fuel assemblies of VVER reactor with various nuclear data libraries.

10th

National Conference on Nuclear Science and Technology,Vung Tau, June 2013.


VINATOM-AR 13--08


62

II.1. LEU and MOX assemblies

The VVER hexagonal fuel assemblies consist of 331 cylindrical rods. Fuel cladding and

structural materials made by Zr-Nb composition. Fuel rods in the LEU assembly are classified into

4 types: 300 UO2 rods with 3.7%w/t enrichment, 12 absorbed burnable rods (UO2-Gd2O3-(UGD))

with 3.6%w/t UO2 and 4.0%w/t Gd2O3, a water rod put in the center of the assembly and 18 guide

tubes located at positions as shown in Figure 1.The fuel rods in MOX assembly are classified into 6

types: first layer consisting of 66 fuel rods with 2%w/t enrichment, second layer 96 fuel rods with

3%w/t, 138 fuel rods with 4.2%w/t in the center, 12 UGD rods, 1 water rod, 18 guide tubes in the

same positions as in the LEU assembly.

Figure1: LEU (left) and MOX (right) fuel assemblies.

II.2. State conditions

Table 1: State conditions.

State Description

Fuel

Temp.

(K)

Moderator

Temp. (K)

135Xe and

149Sm

Boron

concentration

in moderator

(g/kg)

S1 Operating poisoned hot state 1027 575 Eq. 0.6

S2 Operating state 1027 575 0 0.6

S3 Isothermal hot state with Boron 575 575 0 0.6

S4 Isothermal hot state without Boron 575 575 0 0

S5 Cold state 300 300 0 0

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63

State conditions are listed in Table 1.The physical characteristics of the LEU and MOX

assemblies are calculated in the states: S1 is the operating poisoned hot state with 135

Xe and 149

Sm,

S2 is the operating hot state, S3 is the isothermal hot state with Boron, S4 is the isothermal hot state

without Boron, S5 is the cold state.

III. RESULTS AND DISCUSSIONS

III.1. Infinite multiplication factor versus burnup

Figure 2: The infinite multiplication factor versus burnup.

Figure 2 shows the infinite multiplication factor (kinf) of the LEU and MOX assemblies

versus burnup evaluated from 0GWd/t to 40GWd/t. In the LEU assembly, we can see in the burnup

range from 0 to 8GWd/t, kinf increases lightly from 1.147 to 1.155. After that, kinf decreases steadily

from 1.155 to 0.9. In the MOX assembly, kinf decreases from 1.159 to 0.895. The kinf of MOX fuel is

lower than that of the LEU. This is due to two reasons: (i) During the fuel burning 239

Pu in the

MOX produces more neutron absorbers than 235

U in the LEU, and (ii) 238

U in the LEU fuel can be

converted into fissile material 239

Pu. At the beginning of cycle, because MOX fuel produces more 135

Xe and 149

Sm than LEU fuel, the contribution of UGD rods in MOX assembly is not much as in

LEU assembly, so gradient of the kinf curve in MOX assembly is not high as in LEU assembly.

In Figure 2, the grey BM straight line is the benchmark mean value of kinf and the other ones

are kinf obtained based on three nuclear data libraries mentioned above. For the MOX fuel the kinf

values are very close to the benchmark mean value. For the LEU assembly, the library ENDF 7.0

gives the kinf value deviated 1.5% from the benchmark one, the JENDL 3.2 and JENDL 3.3give kinf

close to the benchmark in the range from 0GWd/t to 15GWd/t with a small deviation of 0.2%.

However, at the kinf values greater than 15GWd/t the deviation increases up to 1.5%. It can be

concluded that the deviation between the kinf coefficients obtained from the LEU and Benchmark is

greater than that obtained from the MOX and Benchmark, especially at the high burn-up values.

III.2. Nuclear densities versus burnup

Figure 3 shows nuclear densities of 235

U and 239

Pu versus burnup, where we can see:

- The appearance of 239

Pu in LEU fuel is caused by fuel conversion in fuel-burning

process and the appearance of 235

U in MOX fuel by contribution of UGD rods.

- In LEU assembly, the 235

U concentration at first burnup step is 2.5x10-

4atoms/barn*cm and then decreases to 5x10

-5atoms/barn*cm at the burnup 40GWd/t. The

239Pu

concentration increases dramatically at first burnup steps. This is the reason why kinf curve for LEU

fuel has one peak at 8GWd/t.

VINATOM-AR 13--08


64

- In MOX fuel, the 235

U concentration decreases from 2.07x10-5

atoms/barn*cm at

0GWd/t to 6.45x10-5

atoms/barn*cm at 40GWd/t.

Figure 3: Nuclear densities of 235

U(left) and 239

Pu(right) versus burnup.

The 239

Pu concentration at beginning of the cycle is 2x10-4

atoms/barn*cm and then

decreases to 7x10-5

atoms/barn*cm at 40GWd/t. The 235

U and 239

Pu nuclear densities in LEU and

MOX assemblies calculated by three libraries are very similar to the benchmark mean values.

Figure 4 shows the 135

Xe and 149

Sm concentrations versus burnup plot. As known, two these

isotopes are reactor poisons, and the kinf value is affected by their products. The amount of 135

Xe

and 149

Sm increases rapidly at the first burnup steps. We can see, the 135

Xe and 149

Sm concentration

in the MOX fuel is much higher than in the LEU fuel because the yields of 135

Xe and 149

Sm from

thermal reaction of 239

Pu are higher than from 235

U.[3]

Table 2: Fission product yields (atoms per fission) from thermal fission*

In LEU fuel, the maximum 135

Xe concentration is 3.2x10-9

atoms/barn*cm at 5GWd/t and

then decreases to 2.7x10-9


Figure 4: Poison density in fuel versus burnup

for two cases: 135

Xe (left) and 149

Sm (right).

VINATOM-AR 13--08


65

In MOX assembly, the maximum 135

Xe concentration is 5.4x10-9

atoms/barn*cm at

1GWd/t and down to 3.4x10-9

atoms/barn*cm at 40GWd/t. The accumulated amount of 149

Sm

increases rapidly at first burnup steps and reaches a maximum value of 5x10-8

atoms/barn*cm at

5GWd/t. After that, 149

Sm density decreases to 4x10-8


From Figure 4 we can see that result on 135

Xe and 149

Sm concentrations with three libraries

in LEU assembly are similar to the benchmark mean value at first burnup steps. However, the

deviations increase at high burnup values. The calculations using the library ENDF 7.0 gives the

most difference compared with the benchmark one, for example at burnup 40GWd/t the

corresponding deviations for135

Xe and 149

Sm are 5.82% and 5.94%. In MOX fuel, results with 3

libraries for 135

Xe concentration are higher 4% than benchmark mean value. The calculations

using the library ENDF 7.0 gives the most difference compared with the benchmark one, for

example at burnup 40GWd/t the corresponding deviations for 135

Xe 4.59% and for 149

Sm it’s very

close to the benchmark one.

Figure 5: Nuclear density versus burnup for 155

Gd (left) and 157

Gd (right).

Figure 5 presents the 155

Gd and 157

Gd nuclear densities versus burnup plot. The role of Gd in

fuel assemblies is to equalize reactivity at beginning of the cycle. In general, the Gd concentration

decreases dramatically to 0 when the burnup increases from 0GWd/t to 10GWd/t. For LEU

assembly the results for 155

Gd and 157

Gd concentrations with three libraries are similar to the

benchmark one. For MOX assembly, the corresponding results for 155

Gd concentration are higher

than benchmark one, where the ENDF 7.0 gives the greatest difference. For example, at 6GWd/t,

the corresponding deviation is 15.89%. The results for 157

Gd concentration are similar to

benchmark one in the burnup range from 0GWd/t to 6GWd/t. At high burnup steps157

Gd

concentrations are lower than benchmark, where the ENDF 7.0 gives the greatest difference,

4.76% at 8GWd/t.

III.3. Reactivity coefficients

a. Effect on Boron in moderator

The absorption effect by Boron is obtained in comparison between their activities at

Isothermal hot state with Boron (S3) and without Boron (S4). The value can be calculated by

theformular: (mk).The specific values in LEU and

MOX assemblies at 0, 20, 40GWd/t are presented in Table 3.

VINATOM-AR 13--08


66

Table 3: Effect of Boron in moderator.

Fuel

Assembly Burnup (GWd/t)

BM EDF 7.0 JDL 3.2 JDL 3.3

Δρ Δρ Deviation Δρ Deviation Δρ Deviation

LEU

0 40.23 40.42 0.47% 40.31 0.21% 40.25 0.06%

20 43.44 43.69 0.56% 43.34 0.23% 43.13 0.72%

40 51.41 51.56 0.30% 51.00 0.80% 50.73 1.33%

MOX

0 23.20 23.10 0.42% 23.07 0.59% 22.79 1.77%

20 32.54 32.13 1.25% 31.94 1.83% 31.60 2.88%

40 42.64 41.45 2.79% 41.04 3.75% 40.71 4.54%

The BM in Table 2 is benchmark mean value, while the columns ENF 7.0, JDL 3.2 and JDL

3.3 show the results using libraries ENDF 7.0, JENDL 3.2 and JENDL 3.3.We can see in Isothermal

hot state without Boron, values are higher than in Isothermal hot state with Boron. At high

burnup steps, change in the reactivity coefficients is relatively big. This is because the Boron

concentration in moderator is kept at 0.6g/kg while the fuel reactivity decreases.

The Δρ values for LEU assembly are more much higher than in MOX assembly. This is due

to a fact that in the burning process the MOX fuel produces more neutron absorbers than LEU fuel.

For this reason, the absorption effect by Boron in MOX assembly is not strong as in LEU assembly.

Compared with the benchmark mean value, the results given by ENDF 7.0 are in good

consistence, where a minimum deviation is 0.3% and the maximum is 2.79%.The corresponding

deviations are higher in cases of the JENDL 3.2 and JENDL 3.3, the maximum deviations are

3.75% and 4.54% for JENDL 3.2 and JENDL 3.3, respectively.

b. Effect on fuel temperature

Effect on fuel temperature is obtained by the reactivity comparison between the Operating

state(S2) and Isothermal hot state(S3). The values can be calculated by theformular:

(mk).The specific values in LEU and MOX

assemblies at 0, 20, 40GWd/t are presented in Table 4.

Table 4: Effect of fuel temperature.

Fuel




LEU

0 -9.86

-

10.52 6.71%

-

10.42 5.68%

-

10.46 6.06%

20

-

12.87

-

12.74 1.01%

-

12.46 3.16%

-

12.68 1.46%

40

-

15.63

-

14.97 4.24%

-

14.64 6.36%

-

14.85 5.00%

MOX 0

-

12.18

-

11.80 3.10%

-

11.68 4.11%

-

11.74 3.58%

VINATOM-AR 13--08


67

20

-

13.84

-

13.76 0.58%

-

13.65 1.38%

-

13.68 1.18%

40

-

15.98

-

15.37 3.81%

-

15.16 5.11%

-

15.19 4.93%

In Table 4, when fuel temperature increases from 575K to 1027K, Δρ decreases from

9.86mk at 0GWd/t to 15.63mk at 40GWd/t in LEU assembly and from 12.18mk at 0GWd/t to

15.98mk at 40GWd/t in MOX assembly. Compared with the benchmark the library ENDF 7.0 gives

a greater deviation than two the other libraries. For the ENDF 7.0 the maximum deviation is 6.71%

and minimum is 0.58%, while for the JENDL 3.2 and JENDL 3.3 the maximum deviations are 6.36

and 6.06%, and the minimum ones are 1.38 and 1.18%, respectively.

c. Effect on Isothermal hot state.

Effect on Isothermal hot state is obtained by the reactivity comparison between the

Isothermal hot state without Boron (S4) and Cold State(S5). The values can be calculated by

the formular: : (mk). The specific in LEU and

MOX assemblies at 0, 20, 40GWd/t are presented in Table 5.

When the fuel and moderator temperatures increase the negative reactivity is quite high. In

LEU assembly the Δρ values increase from 41.73mk at 0GWd/t to 50.3mk at 40GWd/t. In MOX

assembly the Δρ increase from 47.96mk at 0GWd/t to 52.73mk at 40GWd/t.

Table 5: Effect on Isothermal hot state.

Fuel




LEU

0

-

41.73

-

43.22 3.58%

-

42.01 0.68%

-

42.72 2.37%

20

-

47.92

-

48.78 1.80%

-

47.79 0.27%

-

47.43 1.03%

40 -50.3

-

50.99 1.38%

-

50.00 0.60%

-

48.80 2.98%

MOX

0

-

47.96

-

48.51 1.14%

-

48.62 1.38%

-

47.37 1.23%

20

-

54.28

-

54.44 0.30%

-

54.00 0.51%

-

52.34 3.58%

40

-

52.73

-

54.49 3.33%

-

53.45 1.36%

-

51.40 2.54%

Library JENDL 3.2 gives the results closest to the benchmark mean value, its maximum and

minimum deviation is, respectively, 1.38% and 0.27%. The ENDF 7.0 and JENDL 3.3 give the

results with higher deviations, typically maximum deviation of 3.58%.

VINATOM-AR 13--08


68

IV. CONCLUSION

In this report, we presented the calculation results on the infinite multiplication factor (kinf),

nuclear densities of 235

U, 239

Pu, 135

Xe, 149

Sm, 155

Gd, 157

Gd; reactivity coefficients (Δρ) versus

burnup for LEU and MOX assemblies using three nuclear data libraries ENDF 7.0, JENDL 3.2 and

JENDL 3. All the obtained results were compared with the benchmark mean values.

The results on infinite multiplication factor, nuclear densities obtained from two libraries

JENDL 3.2 and JENDL 3.3 are closer to the benchmark than library ENDF 7.0. However, the

results on the reactivity coefficients by ENDF 7.0 is better than two the others libraries. Thus, we

can conclude on the advantage and disadvantage of each data library used in analyzing the

neutronic characteristics of VVER. As a result, the data selection depends on both physics and

calculation code.

REFERENCES

[1] NEA/NSC/DOC, “A VVER-1000 LEU and MOX Assembly Computational Benchmark.

Nuclear Energy Agency, Organization for Economic Co-operation and Development”,

10/2002.

[2] Keisuke Okumura, Teruhiko Kugo, Kunio Kaneko, Keichiro Tsuchihashi, “SRAC2006: A

Comprehensive Neutronics Calculation Code System”, 04/2007.

[3] M. E. Meek and B. F. Rider, “Compilation of Fission Product Yields,” General Electric

Company Report NEDO-12154, 1972.

[4] VVER-1000 MOX Core Computational Benchmark.

[5] NEA/NSC/DOC(2002)/6 : VVER-1000 Coolant Transient Benchmark, 2002.

[6] Nuclear fuel for VVER reactors, Fuel company of Rosatom.

VINATOM-AR 13--09

The Annual Report for 2013, VINATOM 69

MODELING AND ANALYSIS OF THERMAL HYDRAULIC PHENOMENAFOR VVER-1000 REACTOR WHEN TRIP OUT OF ONE OR TWO MAIN

COOLANT PUMPS BY RELAP/SCDAPSIM CODE

Le Thi Thu, Pham Tuan Nam, Nguyen Thi Tu Oanh and Nguyen Huu TiepInstitute for Nuclear Science and Technology, Vietnam Atomic Energy Institute

179 Hoang Quoc Viet, Nghia Do, Cau Giay, Ha Noi

ABSTRACT: RELAP5 - a thermal hydraulic system code - in recent years is used by many reseachers inVietnam for the reactor thermal-hydraulic analysis. In the other hand, VVER-1000 reactor is selected to be thenuclear reactor technology for the first nuclear power plant in Vietnam. So the studying on VVER-1000reactor is very important. The project’s purpose is modeling the thermal-hydraulic systems of VVER-1000reactor. The project also targets enhancement of experiences in using RELAP5/SCDAPSIM code andmodeling for components of VVER-1000 reactor in steady state and transient, including: steady state at 100%power, transient with switch off 1 or 2 main coolant pumps. The thermal hydraulic parameters were analysisedversus time. The thermal hydraulic parameters, such as: outlet pressure, coolant temperature, maximum fueltemperature, water level of pressurizer and steam generator, etc. were compared, analysed and assessed. Insteady state, the errors are less 10 per cent.

1. STRUCTURES AND PRINCIPLES OF VVER-1000 THERMAL HYDRAULICSYSTEMS

In this part, studied about the structures, principles of VVER-1000 thermal hydraulicsystems, including: reactor core, main coolant pump, steam generator, pressurizer.

Figure 1 illustrates the main components of VVER-1000 reactor.

Figure 1: Main components ofVVER-1000 reactor.

Project information:- Code: CS/13/04-02- Managerial Level: Institute- Allocated Fund: 50,000,000 VND- Implementation time: 12 months (Jan 2013- Dec 2013)- Contact email: [email protected] Paper published in related to the project: (None)

VINATOM-AR 13--09

The Annual Report for 2013, VINATOM70

2. THERMAL HYDRAULIC AND GEOMETRY DATA OF THE MAINCOMPONENTS OF VVER-1000 REACTOR

In this part, collected thermal hydraulic and geometry data of VVER-1000/V392 design.Table 1 shows the main thermal hydraulic parameters of VVER-1000/V392. Table 2 shows themain geometry parameters of fuel assembly.

Table 1: The main thermal hydraulic parameters of VVER-1000/V392.

Parameters Value

1. Number of loops 42. Thermal power, MW 30003. Outlet pressure, MPa 15.74. Iutlet temperature, oC 2915. Outlet temperature, oC 3216. Core mass flow, m3/h 860007. Mass flow per a cold leg, m3/h 215008. Core mass flow when trip out of one main coolant pump, m3/h 637009. Core mass flow when trip out of two opposite main coolant pumps,m3/h

40000

10. Core mass flow when trip out of two adjacent main coolant pumps,m3/h

40800

11. Maximum linear power rate, W/cm 44812. Steam pressure at head of steam generator, MPa 6.2713. Steam temperature, oC 278.514. Steam mass flow rate/ SG, t/h 147015. Humidity not execced, % 0.216. Average burn up of fuel assembly, MWday/kgU 54.617. Maximum burn up of fuel assembly, MW ngày/kgU 56.918. By bass mass flow rate, % 319. Feedwater temperature at nominal power, oC 22020. Feedwater temperature at disconnect HPH and zero power, oC 16421. Feedwater temperature at disconnect HPH and nominal power, oC 18622. Core pressure drop, MPa 0.38723. Design parameters of primary system

- Pressure, MPa- Temperature, oC

17.64350

24. Design parameters of second system- Pressure, MPa- Temperature, oC

7.84300

VINATOM-AR 13--09


Table 2: The main geometry parameters of fuel assembly.

Parameter Value

1. Hight fuel assembly, mm 4570

2. Hight cold fuel assembly, mm:

- Bottom part of fuel

- Active fuel part

- Top part of fuel

281

3530

759

3. Number of fuel rod in a fuel assembly 312

4. Pitch distance, mm 12.75

5. Material of fuel UO2 andUO2+Gd2O3

6. Fuel mass of a fuel assembly, kg 505.4

7. Fuel density, kg/m3 (10.4 to 10.7) x103

8. Material of cladding Alloy110

9. Outside diameter of fuel pin, mm 7.6

10. Inside diameter of fuel pin, mm 1.2

11.Outside cladding diameter, mm 9.1

12. Inside cladding diameter, mm 7.73

13. Guide tube:- Number

- Material

- Total hight, mm

18

Alloy635

4222

14. Number of grid spacer 15

3. MODELING AND INPUT FILE BY RELAP/SCDAPSIMFigure 2 is the nodalization of VVER-1000 reactor in RELAP/SCDAPSIM. The

components are modeled, such as: Core, 4 main coolant pumps, 4 steam generators, pressurizer,main pipes, feed waters …

Input file included: hydrodynamics components, heat structers, trip and logic, reactorkenitics.

VINATOM-AR 13--09


Figure 2: Nodalization of VVER-1000

Figure 2: Nodalization of VVER-1000 reactor

4. CALCULATION AND RESULTS ANALYSIS4.1. Steady stateThe calculation results show in table 3. This results are compared with the design data in the

steady state. The errors are less than 10 per cent. So this calculation results is good.

Table 3: Calculation at 100% power.

Parameter Calculationvalue Design value Error (%)

Thermal power 3000 MW 3000 0 %

Outlet pressure 15.7 MPa 15.7 0.3 MPa 0%

Inlet temperature 289.30 ºC 291 ºC 0.58 %

Outlet temperature 319.24 ºC 321 ºC 0.55 %

Core mass flux 83464 m3/h 86000 m3/h 2.95 %

Core pressure drop 0.3856 MPa 0.387 MPa 0.36 %

Feedwater temperature 220 ºC 220 ºC 0 %

Steam generator water level 2.51 m 2.7 m 7 %

Steam temperature 278 ºC 278.5 ºC 0.18 %

Pressurizer water level 8.194 m 8.17 m 0.29 %

Top pressurizer pressure 6.266 MPa 6.27 MPa 0.06 %

VINATOM-AR 13--09


4.2. TransientThe senarior is trip out of one main coolant pumps when the reactor was operating at 100%

power. The events is showed in table 4.

Table 4: The events of trip out of one main coolant pumps [1].

Time, s Event Setpoint for actuation

0.0 Trip out of one operating maincoolant pump sets

Initiating event

6.5 The first signal for reactor scram (isignored)

The event occurs when reactor poweris operating to exceed 75% power andone of main coolant pump sets trip outof.

17.1 The second signal for reactor scram

20.6 Start of EP control rods removement

25.6 Start of TG stop valves closing By the fact of reactor scram in 5 ssince the moment of setpoint reaching.The time of stop valves closing isassumed 0.6 s

32.0 Start of BRU-A opening in steamlines of SGs

Pressure in the steam lines exceed 7.2MPa

Control pressure is 6.67 MPa

3600.0 End of calculation

The calculation results is illustrated from figure 3 to figure 8.

Figure 3: Coastdown of main coolant pump.

VINATOM-AR 13--09


Figure 4: Outlet pressure versus time.

Figure 5: Inlet and outlet temperature.

Figure 6: Head SG pressure.

VINATOM-AR 13--09


Figure 7: Water level of pressurizer.

Figure 8: % power and % mass flow rate change versus time.

The calculation results showed that the reactor was safety during occurring the transient. Infigure 8, it explain the outlet pressure and temperature changes.

Trip out of two main coolant pumps:The senarior was trip out of two main coolant pumps when the reactor was operating at

100% power. The events is showed in table 5.

Table 5: The events of trip out of one main coolant pumps [1].

Time, s Event Setpoint for actuation

0.0 Trip out of one operating maincoolant pump sets

Initiating event

VINATOM-AR 13--09


6.5 The first signal for reactor scram (isignored)

The event occurs when reactor poweris operating to exceed 75% power andone of main coolant pump sets trip outof.

8.0 Start of EP control rods removement

13.0 Start of TG stop valves closing By the fact of reactor scram in 5 ssince the moment of setpoint reaching.The time of stop valves closing isassumed 0.6 s

22.5 Start of BRU-A opening in steamlines of SGs

Pressure in the steam lines exceed 7.2MPaControl pressure is 6.67 MPa

3600.0 End of calculation

The calculation results of this transient is illustrated from figure 9 to figure 14.

Figure 9: Coastdown of the main coolant pump.

Figure 10: Outlet pressure versus time.

VINATOM-AR 13--09


Figure 11: Inlet and outlet fluid temperature.

Figure 12: Head SG pressure. Figure 13: Water level of pressurizer.

Figure 14: % power and % mass flow rate change versus time.

The thermal hydraulic phenomena are the same with two transients, be only differencechanges versus time. The reactor was safety during occurring the transients (trip out of one or twomain coolant pumps).

VINATOM-AR 13--09


5. CONCLUSIONThe subject’s contents were studied the technology of VVER-1000 reactor and modeled the

thermal hydraulic systems of VVER-1000 in the steady state and the transients. The calculationresults compared the design data and analysised versus time. The limitation of the transientcalculations is not calculated MDNBR (Minimum Departure from Nucleate Boiling Ratio).Actually, MDNBR is one of the shutdown signals in the transient (trip out of one or two maincoolant pumps). Thus, the modeling should be validated and verified to get better results.

The studied contents were enhanced the experience of the working group. The productionsof the study are the final report and one paper. The name of the paper: thermal hydraulic analysis ofloss of flow accident in VVER-1000 reactor using RELAP5 code. This paper is preparing to presentat the national scientific conference of young staff in october 2014.

REFERENCES

[1] Risk engineering LTD. Training course "Introduction to NPP technology, Reliability, Safetyand management engineering and software development services.

[2] Rel-885-SG. Risk engineering LTD. Sofia, Bulgaria, 2012.[3] VVER-1000 Coolant Transient Benchmark. PHASE 1 (V1000CT-1) Vol. I: Main Coolant

Pump (MCP) switching On Final Specifications. Boyan Ivanov and Kostadin Ivanov NuclearEngineering Program, USA; Pavlin Groudev and Malinka Pavlova INRNE, Academy ofSciences, Bulgaria; Vasil Hadjiev Nuclear Power Plant Kozloduy, Bulgaria; US Departmentof Energy. NUCLEAR ENERGY AGENCY ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT.

[4] Nuclear Safety Analysis Division, Information Systems Laboratories, Inc.Rockville,Maryland Idaho Falls, Idaho. RELAP5/MOD3.3 CODE MANUAL VOLUME II:APPENDIX A INPUT REQUIREMENTS. January 2002.

[5] Nuclear Safety Analysis Division, Information Systems Laboratories, Inc. Rockville,Maryland Idaho Falls, Idaho. RELAP5/MOD3.3 CODE MANUAL VOLUME IV: MODELSAND CORRELATIONS. December 2001.

VINATOM-AR 13--10


81

STUDY THE OPERATION OF SUB-SYSTEM FOR CYCLOTRON

KOTRON13 WITH THE PURPOSE OF OPERATION AND MAINTENANCE

OF THIS EQUIPMENT

Nguyen Tien Dung, Pham Minh Duc, Le Viet Phong, Vu Duy Truong and Nguyen Xuan Truong

Department of accelerator, Hanoi Irradiation Center, Vietnam Atomic Energy Institute

ABSTRACT: In the framework of bilateral collaboration between Ministry of Science and Technology Korea

and Vietnam, a new PET cyclotron center KOTRON13 has been installed at Vietnam Atomic Energy Institute

with the production of radio-isotope 18

F, 11

C,.. used for PET. The cyclotron center is also to be the training

laboratory of accelerator’s technology, radiochemistry, vacuum technique,.. for staffs of VAEI and students of

universities. The project “study the operation of sub-system for cyclotron center KOTRON13 with the purpose

of operation and maintenance this sub-system” is carrying out in order to understand the principle and

operation of it. The main subjects in 2013 are focused in 2 facts: The system for environment inside cyclotron

center such as temperature, humidity, air atmosphere, electric power supply,.. and operation of radiation

protection system. The system used for condition of environment is constructed following the guide from

cyclotron supplier SAMYUONG. The radiation protection system is designed and constructed following the

guide from IAEA. The result of project: to get training and practicing the operation of the sub-system for staffs

of KOTRON13 center. The report on safety of the radiation protection of KOTRON13 center is presented at

10th

Nuclear conference at Vungtau city in 2013.

DETAILS OF REPORT

The contents of project are focused in 2 facts: To understand the principle operation and

requirements of the sub-system for environment inside cyclotron center and the operation of

radiation protection system.

1. The principle operation and requirements of the sub-system for environment

The sub-system includes the chiller gauge, air-exhaust and air-conditioner system.

Samyuong chillers, included external cooling system and heat exchanger [4],.. is installed in

cyclotron room. The first part of Chiller, operated like the air-conditioner, decreases the temperature

of water tank to the range from 4 to 35oC. The second part, included heat exchanger and water

manifold, carry the cooling water from water tank to cyclotron in order to cool for many

components such as magnet coil, vacuum pump, target,... Air- exhaust system is constructed from

2 fan motors with the capacity of 5000 m3 per hour. The velocity of a fan motor is controlled by

inverter LS model SV055iG5A. The Air-exhaust system supplies fresh air for laboratories of the

center and keeps a negative air-pressure for cyclotron room, hot-cell and QA/QC room with the

preset value. Air conditioner system, made from DAIKIN company, is installed in each laboratory

room. The temperature inside the room is controlled from 18 to 25oC as the requirement from

SAMYUONG. After calculation the capacity for air-cooling system, 2 set of DAKIN with power


- Code: 38/CS/HĐNV







VINATOM-AR 13--10


82

100,000 BTU are installed in cyclotron room, 1 set of 57,000 BTU is installed in hot-cell room,..

The result of the environment condition at rooms in cyclotron center is showed at following table.

Room Temp. range

(oC)

Deviation

(oC)

Humidity

(%)

Deviation

(%)

Cyclotron room 18~25 ± 3 < 60 5

Control room 18~25 ± 3 < 60 5

Hot cell room 18~25 ± 3 < 60 5

QC room 18~25 ±3 < 60 5

2. The operation of radiation protection system

The radiation protection system is designed and constructed following the guide from

IAEA[6]. It includes the radiation monitoring system and personal radiation dosimeter. When the

cyclotron operates, radiations emit from the following source: electromagnetic radiation emits from

accelerated proton, activated atom emits x-ray, activated nuclear emits gamma ray, stopping power

of electron emits the Bremsstrahlung X-ray and from nuclear reaction: 8O18

+ 1H1 9F

18 + 0n

1 .

Radioactivity from above nuclear reaction with proton 13 MeV, beam current 50 A emits a

thermal neutron with activity of about 106 particles per second [2]. In normal operation of

KOTRON13, gamma radiation dose rate inside cyclotron room is about 106 Sv/h.The radiation

detector has been designed and constructed at 9 positions inside the KOTRON13 center in order to

observe both gamma and neutron ray.

The radiation gamma and neutron are monitoring by the ADM606M station. This station

supports by the CANBERRA of “SMART” detectors for monitoring all type of radiation including

gamma and neutron. Standard communications protocol available at the serial ports is RS-485 ,

which is used for connecting with main computer in radiation protection room. The contact of

output relay from ADM606M, closed when dose rate in cyclotron room is over a limited level, is

connected with the interlock system. The data of radiation at the cyclotron center are recorded and

stored in the main computer.

The interlock system at the center, linked with radiation protection system, is designed by

handshake method. When the conditions of radiation protection is available, it permits cyclotron to

operate and to emit proton beam to target. When the cyclotron operates with radiation dose rate

inside cyclotron room over the limitation, the cyclotron door can not open in order to protect staffs

inside the cyclotron center.

With personal portable dose rate and survey meter for gamma and neutron, the equipment

RADIAGEM-2000 and PNM-200/S are used. With the RADIAGEM 2000, dose rate of gamma

radiation range from 0.01 µSv/h to 100 µSv/h. For neutron radiation, equipment PNM-200/S has

measurement range from 0.2 mrem/h to 20 rem/h with energy range of neutron from 2 keV to 15

MeV. For the hand, foot surface contamination monitor, equipment SIRIUS-5 is installed near the

output door of the cyclotron center. Both gamma and beta contamination from staff are monitoring

when they go out the KOTRON13 center.

3. Conclusion

The content of project concentrates in the 2 objects: The operation and requirement of sub-

system for environmental condition inside cyclotron center and operation of radiation protection

system. Both tasks are adapted the requirement from SAMYUONG and IAEA. The report on

safety of the radiation protection of KOTRON13 center is presented at 10th

Nuclear conference at

VINATOM-AR 13--10


83

Vungtau city in 2013. The knowledge of sub-system operation is also helpful for staffs in the works

of the installation and maintenance of PET cyclotron center.

REFERENCES

[1] Y. S. Kim et. al., “New Design of the KIRAMS-13 cyclotron for regional cyclotron

center”; APAC’2004, Gyeongju, March 2004.

[2] Samyuong Unitech Co,. Ltd, “Site planning”.

[3] Reference manual of Canberra ADM606M Portable Multifunction Ratemeter/Scaler.

[4] Reference manual of Samyuong Chiller.

[5] Reference manual of Sirius-5™ - Hand, Cuff and Foot Surface Contamination

Monitor.

[6] IAEA technical report series number 465; Cyclotron produced radio-nuclides: Principles

and Practice.

VINATOM-AR 13--11


84

APPLICATION OF PROMPT GAMMA NEUTRON ACTIVATION

ANALYSIS AT THE N0.2 HORIZONTAL CHANNEL OF THE DALAT

NUCLEAR RESEARCH REACTOR USING A COMPTON-SUPPRESSION

SPECTROMETER

Tran Tuan Anh, Nguyen Xuan Hai, Nguyen Canh Hai, Pham Ngoc Son,

Ho Huu Thang and Dang Lanh

Nuclear Physics and Electronics Dept., Nuclear Research Institute, Vietnam Atomic Energy Institute

ABSTRACT: A Compton-suppression spectrometer for Prompt Gamma Activation Analysis (PGNAA) has

recently been established. The thermal neutron flux was measured to be 1.03 ×106 n.cm

-2.s

-1 at the sample

position. The corresponding Cd-ratio for gold was found to be 230. The initial parameters for the Compton-

suppression system such as gains and energy cutoff were optimum. The gamma background reduces about 2

times in the Compton suppression mode in energy range below 1 MeV. The sensitivities, detection limits

(LOD) and concentrations for B, Al, Si, K, Ti, Gd, Sm, Cd, Ca, Na, Fe in geological samples and H, B, C, N,

Cl, K, Cd, Na in biological samples have been determined.

INTRODUCTION

The Prompt Gamma Neutron Activation Analysis (PGNAA) has been applied for analyzing

light elements as H, B, N, Si, K… in geological and biological materials on the thermal neutron

beam of N0. 4 horizontal channel, Dalat Research Reactor [1]. However, the detection limits of

those elements are still high due to neutron and gamma backgrounds at the channel. In 2011, a new

thermal neutron beam at the N0. 2 channel has been established and used for basic and applied

researches and training. The neutron flux of the beam is 1.03 x 106

n.cm-2

.s-1

and Cadmium ratio is

230. Besides, a new Compton-suppression spectrometer with HPGe-BGO detectors has been setup

at the beam for PGNAA [2].

The aims of the project are to establish optimal parameters for the Compton-suppression

spectrometer for qualitative analysis of various materials such as geological, biological,

environmental samples using PGNAA method.

I. EXPERIMENTS

I.1 Sample preparations

Accurate determination of traces of Boron is important for various specific requirements in

fields such as the geochemical, cosmochemical, agricultural and material sciences and more

importantly in the study of reactor materials. In order to establish a relationship between count rates

(cps) of prompt gamma ray of 478keV (10

B) and amount of B which varied from 5 µg to 50 µg. The

samples were prepared from the standard B solution (H3BO3) diluted on filter papers and heated at


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VINATOM-AR 13--11


85

temperature of 600C and then wrapped and heat sealed in polyethylene films. For determinations of

LOD and concentrations of B, Al, Si, K, Ti, Gd, Sm, Cd, Ca, Na, Fe in geological samples and H,

B, C, N, Cl, K, Cd, Na in biological samples, 08 reference materials were chosen as follows: NIST-

2711a (Montana soil), NIST-278a (Obsidian rock), IAEA SOIL-7 (Soil), NIST-679 (Brick clay),

IAEA SL-1 (Lake sediment), NBS-1633a (Coal Fly Ash), BCR-281(Rye grass) and NBS-1577a

(Bovine liver). The samples were also heated at 120oC during 3 hours and at 45

oC during 48 hours

for geological and biological samples, respectively. The sizes of the samples were 1.5 x 1.5 cm2

corresponding to amounts of 1 - 1.5g

I.2 Experimental arrangement

The PGNAA system was placed at the thermal neutron beam of the N0.2 channel, Dalat

Research Reactor. The neutron flux of the beam was 1.03 x 106

n.cm-2

.s-1

and Cadmium ratio is 230.

The Ge detector is set with its axis perpendicular to the neutron beam at a distance of 39.5cm from

the sample position. The Compton suppression mode has been set up to obtain prompt gamma rays

by Genie 2000 software. The neutron beam guide, shielding system and block diagram of the

electronics for Compton suppression spectrometer are shown in Fig. 1 and Fig. 2.

Figure 1: The neutron beam guide, shielding system at the N0.2 neutron channel.

Figure 2: Block diagram of the electronics for Compton suppression spectrometer.

Neutron beam

Compton

suppression

spectrometer

VINATOM-AR 13--11


86

II. RESULTS AND DISCUSSION

II.1 Analytical sensitivity and detection limit of Boron [3, 4]

05 standard samples of B were irradiated and the prompt gamma rays were measured for a

period of time to produce a statistically sufficient count. Analytical sensitivity and detection limit of

Boron were then determined from the slope of the calibration curve between count rates of 478 keV

peak (10

B) and amounts of Boron (Fig. 3). From the linear fitting curve, we determined the

analytical sensitivity and detection limit of Boron are 520 cps/mg and 1.21 g, respectively.

10 20 30 40 50

0

5

10

15

20

25

cp

s

g B

Exp data

Linear fitting

Model Line

Equation y = A + B*x

Reduced Chi-Sqr

0.0301

Adj. R-Square 0.99956

Value Standard Error

cps A -2.79 0.158620

cps B 0.520 0.00544162

Figure 3: Calibration curve of Boron at the thermal neutron beam.

II.2 Detection limit of elements in geological and biological materials [5]

The geological and biological materials have complex matrices because of various elements

in the sample. To determine detection limits of elements, reference materials are chosen for

experimental measurements. Prompt gamma rays spectra of NBS-1633a reference material in

Single and Compton suppression modes were shown in Figure 4.

Figure 4: Prompt gamma ray spectra of the Coal Fly Ash.

Single

Compton suppression

VINATOM-AR 13--11


87

Detection limits of B, Gd, Sm, Cd, Ca, Al, Si, K, Ti, Na and Fe in geological, sediment,

environmental and biological samples are given in Table 1 and Table 2.

Table 1: Detection limits of elements.

# Element E

(keV)

Geological

sample Sediment Coal Fly Ash

1 B (g/g) 478 1.1 - 1.8 - 1.89

2 Gd (g/g) 182 2.0 - 6.4 1.35 2.56

3 Sm (g/g) 334 1.3 - 3.6 0.91 2.22

4 Cd (g/g) 559 1.8 - 5.8 0.01 0.29

5 Ca (%) 1942 0.1 - 4.5 0.19 2.35

6 Al (%) 1778 0.2 - 0.8 0.21 1.90

7 Si (%) 3539 1.2- 6.7 - 4.16

8 K (%) 771 0.2 - 1.7 0.17 0.68

9 Ti (%) 1381 0.04 - 0.1 0.04 0.11

10 Na (%) 472 0.01 - 0.03 0.01 0.03

11 Fe (%) 352 0.5 - 2.3 0.94 3.26

Table 2: Detection limits of elements in biological samples.

# Element E (keV) Rye Grass Bovine liver

1 B (g/g) 478 2.4 1.44

2 Cd (g/g) 559 0.05 0.17

3 Cl (g/g) 1165 - 0.12

4 K (%) 771 5.9 1.5

5 N 1885 - 33.2

6 Na (%) 472 - 0.9

- Detection limits of B, Gd, Sm, Cd are 0.1-5 µg/g and Ca, Al, Si, K, Ti, Na, Fe are 0.1-

7% in geological samples.

- Detection limits of B, Cd, Cl are 0.1-3 µg/g and K, N, Na are 0.1-35% in biological

samples.

II.3 Concentration of elements in geological and biological materials [6].

Concentrations of elements in analytical samples were determined by comparing to

concentrations of the reference samples in the same measured conditions. The results of

concentrations of elements in in geological and biological reference materials are given in Table 3

and Table 4.

VINATOM-AR 13--11


88

Table 3: Concentrations of elements in a soil sample.

# Element

NIST-2711a (Montana soil)

Measured

value Reference value

U-score

(z-score)

1 B (g/g) 50.5 ± 3.0 50 (0.09)

2 Gd (g/g) 7.6 ± 3.3 5 (5.18)

3 Sm (g/g) 6.96 ± 1.07 5.93 ± 0.28 0.49

4 Ca (%) 2.43 ± 0.59 2.42 ± 0.06 0.01

5 Al (%) 7.1 ± 0.3 6.72 ± 0.06 1.24

6 Si (%) 31.7 ± 3.9 31.4 ± 0.7 0.06

7 K (%) 2.39 ± 0.3 2.53 ± 0.1 0.48

8 Ti (%) 0.29 ± 0.06 0.32 ± 0.01 0.49

9 Na (%) 2.0 ± 0.5 1.2 ± 0.01 1.71

10 Fe (%) 3.01 ± 0.35 2.82 ± 0.04 0.54

Table 4: Concentrations of elements in a grass sample.

# Element

BCR-281 (Rye grass)

Measured

value

Reference

value

U-score

(z-score)

1 B (g/g) 5.66 ± 0.64 5.64 ± 0.56 0.02

2 C (g/g) 58.0 ± 9.3 - -

3 N (g/g) 41.3 ± 25 33.2 ± 0.5 0.32

4 Cl (g/g) 0.55 ± 0.07 -

5 K (%) 31.4 ± 7.6 33 (0.48)

6 Cd (%) 0.31 ± 0.05 0.12 (15.8)

7 Na (%) 0.21 ± 0.1 - -

In this work, 10 elements of B, Gd, Sm, Ca, Al, Si, K, Ti, Na, Fe and 07 elements of B, C,

N, Cl, K, Cd, Na in geological and biological samples have been determined of concentrations by

using a comparison method. The obtained values are in quite agreement with reference values in

acceptable uncertainty from 1-20%.

III. CONCLUSIONS

The project has carried out following tasks:

- General introduction of principle, method and equipment for PGNAA including thermal

neutron beam, Compton suppression spectrometer, analytical sensitivity, detection limit and

concentration.

VINATOM-AR 13--11


89

- Determination of detection limits and concentrations of B, Gd, Sm, Cd, Ca, Al, Si, K,

Ti, Na, Fe and B, Cd, Cl, K, N, Na in geological and biological reference materials.

- Establishment of analytical procedures for B, Gd, Sm, Cd, Ca, Al, Si, K, Ti, Na, Fe and

B, Cd, Cl, K, N, Na in geological and biological materials.

The obtained results of this work are improved that the Compton suppression spectrometer

established at the horizontal channel N0.2 of the Dalat Research Reactor has been applied for multi

element analysis, particularly for B and Si. It is expected that with the development of K0-PGNAA

method in the immediate future, the utilization of the thermal neutron beam in elemental analysis by

PGAA will certainly be more promising.

REFERENCES

[1] Nguyễn Cảnh Hải. Xây dựng quy trình phân tích định lượng các nguyên tố B, H, N, S, C, P,

Si, Cd, Gd trong mẫu đất đá và mẫu sinh học sử dụng thiết bị phân tích kích hoạt nơtron

gamma tức thời (PGNAA) mới được nâng cấp tại Lò phản ứng hạt nhân Đà Lạt. Đề tài

KHCN cấp cơ sở, 2005.

[2] Phạm Ngọc Sơn. Báo cáo tổng kết đề tài nghiên cứu khoa học cấp bộ-năm 2009-2011: Phát

triển dòng nơtron phin lọc trên kênh ngang số 2 của Lò phản ứng hạt nhân Đà Lạt. Mã số:

ĐT.08/09/NLNT, Viện Nghiên cứu hạt nhân Đà Lạt, 2012.

[3] C. YONEZAWA. Development of a neutron capture prompt gamma-ray analysis system and

basic studies of element analysis using this system. JEARI-memo 09-030, 1997.

[4] S. Baechler et al. Prompt gamma-ray activation analysis for determination of boron in

aqueous solutions. Nucl. Instrum. Methods A 488, pp. 410-418, 2002.

[5] D. A. Gedcke, How counting statistics controls detection limits and peak precision, AN59

Application Note, ORTEC.

[6] Quality aspects of research reactor operations for instrument neutron activation analysis.

IAEA-TECHDOC-1218, 2001.

VINATOM-AR 13--12


90

RESEARCH AND PRODUCTION OF CALORIMETER FOR MEASURING

IRRADIATION DOSES ON 10MeV ELECTRON BEAM ACCELERATOR

Cao Van Chung, Nguyen Hoang Hai, Nguyen Anh Tuan and Tran Van Hung

Research and Development Center for Radiation Technology,


ABSTRACT: Calorimeter, used in measuring dose irradiated by 10MeV electron beam, was researched and

produced at VINAGAMMA. Tri-dimensional of Polystyrene disc was determined, a cylinder with 136 mm in

wide and 18 mm in thick, the same size as descripted in ISO/ASTM 51631-2003(E). Dose distribution inside

polystyrene structure versus radius and thickness were estimated. Correction factor for calorimeter produced is

0.02; the different compared with transfer calorimeter from Gex Corp. is less than 3%.

1. OBJECTIVES

- Tri-dimensional of Polystyrene disc.

- Calorimeter.

2. APPROACH

MCNP code [2] is used for evaluating dose distribution inside polystyrene disc (PD) with

various sizes in thickness and radius. The thickness and radius of PD are chosen base on depth dose

profiles and radius dose profiles.

3. RESULTS

Calorimeter determine absorption dose by the head product in irradiation processing, the

head created in side PD proportion with irradiation dose. The shape of PD directly effect to the

result measure by calorimeter. MCNP code was used for calculating dose distribution inside many

shapes of PD.

3.1 Thickness of PD

Dose distributions in polystyrene cylinder with various thicknesses were calculated (Table 1,

Figure 1). The thickness of PD normally is one third of mean free path of electron (~5 cm in water)

is 1.8 cm. With this thickness, average dose of PD is 1.17 of surface dose.

Table 1: Average dose in various thickness of PD.

Thickness of PD (mm) Average dose (kGy)

0.3 1.0915 0.001


- Code: CS/13/07-05






VINATOM-AR 13--12


91

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 10 20 30 40 50 60 70

mm

kG

y

0.6 1.1097 0.001

1.3 1.1307 0.001

2.5 1.1577 0.001

5 1.1916 0.001

10 1.2329 0.002

18 1.2814 0.002

30 1.3653 0.003

40 1.4042 0.003

50 1.2688 0.004

60 1.0609 0.003

Figure 1: Average dose in PD with thickness from 0.3 mm to 60 mm.

PD in thickness 18 mm has the correct factor of 1.17.

3.2 Radius of PD

Table 2: Average dose in radius in 18 mm thickness PD with various radius.

Radius (mm) Average dose (kGy)

200 1.2882 0.001

130 1.2814 0.003

69 1.2692 0.003

34.5 1.2522 0.002

17.25 1.2095 0.004

8.625 1.1349 0.006

VINATOM-AR 13--12


92

1

1.05

1.1

1.15

1.2

1.25

1.3

1.35

0 50 100 150 200 250 300 350 400 450

mm

kG

y

Figure 2: Average dose in various diameter of PD.

Figure 2 show that, with radius larger than 69 mm, bound effect is un-significantly to the

average dose.

3.3 Produce calorimeter

With tri-dimension of PD determined above, the PD was produced form polystyrene on

Toyoseiky machine at 2200C of temperature, 30 minutes and pressure of 5 kg/cm

3. Produced PD

has 1.06 in density.

Figure 3: Produce PD.

3.4 Thermistor

Measuring temperature in PD, a thermistor has proper of 2,000 ohm at 250C is used

(MCD_2K7MCD1 [3]). This thermistor then placed at 20 mm from edge of PD.

VINATOM-AR 13--12


93

Figure 4: Structure of MCD_2K7MCD1.

A completed calorimeter is showed in Figure 5.

Figure 5: A completed calorimeter.

3.5 Determined dose via variation of temperature in calorimeter

The temperature of PD increases during irradiation process, the heat producing inside PD

proportion with the dose by the equation 1.

D = T. K (1)

where T is the heat produced in irradiation process (T = f(R1) – f(R2); K is specific heat of

polystyrene and the unit for the dose D is kGy.

In (1), a part of energy produce chemical reaction is not including; with the material as

polystyrene, this part is smaller then the other so should be skipped.

The temperature increasing is measured by resistant of thermistor. The relation between

temperature and resistant are showed in equation (2).

310

ARLn

BRft

(2)

Constants A = 5.204, B = 4291.77 and unit for temperature t is 0C.

Some time, the specific heat is a constant factor, but in this application the temperature in

equation (3) affected [4].

20108.0022.1.0108.0022.1 21 TT

TK

(3)

A foam box always protects the PD, but these are small part of heat exchange between PD

and environment, this approximate about 0.02 degrees in Celsius.

VINATOM-AR 13--12


94

For all, dose calculate equation now can be rewrite as:

D = K [f(R1) – f(R2) – Ta] (4)

Calorimeter produced has good agreement with calorimeter supplied by Gex.Co, an expert

company in calorimetric supplier, in practices on 10 MeV electron accelerators.

Table 3: Dose measured by Gex calorimeter and produced in this article.

Taget dose

(kGy)

Gex’s calorimeter

(kGy)

Produced

calorimeter (kGy)

Diffirent

(%)

Correct

factor

5 4.20 4.38 4.2 0.02

10 9.75 9.80 0.5 0.0025

15 15.50 15.42 0.5 0.0025

20 20.98 20.98 <0.1 0

25 25.75 25.73 <0.1 0

3.6 Dose measurement procedure

a. Measure resistant of thermistor by suitable digital multi-meter has measure current

lower then 100 A.

b. Make sure that PD is subterraneous in foam box.

c. Take calorimeter on conveyer to irradiation place.

d. Quickly measuring resistant of thermistor after irradiate.

e. Use the (1), (2), (3) equation to calculate the dose.

Calorimeter shout be used again, but make sure that the resistant of thermistor must lager

then 800

4. CONCLUSIONS

With the shape of cylinder with 138 mm in diameter and 18 mm in thickness of polystyrene

material; The calorimeter has good practice in dose measurement on 10 MeV electron accelerator.

The diffirence betwen produced calorimeter with a tranfer dosimeter is petty. The produced

calorimeter has life time more than 2.000 kGy, in some case, 4.000 kGy life time is accepted.

Totaly cost for proceduce a completed calorimeter is less then 50$, cheaper than 750$ for a foreign

calorimeter.

REFENCES

[1] ISO/ASTM 51631-2003 (E) Standard Practice for Use of Calorimetric Dosimetry Systems for

Electron Beam Dose Measurements and Routine Dosimeter Calibration.

[2] J.F.Briesmeister, MCNP-A General Monte Carlo N-Particle Transport Code Version 4C2,

Transport Methods Group, Los Alamos National Laboratory, 1997.

[3] Micro-BetaCHIP Thermistor Probe (MCD).

[4] RISO, HDRL-I-11 Manufacture and Calibration of polystyrene calorimeters.

VINATOM-AR 13--13


95

RESEARCHING, BUILDING A SOFT-PROCESSOR AND ETHERNET

INTERFACE CIRCUIT USING EDK

Tuong Thi Thu Huong, Pham Ngoc Tuan, Truong Van Dat,

Dang Lanh and Chau Thi Nhu Quynh

Nuclear Physics and Electronics Dept., Nuclear Research Institute,


ABSTRACT: The processor is an indispensable component in the measurement and automatic control systems.

This report describes the fabrication of a soft-processor (32-bits, on-chip block RAM 64K, 50M clock, internal

and peripheral bus) for receiving, sending and processing of data Ethernet packets. This processor is fabricated

using the XPS component from EDK (Xilinx) software toolkit. After that, it is configured on the FPGA named

Spartan XC3S500E circuit. A firmware of a processor for controlling the interface between processor and

Ethernet port is written in C language and can play a role of a HOST (station) which has its own IP to connect

to Ethernet network. Besides, there are some needed parts as follows: an Ethernet interfacing controller chip, a

suitable cable providing a speed up to 100Mbs and an application program running under Window XP

environment written in LabView to communicate with soft-processor.

INTRODUCTION

Nowadays, FPGA (Field Programmable Gate Array) is a device which has generally been

used because its properties as follows: reconfigurability and high flexibility in design and

fabrication. Thank to the FPGA with the afore-mentioned properties, a generation of a specific

processor is playing a role as a hardware as well as a firmware for control of hardware components

created inside the FPGA.

The advantages of FPGA can reduce computational time and simplified designs. In the

framework of the topic, in order to communicate with Ethernet via soft-processor, the XPS (support

of C command set) can be used to generate hardware components and software (firmware) of the

soft-processor and an FPGA board named Xilinx Spartan XC3S500E.

I. REQUIREMENTS AND DUTIES OF TOPIC

The purpose of the project is to design and fabricate a soft processor (called microblaze)

which is able to communicate with Ethernet. This microblaze can be embedded into the FPGA by

using the supported XPS. The application program is running under Window XP environment

written in LabView language can link and receive/transmit information between PC and the soft-

processor.

As a result, a product created through the project is a transfer system including of:

The self-excuted application program running under PC, a modem and the soft-processor as

shown in Fig. 1.


- Code: CS/13/01-03







VINATOM-AR 13--13


96

Figure 1: Data transfer system between soft-processor and PC via modem.

II. SUPPORTED TOOLKITS AND TECHNIQUES

1. Overview of the system

1.1. The fabrication of soft-processor

The diagram of fabrication of soft-processor is shown in Fig.2.

Figure 2: Steps to create and embed an FPGA soft-processor.

VINATOM-AR 13--13


97

1. Peripherals: LMB, PLB, OPB, Ethernet, LEDs, RS232 created in *.MSS, *.mpd,

*.MHS file.

2. Creating the library related to the soft-processor and peripherals.

3. Compiling firmware file and C-function library (mb-GCC), *.OUT file created.

4. Creating the platform to have a core and netlists.

5. A collection of *.UCF, *.ED files, core and netlists, use of iMPACT for creating *.Bit

file, *.MCS file. Finally, the MCS file will be loaded into ROM for operating.

1.2. The create of application program on PC

The basic functions supported in LabVIEW TCP: open connection, read and write data via

Ethernet.

Figure 3: TCP connection, TCP write, TCP read.

2. System design

The Xilinx Spartan XC3S500E board is used because it contains an FPGA which is able to

embed the soft-processor, and also supports RJ45 Ethernet port. The design of system is divided

into two parts: hardware part is the 32-bit microprocessor while software part is a firmware. Both of

them are created by XPS from Xilinx Company.

2.1. Hardware design

The XPS has Wizard supporting users to design conveniently. In addition to creating a 32bit

soft-processor, 64K internal RAM, and more peripherals such as Ethernet, RS232, LEDs...

After that, connection of input/output port with peripherals (*.UCF file), producing address

automatically, generating library functions relating to microprocessor software and peripherals.

VINATOM-AR 13--13


98

Figure 4: Bus Interface of soft-processor.

2.2. Software design (firmware)

The libraries created in hardware design can be used for the software (firmware). With

support functions such as read/write registers, cache....TCP/IP protocol is used for connection and

data transfer. The firmware received and performed a TCP packet from PC and then created a

require packet. This packet was sent to PC via Ethernet.

3. Setup and verify the characteristics

In the project, the components including FPGA named XC3S500E, 50MHz internal clock,

LAN83C185 Ethernet chip, 8 LEDS display, RS232 port, Platform Flash PROM (configure the

FPGA and program the soft-processor), 10/100 Mbs Ethernet port, USB for JTAG, MAC address is

Xilinx_02:22:5E (00:0A:35:02:22:5E) were used.

MAC address of the computer is HonHaiPr_59:0B:A3 (94:39:E5:59:0B:A3), IP is

192.168.1.105, PORT is 3363.

Wireshark software was used to capture all packets going through the computer network

card as shown in Fig.5.

Figure 5: Connected, transmited, received frames captured in Wireshark.

VINATOM-AR 13--13


99

III . CONCLUSION

The project has successfully designed and fabricated nuclear instruments based on soft-

processor including software and hardware. The advantages of this approach are as follows:

- Economics: less hardware devices, small chip, small size of ROM.

- Flexibility: design of 8, 16, 32, 64 bits microcontroller, depending on demands, creating

arbitrary RAM only changed the parameters on software, connecting with expected peripherals

easily.

- Convenience: embedded directly into the FPGA and reusable.

- Compact: all components intergrated inside FPGA.

The project has also succeeded in firmware design for TCP/IP protocol transfer data via

Ethernet. The obtained results will help remote measurement systems transfer data conveniently.

REFERENCES

[1] Xilinx, MicroBlaze Processor Reference Guide, Embedded Development Kit EDK 10.1i.

[2] Xilinx, XPS Ethernet Lite Media Access Controller.

[3] Transmit Control Protocol, Internet Protocol version 4, Address Resolution Protocol, MAC

address, check sum, http://en.wikipedia.org/wiki/

http://en.wikipedia.org/wiki/

VINATOM-AR 13--14


100

A STUDY OF CHARACTERISTICS OF HELIUM-3 (HE-3)

PROPORTIONAL COUNTERS IN ORDER TO DESIGN ELECTRONIC

CIRCUITS FOR NEUTRON DETECTION

Vu Van Tien, Nguyen Van Sy, Nguyen Thi Bao My,

Nguyen Thi Thuy Mai and Ho Quang Tuan


179 Hoang Quoc Viet, Cau Giay, Ha Noi


- Code: CS/13/04-01






ABSTRACT: This study aims to research and develop function circuits, electronic blocks, programming

software for He-3 proportional counters using commonly in neutron detection. Results are compared with

those of a neutron dosimeter available in Institute for Nuclear Science and Technology (INST). Although the

method has been known for a long time on the world, it is newly used in VietNam. If the study is applied in

reality, neutron dosimeters will be manufactured with acceptable price, high quality, and easy maintenance

which are suitable with domestic demands. It contributes to nuclear safety and economy-society development.

I. INTRODUCTION

Currently, nuclear science and technology are growing rapidly due to demands of the life

and national economy. Promotion of nuclear energy has become a major policy of the government.

However, scientific researchers and nuclear engineers are in serious shortage of both quantity and

quality, especially in the nuclear equipment. In order to improve the capability to do and use

research as well as to approach step by step and to come to master nuclear technology, there should

be appropriate investments for nuclear research and training through specific topics, scientific

research and nuclear technology projects.

In the development of science and nuclear technology, researching, designing and

manufacturing equipment for nuclear detection, especially dosimeter devices are becoming an

urgent need in our country today.

Neutron radiation is particularly dangerous for the human body due to a coefficient of high

linear energy transfer (LET). Therefore safety problems for neutron need special attention. That is

why the need to conduct research relating to the implementation of the neutron as well as the

fabrication of devices recorded neurons, especially neutron dosimeters.

II. METHOD

1. Theoretical Foundations

Neutron is a uncharged particle which does not ionize atoms directly. Neutron is detected

indirectly through charged particles and photons produced by interaction with nucleus.

If we know the mechanism of neutron interaction, we can get information of neutron from

the reaction products. There are several types of interactions are used, including elastic scattering

and absorption of neutron.


VINATOM-AR 13--14


101

Neutron detection is performed by using 3He or BF3 gas-filled counters and scintillation

detectors doped neutron absorption elements such as Boron, Li etc. Proton- recoil is detected by

counters contained hydrogen or methane. Activation method is also used to detect neutron.

The energy of neutrons (from thermal energy to several tens of MeV) is often detected

indirectly through the absorption reaction using the absorber materials with high cross sections such

as 3He,

6Li,

10B, and

235U. Each of these reacts by emission of high energy ionized particles,

the ionization track of which can be detected by a number of means. Commonly used reactions

include 3He (n, p)

3H,

6Li (n, α)

3H,

10B (n, α)

7Li and the fission of uranium. Since these materials

are most likely to react with thermal neutrons (i.e., neutrons that have slowed to equilibrium with

their surroundings), they are typically surrounded by moderating materials. This slowing down of

neutrons is known due to ionization energy losses in elastic scattering between neutron and light

nuclei such as proton, deuterium, or carbon.

In many neutron dosimeters, counters are usually surrounded by a large volume of

moderating materials to recorded fast neutron.

Neutrons can be detected using 3He filled gas proportional counters through

3He (n, p)

3H

reaction. A typical counter consists of a gas-filled tube with a high voltage applied across the anode

and cathode. A neutron passing through the tube will interact with a He-3 atom to produce tritium

(hydrogen-3) and a proton. The proton ionizes the surrounding gas atoms to create charges, which

in turn ionize other gas atoms in an avalanche-like multiplication process. The resulting charges are

collected as measurable electrical pulses with the amplitudes proportional to the neutron energy.

The pulses are compiled to form a pulse-height energy spectrum that serves as a "fingerprint" for

the identification and quantification of the neutrons and their energies. If incident neutron is a fast

neutron with energy of En, the energy of the fusion reaction is equal to En + Q, Q is sum of kinetic

energy of 3H and proton.

2. Electronics

In order to measure neutron dose, neutron dosimeter needs to be converted to the

corresponding neutron dose. This is a filter technique made detector response as a function of

energy. The filter will reduce detector’s efficiency, which is the most difficult in designing high

sensitive neutron dosimeters. In a common neutron dosimeter, neutron counter is set at the center of

a sphere of moderating materials made by many layers of different materials. The materials slow

down kinetic energy of neutron. Polyethylene is one of those materials.

Figure 1: Logic diagram for neutron detection.

High Voltage Power

Signal process

block

PC

microchip

He-3

n

n

n n

n

http://en.wikipedia.org/wiki/Particle_identification#Specific_ionization

http://en.wikipedia.org/wiki/Thermal_neutron#Thermal_neutrons

http://en.wikipedia.org/wiki/Neutron_moderator

VINATOM-AR 13--14


102

R13

2 2 M

R16

2 2 M

C14

10N/3KV

G N D

2

NUETRON DETECTOR TUBLE

G N D

C17

100PF/3KV

8

1

4

3

2

U4A

TL082

8

4

7

5

6

U4B

TL082

1 2 V

1 2 V

G N D

C15

1 0 0 N

C13

1 0 P F

R14

3 0 0 k

R17

1 K

R15

2 0 K

C18

2 0 N

G N D

C16

1 0 0 N

G N D

R20

2 0 K

R26

2 0 K

R21

1 0 K

C19

1 0 u F

G N D

C21

10UF

G N D

G N D

1 2 V

R18

3 0

1

B N C

G N D

G N D

1

2

3

4

5

6

7

8

U 5

LM311N

1 2 V

C20

1 0 0 N

R19

2 0 0

G N D

G N D

R23

1 0 K

1 2 V

R24

1 0 K

R25

1 0 K

C23

2 0 p F

3

1

2

R V 2

1 0 K

C22

1 0 0 N

G N D

R22

1 0 K

R27

1 0 K

1 2 V

G N D

1

2

3

U1A

CD4093BCN

5

6

4

U1B

CD4093BCN

8

9

1 0

U1C

CD4093BCN

1 2

1 3

1 1

U1D

CD4093BCN

8

3

2

4

1

U2A

LM393N

R 2

5 6 0 k

R 1

3 3 0 k

D 1

D

C 2

1 N

1 2 V

C 5

10UF

G N D

G N D

3

1

2

R V 1

2 5 0 K

R 5

2 0 k

R 7

1 M

C 8

1 0 0 N

G N D

C 9

1 0 N

R 9

1 M

G N D

R10

2 G

G N D

U 3

LM336

G N D

R 4

1 0 0 K

1 2 V

R 8

5K6

G N D

G N D

1

1

2

2

3

3

T R 1

TRF4

1 2 V

C 3

1 0 0 N

G N D

D 2

D D 3

D

D 4

D

C 4

10N/2KV

C 1

10N/2KV

G N D

C10

10N/2KV

G N D

C11

10N/2KV

C12

10N/2KV

G N D

G N D

R11

1 0 M

V R E F

R 6

2.2M

1 2 V

1 0 0 0 T

1 0 0 T

0 T

C 7

10N/2KV

C 6

10N/2KV

D 5

D

D 6

D

R12

1 0 M

R 3

1 0 0 k

T 1

C535

1 2 V

Q 1

D438

R30

1 0 k

RA0/AN0

2

RA1/AN1

3

RA2/AN2/VREF-

4

RA3/AN3/VREF+

5

RA4/T0CKI

6

RA5/AN4/SS

7

RB0/INT

2 1

R B 1

2 2

R B 2

2 3

RB3/PGM

2 4

R B 4

2 5

R B 5

2 6

RB6/PGC

2 7

RB7/PGD

2 8

RC0/T1OSO/T1CKI

1 1

R C 1

1 2

R C 2

1 3

R C 3

1 4

R C 4

1 5

RC5/SDO

1 6

RC6/TX/CK

1 7

RC7/RX/DT

1 8

VSS

8

VSS

1

9

MCLR/VPP

1

OSC1/CLKIN

9

OSC2/CLKOUT

1 0

V

D

D

2

0

U 4

PIC16F876-04/P

G N D

V C C

1 0 0 n F

C 8

1 0 u F

C 5

G N D

G N D

3 3 p F

C 6

3 3 p F

C 7

4MHz

U 3

*

8

9

1 0

U2C

CD4011BMN

R20

1 0 k

V C C

G N D

1

2

3

RS-1 G N D

V C CG N D

1 0 u F

C 4

S 2

1 K

R14

Res3

1 2

1 3

1 1

U2D

CD4011BMN

K 1

K 2

G N D

V C C

G N D

L C D 4

L C D 5

L C D 6

L C D 7

RS_LCD

EN_LCD

R16

3 k

G N D

D 4

1N4007

D 6

4 1 4 8

A

1

K

2

D 5

4 1 4 9

G N D

3

1

2

R V 2

1 0 k

C 9

1 0 0 N

G N D

G N D

V C C

R19

1 K

R18

1 K

DS2

L E D 1

DS3

L E D 1

V C C

R13

1 0 0 K

G N D

C 2

1 0 0 P F

5 6

4

U2B

CD4011BMN

1 2

3

U2A

CD4011BMN

1

2

3

4

5

6

7

8

9

1 0

JP4

L C D

S C

1

S E

2

T C

3

G N D

4

COMP

5

V D D

6

Ipk

7

D R

8

U 8

MC33063A

G N D

C40

2 N

G N D

R39

1 0 0 K

G N D

R35

1 0 0

R37

0.2

9 V

C37

4 7 0 u F

G N D

R34

1 0 0

R36

1 k

R38

1 k

G N D

B

C

E

Q 2

H1061

G N D

G N D 1

D11

D Schottky

D 8

D Schottky

D10

D Schottky

D 9

D Schottky

C35

CAP1

C36

CAP1

C38

CAP1

C39

CAP1

+ 1 2 V

-12V

G N D

T 3

Trans CT

R40

1 M

1 2 V

Figure 2: Schematic electronic diagram.

The high voltage can be adjusted from 0 VDC to 2000 VDC giving the current from 20 mA

to 30 mA.

The neutron is converted through the nuclear reaction 3He + n ->

3H + p into charged

particles tritium (3H) and proton which then ionizes the surrounding gas atoms to create charges.

The resulting charges are collected as measurable electrical pulses with the amplitudes proportional

to the neutron energy. The pulses are amplified and convert to TTL pulse. They are sent to

microchip and then to a PC for displaying and storage.

III. RESULTS

Detector He-3 is set at the center of a 2.5 inch diameter polyethylene sphere. Polyethylene

will efficiently slow down neutrons to energies that the detector can respond to.

Figure 3: Photograph of detector.

http://en.wikipedia.org/wiki/Tritium

http://en.wikipedia.org/wiki/Hydrogen_atom

VINATOM-AR 13--14


103

1. A survey of characteristics of the He-3 counter

Since we don’t have a standard neutron source at INST, we used a 252

Cf neutron sources

(belonging to RAS-80/89 project) and a source from “Coal ash analysis equipment using PGNAA

technique (PGNAA_Prompt Gamma Neutron Activation Analysis)” project.

Signals, recorded every minute, are averaged over 6 to 12 measurements. The computer will

automatically save the results and stop measurement in certain time.

Figure 4: Plan view of the dose measurement.

Table 1: Variation of counting rate against applied voltages for a 3He-gas counter.

High voltage (V) 800 900 950 1000 1050 1100 1150 1200 1250

Count/min 0 19 56 105 135 165 191 192 201

High voltage (V) 1300 1350 1400 1450 1500 1550 1600 1650 1700

Count/min 201 206 217 224 227 267 311 399 616

0

100

200

300

400

500

600

700

800 1000 1200 1400 1600 1800

252Cf neutron source

Coal ash

Figure 5: Plot of variation

of counting rate against

applied voltages for a 3He-

gas counter.

VINATOM-AR 13--14


104

The counting rate quickly rises as the voltage is increased. After the quick rise, the counting

rate levels off. This range of voltages is termed the "plateau" region. Eventually, the voltage

becomes too high and we have continuous discharge. The threshold voltage is the voltage where the

plateau region begins. Proper operation is when the voltage is in the plateau region of the curve. For

best operation, the voltages are set from 1250 VDC to 1350 VDC.

2. Counting rate corresponding to dose ratio

We used NEUTRON MONITOR 2222A He-3 to measure dose ratio at 3 positions and

compare with the result of He-3 counter.

2 µSv/h 6 µSv/h 12.5 µSv/h

Figure 6: Plan view of 3 positions in the measurement

of counting rate corresponding to dose ratio.

Table 2: Counting rate against neutron dose ratio.

Dose µSv/h Count/min

2 89

6 287

12.5 620

Figure 7: Plot of counting rate against neutron dose ratio.

R2 is equal to 0.9999. The figure shows a linear relation between counting rate and dose

ratio.

252Cf neutron source 252Cf neutron source

Coal ash Coal ash

252Cf neutron source

Coal ash

VINATOM-AR 13--14


105

IV. CONCLUSION

The report presents a successful home-made electronics at INST for neutron detection. The

method that we had used to study neutron dose have been described. The results are in agreement

with expectation.

REFERENCE

[1] Trần Tuấn Anh. Phát triển phương pháp đo tiết diện nơtron toàn phần sử dụng ống đếm He-3

trên các dòng nơtron phin lọc lò phản ứng hạt nhân Đà Lạt, đề tài 2007.

[2] Nguyễn Văn Hùng. Nghiên cứu, thiết kế và chế tạo hệ thống thiết bị thực nghiệm để đo một

số đặc trưng vật lý neutron, phân tích kích hoạt và định liều neutron phục vụ công tác đào tạo

nhân lực hạt nhân, đề tài 2010-2011.

[3] Nguyễn Thanh Tuỳ. Nghiên cứu xây dựng hệ thiết bị phân tích sử dụng kỹ thuật PGNAA với

ống phát nơtron, đề tài 2009-2010.

[4] Nguyễn Triệu Tú. Ghi nhận và đo lượng bức xạ. (ĐHQG Hà Nội).

[5] http://quantumfireball3.blogspot.com/

[6] http://www.science.mcmaster.ca/medphys/images/files/courses/4R06/note9.pdf

[7] http://www.canberra.com/products/hp_radioprotection/pdf/Dineutron-SS-C38294.pdf

[8] http://www.parttec.com/docs/Helium3_alternatives_AAASBreakout_4-6-2010.pdf

http://quantumfireball3.blogspot.com/

http://www.science.mcmaster.ca/medphys/images/files/courses/4R06/note9.pdf

http://www.canberra.com/products/hp_radioprotection/pdf/Dineutron-SS-C38294.pdf

http://www.parttec.com/docs/Helium3_alternatives_AAASBreakout_4-6-2010.pdf

VINATOM-AR 13--15


109

CORROSION SURVEILLANCE IN PIPE BY COMPUTED RADIOGRAPHY

Nguyen The Man, Dao Duy Dung, Dang Thu Hong, Le Duc Thinh,

Ha Hong Thu and Nguyen Trong Nghia

Center for Non-Destructive Evaluation, Vietnam Atomic Energy Institute

Nguyen Tuan, Thanh Xuan, Ha Noi

ABSTRACT: “Computed radiography” (CR) is a technique of digital industrial radiology which is developed

to replace conventional radiography. With a CR system, the detection of the outer and inner wall surface of the

pipe is done usually by edge detection and filter algorithms of the profile line at the position under

investigation. Applying in industries, radiographic examination shall be performed in accordance with a

written procedure. This paper summarizes collected knowledge and experimental results to establish a

procedure for radiography applications in monitoring corrosion in small bore pipes.

Keywords: Radiography, corrosion, pipeline.

1. INTRODUCTION

In the oil, gas and chemical industries, corrosion is most common cause of piping failure.

Therefore, detection of corrosion has been a major problem for the oil, gas and chemical industries

for many years. Various NDT methods can be used such as ultrasonic testing, eddy current testing,

etc. But only profile radiographic testing is most suitable to examine insulated piping. Beginning

period of the subject, we study overview on corrosion, techniques for corrosion examination and

digital industrial radiology. After experimental performances, a CR procedure for corrosion

examination would be established. In the end of the subject, this procedure would be applied in

industrial service.

2. EXPERIMENTS

In Vietnam, CR-35 system of Durr manufacturer with laser scanner and white imaging

plates is used. It has basic spatial resolution at 50μm and normalized signal to noise ratio at 70.

Before application, three specimens of various diameters were tested by tangential projection

technique (see results in Table 2). After radiation exposure by radiation source, IP is read out by

scanner. Radiograph shows directly image of the pipe wall.

The corrosion evaluation in piping is based on the wall thickness measurement. So,

tangential radiographic projection technique is most suitable to use. Figure 1 shows the tangential

radiographic projection set-up.


- Code: CS/13/09-01






VINATOM-AR 13--15


110

Figure 1: Tangential radiographic projection technique.

The arrangement 1(a) is applied for small pipes. For the larger pipes, arrangement 1(b)

should be used. Utilizing the tangential mode, the maximum penetrated wall thickness shall be used

to determine used radiation source. Table 1 shows Maximum paths through schedule 40, 80 & 160

pipes of various diameters

Table 1: Pipes of various diameters.

Nominal

Bore (inches)

Outside diameter,

OD (mm)

Schedule Wall thickness,

WT (mm)

Max Tangential

path (mm)

2 60.3

40 3.9 29.7

80 5.5 34.7

160 8.7 42.4

3 88.9

40 5.5 42.8

80 7.6 49.7

160 11.1 58.8

4 114.3

40 6.0 51.0

80 8.6 60.3

160 13.5 73.8

5 141.3

40 6.6 59.6

80 9.5 70.8

160 15.9 89.3

6 168.3 40 7.1 67.7

(b)

(a)

VINATOM-AR 13--15


111

80 11.0 83.2

160 18.3 104.8

8 219.1

40 8.2 83.2

80 12.7 102.4

160 23.0 134.3

Figure 2: The profile of pipe.

With calibration of pixel size, the apparent wall thickness can be determined between inner

edge and outer edge of pipe wall image (see Figure 2). According to the geometrical set-up of the

tangential projection technique, the true wall thickness is:

w = w' x (f − R)/f

where: w’ is the apparent wall thickness,

R is the pipe radius (including insulation),

f is the Source-Film Distance (SFD).

Table 2: Results of experimental test.

Object Description Examination

description

Measured

value

Remark

Specimen P01

OD: 60.3 mm

WT: 2.77 mm

X-ray

- kV: 250

- mA: 1

SFD: 700mm

Laser Power: 6 mW

High Voltage: 650

RMP: 3000

Scanning

Resolution: 50 µm

2.63mm

Isulated pipe

VINATOM-AR 13--15


112

Specimen P02

OD: 60.3 mm

WT: 2.77 mm

Se-75, 30Ci

SFD = 700 mm

Laser Power: 6 mW

High Voltage: 650

RMP: 3000

Scanning

Resolution: 25 µm

2.71mm

Specimen P03

OD: 60.3 mm

WT: 5.54 mm

Ir-192, 40Ci

SFD = 700 mm

Laser Power: 6 mW

High Voltage: 650

RMP: 3000

Scanning

Resolution: 50 µm

5.50 mm

3. CR PROCEDURE FOR CORROSION EXAMINATION

The most important part of the subject is written procedure. We have established a

procedure which defines the conditions of performing the computed radiographic examination for

corrosion in accordance with the ASTM 2007-00 Standard Guide for Computed Radiography,

ASME Boiler and Pressure Vessel Code for carbon Steel, Alloy Steel with type piping, vessel

nozzle with outside Diameter ≤ 2 inches. The procedure involves:

- Personnel: training qualification and certification requirement on digital industrial

radiology;

- Surface preparation;

- Backscattering radiation;

- System of identification: permanent identification on the radiograph traceable relating

contract/job, component, and No. of piping,…

- Equipment and materials: Radiation source, CR system and other;

- Viewing conditions, monitor, image processing and storage of digital radiographs;

- Calibration;

- Examination technique: Tangential radiographic projection technique and Double wall

radiographic projection technique;

- Locations marker;

- Use of IQIs: ASTM IQIs and duplex IQI;

- Evaluation;

- Documentation;

- Radiation safety.

VINATOM-AR 13--15


113

4. EXAMINATION APPLICATION IN INDUSTRIAL SERVICE

Lan Tay platform and Nam Con Son Pipeline are units of petroleum industry in Viet Nam. It

supply gas a maximum 21 million cubic meters of gas a day for thermal power plants which are

responsible for around a third of the Vietnam’s power output. With time, piping system is degraded

by main reason of corrosion processes and Lan Tay platform and NCSP must be stopped to

maintenance and repair. It influences national electric output. Therefore, some process piping items

are examined in-service. 250 insulated piping were examined. One of examinations by CR is shown

in Figure 3.

Figure 3: Pipe corrosion examination by CR.

5. CONCLUSION

We have achieved positive initial result of CR application. Computed radiography was

accepted by customer as a suitable technique for corrosion evaluation piping of petroleum

processing facilities in Vietnam.

REFERENCES

[1] API 570, “Piping Inspection Code: Inspection, Repair, Alteration, and Rerating of In-Service

Piping Systems”-American Petroleum Institute.

[2] API RECOMMENDED PRACTICE 574 “Inspection Practices for Piping System

Components” -American Petroleum Institute.

[3] IAEA-TECDOC-1445 “Development of protocols for corrosion and deposits evaluation in

pipes by radiography”-IAEA, April 2005.

[4] “Radiographic Evaluation of Corrosion and Deposit: IAEA Coordinated Research Project on

Large Diameter Steel Pipes, Evaluation of Corrosion and Deposit by RT”-BAM, IAEA

(2004), 16th WCNDT Montreal, Sept. 2004.

[5] “Advances NDE Techniques and Reliability Engineering Assessments for Piping and Storage

Tanks in Refineries and Petrochemical Plants”-IIS, Italian institute of welding, 2005.

[6] “New Developments in Automated Inspection for Corrosion under Insulation” - The Welding

Institute, UK, 2006.

VINATOM-AR 13--16


114

STUDY OF PREPARATION AND SURVEY OF RADIOISOTOPES TRACER

APPLICATIONS OF GOLD NANOPARTICLES IN THE MULTI-PHASE

INDUSTRIAL PROCESSES

Huynh Thai Kim Ngan, Trịnh Cong Son, Duong Thi Bich Chi, Tran Tri Hai, Nguyen Huu Quang,

Bui Trong Duy, Le Trong Nghia and Ngo Duc Tin

Centre for Applications of Nuclear Technique in Industry, Vietnam Atomic Energy Institute

No.1, DT 723 Street, Da Lat City, Lam Dong Province, Vietnam

ABSTRACT: Gold nanoparticles (AuNPs) were prepared by Turkevich and Brust method. The labeled gold in

liquids is the colloidal form with nano size particle of gold. This particles is of high dispersity in the liquid

phase that makes them a good physical tracer. The stability and disolve of AuNPs in solvents such as water,

toluene are hereafter discussed. The size of AuNPs was determined through UV-Visible spectroscopy (UV-

Vis) and transmission electron microscope (TEM).

Keywords: Gold nanoparticles, UV-Visible spectroscopy, transmission electron microscope.

I. INTRODUCTION

Nanotechnology is one of the fastest growing new areas in science and engineering. The

subject arises from the convergence of electronics, physics, chemistry, biology and materials

science to create new functional systems of nanoscale dimensions. Nanotechnology deals with

science and technology associated with dimensions in the range of 0.1 to 100 nm.

Two complementary approaches to nanomaterials are studied:

- The Top-Down approach - where one starts with the bulk material and machines his

way down to the nano-scale, and

- The Bottom-Up approach, starting at the molecular level and building up the material

through the small cluster level to the nanoparticle and the assembly of nanoparticles.

Gold nanoparticles present their color in the visible range of from wine red to blue or light

green. The color in terms of wave length is from 510 nm to 550 nm. The energy absorbed by the

gold particles is depended on the energy bands formed by each single particle. A single particle can

be considered as a quantum well which has various molecular orbitals (MOs). The energy gaps

between MOs in a nanoparticle will then be able to either adsorb or emit the energy from 1.0 to 1.7

eV. This feature helps to visually determine the size of gold nanoparticle.

In this study, gold nanoparticles (AuNPs) in water is created by reduction of HAuCl4 into

Au0, however the stabilizer is needed to control the particle size and avoid the precipitation. In

water phase citrate can be used for stabilization. For organics such as condensate, toluene, gold

nanoparticles is transferred from water phase by the transformer such TOAB (tetraoctylammonium

bromide) and reduced by NaBH4 (Sodium Borohydrate).


- Code: CS/13/06-02



- Implementation time: 12 months (May 2013 - Apr 2014)



http://en.wikipedia.org/wiki/Tetraoctylammonium_bromide



VINATOM-AR 13--16


115

The characteristic of AuNPs in water and in toluene are studied such as: distribution in

solution and in multiphase (water/toluene), stability in ambient or high temperature. Besides,

AuNPs is created by HAuCl4 labled Au-198 and their characteristic is disscused.

II. RESULTS AND DISCUSSION

1. Preparation of AuNPs in water

Figure 1: TEM and UV-vis spectrometry of AuNPs in water

50ml of a solution HAuCl4 0.57mM in distiled water is placed in round botom and

connected with condenser, stirred by magnetic stirrer and heated by oil. When the solution boil,

4ml of a TSC 0.1M. The reation as follows:

3(H2CCOOH)2C(OH)COO- + 2AuCl4

- 3(H2CCOOH)2C=O + 2Au + 8Cl

- + 3CO2 +

3H+

TEM photograph showing the AuNPs uniform in shape and size, average diameter is

14.34±2.37nm.

2. Preparation of AuNPs in toluene

20ml of Tetraoctylammonium bromide (TOAB) 5,04 mM in toluene is placed in 100ml

erlenmeyer, then add 7.25 ml of 3.7mM HAuCl4, stir the solution (using magnetic stirrer at No. 6)

in 10 minutes at ambient temperature until the water solution from yellow to colorless, then take the

organic phase. Then drop 0,04 M NaBH4 into the organic solution, it takes them about 15 minutes

for the entire solution turns dark red. Shortly thereafter, maintaining stirring speed and drip 3ml of

dodecanethiol (DT) 17,9 mM in 15 minutes intervals. After the 15-minute period, the vial is

removed from the stirrer and stored in ambient temperature. The size and wathlenge of AuNPs is

measured by UV-Vis and TEM.

VINATOM-AR 13--16


116

Figure 2: TEM and UV-vis spectrometry of AuNPs in toluene.

TEM photograph showing the AuNPs uniform in shape and size, average diameter is

4,59±1,43nm.

3. Preparation of AuNPs labeling Au-198 on water and organics

The labeled gold in liquids is the colloidal form with nano size particle of gold. This

particles is of high dispersity in the liquid phase that makes them a good physical tracer.

Au is known as the metal with isotope Au-198 emmitting gamma is very common tracer due

to not absorption, chemical reaction with material and fluids. Au-198 is produced by neutron

activation of Au-197 which is of 99.6% in abundance, in the nuclear reactor. Au is weighed in the

polyethylene ampoule to charge into the reactor.

The neutron activation equation for estimation of irradiation time, weight of Au is

introduced as following:

)1.(.. .teNA

where:

A: activity, Bq

thermal neutron flux, n/cm2.s

thermal neutron cross section, cm2

N: target nuclides, atom/cm3

AvoNM

mN ..

m: sample weight, g

M: atomic mass, g

isotope abundance

0

5

10

15

20

25

2,30 3,25 3,97 4,59 5,13 5,62 6,06 6,48 6,88

Fre

qu

en

cy, %

Diameter, nm

VINATOM-AR 13--16


117

NAvo: Avogadro Number = 6.023 x 1023

decay constant, s-1

, 2/1

)2ln(

T

t: irradiation time, s

T ½ : decaying time, s

Table 1: Parameters of irradiation Au in Đà Lạt reactor

Reaction Cross section

(barn)

T ½

Weight of

sample

Irradiation

time, min

Activity

(mCi)

197Au(n,γ)

198Au 98 2.7day 20mg 15 0.78

Radioactive material is then transferred in the calibration cylinder for calibration of activity

using detector BGO 3’x3”, MCA Digidart and simulation by MCNP code.

Ashing Au-198 by aqua regia to make HAuCl4 as following:

Au + 3HCl +HNO3 → HAuCl4 +NO2+ H2O

Then preparation of AuNPs labeling Au-198 on water and toluene by procedure as above.

4. Test of characteristic of AuNPs

Distribution of retention time of AuNPs on glass and metal is performed by AuNPs labeling

Au-198.

Figure 3: Distribution of retention time of AuNPs on glass.

Table 2: Recovery of AuNPs on glass

No Sample name Recovery, %

1 AuNPs W1 75.40

2 AuNPs W2 90.48

3 AuNPs T1 83.45

4 AuNPs T2 85.90

VINATOM-AR 13--16


118

Table 3: Rate of absorption of AuNPs on metal from time to time

ample name Rate of absorption , %/cm2/h

AuNPs W1 0.0044

AuNPs W2 0.0025

AuNPs T1 0.0039

AuNPs T2 0.0033

III. CONCLUSION

In summary, the Project “Study of preparation and surveying of usability gold

nanoparticles serving applications of radioisotopes tracer in the multi-phase industrial processes

” was performanced from 4/2013 to 4/2014, have achieved the target set, the completion of research

content as follows:

Gold nanoparticles (AuNPs) were prepared by Turkevich and Brust method (uniform in

shape and size, average diameter is 14.34±2.37nm and 4.59±1.43nm, respectively).

This particles is of high dispersity in the liquid phase that makes them a good physical

tracer. The stability and dissolve of AuNPs in solvents such as water, toluene are tested.

However, the results obtained from this study are preliminary in development of multiphase

tracing technology. It is the need to improve in professional and industrial quality to meet the

production requirement actually.

REFERENCES

[1] Jessica Winter, Gold nanoparticles biosensor, 2007.

[2] Thi Ha Lien Nghiem, Thi Huyen La, Xuan Hoa Vu, Viet Ha Chu, Thanh Hai Nguyen,

Quang Tuan Le, Emmanuel Fort, Quang Hoa Do, And Hong Nhung Tran. Synthesis,

Capping And Binding Of Colloidal Gold Nanoparticles To Proteins, ADVANCES IN

NATURAL SCIENCES: NANOSCIENCE AND NANOTECHNOLOGY 1 025009 (5p.),

2010.

[3] Alivisatos AP, Semiconductor Clusters, Nanocrystals, and Quantum Dots, Science, 271, pp.

933-937, 1996.

[4] M. Brust, M. Walker, D. Bethell, D. J. Schiffrin, R. Whyman, Synthesis of Thiol-derivatised

Gold Nanoparticles in a Two-phase Liquid-Liquid System, Chem. Commun, 801, 1994.

[5] D. Kim et. al., Nanotechnology, 17, 4019, 2006.

[6] Kottmann, J.P. Martin, O. J. F. Smith, D. R. Schultz, B, Physical Review, 64, 2001, pp. 402.

[7] M. Kowshik et. al., Nanotechnology, 14, 95, 2003.

[8] Kress-Rogers, E. Phil, Handbook of biosensors and electronic noses. Medicine, food and the

environment, pp. 149-168.

[9] F. Mafune et. al, J. Phys. Chem, 14, 8333, 2000.

[10] M.N. Martin, J.I. Basham, P. Chando, S.K. Eah, Charged gold nanoparticles in non-polar

solvents: 10-min synthesis and 2D self-assembly, Langmuir 26, 2010, pp. 7410.

[11] Murday, J. S. AMPTIAC Newsletter, 6, 5, 2002.

[12] S.D. Perrault, W.C.W. Chan, J. Am. Chem. Soc 131, 17042, 2009.

[13] Richard L.Mc Creery, Raman spectroscopy for chemical analysis, John Wiley& Sons Ltd,

Englad, 2007.

[14] J. Turkevich, P.C.S., J. Hillier, A study of the nucleation and growth processes in the

synthesis of colloidal gold, Discuss. Faraday. Soc 11, 1951, pp. 55-75.1951.

VINATOM-AR 13--17


121

ASSESSING SOIL EROSION RATES FOR A LARGE CATCHMENT

IN THE CENTRAL HIGHLANDS OF VIETNAM USING FALLOUT

RADIONUCLIDES

Phan Son Hai, Nguyen Thanh Binh, Nguyen Minh Dao, Nguyen Thi Huong Lan,

Nguyen Thi Mui, Le Xuan Thang and Phan Quang Trung

Environmental Research Centre, Nuclear Research Institute, Vietnam Atomic Energy Institute

Trinh Cong Tu

Central Highlands Soils, Fertilizers and Environ. Research Center

Tran Tien Dung

Southern Coastal Central Agricultural Science Institute

ABSTRACT: Fallout radionuclides Be-7 and Cs-137 were applied to assess soil erosion rates for a 270.5 km2

catchment with a variety of slope (from 0o to more than 45º), crops or vegetation (natural forest, artificial

forest, perennial crops, annual crops) and a variety of tillage and soil conservation measures. Soil erosion rates

were estimated at 90 areas within the catchment. Each sampling area has at least one feature of the slope,

rainfall, crops, farming practice different from others. Soil erosion rates in this region depend significantly on

the slope, crops and farming techniques. Averaging over crops, soil erosion rates by slopes 0 - 5º, 5 - 15º, 15 -

25º and 25 - 35º are 5.0, 12.8, 18.9 and 21.3 t ha-1

y-1

, respectively. Forest land has the least soil erosion rates,

ranging between 0.5 t ha-1

y-1

and 14 t ha-1

y-1

depending on the slope. Annual crops land has the highest soil

erosion rates, ranging between 6 t ha-1

y-1

and 42 t ha-1

y-1

when slope varies from < 5o to 32

o. Perennial crop

land has soil erosion rates in the range of 5 t ha-1

y-1

and 39 t ha-1

y-1

. In areas with the same slope, the soil

erosion rate is the highest for cashew plantations, lower for mulberry field and the lowest for tea or coffee

plantations. Soil erosion has resulted in losing a significant quantity of plant nutrients such as OM, N, P2O5 and

K2O every year. Generally, lost nutrient quantities due to soil erosion are proportional to erosion rates. Some

areas of annual crop land lost a large amount of nutrients every year, up to 1435 kg OM, 79 kg N, 54 kg P2O5

and 36 kg K2O. Similarly, perennial crop lands in this region could lost up to 1736 kg OM, 91 kg N, 66 kg

P2O5 and 40 kg K2O every year. Owing to soil erosion, the catchment has lost about 211200 tons of surface soil

per year during last 50 years, corresponding to the rate of 7.8 t ha-1

y-1

. This amount of eroded soil was

deposited in drainage of the catchment and in reservoirs. Consequently, the drainage capacity was reduced and

the frequency of flooding increased during rainy season. Additionally, life-span of irrigative or hydroelectric

reservoirs considerably decreased. Ham Thuan reservoir supplying water to a 300 MW hydroelectric power

plant in this region is a typical example with the loss of capacity of about 418 970 m3

per year. There is an

existence of farming practice models which could reduce soil erosion rates by 30% - 45% in comparison with

others having the same slope and rainfall. Although these models did not give the effectiveness as good as


- Code: 01/2012/HD-DTCB






1. Phan Son Hai, et al., Application of fallout radionuclides to estimate soil erosion rates at areas having

different farming practices in the Lamdong Region, J. Vietnam Soil Science, 43 (2014).

2. Phan Son Hai, et al., Assessment of soil erosion rates for different land uses in the region of Lamdong

province using fallout radionuclides, Journal of Science and Technology (under review).

3. Phan Son Hai, et al., Assessing the effectiveness of soil conservation measures to reduce soil erosion

rates for sloping land in the Central Highlands of Vietnam using fallout radionuclides, Submitted to

Newsletter of WOCAT/LADA.

VINATOM-AR 13--17


122

those developed by researchers, they have been created and accepted by farmers. Popularizing these optimal

farming practices for farmer’s imitation is feasible for this region. This approach is probably suitable to current

farming culture of local farmers.

I. INTRODUCTION

About 75% of Vietnam territory is sloping land where the third of population are living with

the major practice of farming. Owing to the demand of economic growth, the use of sloping land is

more intensified with time in term of both the frequence of land use and expansion of cultivated

area. Meanwhile, soil conservation measures have not been implemented. The loss of nutrients

owing to soil erosion has been compensated by adding chemical fertilizers and growing stimulators.

By this way, the Vietnamese agricultural system has contributed to contamination of surface and

ground water in catchments. The establishment of sustainable agriculture in sloping land is essential

for our country in this stage. Soil erosion rates for different land uses at catchment level and the

effectiveness of soil conservation measures are useful informations to help set up and maintain

sustainable agriculture.

For assessment of soil erosion rates, different techniques have been applied in Vietnam.

Conventional methods have been applied for several decades, of wich runoff plots have been being

the most widely used (Thai Phien, 1998). Radionuclide Cs-137 has been applied for estimation of

soil erosion rates for more than ten years (Phan Son Hai et al., 2000, 2003, 2004, 2006; Trinh Cong

Tu et al., 2005; Nguyen Hao Quang, 2000; Nguyen Quang Long, 2004; Bui Đac Dung et al., 2005).

The combined use of Be-7 and Cs-137 to assess soil erosion rates for different periods of time, as

well as to assess the effectiveness of soil conservation measures at landscape level has been carried

out in the Central Highlads (P.S. Hai, et al., 2006, 2007, 2011).

In general, soil erosion investigations were carried out for small areas and based mainly on

runoff plots. Fallout radionuclides were also used to assess soil erosion rates for some fields with

the area of several hectares only.

This project was set up to study soil erosion for a large catchment of about 300 km2 using

fallout radionuclides. The experimental results in detail were given in the “Report on

implementation of the MOST's scientific and technological project, period of 2012 - 2013”. Only

main results of the project were presented briefly in this report.

II. STUDY AREA

The study catchment located in

Lamdong province has the area of

270.52 km2. It consists of three

communes of Bao Lam District (Tan

Lac, Loc Thanh, Loc Nam) and three

communes of Di Linh District (Hoa

Bac, Hoa Nam, Hoa Ninh) as showed

on Figure 1. It is a part of the 1280

km2 catchment of Ham Thuan

hydroelectric reservoir. This region

has the average elevation in the range

of 600 - 800 m asl and the annual rainfall varying from 2400 mm to 3000 mm, of which the total

rainfall in rainy season makes up about 60 - 91%.

Fig. 1. The location of study catchment in Lam Dong

VINATOM-AR 13--17


123

III. METHODS OF STUDY

3.1. Classification of catchment area according to the slope

The Degital Elevation Model (DEM) of the study catchment was established based on the

topographic map of Lamdong province scaling 1:10 000 and then the catchment area was divided

into parts with following slopes: < 5º, 5-15o, 15-25

o, 25-35

o and > 35

o.

3.2. Classification of catchment area according to plantations

Based on land use maps of lamdong province, the whole area of study catchment was

classified in to four categories: (i) Natural forest land; (ii) Artificial forest land; (iii) Perennial crop

land (Tea, coffee, strawberry, cashew); (iv) Annual crop land.

3.3. Selection of representative sampling sites

Based on the digital maps of the study catchment classified by slope, plantation mentioned

above, together with rainfall, 90 sampling sites were selected according to criterions: (i) Each

location has at least one of four characteristics of slope, plantation, rainfall and soil conservation

measure different from others; (iii) To be able to go these location for collecting samples.

3.4. Sampling method

a) Sampling at referent sites

At each referent location, depth incremental samples at 2 cm intervals were collected down

to 35cm for assessment of the vertical distribution of 137

Cs and depth incremental samples at 1 cm

intervals were collected down to 5cm for assessment of the vertical distribution of 7Be. Then 3 – 5

bulk soil samples were collected for determination of the reference value with the uncertainty of

about 8 – 12% (Phan Son Hai et al., 2003). For 137

Cs measurement, soil cores (diameter 10 cm and

depth 30 cm) were collected. For 7Be measurement, soil samples were collected using a frame made

of angle section steel (thickness 5 mm, width 20 mm, height 40 mm).

b) Sampling at study sites

At each study location, bulk soil samples were taken along a sloping line. The distance

between two sampling points varied from 10 m to 30 m depending on land form. One soil sample

was taken by a cylindrical steel tube (30 cm deep and 10cm in diameter) and the other by a scraper

(20 cm wide, 40 cm long and 4 cm deep) at each sampling point for 137

Cs and 7Be measurements as

mentioned above.

3.5. Analytical methods

a) Analysis of Cs-137 and Be-7

Soil samples were dried, ground into fine powder and put into marinelli beakers with the

mass of about 550 gram and then measured for 24 hours using low background gamma

spectrometers having relative efficiency of 30%. Be-7 and Cs-137 were analyzed using the 478 keV

and 662 keV photo-peaks, respectively. All samples for analysis of Be-7 have been completely

counted for about 40 days since sampling date.

b) Analysis of organic carbon and nutrients

- Total organic carbon was determined according to: TCVN 8941 : 2011.

- Total nitrogen was determined according to: TCVN 6498 : 1999.

- Total phosphor was determined according to: TCVN 8940 : 2011.

- Total kalium was determined according to: TCVN 8660 : 2011.

VINATOM-AR 13--17


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c) Analysis of particle size

Particle size distribution of soil and sediment samples was determined by wet sieving and

Robinson method according to TCVN 8567:2010.

3.6. Conversion models in soil erion assessment

Conversion models used for assessment of soil erosion rates in this study were discribed in

detail by P.S. Hai et al. (2011).

IV. RESULTS AND DISCUSSION

4.1. The feature of topography and land use for study catchment

The slope distribution infered from DEM for study catchment (Fig. 2) showed that the slope

within the catchment varies in a wide range, from several degree to more than 45o. The

classification of catchment area by slope is following: 0 - 5o accounts for 36.4%; 5 - 15

o accounts

for 40.6%; 15 - 25o accounts for 18.1%; 25 - 35

o accounts for 4.7% and > 35

o accounts for 0.12%.

For land use, 31.76% is natural forest; 6.15% is artificial forest; 1.35% is annual crop land and

60.74% is perennial crop land (Tea: 16.60%; coffee: 78.08%; cashew: 0.02%; mulberry: 0.54%;

fruit-trees: 4.76%).

By combining the map of slope and the land use map, in taking account of rainfall, 90

locations around the catchment were selected for sampling, of which 14 sites in forest land, 58 sites

within perennial land and 18 sites in annual crop land.

4.2. Inventories of Be-7 and Cs-137 at reference sites

The reference inventory of Be-7 and Cs-137 more and less varies from site to site within the

catchment. The reference inventory of Cs-137 is in the range of 385 - 563 Bq/m2 (Average: 500

Bq/m2). The variation in the

inventory of Cs-137 mainly

concerned the variation of

rainfall (rainfall: 2400 –

2980 mm). Reference

inventories of Be-7 range

between 195 Bq/m2 and 340

Bq/m2 (Average: 269

Bq/m2). Owing to short life

of Be-7, the inventory value

depended on the time of

sampling apart from rainfall.

Figure 2: Digital elevation model DEM (a) and sloping map of study catchment (b)

(a) (b)

Figure 3: Soil erosion rates over 50 years according to the slope

VINATOM-AR 13--17


125

4.3. Soil erosion ratesa) Soil erosion rates at sampling areas

Soil erosion rate within study catchment

varied from site to site depending on the slope and

land use (Figure 3). Soil erosion rates were the lowest

of all for natural forest land and vary from 0.5 t ha-1

y-

1 to 9.0 t ha

-1 y

-1 depending on the slope. Artificial

forest land had soil erosion rates varying from 1.5 t

ha-1

y-1

to 14.0 t ha-1

y-1

when the slope ranged from <

5o to > 35

o. For perennials such as tea and coffee

plantation, soil erosion rates were comparable and in

the range of 5 - 34 t ha-1

y-1

when the slope ranged

from 50 to 35

o. On the same slope area soil erosion

rate in mulberry fields was higher than that in tea and

coffee fields and lower than that in cashew fields. Soil erosion rate in annual crop land was the

highest in the all plantations, up to 40 t ha-1

y-1

at 30o slope.

b) Soil erosion rates for whole catchment

The average soil erosion rate for areas having

the slope of 0 - 5º, 5 - 15º, 15 - 25º, 25 - 35º, > 35º

was estimated by averaging soil erosion rate over

individual study sites within each gradient group.

Long-term soil erosion rates in the period of 50 years

by the slope and plantation are given on Figure 4.

Mean soil erosion rate at annual crop land is

comparable to that at tea and coffee plantations for

areas having the slope of more than 25º. These steep

areas have been natural forest before they were

reclaimed for annual crops several years ago.

Therefore, for these steep areas mean long-term soil erosion rates at annual crop fields is not higher

than that at tea and coffee plantation fields. This is contrary to results obtained for areas less than

25º.

Based on the average soil erosion rates and the area by the slope, the annual total soil loss

was assessed for study catchment. Thereby, the annual soil loss was 211,200 tons for whole

catchment in the period of last 50 years (corresponing to 7.8 t ha-1

y-1

). The structure of soil loss (%)

by plantations is given on Figure 5. The area of coffee plantation is about 47.4% of the total

catchment area but 70% of the total soil loss was derived from coffee fields.

Figure 6: Soil loss structure by the slope for each plantation type

Figure 5: Soil loss structure by plantations

Fig 4: Soil erosion rate averaging over

plantations and slope in the 50 year period

VINATOM-AR 13--17


126

Figure 6 presents thr structure of annual soil loss by the slope corresponding to each plantation

within the catchment. The percentage of sediment contribution by slope reflected the status of land

use for study catchment in the past.

c) Soil erosion rates according to farming practices

There were several farming practices to be able to reduce soil loss in the catchment: (i)

Intercroping pantations to improve ground cover; (ii) Creating basins at the base of coffee trees to

retain water and soil; (iii) Contour farming; (iv) Terraced farming. Soil erosion investigations into

these farming practices showed that:

- In a sloping area of 23 - 25º, intercroping pineapple with cashew reduced soil erosion

rate by 40% in comparison with cashew monoculture (from 35 t ha-1

y-1

to 21 t ha-1

y-1

).

- In a sloping area of 18 - 20º, 1.2m contour lines farming decreased soil erosion rate by

36% in comparison with cultivation without contour lines for tea plantation (from 26 t ha-1

y-1

to 16

t ha-1

y-1

). Similarly, soil erosion rates at 8 - 10º tea fields with 1.4m contour lines decreased by

40% (from 17 t ha-1

y-1

to 10 t ha-1

y-1

).

- For coffee plantation, creating basins reduced soil erosion rate by 32% in comparison

with the control at 14 - 16º sloping areas (from 26 t ha-1

y-1

to 18 t ha-1

y-1

).

- Contour mulberry rows, together with intercroping corn on 10 - 12º sloping areas

decreased soil erosion rate by 33% in comparison with the control (from 23 t ha-1

y-1

to 15 t ha-1

y-1

).

4.4 Soil erosion impacts

a) On site impacts

The amount of soil nutrient lost every year due to soil erosion was assessed by using the

content of OM, N, P2O5 and K2O in the 0 – 3.5 cm soil layer and soil erosion rates. Generally, lost

nutrient quantities due to soil erosion are proportional to erosion rates. For forest land, some areas

with high soil erosion rates lost 598 kg OM, 29 kg N, 19 kg P2O5 and 12 kg K2O per hectare every

year. Some annual crop areas lost a large amount of nutrients every year, up to 1,435 kg OM, 79 kg

N, 54 kg P2O5 and 36 kg K2O per hectare. Similarly, perennial crop areas suffering severe soil

erosion lost up to 1,736 kg OM, 91 kg N, 66 kg P2O5 and 40 kg K2O every year.

Results obtained from this study showed that for most study areas OM contents in the 0-30

cm soil layer are greater than the average value in cultivated sloping land in Viet Nam (The average

of about 2% by Nguyen Van Bo et al., 2001). However, 20 investigation locations had OM contents

less than 2%.

Particle size analysis of soil samples showed that coarse fractions like sand and silt in the 0

– 3.5 cm soil layer are higher than those in the 0 – 30cm soil layer for most sampling points. This

means that soil erosion brought about the change in physical property of surface soil. For a long

time, the change in particle size compositions can result in changing other chemical and physical

properties of surface soil.

b) Off site impacts

As mentioned above, the rate of soil loss for whole catchment is 211,200 tons per year

(mean: 7.8 t ha-1

y-1

). This amount of eroded soil silted the drainage of catchment and reservoirs.

The study catchment is a subcatchment of the Ham Thuan Reservoir’s catchment.

According to research results in the year 2010, Ham Thuan Reservoir lost it’s capacity of about

418,970 m3 every year owing to sediment from it’s catchment. This means that a sediment amount

of about 523,710 tons reached the reservoir from it’s catchment, corresponding to the average

sediment yield of 4.09 t ha-1

y-1

. With the assumption that the mean soil erosion rate of study

VINATOM-AR 13--17


127

subcatchment is comparable to that of Ham Thuan reservoir’s catchment, about 52.5% of eroded

soil within the whole catchment was deposited in Ham Thuan reservoir. The rest was deposited in

the catchment’s drainage.

4.5 Main factors affecting soil erosion in the study catchment

Owing to dry season lasting about 5 months with very little rainfall the binding between soil

particles by colloids becomes weaker. Therefore, surface soil is more susceptable to erosion under

havy rain storms at the begining of rainy season. Investigations on run-off plots by Phan Son Hai et

al. (2007) showed that the amount of soil loss in the first month of rainy season could account for

40% to 50% of total soil loss during a year. Leaving bare soil surface or bad ground cover during

the first period of rainy season would increase soil erosion rate in comparison with other period of

time under the same rainfall. Severe soil erosion at cashew land mentioned above is a typical

example on the effect of rain storms at the begining of rainy season. Cashews usually defoliate in

dry season, therefore land surface is bare during heavy rainstorms at the beginning of rainy season,

resulting in serious soil erosion. For rainfed annual crops cultivation is usually started at the

begining of rainy season. Therefore, land surface is almost bare at this time, resulting in severe soil

erosion in this stage.

The majority of study catchment area is sloping land, of which about 23% have the slope

greater 15o. During rainy season, surface water flow increases with increasing slope, resulting in

intensifying soil erosion rate. A dense tree canopy can reduce the effect of rain drops on soil surface

resulting in decreasing rainsplash erosion. However, it do not decrease surface water flow – a factor

can bring about soil erosion. Different from forest, residues are usually cleared from soil surface for

cultivated land. Therefore, surface water flow at cultivated land is usually greater than that at forest

land. Consequently, soil erosion rate at perennial land is much higher than that at forest land unnder

the same slope and rainfall. In order to reduce soil erosion rate, many soil conservation techniques

have been applied in this catchment such as terraced farming, creating basins at the base of coffee

trees, creating contour-hedgerows, contour farming.

V. CONCLUSIONS

Fallout radionuclides Be-7 and Cs-137 were applied to assess soil erosion rates for a 270.5

km2

catchment with a variety of slope (from 0o to more than 45º), crops or vegetation (natural

forest, artificial forest, perennial crops, annual crops) and a variety of tillage and soil conservation

measures. Results obtained from this research have proved the advantages of fallout radionuclide

technique in assessing soil erosion rates and the effectiveness of soil conservation measures at large

catchment level. Especially, Be-7 technique allows us to estimate quickly the effectiveness of soil

conservation techniques at landscape level.

Soil erosion rates were estimated at 90 areas arranged in 5 slope groups: 0 - 5º, 5 - 15º, 15 -

25º, 25 - 35º and > 350 within the catchment. Soil erosion rates in the catchment varied in a wide

range, from 0.5 t ha-1

y-1

to 42.2 t ha-1

y-1

depending on the slope, plantation and farming practices.

By plantations, forest land had the lowest soil erosion rate and annual crope land had the highest

soil erosion rate in all. For perennial crops, under the same slope soil erosion rates in turn reduced

as follows: cashew, mulberry and tea/coffee plantations.

Soil erosion has resulted in losing a significant quantity of plant nutrients such as OM, N,

P2O5 and K2O every year. Generally, lost nutrient quantities due to soil erosion are proportional to

erosion rates. Some areas of annual crop land lost a large amount of nutrients every year, up to

1,435 kg OM, 79 kg N, 54 kg P2O5 and 36 kg K2O. Perennial crop land suffering severe erosion

could lose up to 1,736 kg OM, 91 kg N, 66 kg P2O5 and 40 kg K2O every year.

VINATOM-AR 13--17


128

Owing to soil erosion, the catchment has lost about 211,200 tons of surface soil per year

during last 50 years, corresponding to the rate of 7.8 t ha-1

y-1

. This amount of eroded soil was

deposited in drainage of the catchment and in reservoirs. Consequently, life-span of irrigative or

hydroelectric reservoirs fast decreased. Ham Thuan reservoir supplying water to a 300 MW

hydroelectric power plant in this region is a typical example with the loss of capacity of about

418,970 m3

per year.

There is an existence of farming practice models which could reduce soil erosion rates by

30% - 45% in comparison with the controls. Although these models did not give the effectiveness

as good as those developed by researchers, they have been created and accepted by farmers.

Existing soil conservation measures created empirically by farmers. Therefore, the effectiveness of

these models varied in a wide range and did not get the optimal conditions.

REFERENCES

[1] Bui Dac Dung, et al., Comparing soil erosion and deposition rates assessed by Cs-137

technique with those assessed by runoff plots, The Sixth National Conference on Nuclear

Science and Technologies, Dalat City, 26-27/10/2005.

[2] Nguyen Van Bo, et al., The basic information on principal soil types in Vietnam, World

Publisher, Hanoi,2001.

[3] Nguyen Quang Long. Preliminary study on combined use of Pb-210 and Cs-137 to assess

soil erosion rates and nutrient loss. Report on the Institute Project (2004), Vietnam Atomic

Energy Institute, 2004.

[4] Nguyen Hao Quang, Preliminary application of Cs-137 technique to assess soil erosion rates

in an artificial forest area at Song Da, Report on the National Project (2000), Forest Science

Institute of Vietnam, 2000.

[5] Phan Son Hai, et al. Establishing the relationship between Cs-137 loss and soil erosion.

Report on the National Project BO/01/01-03 (2003), Vietnam Atomic Energy Institute,2003.

[6] Phan Son Hai, et al., Spatial variability of 137

Cs inventory at reference sites and influence of

sampling strategy on the uncertainty in estimation of soil erosion rates, Proc. of the fifth

National Conference on Nuclear Physics and Techniques, Ho Chi Minh City, pp. 234-

237,2003.

[7] Phan Son Hai, et al., Establishment of relationship between 137

Cs loss and soil erosion rates

for the region of Central Highlands, J. Vietnam Soil Science 26, pp. 92–94, 2006.

[8] Phan Son Hai et al., Assessment of soil erosion rates and effectiveness of soil conservation

measures using fallout radionuclides and plots, J. Vietnam Soil Science, 27 (2007), pp. 154-

159, 2007.

[9] P.S. Hai et al., Application of Cs-137 and Be-7 to access the effectiveness of soil

conservation technologies in the Central Highlands of Vietnam, IAEA-TECDOC-1665, pp.

195-206, 2011.

[10] Thai Phien & Nguyen Tu Siem (Ed.). Sustainable farming on sloping lands in Vietnam –

Research results in the period of 1990-1997. Agriculture Publisher, Hanoi, 1998.

VINATOM-AR 13--18


129

STUDY ON METHOD FOR SIMULATION OF PARTITIONING

TRACERS IN DOUBLE POROSITY MODEL OF FRACTURED

BASEMENT FORMATIONS

To Ba Cuong, Nguyen Hong Phan, Tran Tri Hai, Le Van Son and Le Van Loc

Centre for Applications of Nuclear Techniques in Industry,Vietnam Atomic Energy Institute


ABSTRACT: Single well tracer test (SWTT) has been widely used and accepted as a standard method for

residual oil saturation (SOR) measurement in the field. The test involves injecting of the partitioning

tracers into the reservoir, producing them back and matching their profiles using a suitable simulation

program. Most of simulation programs were first developed for sandstone reservoir using single porosity

model cannot be applied for highly heterogeneous reservoirs such as fractured basement and carbonate

reservoirs. Therefore a simulation code in double porosity model is needed to simulate tracer flow in our

fractured basement reservoirs. In this project, a finite-difference simulation code has been developed by

following the Tang’s mathematical model to simulate the partitioning tracers in double porosity medium. The

code was matched with several field tracer data and compare with results of t h e University of Texas’s

chemical simulator showing an acceptable agreement between our program and the famous UTChem

simulator. Besides, several experiments were conducted to measure residual oil saturation in 1D column and a

2D sandpad model. Results of the experiments show that the partitioning tracers can measure residual oil

saturation in glass bead models with a relatively high accuracy when the flow velocity of tracer is sufficiently

low.

I. OBJECTIVE

The objective of this project is to find out an existing mathematical method for simulating of

partitioning tracers in double porosity media, build a simulation program for single-well tracer test

in double porosity and validate the program with a physical experiment.

Based on that, we follows the JS.Tang’s mathematical model [5] for building a simulation

program of Single well tracer test in double porosity media, then we validate the program with

several field tracer data which have been reported in the literatures; and we also compare our

program with the famous simulation program of the University of Texas named UTChem. The

comparing results showed that our program gave an acceptable match with field data as well as with

results of the UTchem simulator.

Besides, we have conducted some experiments to measure residual oil saturation in glass

bead column and a 2D sandpad model. Results of the experiments show that the partitioning tracers

can measure residual oil saturation in glass bead models with a relatively high accuracy when the

flow velocity of tracer is sufficiently low; in other words, found that the higher flow rate of tracer,

the lesser oil can be detected from tracer method.


- Code: CS/13/06-01






Phan NH, Cuong TB, Son LV, An aproach for simulation of single-well tracer test in double porosity

media, 10th National Conference on Nuclear Science and Technology, Vung Tau City, 15-16 Aug

2013 (in Vietnamese).


VINATOM-AR 13--18


130

II. BUILDING OF SIMULATION PROGRAM FOR SINGLE WELL TRACER

TEST IN DOUBLE POROSITY MEDIA

II.1 The mathematical model of Tang

Based on the previous models of Deans[3] and Grigorievich[4], JS.Tang[5] has developed a

new mathematical model for simulating of partitioning, reacting tracers in a single-well tracer test

in double porosity media. In this model, heterogeneities of double porosity formation are described

by 2 separate regions: the flowing region or flowing pore characterizes for large fractures or

channels where fluids can move and the non-flowing region or non-flowing pore, characterizes for

rock matrix and micro fractures where there is no flow, but its fluids can exchange with the flowing

pore by molecular diffusion at the interface. The flow of tracers obeys the convection-dipersion

equation with the following assumptions:

- There is no mass transfer resistance across phases, so tracers always attain instant

equilibrium between oil and water.

- Reaction rate of the partitioning tracer to form the non-partitioning tracer is constant.

Figure 1: A basic volume of the model (left) and the calculation grid (right).

A single well tracer test was implemented in the following steps: first, a partitioning tracer

(Ester) was injected into the formation as a pulse during a short time; after that water was injected

to push the tracer bank far away from the wellbore, when the tracer bank reaches certain distance,

the well was then shut, leaving Ester to react with water to form another tracer named Alcohol that

cannot partition between oil and water. Finally the two tracers were pull back and analyzed at the

well head. In addition, to make sure that the tracers were recovered completely, a monitoring tracer

called “cover” was also injected continuously during the ester injection and water pushing periods.

The equations describe movement of tracers in dimensionless form are as below[5]:

Equation of Ester:

In flowing pore (fracture):

j,Dj,Dh

*

j,Dj,DDa

j,D

,Pe2

DD

j,D

r,PeD

DD

j,D

D

,D

D

j,D

r,D

D

j,DCKCCN

CN

r

1

r

CNr

rr

1C

r

u

r

Cu

t

C

(1)

In non-flowing pore (matrix):

*

j,D

*

j,Dh

*

j,Dj,D

*

Da

D

*

j,DCKCCN

t

C

(2)

Equation of alcohol:


VINATOM-AR 13--18


131

j,D

,Pe2

DD

i,D

r,PeD

DD

i,D

D

,D

D

i,D

r,D

D

i,D

j

iC

Nr

1

r

CNr

rr

1C

r

u

r

Cu

t

C

1

1

j,Dj,Dh

*

i,Di,DDa CKCCN (3)


*

j,D

*

j,Dh

*

i,Di,D

*

Da

D

*

i,D

*

j

*

i CKCCNt

C

1

1

(4)

Equation of mass balance tracer (cover)


c,D

,Pe2

DD

c,D

r,PeD

DD

c,D

D

,D

D

c,D

r,D

D

c,D

j

cC

Nr

1

r

CNr

rr

1C

r

u

r

Cu

t

C

1

1

*

c,Dc,DDa CCN (5)


*

c,Dc,D

*

Da

D

*

c,D

*

j

*

c CCNt

C

1

1

(6)

in which, CD-dimensionless concentration of tracers; uD,r, uD,radial and angular

dimensionless interstitial velocities; NPe,r, NPeradial and angular Peclet numbers; NDa-

dimensionless mass transfer coefficient of tracer between flowing and non-flowing pore; Kh-

reaction rate constant of ester and is the alcohol/ester molar volume ratio.

II.2 Building of simulation program

Based on the mathematical model of

Tang[5], we have developed a simulation code

using finite difference method to solve the

equations from (1) to (6) for three tracers in a

polar coordinate system, we used the central

finite difference scheme in space, implicit time

scheme in the flowing pore (Eq. 1, 3 and 5) and

explicit time scheme in non-flowing pore (eq.

2, 4 and 6). Those equations were solved

simultaneously, then for every tracer, the mass

transfer process between flowing and non-

flowing pores was solved sequentially.

The adjacent picture is the interface of the program

The program SWTT was written in Fortran to simulate single well tracer test in double

porosity formation. The program can handle for multi layer and the effect of fluid drift.

The code was then tested by matching of several field tracer data which have been reported

in the literatures and compared with results of the University of Texas Chemical simulator

(UTChem).

V drift =

0.3m/s

VINATOM-AR 13--18


132

Figure 2 and 3 show the matching results of 2 field data reported in the Final report of

Deans[2], in which, the partitioning tracer was used is ethyl acetate and the secondary tracer is

ethanol.

The residual oil saturation values (Sor) estimated from our program were 11% in Test#3 and

27% in Test#28, that were in range of the Sor values which have been pre-determined from other

methods (12.5 ±1.5% in test #3 and 29 ±2% in test #28).

Figure 2: Comparison of field data and simulation results (Ethyl Acetate profiles).

Figure 3: Comparison of field data and simulation results (Ethanol profiles).

III. TRACER EXPERIMENTS

In order to validate the partitioning tracer method to determine residual oil saturation,

several experiments were conducted in 1D column and a 2D sandpad model. In which, the porous

media was made by glass bead, the sewing machine oil was used as organic phase, and the tracers

used were ethyl acetate (as partitioning tracer) and ethanol (as non partitioning tracer).

III.1 Partitioning coefficients measurement

The partitioning coefficients (Kd) of ethyl acetate and ethanol between oil and water

were measured by pumping oil and a mixture of water, ethyl acetate and ethanol (1000ppm/each)

through a very long (10m) and small diameter (1/16”) pipe. Due to the small diameter and long

length of the pipe, the contacting interface between oil and water was increased thus the

VINATOM-AR 13--18


133

concentrations of tracers in two phases reached the equilibrium state after certain time. Figure 5 is

the concentration of tracer at the effluent of the pipe. By this way, the partitioning coefficients of

two tracers was determined:

Kdethanol = 0 and KdEthyl Acetate = 1.48

Figure 4: Experimental system for Kd measurement.

Figure 5: Concentration of tracer at the effluent samples.

III.2 Tracer experiments for residual oil saturation measurement in column

Residual oil saturation

experiments were conducted

using a stainless-steel column

with diameter of 1.7cm and

length of 29.5 cm. First, the

column was packed by glass

bead with grain size of 100-150

micron to create the porous

media, then oil was injected at

0.5 mL/min to make the column

saturated with oil. After that,

water was injected through the

column at different flow rates

(0.2, 0.5, 1.5 and 5mL/min) to

observe the oil saturation

change in the column. Fig 6

shows the amount of oil left in the

column (So,%) versus the numbers

of pore volume injected (PV)

10m, 1/16”

Figure 6: Remaining oil saturation in the column at

different water injection rates.

VINATOM-AR 13--18


134

Results of the experiments show that: the higher water injection rate, the lesser oil can be

recovered from the column. For instant: at the water injection of 0.2 mL/min, the amount of oil

left in the column was 20% after injection of 5PV, while this amount was still 31% after injection

up to 9PV when water flow rate was 5mL/min. It means that, the swept efficiency of water is lower

at high injection rate and higher at low injection rate. This is an interest remark need to be

considered for designing of water injection in the real field.

Tracer experiment

Two tracer experiments were run at 0.2 mL/min and 1.5mL/min. The mixture of ethanol and

ethyl acetate (12,000 ppm/each) were injected into the column as a pulse of 2mL and samples were

taken at the outlet for analyzing concentrations of tracer using Gas chromatography system.

Figure 7: Experiment data of tracer concentration in two experiments.

Figure 8: Comparison between true residual oil in the column

and the Sor value estimated from tracer method.

Figure 7 shows the experimental concentration of tracers in the effluent samples. The

residual oil saturation (Sor) calculated from tracer method was 16.9% pore volume in the

experiment at 0.2mL/min (corresponds to a velocity which passed through the cross-section of the

column was 0.23 cm/min). This number was really match with the true residual oil saturation

remained in the column, was 16.4%. On the contrary, in the experiment at 1.5 mL/min (corresponds

to a velocity of 1.78 cm/min), the residual oil calculated from tracer method was only 13.6% while

the true residual oil remained in the column were 28.5%. These results implied that: the higher

velocity of tracer, the lesser oil can be detected from the column. In other words, the higher

flow rate of water, the higher uncertainty in Sor value determined by tracer method. Figure 8 is the

comparison between true value of residual oil in the column and the Sor value calculated from

tracer method.

VINATOM-AR 13--18


135

However this conclusion need to be validated by conducting more experiments at different

flow rates to investigate the effect of phase contacting time on error of the Sor value determined

from tracer method.

III. 3 Tracer experiment for residual oil saturation measurement in 2D sandpad

A physical model of 2D sandpad was built using a mica-glass box with the sizes of

42.7x18x0.8cm. The box was packed by glass bead with grain size of 300-425 micron. Water and

oil were pump into and produced from the sandpad via a line of many tiny holes located at bottom

and top of the model (Fig.9)

Figure 9: The sandpad model.

Tracer experiment was run as the same procedure with in the column: firstly, oil was

pumped though the sandpad at 0.5 mL/min to make the pad saturated with oil. Then water was

pumped at 2mL/min during 6PV. The remaining oil saturation after 6PV was 9.85% pore volume.

After that, two tracers (ethanol and ethyl acetate) was injected as a pulse of 2mL. The samples were

collected at outlet of the model. Concentration of tracers were analyzed in GC. Figure 10 (left) is

the experimental tracer response curves in sandpad experiment and (right) is the picture of residual

oil saturation during water injection in the sandpad.

Figure 10: Tracer experiment data (left) and Images of residual

oil saturation during water injection (right) in sandpad.

Injection point

Production point

VINATOM-AR 13--18


136

The residual oil saturation value (Sor) calculated from tracer experiment was 9.1% with a

relative error of 7.6% in comparison with the true residual oil value in the sand pad (9.85%).

To validate the experimental results, a numerical model was built using the UTCHEM

reservoir simulator to simulate the movements of tracer through the sandpad. The comparison

shows that there is a little bit different between the UTchem simulation results and the experiment

data (Fig 11). The reason may be explained by the effect of “non-uniform” of flow at the injection

point, because there are just a few small holes at the injection edge in which water can flow, as

illustrated on the Fig.12.

Figure 11: Comparison of experimental data and simulation results by UTchem.

Figure 12: Illustration of the “non-uniform flow” that causes differences between the

simulation results and experiment data.

IV. CONCLUSION

In this project, we have built a simulation program to simulate the single-well tracer test in

double porosity media. The program was used to match with several field tracer data which have

been reported in the literatures and compared with the result of the University of Texas Chemical

simulator (UTchem). The comparison showed that our program gave an acceptable match with field

data as well as with UTChem’s simulated results. In addition, several experiments were conducted

to measure residual oil saturation in 1D column and a 2D sandpad model. Results of the

experiments show that the partitioning tracers can measure residual oil saturation in glass bead

models with a relatively high accuracy when the flow velocity of tracer is sufficiently low. Or in

other words, the higher velocity of flow, the higher uncertainty in Sor value determined by tracer

method.

VINATOM-AR 13--18


137

REFERENCES

[1] Deans, H., & Carlisle, C. Single-Well Chemical Tracers Test Handbook. Chemical Tracers

Inc., Houston, TX, (307), 1988.

[2] Deans, H.A. and Majoros, S. The Single-Well Chemical Tracer Method for Measuring

Residual Oil Saturation, Final report, Contract No. DOE/BC20006-18, US DOE, 1980.

[3] Deans, H. A., & Carlisle, C. T. Single-Well Tracer Test in Complex Pore Systems. Society of

Petroleum Engineers. doi:10.2118/14886-MS, 1 January 1986.

[4] Grigorievich, B. P., & Archer, J. S. Two Tracer Test Method for Quantification of

Residual Oil in Fractured Porous Media. Society of Petroleum Engineers.

doi:10.2118/25201-MS, 1 January 1993.

[5] Tang, J. S. A New Double-Porosity Single-Well Tracer Simulator with Fluid Drift for

Residual Oil Saturation Measurement in Carbonate Reservoirs. Petroleum Society of

Canada. doi:10.2118/2002-047, 2002.

[6] Tomich, J. F., Dalton, R. L., Deans, H. A., & Shallenberger, L. K. (1973). Single-Well

Tracer Method To Measure Residual Oil Saturation. Society of Petroleum Engineers.

VINATOM-AR 13--19


138

STUDYING THE POSSIBILITIES OF USING THE RADIUM ISOTOPES

TO DETERMINE THE MASS AGES AND CIRCULATION

OF THE COASTAL WATER

Nguyen Thi Huong Lan, Phan Son Hai, Nguyen Van Phuc, Phan Quang Trung,

Nguyen Thi Mui and Nguyen Minh Dao

Center for Environmental Research and Monitoring, Nuclear Research Institute,


ABSTRACT: Radium isotopes are the effective indicators in assessing the water mass age, mixing of water,

distribution of some radioactive elements and their behavior in coastal and marine. The pre-concentration and

analyse techniques and counting on alpha spectrometry can determine the radium isotopes in seawater where

there is a low concentration level. Radium in seawater is pre-concentrated with MnO2, Fe(OH)3 or adsorbed on

MnO2 fiber before separating radium by PbSO4. Radium isotopes are separated from Th, Ac, Po, U, Pb by

passing through ion exchange resin. The radium source is electrodeposited on stainless steel disk by ethanol

solution.

1. INTRODUCTION

The method which is used in this subject allows analyzing all the radium isotopes that are

alpha emitters. There for, the working time not only shipboard but also in laboratory can be

reduced. Furthermore, together with some analytical procedures and spectrometry, this method can

determine the radium in seawater at low concentration level.

2. EXPERIMENTS

2.1. Equipments

The Gamma Spectrometry HPGe

The Alpha Spectrometry

2.2. Reagents

- Current Generator 30 V – 1.5 A

- HDPE buckets 200 Liters

- HDPE cans 30 Liters, 10 Liters

- Beakers 5 L, 500 mL, 250 mL, 150

mL, 100 mL

- Tributyl phosphate

- Xylene

- Diethyl ether

- Cation Resin Dowex 50W-X8, H+

form (Merck)

- Anion Resin Dowex 1-X8, Cl- form


- Code: CS/12/01-02



- Implementation time: 18 months (Jun 2012- Jan 2014)



Nguyen Thi Huong Lan. Studying the method of preconcentration radium in seawater by manganese

fiber and determination of radium on alpha spectrometer. To be presented in the Youth Conference

on Nuclear Science and Technology, Hanoi, 2014.


VINATOM-AR 13--19


139

- Ion exchange columns

- Hydraulic vacuum valve

- Funnels 250 mL, 100 mL

- Standard solution 229

Th

- HNO3 68%

- HCl 36%

- NH4OH 25%

- H2O2

- Ethanol

- 2-Propanol

(Merck)

- KMnO4

- MnCl2

- KOH

- Hydroxylamine

- NaNO2

- NaCl

- FeCl3

- Ammonium citrate

- Ammonium acetate

- Bromocresol green Indicator

- Filter paper.

2.3. Procedures

This subject carried out three procedures to analyzing radium in seawater. Radium in sea

water was co-precipitated with MnO2, Fe(OH)3 and adsorbed on MnO2 fiber before separating

radium by PbSO4.

2.3.1 Co-precipitation with MnO2: 100L seawater is pumped into a bucket, then

acidization before adding tracer 225

Ra. Radium and other isotopes were co-precipitated by the

carrier KMnO4/KOH and MnCl2 solutions at pH 8. The precipitation was carried to the laboratory,

then adding HCl acid with H2O2 to making it completely dissolved. The radium is once again

coprecipitated with Fe(OH)3 and C2H5OH, the pH was adjusted to 8 by NH4OH. The precipitation

of above step was dissolved by conc. HCl acid and then evaporated. Radium was separated from

others isotopes by extracting with TPB/xylene (1:1) solution in two times. The extracted solution

was evaporated, dissolved before had passed through cation exchange column. Radium was finally

separated by 9M HCl solution. The radium solution was evaporated and then dissolved by 0.1M

HCl before deposited NH4OOCH3/HNO3 solution on the stainless steel disk at 600mA in 3 hours.

2.3.2 Co-precipitation with Fe(OH)3: radium in 100L of sea water was precipitated by

adding carrier FeCl3 and Fe(OH)3. The chemical recovery was checked by adding tracer solution 225

Ra. The precipitation was brought to the lab and dissolved with 9M HCl. The radium was

extracted by TPB/xylene (1:1) solution in two times. Then, the radium solution was passed through

two anion exchange columns with different environment. Radium was eluted by 8M HNO3 when

passing through cation exchange column. The eluate with radium was deposited in

NH4OOCH3/HNO3 solution on stainless steel at 600mA in 3 hours.

2.3.3 Co-precipitation with MnO2 fiber: This procedure is collaborated with the pre-

concentration technique by MnO2 fiber. Radium in seawater is absorbed on MnO2 fiber by passing

100L seawater through 30g MnO2 fiber. Ra is eluted from the adsorbed fiber by 5.0 M HCL and a

few drops of H2O2. The radium is extracted from the sample by coprecipitation with carrier

Pb(NO3)2 and K2SO4 and H2SO4 solutions. The precipitation was dissolved by 0.1M EDTA at pH

10 before passed through anion exchange column to separation radium from Th and Ac. The

solution from the anion exchange column step was added 5M CH3COONH4 and 0.5M EDTA and

adjust pH 4-5 by 6M HNO3 before passed through cation exchange column. Th, Ac, Pb was eluted

by CH3COONH4 and HCl. Radium was finally eluted by 6M HNO3. The eluate was deposited with

ethanol solution on stainless steel at 120mA in 2 hours.

VINATOM-AR 13--19


140

3. RESULTS AND DISCUSSION

The concentration of radium isotopes in the seawater collected in Phuoc Dinh, Ninh Thuan

province are given in following table:

Table 1: Specific activity of radium isotopes in seawater

- Phuoc Dinh-Ninh Thuan Province.

Sample

code Lat. Long.

Specific activity and error

Ra-226

(mBq/L) Sdv

Ra-224

(mBq/L) Sdv

Ra-223

(mBq/L) Sdv

SW01 11023’10’’ 109

004’15” 0.24 0.09 0.14 0.06 0.006 0.003

SW02 11023’25” 109

003’57” 0.21 0.09 0.12 0.05 0.030 0.010

SW03 11023’40” 109

003’34” 0.14 0.07 0.42 0.21 0.039 0.019

SW04 11023’59” 109

003’07” 0.12 0.06 0.04 0.02 0.009 0.004

SW05 11024’08” 109

002’46” 0.13 0.06 0.07 0.03 0.008 0.004

SW06 11025’09” 109

001’33” 0.39 0.19 0.45 0.21 0.025 0.010

SW07 11025’32” 109

001’36” 0.31 0.15 1.15 0.50 0.018 0.008

SW08 11025’52” 109

001’42” 0.25 0.11 2.19 0.95 0.021 0.010

The results have large errors due to low recovery of radium, a small number of counts

obtained, leading to errors due to large statistical count. Accordingly, the results show that the Ra

concentrations are in the range Ra concentrations in seawater have been published. The samples

SW9, SW10, SW11 have higher levels of Ra concentration because those samples were collected

closely to shore. For samples SW2, SW3, SW4, SW5, SW6 have lower concentrations because of

these samples were taken with increasing distance from the shore. Ra concentrations were

determined by 3 alpha emitters 226

Ra, 223

Ra and 224

Ra.

The procedures by using MnO2, Fe(OH)3 are time-consuming, cumbersome and strenuous

while bad results. The improved technique by adsorbing on MnO2 fiber before separating radium by

PbSO4 is more feasible because of its advantages. With a short time of preparation, all the radium

isotopes can be determined. Within the limits of this subject, the method of analyzing radium by

coprecipitation with PbSO4 has brought quite low recovery yield. Although the radium recovery

yield achieved only 50-60%, the yields were stable by every experiment. Therefore, there is the

need to carry out some more experiments to improve the procedure as well as the chemical yields.

The coprecipitation radium with PbSO4, then separation from other elements by using ion

exchange columns can give good resolution spectra.

4. CONCLUSIONS

Radium preconcentration method in seawater by MnO2 fiber and analyzing radium by

precipitation with PbSO4 are the confidence methods in environmental analyzing techniques. Since

the preconcentration step has not improved in term of this subject, some further experiments should

be carried out to assessing the ability of these methods.

VINATOM-AR 13--19


141

REFERENCES

[1] GUOGANG JIA, JING JIA, Determination of radium isotopes in environmental samples

by gamma spectrometry, liquid scintillation counting and alpha spectrometry: A review of

analytical methodology, Journal of Environmental Radioactivity 106 (2012).

[2] H.W.KIRBY, MURRELL L. SALUTSKY, The Radiochemistry of Radium, USA (1964).

[3] International Atomic Energy Agency, Analytical Methodology for the Determination of

Radium Isotopes in Environmental Samples, IAEA Analytical Quality in Nuclear

Application No. IAEA/AQ/19, (2010).

[4] International Atomic Energy Agency, The Environmental Behavior of radium, IAEA

Technical Reports Series 310, Vienna (1990).

[5] J.K. COCHRAN, P.MASQUÉ, Natural radionuclides applied to coastal zone processes,

Marine Radioactivity, (2004).

[6] M. BOURQUIN, Comparison of techniques for pre-concentrating radium from seawater,

Marine Chemistry 109, pp. 226-237, 2008.

[7] M.T. CREAPO, Adsorption of some actinide elements on MnO2, The Science of the Total

Environment, 70, pp. 253-263, Netherlands, 1988.

[8] MARTIN, P., HANCOCK,G.J., Routine analysis of naturally occurring radionuclides in

environmental samples by alpha-particle spectrometry, Supervising Scientist Report 180,

Supervising Scientist Division, Darwin NT, (2004).

[9] NGUYEN THANH BINH, The results of researches in marine radioactive in Vietnam,

period 1999-2003 , Nuclear Research Institute.

[10] NGUYEN TRONG NGO, The surveys and assessments on the marine radioactive at the

expected positions for Nuclear Power Plans in Ninh Thuan Province, (2011).

[11] NGUYEN VAN PHUC, The researches on establishment the scientific and technical basis

to setting up the marine environmental monitoring program in Vietnam, (2011).

VINATOM-AR 13--20


142

STUDYING, DETERMINING THE RADIONUCLIDE OF TRITUM IN THE

WATER SAMPLES (RAIN, SURFACE WATER) BY USING LIQUID

SCINTILLATION COUNTING (TRi-carb 3180TR/SL)

Nguyen Thi Linh, Nguyen Dinh Tung, Truong Y, Le Nhu Sieu,

Nguyen Van Phuc, Nguyen Van Phu and Nguyen Kim Thanh

Center for Environment Research and Monitoring,

Nuclear Research Insititute, Vietnam Atomic Energy Institute

1- Nguyen Tu Luc, Dalat, Lam Dong

ABSTRACT: Tritium in the environment is of natural or man-made origin. Tritium is a radioactive isotope that

occurs in the environment and is associated with the interaction of cosmic ray in the atmosphere. However, the

most significiant sources of tritium in the environment results from nuclear weapons testing in the atmosphere

carried out during the late 1950s and early 1960s. Today, the most important new sources of tritium in the

environments, such as power stations, processing and using of isotopes released the local tritium. The objective

of this study is the application of the liquid scintillation technique to tritium analysis in water samples (rain,

and surface waters). Following the Eichrom Tritium Column technique, an aliquot of the passed tritium resin

sample (10 mL) is mixed with 10 mL of scintillation cocktail (Ultima Gold LLT, Packard) in 20-mL plastic-

container vials and the sample activity is determined using a liquid scintillation spectrometer, Tri-carb

3180TR/SL. Counting efficiency is evaluated with internal standards. The tritium concentrations of water

samples that were collected from DaLat, Lamdong range between 0 to 36.2 TU.

Keyword: Tritium concentration, liquid scintillation counting, water samples.

1. INTRODUCTION

Now, liquid scintillation counting is the most popular method to measure the tritium

concentration in the low level environmental samples. It takes, however, much time with a lot of

doing to distill off the impurities in the sample before mixing the sample with the liquid scintillation

cocktail.

In the present work, a low background liquid scintillation system detector Tri-carb

3180TR/SL is used to determine tritium concentration in some different types of water: drinking

water, precipitation and surface water. Establishing an appropriate routine procedure for tritium

measurement in water sample was the main goal of our study. In the light of it, we integrated in

investigate optimal procedures such as counting region optimization under variable quench

conditions in order to improve the limit of detection; established the analytical protocol of tritium

concentration in water using EiChrom tritium column method and liquid scintillation spectrometer.

The process would include collection, storage, preparation/extraction of the sample, the preparation


- Code: CS/13/01-06






Nguyen Thi Linh, Nguyen Dinh Tung, Truong Y, Le Nhu Sieu, Nguyen Van Phuc, Nguyen Van Phu,

Nguyen Kim Thanh. Determining the Radionuclide of Titium in the Water Samples in Dalat by Using

Liquid Scintillation Counting (Tri-carb 3180TR/SL). To be published in Journal of Analytical Sciences

No.2/2-2015.

VINATOM-AR 13--20


143

for counting and the actual sample counting. The goal of the optimization would be to attain an

adequate tritium determination. The investigated method for measurement of tritium concentration

in water is time saving, sensitive, and can be applied for all types of water.

Eichrom's Tritium Column is designed to replace distillation for most routine tritium

analyses of aqueous samples. The column works by removing potential interferences in the LSC

spectrum, just as distillation does. It is not intended to be an enrichment procedure, and as such, it

should be used only in situations where the required detection limit can be achieved by the direct

counting of a 10 mL aliquot of the sample (plus cocktail) processed through the tritium column.

Fig.1 shown the composition of the Tritium Column explains the purpose and capacity of

each component. The Diphonix® Resin removes cations in exchange for hydrogen ions and its

theoretical capacity is 0.8 mEq per column. The anion resin is standard chloride form analytical

grade 1X-8 resin. It exchanges anions in the sample for chloride ions. (It is recommended that the

sample pH be >1.) The polymethacrylate component removes organically bound tritium and

carbon-14 [7,13]. Counting efficiency is evaluated with internal standards. Determining detection

limit of the analytical method at our laboratory is 0.15Bq/lit or 1.3 TU, efficiency of internal

standard of 25% (20 ml –Vial, ratio of coctail and sample 1:1) at Nuclear Research Institute.

2. EXPERIMENTS

2.1. Special Aparatus and Reagents

- Packard Tri-Carb 3180TR/SL spectrometer,

- 20ml plastic scintillation vials

- Background source-sealed 20-mL scintillation vial with cocktail.

- Standardized solutions of 3H water,

- Ultima Gold-LLT cocktail,

- Tritium column-prepacked column

2.2. Sampling

The water samples are collected in 0.5-1L clean, well-sealed polyethylene bottles, and they

are transported to the laboratory in refrigerated containers. Rain water samples were collected at the

Nuclear Research Institute station, 01 Nguyen Tu Luc St.Dalat City, Lamdong Province, at a

latitude 11o57’ N, longtitude 108

o26’ E, 1500m high; Suface water samples were Xuan Huong lake

(at a latitude 11o57’ N, longtitude 108

o26’ E) and Suoi Vang (at a latitude 12

o00’ N, longtitude

108o22’ E).

Accordingly, this study was undertaken in order to analysis of 3H in 18 evironmental

samples collected in Dalat in 2013 (12 surface water, 6 rain and fallout samples); measurment,

calculation and statistics following the method of experimental research established. The results

obtained through this research have been shown in table and figure below.

2.3. Experimental Procedure

We investigated the possibility of an alternative method with Eichrom tritium column for

purification of tritium prior to measurment by Liquid Scintillation counter. Shown in Fig.1 are the

three components in the Tritium Column.

VINATOM-AR 13--20


144

2.3.1. Preparation of samples

The water samples filtered through a micron filter; for each sample solution, place a tritium

column in the column rack, and a waste tray below the column in the column rack; Add 10 ml of

deionized distilled water into each column to condition resin and allow to drain; Measure 25ml of

sample and add to the top of the column, discard first 5 ml of sample, place a clean, labelled beaker

beneath the column and collect the remaining 20 ml of sample; remove an liquot of sample

collected in the beaker (10 ml) and add to a LSC vials; Add the appropriate amount of Ultima Gold-

LLTcocktail, shake the vial to mix and count vials in Tricarb 3180TR/SL. Peraparation other liquot

of sample and add a small volume of internal standard solution into one of the counting vials.

2.3.2. Counting procedure

After shaking, clean the counting vials, avoid any contact with the light-transmitting parts of

the counting vials. Place the counting vials in a fixed sequence in the liquid scintillation counter:

background, sample 1, sample 1 with internal standard added, sample 1, background, sample 2,…

Before counting, it is advisable to equilibrate the counting vials in the liquid scintillation

counter for light and temperature adaptation, e.g. overnight, thus reducing the interfering

luminescence during counting. Energy regions set for 3H counting: Region A (0.5-4.5 KeV); B (0.5-

5.5 KeV); A (0.5-18.6KeV), using the guidance found in the applicable LS counter manual.

Counting is performed for 10 cycles of 100 min and the tritium activity is calculated for each

sample by averaging the counting values. Low tritium activity concentrations may require a longer

counting period, depending on the desired counting accuracy.

2.3.3. Calculations

The counting efficiency of the sample is calculated using the following expression:

Di

CCE sis

where Cs+i is the count rate of the sample after the addition of the internal standard, Cs is

the count rate of the sample before the addition of the internal standard, and Di is the disintegration

rate of the added aliquot of internal standard. The disintegration rate of the sample, Ds, may then be

calculated as follows:

Ds = Cs/E or

Figure 1: Composition of Tritium Colum.

Prefilter Resin

Anion Resin

Diphonix® Resin

VINATOM-AR 13--20


145

Calculate isotope activity:

60

VE

CC Bs

AT

where AH-3 is isotope activityof tritium (Bq/lit), Cs is the count rate of the sample, cpm, CB

is the count rate of the blank sample, cpm; V is volumn of analytical sapmple.


After sampling, purification of 3H in the water samples collected at Dalat in 2013 (12

surface water, 6 rain and fallout samples); measurment, calculation and statistics following the

method of experimental research established, tritium-specific activities (Bq/L or TU) and counting

efficiency of the samples are presented in Table 1, Fig. 2, and Fig.3.

Table1: The tritium-specific activities in the water samples collected in Dalat City.

TT Sampe Code Efficie

ncy,E

Activity of 3H, Bq/lit

Activity of 3H, TU

1 Xuan Huong lake 02/13 NHXH0213 24.87 0.15 ± 0.10 1.3 ± 0.8

2 Suoi Vang lake 02/13 NHSV0213 26.42 < 0.15 < 1.3

3 Xuan Huong lake 04/13 NHXH0413 25.23 < 0.15 < 1.3

4 Xuan Huong lake 05/13 NHXH0513 25.18 < 0.15 < 1.3

5 Suoi Vang lake 05/13 NHSV0513 24.50 0.63 ± 0.08 5.3 ± 0.6




9 Rain water, Dalat 09/13 MDL0913 24.40 0.17 ± 0.09 1.4 ± 0.8






15 Fallout water, Dalat 11/13 RLDL1113 26.47 4.31 ± 0.45 36.2 ± 3.8

16 Rain water, Dalat 25/11/13 MDL1113 22.35 0.29 ± 0.12 2.4 ± 1.0

17 Rain water, Dalat 11/13 RLDL1113 26.47 0.74 ± 0.10 6.2 ± 0.8




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Figure 2: Variability of activity of 3H (TU) in the water samples collected in 2013.

Figure 3: Variability of the counting efficiency of 3H evaluated with internal standards.

From the these results we found that establishing an appropriate routine procedure for

tritium measurement in water sample using a low background liquid scintillation system detector

Tricarb 3180 TR/SL.

The results obtained in 2013 shown values of tritium concentration ranging from 1.7 ± 0.0.8

to 6.6 ± 1.1 TU were reported for the water samples collected at Dalat. The setteled procedure can

be applied to determine tritium concentration in different types of water: drinking water,

precipitation, surface water, seawater and wastewater. Even if the uncertainty of the method is high,

and even if tritium levels in the environment continue to decrease, the direct measurement of tritium

concentration in water sample can still be a more rapid and cheaper measurement method for the

radioactivity environmental monitoring program.

4. CONCLUSIONS

Our results show that the LSC methodology applied allows for measuring tritium levels in

water samples from different origins.

TU Activity of Tritium in the water samples collected in Dalat, 2013

E,% Control chart for the counting efficiency of 3H, mean = 25.54 ± 0.91%

VINATOM-AR 13--20


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From the information reported in table 2, it can be concluded that the method presented in

this paper fulfill laboratory requirements as obtained results are optimal. Moreover, this is a simple,

quick and economic technique; the samples were finally measured in a Perkin Elmer Tri-carb

3180TR/SL liquid scintillation equipment. The investigated method for tritium monitoring is time

saving, sensitive, and can be applied for all types of water to contribute to the environmental

monitoring program at Nuclear Research Institute.

5. RECOMMENDATIONS

- It shoud be suitably equipped for The tritium enrichment system using electrolysis

method in order to improve the limit of detection of low level tritium concentration such as sea

water, ground water samples, etc.

- Extend the establishing of the method and analysis of tritium concentration in the

environmental samples (gas, sea water, rain water, fallout) that is collected at Dalat and Ninh

Thuan.

REFERENCES

[1] S.A. Mc Quarrie, C. Ediss, L.I. Wiiebe, Advances in Scintillation Counting, Canada, 1983.

[2] Charles J.Passo, Gordon T.Cook, Handbook of Environmental Liquid Scintillation

Spectrometry: A comparision of Theory and methods, USA, 2006.

[3] Michael F. L’Annunziata (Ed.); “Handbook of RADIOACTIVITY ANALYSIS, Second

Edition” Academic Press, San Diego, (2003).

[4] Donald. L. Horrocks, Applications of Liquid Scintillation Counting, ACADEMIC Press,

1974.

[5] Aleksandra Sawodni, Anna Dazdur and Jacek Pawlyta, Measurments of Tritium

Radioactyvity in Surface Water on The Upper Silesia Region, Journal on Methods and

Applications of Absolute Chronology, Vol.18, 2000.

[6] ISBN. 978-0-662-47497-5: “Standards and Guidelines for Tritium in Drinking Water”;

Published by the Canadian Nuclear Safety Commission (CNSC), 2008.

[7] Stanis. Overview of The Environmental Monitoring Program for Tritium in Spainish River

Waters, Advances in Liquid Scintillation Spectrometry, 2005.

[8] J Eikenberg, M Jäggi, H Beer, H Baehrle, Tritium concentrations in Waters of Ljubljansko

bajie, Slovenia, Advances in Liquid Scintillation Spectrometry, 2008.

[9] S. Forkapic, J. Nikolov, N. Todorovic, D. Mrdja and I. Biki “Tritium Determination in

Danube River Water in Serbia by Liquid Scintillation Counter”, World Academy of Science,

Engineering and Technology 76, 2011.

[10] Trịnh Văn Giáp, Báo cáo tổng kết đề tài cấp bộ về: “Thiết lập quy trình xác định hàm lượng

các đồng vị của Hidro và Oxi trong nước nhằm tiến tới nghiên cứu nước ngầm Hà Nội”, mã

số: BO 02/04-02, Hà Nội, 2003.

[11] Daina riekstina; olgerts Veveris; Anita Skujina; Antra Zalkalne, LSC 2005, Advance in LSC,

pp.355-357, 2005.

[12] Z Tosheva, A Kies, P Letissier, M Langer “Easy and rapid Estimation of Environmental

Tritium with Eichrom Column and LSC measurment” LSC 2005, Advance in LSC, pp. 395-

400, 2005.

[13] Popy IntanTajahaja and Putu Sukmabuana. The Separation of Tritium Radionuclide from

Environmental Samples by Distillation Technique- Advances from Modeling to

Applicaations. 2012.

[14] Ji-Gen Lua,Yan-Jun Huanga, Li-HuaWang, Fang Li, Shu-Zhen Li,Yuan-Fu Hsia.3H and

90Sr

background in water around Tianwan NPP. China; Radiation measurments 42, pp.74-79,

2007.

VINATOM-AR 13--21


151

STUDY ON PREPARATION OF 177

Lu, LABELING WITH DOTATATE FOR

USING IN DIAGNOSIS AND TREATMENT NEUROENDOCRINE TUMORS

Duong Van Dong, Bui Van Cuong, Pham Ngoc Dien, Chu Van Khoa, Mai Phuoc Tho,

Nguyen Thi Thu and Vo Thi Cam Hoa

Center for Research and Production of Radioisotope,

Nuclear Research Institute, Vietnam Atomic Energy Institute

ABSTRACT: Due to its physical and chemical characteristics, 177

Lu is a very attractive radionuclide for use in

nuclear medicine. Its main usage is in the treatment of neuroendocrine tumours but its applicability in the

treatment of colon cancer, metastatic bone cancer, non-Hodgkin‘s lymphoma, lung, ovarian, and prostate

cancer, has also been studied. Two alternative production routes are generally applied to obtain 177

Lu, namely

the direct route based on neutron irradiation of lutetium targets and the indirect route based on neutron

irradiation of ytterbium targets followed by radiochemical separation of 177

Lu from ytterbium isotopes. The

comparison of theoretically calculated and experimentally determined yield for 176

Lu(n,)177

Lu reaction is

presented.177

Lu could be produced with a specific activity of 42 mCi/mg by neutron activation using

enriched 176

Lu (2.59%) target when irradiation was carried out at Dalat Nuclear Research Reactor with thermal

neutron flux of 2×1013

n/cm2/s for 100h. The indirect production route as an alternative production route,

177Lu

could be obtained as carrier-free from beta decay of 177

Yb produced by neutron activation of 176

Yb. In this

way, enriched target material was used but it may be the neutron capture cross section is only 2.4 b so resulting

in low activity just enough to study the separation process of 177

Lu from 177

Yb. In the other hand the study on

labeling 177

Lu with DOTATATE is also described the optimization of the reaction conditions to obtain the

complex 177

Lu-DOTA-TATE with a radiochemical purity > 99%, even so the studies of stability in vitro to the

dilution in saline solution during 72 hours. The bio-distribution studies of this product in mice and rabbit are

also investigated.

Key words: Production of 177

Lu, nuclear reactor IVV-9, DOTATATE.

INTRODUCTION

In recent years,177

Lu has emerged as a promising short-range β- emitter for targeted

radiotherapy. It can be employed as an alternative to 131

I or a complement to 90

Y, 177

Lu [T1/2 = 6.73

d, Eβmax = 0.497 MeV, Eγ = 113 keV (6.4%) and 208 keV, (11%)] is being considered as another

viable alternative for the development of new agents for PRRT. The use of 177

Lu provides an

additional advantage of emission of accompanying low-energy, low-abundance gamma photons

suitable for carrying out simultaneous imaging studies. While the high thermal neutron capture

cross-section of 176

Lu (2100 b) makes it quite convenient to produce high specific activity.

177

Lu production could be used moderate flux reactors. The comparatively longer half-life

of 177

Lu provides logistic advantages over the use of PRRT. Moreover, the tissue penetration range

of 177

Lu (maximum range 2 mm) is more favourable than that of 90

Y (maximum range ~12 mm),

especially for smaller metastases

Unlike 90

Y, 177

Lu provides an additional advantage of the possibility to perform

scintigraphic and dosimetric studies with the same agent employed for therapeutic purpose.


- Code: ĐTCB/11/01-02



- Implementation time: 30 months (Jan 2011- Jun 2013)



VINATOM-AR 13--21


152

Although 90

Y is obtainable in no carrier-added (NCA) from a90

Sr-90

Y generator, but there exists the

stringent requirement of purification from 90

Sr, a natural bone seeker with a long T1/2 of 28.3 years.

On the other hand,177

Lu can be easily obtained in radionuclidically pure form. The excellent

radionuclidic purity of 177

Lu during using of enriched Lu (>60% in 176

Lu) target.

I. EXPERIMENTS

I.1. Equipments

The Dalat Research Reactor of 500kW; HPLC-LCMS, (Shimadzu); Calibrator ISOMED

2000 (Germany); Counter Caprac (Capintec); Heated magnetic stirrer; Micropipette; Thermostat;

Bottles; Glassware…

I.2. Reagents

- DOTATATE was purchased from piCHEM R&D (Austria), (GMP-grade, >95% (HPLC);

Hydrogen peroxide: concentration 35%, residue on evaporation 0.05%, heavy metals 0.0001%;

Hydrochloric acid: concentration 35.0 ~ 37.0%, residue on evaporation 0.001%, heavy metals

0.000005%; Sodium acetate containing 40 mg/mL, 2,5-dihydroxybenzoic acid.

- Pure water: Purified by The PURELAB® Ultra, ultra pure water production system,

conductivity ≤ 18.2 MΩ.cm

- Target specification and preparation: Lu2O3 99.99% (Sigma-Aldrich), Natural and

enriched >60% in176

Lu

Impurity details:

Y2O3 < 5 ppm, CeO3 < 5 ppm, Pr2O3 < 5 ppm, Nd2O3 < 5 ppm, Sm2O3 < 5 ppm, EuO3 < 5

ppm, Gd2O3 14 ppm, Tb2O3 < 5 ppm, Dy2O3 < 5ppm, Ho2O3 < 5 ppm, Er2O3 < 5 ppm, Tm2O3 < 7

ppm, Yb2O3 22 ppm, La2O3 < 5 ppm, CaO < 30ppm, Fe2O3 < 5 ppm, SiO2 30ppm.

II. PROCEDUCES

II.1. 177

Lu production

Target preparation and irradiation

Material target: Lu2O3 99.99%.

+ Target weight: be accurately weighed by analytical balance.

+ Irradiation container: The target is contained in quartz ampoule and placed in dedicated

aluminum containers for irradiation.

- Irradiation

Based on these calculations, the neutron irradiation is established on the basis of ensuring

the general requirements for radiation safety and occupational safety.

+ Irradiation position: neutron trap, thermal neutrons plux: ~ 2.1013

.cm-2

.s-1

.

+ Irradiation time: 100-130 hours.

+ Cooling time: 30-48 hours

Preparation of 177

LuCl3

After cooling, the irradiated target is transferred to the box production, Where irradiated

target was dissolved in 8M hydrochloric acid in 3 neck flask fitted with a reflux condenser and

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153

heating by Heated magnetic stirrer in the presence of H2O2 30% within 2-4 hours, after the target

have been dissolved completely, the evaporation will be carry out until appear white residue 177

LuCl3, then turn off the heater to cool. After that, cold target will be re-dissolved with 5 ml of

HCl 0,05M, thus the 177

LuCl3 is obtained. The next stage is the quality control and other research

applications.

Radionuclides used in nuclear medicine generally or 177

Lu particularly often mix some kind

of similar radioactive isotopes or same group, they can join in the labeling reaction or to exist in

free state. Evaluation of this impurity is called radionuclide purity. Pharmacopoeia standards define

radionuclide purity must be more than 98%.

The radionuclide purity is checked by diluting the solution, then used a micropipette take 2-

5 (dilution estimated that the maximum activity is less than 107cpm/ml). The measurement

samples are made simultaneously for at least 3 samples for getting the average result, The gamma

spectrometer is used for recording radionuclide purity. The main gamma peaks of 177

Lu are 72, 113,

208, 250 and 321 keV.

II.2. 177

Lu-DOTATATE preparation

Radiolabelling of DOTATATE is carried out by adding 100 μL of 0.4M sodium acetate

containing 40 mg/mL of 2,5-dihydroxybenzoic acid at pH 4.5 (solution A) to 10 μg of DOTATATE

(0.4 mg/mL in 0.4M sodium acetate at pH 4.5) (solution B). The pH of the 177

LuCl3 solution is

adjusted to 3–4, and 25 μL of this solution (containing 0.25 μg of Lu, 20 Ci/mg) (solution C) is

added to the mixture of solutions A and B. The final reaction mixture (solution A + solution B +

solution C) is incubated at 80–90°C for 30 min. A protocol for the preparation of 177

Lu-

DOTATATE is presented in Table 1.

Table 1: Protocol for preparation of 177

Lu-DOTATATE

Reagent Amount/volume

Solution A: CH3COONa buffer (pH=4.5)

containing of 2,5-dihydroxybenzoic acid-

concentration of 40mg/ml

100l

Solution B: CH3COONa buffer (pH=4.5)

containing of 0.4 mg/ml DOTATATE 25l (10g of DOTATATE)

Solution B: 177

LuCl3 solution (pH 3-4) 25l (0.25-0.50 g of Lu, 5mCi

Process: Adding of solution C to a mixture of

solution A and B

Labelling of 177

Lu with DOTATATE by optimization studies

Optimization studies of 177

Lu labelling of DOTATATE various parameters such as ligand

concentration, incubation time and temperature, were varied extensively in order to arrive at the

protocol for maximum complexation. Keeping the reaction volume at 200 μL, the amount of

DOTATATE was varied from 5 to 100 μg in order to determine the optimal ligand concentration

for obtaining maximum complexation. The characterization of the labelled conjugate and the

complexation yield were determined by paper chromatography in 50% aqueous acetonitrile. The

radiochemical purity of the labelled product was estimated by PC, TLC and HPLC analysis using

the gradient elution technique described above.

Stability of the 177

Lu-DOTATATE

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154

The stability of the radiolabelled peptides prepared under the conditions described above

was studied. The 177

Lu-DOTATATE was found to be adequately stable over a period of 3 d at room

temperature. The addition of free radical scavengers such as 2,5-dihydroxybenzoic acid (40 mg/ml

of the final mixture) was found to be essential for the storage of high specific activity 177

Lu labelled

DOTATATE preparations.

Quality control

- Thin layer chromatography

Thin layer chromatography studies are carried out on silica gel (aluminium sheets, Merck) in

10 cm strips as the stationary phase. Ammonium hydroxide: methanol:water (1:5:10) is used as the

mobile phase. While the free activity remains at the point of origin (Rf = 0), the radiolabelled

peptide migrates to an Rf of 0.4.

- Paper chromatography

The paper chromatography studies are carried out using 10 cm long Whatman 3MM

chromatography papers. For these studies, 5 μl of the test solution is spotted at 1.5 cm from the

lower end of the paper strips, which are developed in 10% ammonium acetate in methanol (30:70

vol./vol.). The strips are subsequently dried and cut into 1 cm segments. The radioactivity

associated with each segment is measured in a well type NaI(Tl) detector. While free activity

remains at the point of origin, the radiolabelled peptide migrates to an Rf of 0.7-0.8. Percent of

labeling efficiency is calculated by using the formula:

A177Lu-DOTATATE

Labeling eficience (%) = x100

A177Lu + A177Lu-DOTATATE


III.1. Preparation of 177

Lu

III.1.1. Theoretical calculation results

Radioactivity produced by the reaction of (n, γ) in the irradiation time τ is calculated

from the formula:

1

693.023

1 1.100

....10.023.6)(

Tac eM

gGA

where:

6.023.1023

: Avogadro number

neutron flux: 2.1013

n/cm2.s

ac: activation cross-section: 2050b=2050.1024

cm2

G: isotopic abundance: 2.59% 176

Lu

g: weight of the irradiated sample gram: 1000g

M: atomic weight: 174.97g

T1: half-life: 160h

: irradiated time: 108h

The result after fill all numbers is: 42mCi/mg 176

Lu

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Table 2: The result consult the reference at time of 4,5 day

Table 3: Results calculated using the Excel program

Calculated yields of Lu-177 from enriched Lu-176 (2.59%) target

Irradiated in DNR

Neutron flux(cm2･sec) 2.30E+13

Enrichment of Lu-176 0.0259 0.026

Cross section of formation of Lu-177 2050 2.05E-21

t1/2 (h) Lu-177 161.616h

Number of atoms of 176, in 1mg Lu 176

Lu 8.86192

E+16

=0.001x0.026/176

x6.023E+23

T(hour) A(Lu-177)

Bq/mg

110 1.57151E+09 = 42mCi/mg

VINATOM-AR 13--21


156

III.1.2. Processing of irradiated target and radioactivity measuring

After cooling, the irradiated target is transferred to the box production, Where it was

dissolved in 8M hydrochloric acid in 3 neck flask fitted with a reflux condenser and heating by

heated magnetic stirrer in the presence of H2O2 30% within 2-4 hours, after the target have been

dissolved completely, the evaporation will be carry out until appear white residue 177

LuCl3, then

turn off the heater to cool. After that, cold target will be re-dissolved with 5 ml of HCl 0,05M.

The stock solution is diluted into 10ml (to mark solution I), then re-dilute one time more by

using 100l solution I dilute into 10ml (to mark solution II).

Get about 1μl -5μl solution II made into 3 samples and qualitative spectrometer on gamma

spectrometer (multi-channel gamma spectrometer system DSPEC ORTEC HPGe detector, the

relative record efficiencies of 58%, energy resolution of 1.9 keV) the collected spectrum as shown

in Figure 2.

Table 4: Measuring results achieved of 3 177

Lu samples

Sample of Lu-177 (1) Measuring time

300sec

starting measure 14h38

208 keV HS position 5 0.003346997

Counter 64231

Activity at measurement time = 581534,3482

5.82E+05 Bq


300sec


208 KeV HS position 5 0.003346997

Counter 64801


5.87E+05 Bq


300sec


208 KeV HS position 5 0.003346997

Counter 648503


5.85E+05 Bq

A measure of the average: 5.85x105 Bq

- (Amount: 1 µl solution II)

- Cooling time: 136h40, Ended after 30’

- Decay factor of 177

Lu at 136h40’ was 0.5548

- Experimental activity:

5,85x105x10

2x5x10

3 = 14,1 Ci/0,395g Lu = 36mCi/mg Lu

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157

1x0,5548x3,7x1010

Table 5: The Theoretical and experimental results

Result Activity of

Theoretical

calculation

Activity of

consultation

Activity calculated

using the Excel

program

Experimental

Activity

Activity/mg 42.0mCi 42.0mCi 42.0mCi 36 mCi

III.1.3. Quality control results

Figure 1: The result of Radiochemical purity > 97%

Figure 2: Gamma spectrometry results

of 177

Lu

Figure 3: Beta spectrometry results

of 177

Lu

Comment: The Experimental activity is always lower than the actual activity theory. This is

actually considered appropriate, because theoretical results are calculated under ideal conditions,

while the actual production depends very much experimental parameters. Maybe, because of the

VINATOM-AR 13--21


158

decrease of neutron flux; and many experimental factors such samples are placed in the irradiation

container as aluminum material, taget density, temperature ...

The Quality control results: The result of Radiochemical purity > 99.9% and The result of

Radionuclides purity >99%.

III.2. Preparetion of 177

Lu-DOTATATE

III.2.1. Radiolabelling optimization

The radiolabelling yield of 177

Lu-DOTATATE as a function of pH, incubation time and

incubation temperature is presented in Fig. 4, 5 and 6, respectively. The results indicate that high

labelling yield of 177

Lu-DOTATATE was obtained at pH 5 with incubation during 25-30 min at a

temperature of 90oC. The effect of varying the molar ratio of Lu to DOTATATE is shown in Fig.7

Figure 4:The influence of pH on

the radiolabeling process

Figure 5: The influence of time on


Figure 6: The influence of temperature on


Figure 7: The influence of concentration on


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159

Figure 8: The influence of storage time on the radiolabeling process

III.2.2. Bio-distribution control

Rats are the animals most commonly used for testing of 177

Lu -DOTATATE. Using three

Rats are studied at each time point.

The animals are weighed before being injected with the radiopharmaceutical and are kept in

separate numbered cages. The 177

Lu–DOTATATE is prepared by using the lyophilized kit vial to be

tested following the instructions enclosed in the kit. Generally, 0.1-0.5 ml of the preparation is

injected per animal via the tail vein. The injected activity is calculated by taking the difference

between the weight of the loaded syringe and that of the syringe after injection.

At the end time point, the animals are sacrificed and a blood sample is taken by heart

puncture. The organs of interest are carefully dissected, rinsed in saline and placed in individual

disposable plastic tubes or bags and accurately weighed. The tail, which is the site of injection, is

removed and kept separately.

The activity in the organs, tail and carcass is measured either in an isotope dose calibrator or

in a NaI(Tl) crystal scintillation counter. The total retained dose (%TRD) is calculated as follows:

where A is the activity or counts in the organ, and B is the activity or counts in all organs

and the carcass except for the tail. To accurately estimate the activity and to account for decay

corrections in the 99m

Tc activity, standard solutions of the radiophar-maceuticals are prepared.

A typical experiment is given below.

Preparation of standard solution

Draw 0.5 ml of the 177

Lu–DOTATATE in a syringe and estimate its weight by weighing the

empty syringe and the syringe with solution and calculating the difference. Dispense this 177

Lu–

DOTATATE solution into a clean 100 ml glass beaker and add 20 ml of distilled water. This

solution is taken as the standard for estimation of the total activity that is injected into the animals.

The activity retained in the organs is calculated as follows:

If using a NaI(Tl) scintillation counter, the activity retained in the organs

is calculated as:

where Wi is the weight of injection and Ws is the weight of the standard. All the

counts are corrected for background activity.

Rabbits scans

To examine the in-vivo retention, white rabbits (7 week-old) were used. The animals were

kept individual cages at 20 1oC with a relative humidity of 75 10% and 12 h light/dark cycle.

The amimals were allowed free access to food and water, and left to acclimatize for 1 week. 177

Lu–

DOTATATE was administered intraven-ously to the rabbit via an ear vein for the image tests such

as dynamic kinetics and serial images scan using a gamma camera (SPECT-GE).

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160

The experimental

Seven weeks old white male rabbits (2023.4 100g, n=3), which were anesthe-tized with

Ether, were used for imaging studies. Each rabbit was injected with 177

Lu-DOTATATE via an ear

vein with 111 MBq-/0.5ml. All the rabbit were placed in a posterior position.To confirm the

dynamic kenitics of 177

Lu-DOTATATE, whole body dynamic images for 4h and some static images

at the predeteminated time intervals were obtained using a gamma camera fitted with a low energy

all purpose collimator. Window was centered around 208KeV. Images were scanned by system of

(GE-SPECT).

Order Organ

Time after injected (%)

1 h 4 h 24 h 7 d

1 Blood 0,94±0,35 0,13±0,05 0,15±0,03 0,04±0,005

2 heart 0,26±0,05 0,083±0,02 0,24±0,06 0,05±0,01

3 lungs 4,27±0,37 2,10±0,17 1,14±0,39 0,023±0,02

4 liver 0,29±0,03 4,27±0,033 3,70±0,54 0,046±0,01

5 spleen 0,38±0,06 0,26±0,06 1,90±1,00 0,10±0,04

6 kidney 6,70±0,60 6,05±1,00 1,50±0,30 0,33±0,07

7 stomach 9,00±1,00 5,12±0,71 2,09±0,18 0,28±0,077

8 S. ntestine 1,20±0,30 2,38±0,42 0,41±0,11 0,031±0,01

9 Big intestine 1,23±0,15 2,51±1,20 0,94±0,10 0,13±0,02

10 brain 0,032±0,00 0,028±0,01 0,031±0,01 0,015±0,00

11 pancreas 9,34±3,45 3,18±1,31 0,50±0,05 0,099±0,02

12 muscle 0,12±0,02 0,10±0,11 0,054±0,01 0,03±0,005

13 bone 0,00± 0,00± 0,00± 0,10±0,05

Figure 9: Biodistribution of 177

Lu-DOTATATE

in rat Figure 10: Biodistribution of

177

Lu-DOTATATE

in rabbit

Comment: 177

Lu-DOTATATE was stable than 72 hours after labeling. The results indicate

that high labelling yield of 177

Lu-DOTATATE was obtained at pH=5 with incubation for 25-30 min

at a temperature of 80-90oC. The effect of varying the molar ratio of Lu to DOTATATE is shown in

Fig. 7. The stability of the 177

Lu-DOTA-Tyr3-octreotate was followed by 3 days, and in procedure,

the radiochemical purity was over 99%. Biodistribution studies showed fast blood clearance and the

kidneys were the critical organs.

IV. CONCLUSION

Through the study results can be concluded that the Da Lat Nuclear Reactor in can only be

prepared with carriers 177

Lu using highly enriched target of 176

Lu2O3> 64%. In this study, subject

developed the production processes and institutional standards, ensuring all quality control criteria

of radiopharmaceuticals have met the application requirements.

The radiolabelling procedures for DOTATATE using 177

Lu were optimized, and relevant

quality control parameters were standardized. According to this labeling procedure, the

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161

radiochemical purity is more than 99%. In vivo biodistribution studies in normal mice revealed that

the 177

Lu-DOTATATE have suitable pharmacokinetic properties.

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Gaudiano, J. Kropp, J. Guhlke, H. Palmedo and H. J. Biersack, Appl. Radiat. Isot., 49, 309,

1998.

[8] Technical Reports Series No. 458, Comparative Evaluation of Therapeutic

Radiopharmaceuticals, IAEA, Vienna, 2007.

[9] Technical Reports Series no. 466, Technetium-99m Radiopharmaceuticals Manufacture of

kits, IAEA, Vienna, 2008.

[10] Activation and Decay tables of Radioisotopes, Budapest, 1973.

[11] K. Hashimoto, H. Matsuoka, S. Uchida, Production of no-carrier-added 177

Lu via the 176

Yb(n,

)177

Yb, 177

Lu process, Journal of Radioanalytical and Nuclear Chemistry, Vol. 255, No. 3,

pp. 575–579, 2003.

VINATOM-AR 13--22


162

ENVISAGEMENT OF ANALYTICAL PROCESS FOR 13

C/12

C ISOTOPE

RATIO (13

C) IN BENTHIC BIVALVE SAMPLES BY THE ISOTOPE RATIO

MASS SPECTROMETRY (EA-IRMS)

Ha Lan Anh, Vo Tuong Hanh, Vo Thi Anh and Nguyen Hong Thinh

Institue for Nuclear Science and Technology, Vietnam Atomic Energy Institute

ABSTRACT: The procedure for carbon isotope ratio analysis 13

C/12

C (13

C) in benthic bivalve samples was

envisaged. The procedure include: i) chemical processing and ii) carbon isotope ratio analysis

C by the

isotope ratio mass spectrometry (EA-IRMS) with on-line combustion of samples to CO2. The conditions of the

sample processing on temperature, time and preservation are optimizated to avoid the isotope fractionation.

The procedure for carbon isotope analysis 13

C by EA-IRMS consists of the sample combustion at 1030oC

with chromium oxide and silvered cobaltics oxide catalysts. The samples were completely combusted to CO2

by Cu column and the derived CO2 were transported to ion source before separating by following masses in

IRMS. The accuracy of the analysis was made by the comparison with international standards (IAEA CO-8,

IAEA CO-9 and NBS 19) and the precision of the 13

C value obtained was usually better than ± 0.3‰.

1. INTRODUCTION

Stable isotopes are frequently used as tracers in biological systems, and their ability to track

changes and processes over time has made them increasingly important to ecological research. For

ecologists, stable isotopes provide a natural way to directly trace details of element cycling in the

environment (Fry B, 2006).

The use of stable isotopes as tracers requires that the different potential sources have distinct

isotopic values and that stable isotopes do not undergo significant fractionation (Dawson et al.,

2002). In many fields of science, stable isotopes are used as tracers to determine the proportional

contributions of several sources to a mixture. Applications range from water use by plants to the

study of migration and diets in animal ecology. Stable isotope measurements of animal tissues may

give information on the animal diet or location of feeding provided that isotope signatures vary

among potential dietary components and locations of feeding (Bugalho M. N. and et al, 2008).

Stable carbon isotope ratio values (δ13

C) have found increasing use in providing time-

integrated information of feeding relationship and energy flow through food webs. This ratio can

trace the movement and assimilation of nutrient and organic matter soures, such as sewage effluent,

within food chains of coastal systems.


- Code: CS/13/04-06






Ha Lan Anh, Vo Tuong Hanh. Envisagement of analytical process 13

C/12

C isotope ratio (13

C) in

benthic bivalve samples by the isotope ratio mass spectrometry (EA-IRMS). The proceeding of the 10th

national conference on nuclear science and technology, Vung Tau,15-17/8/2013, 5pages (in

Vietnamese).


VINATOM-AR 13--22


163

1.1. Measurement notation

Studies examining stable isotopes at or near natural abundance levels are usually reported as

delta, a value given in parts per thousand or per mil (“‰”).

Delta values are not absolute isotope abundances but differences between sample readings

and one or another of the widely used natural abundance standards which are considered delta =

zero (e.g. Pee Dee Belemnite for C, At%13

C=1.1112328). Absolute isotope ratios (R) are measured

for sample and standard, and the relative measure delta is calculated:

δX = ( 1tan

dards

sample

R

R)*1000

where: X is 13

C and R is 13

C/12

C

1.2. Standard materials and calibration

The common reference for δ13

C, the Chicago Pee Dee Belemnite (PDB) Marine Carbonate

Standard, was obtained from a Cretaceous marine fossil, Belemnitella americana, from the PeeDee

formation in South Carolina. This material has a higher 13

C/12

C ratio than nearly all other natural

carbon-based substances; for convenience it is assigned a delta 13

C value of zero, giving almost all

other naturally-occurring samples negative delta values.

All original supplies PDB have been used up and replaced by secondary standards prepared

by the U.S. National Bureau of Standards (for instance NBS-21 graphite, having a carbon isotope

ratio of -28.10‰ compared to PDB).

2. SAMPLING AND METHODS

2.1. Sampling

Benthic (clams and oyster) were individually measured their sizes, i.e. their length, their

height and their width, weighed and recorded. They were kept living 2 days or 3 days in water to

evacuate their gut content after that they were opened. The opened individuals were collected whole

soft tissue. Each sample was collected, separated into 4 parts. Three parts contained in glass bottles,

all samples then transferred to the laboratory and there the samples were dried at 40oC, 60

oC, 105

oC

by oven, 1 part contained in PE plastic bottles, kept in freezer and there the samples were freeze-

dried. Dried samples were powdered and kept in exsiccator until analysis.

2.2. Method of stable isotope analyses

a. Principle analyses

Benthic ((clam: MT) and oyster: MN) samples were weighed into a small tin capsule and

loaded into the Solid AutoSampler of isotope ratio mass spectrometry (EA-IRMS). When the

AutoSampler is triggered, the sample drops into the combustion reactor that is held at 1030°C. The

sample and capsule melt in an atmosphere temporarily enriched with oxygen, where the tin

promotes flash combustion. The combustion products are carried through on oxidation catalyst of

CrO3 by a constant flow of helium used as a carrier gas. The oxidation product CO2 is passed

through a reduction reactor at 650°C containing copper granules then passed through a magnesium

perchlorate filter to remove water. The remaining CO2, then pass through a short chromatographic

column where they are time-separated. They then pass through a Thermal Conductivity Detector,

and out of the vent on the top of the instrument.

The data system converts the output of the ion detector(s) into digital numbers and computes

the isotopic enrichment of the sample. Stable isotope ratios were then determined on an isotope

ratio mass spectrometer (IRMS) and are expressed relative to the conventional standards.

VINATOM-AR 13--22


164

b. Standard materials

In this research, the normal working standard for carbon was CO2 produced from Carrara

marble. Internal reference materials used were IAEA CO-8, IAEA CO-9 and NBS-19 for δ13

C.

Standard deviations on ten aliquots of the same sample were lower than 0.3‰ for δ13

C. For

calculate result of this study, we use the secondary standards for C, including: 1) Community

bureau of reference-BCR: Cod Muscle (lyophilized) with Reference material C stable isotope

compositions-15.64‰ (minus) correlatively with δ13

C; 2) Oyster Tissue (Freeze dried) with the C

stable isotope compositions is -22.35‰ (minus) correlatively with δ13

C.


3.1. Results

Time for dry samples (Table 1), δ13

C value of benthic tissues ranged between -33.99‰ and -

20.13‰ (Table 2), (Table 3, Fig.1). There values depend on the conditions dry, weight and kind of

sample.

Table 1: Time for dry sample.

No Sample

name

Time of dry sample (day)

105oC 60

oC 40

oC Freezer-dried

1 MT1 2 4 7 6

2 MT2 2 4 7 6

3 MT3 2 4 6 6

4 MT4 2 4 7 6

5 MT9 2 4 5 6

6 MN 1 3 4 5

Table 2: Result of analysis of clam and oyster.

No Sample

name

Conditions dry samples

13C (‰) 105

oC

13C (‰)

60oC

13C (‰)

40oC

13C (‰)

Freezer-dried

1 MT1 -32.3±0.3 -32.4 ±0.3 -32.3±0.3 -32.3±0.3

2 MT2 -32.5±0.2 -32.5±0.3 -32.3±0.3 -32.4±0.3

3 MT3 -32.4±0.3 -32.4±0.3 -32.2±0.3 -32.6±0.3

4 MT4 -32.3±0.3 -32.4±0.2 -32.2±0.3 -32.2±0.3

5 MT5 -32.3±0.3 -32.6±0.3 -32.4±0.3 -32.3±0.3

6 MN 1 -20.3±0.2 -20.8±0.3 -21.0±0.3 -21.1±0.3

7 MN 2 -21.1±0.3 -20.9±0.3 -21.0±0.3 -20.9±0.3

VINATOM-AR 13--22


165

Table 3: δ13

C values depend on weight “age” of benthic on the same condition dry sample

(dry sample by oven at 105oC).

No Sample

name

Weight

(g) Long

(mm)

Wide

(mm)

High

(mm)

13C

(‰)

1 MT4 113.36 11.5 9.5 3.1 -32.21 ± 0.3

2 MT2 114.71 11.5 9.7 2.9 -32.56 ± 0.3

3 MT1 112.78 11.9 9.3 3.1 -32.31 ± 0.3

4 MT3 91.16 10.9 8.5 2.6 -33.66 ± 0.3

5 MT6 90.81 10 8.1 2.7 -33.47 ± 0.3

6 MT5 90.36 10 8.5 2.7 -33.28 ± 0.3

7 MT9 31.12 6.7 4.4 2.5 -33.99 ± 0.3

8 MT10 31.15 6.7 4.2 2.4 -33.85 ± 0.3

9 MT11 31.56 6.9 4.2 2.3 -33.43 ± 0.3

3.2 Discussion

Results dried samples by two methods showed drying time depends on the temperature of

the drying method , with average temperatures of 105oC for 2 days, 4 days and 7 days with 60

oC to

40oC, the higher the temperature the shorter the drying time. In addition, sample drying time by

drying method depends on the “age” (weight ) of the sample, with the big benthics weighing the

sample drying time is longer than the benthic had “old” less than, with dried scallop 105oC

temperature just 24 hours is enough to dry the sample. For freeze-drying process time is 6 days with

dry temperature -50°C, drying time samples by freeze-drying method does not depend much on the

“age” of the organism.

Results δ13

C analysis on mass spectrometer showed no isotope separation phenomenon

occurs due to the drying process templates. For samples were dried at a temperature of 40oC, 60

oC,

105oC and freeze-drying method, δ

13C analysis results showed no difference in outcome analysis,

which showed that the sample drying conditions not occur isotope separation.

The analytical results of samples δ13

C benthics live in freshwater environments and benthic

samples live in saltwater environments showed δ13

C is completely different, reflecting the sharp

differences in habitat conditions related indicators related to δ13

C. For samples that are different

about age, live in the same environment, there is quite clear difference in δ13

C results .

VINATOM-AR 13--22


166

4. CONCLUSION

The experimental results show

- Method of drying the sample in different conditions not occur separating isotopes in the

sample. So that temperature is 105oC fit, for shorten the dry sample time.

- Weight of sample for analysis is little.

- The results of the mass spectrometer analyzes have high reliability.

Acknowledgments

The project was completed under the sponsorship of the Institute for Nuclear Science and

Technology, Institute of Atomic Energy, Ministry of Science and Technology, 2013 base level

project.

REFERENCE

[1] Fry B., Scalan R.S. and Parker P.L., 13

C/12

C ratios in marine food webs of the Torres Strait,

Queensland.

[2] Hand book of stable isotope analytical techniques-volume 2-Pie A. de Groot-Elsevier.

[3] Troy F. Gaston, Antionette Kostoglidis.-CSIRO PUBLISHING, The 13

C, 15

N, and 34

S

signatunes of rocky reef planktivorous fish indicate diffirent coastal doscharges of sewage,

Marine and fresh water research 55, pp. 669-689, 2004.

[4] T. B. Coplen, J. A. Hopple, J. K. Böhlke, H. S. Peiser, S. E. Rieder, H. R. Krouse, K. J. R.

Rosman, T. Ding, R. D. Vocke, Jr., K. M. Révész, A. Lamberty, P. Taylor, and P. De Bièvr,

Compilation of Minimum and Maximum Isotope Ratios of Selected Elements in Naturally

Occurring Terrestrial Materials and Reagents, USGS report, 2006.

[5] S. Bouillon, A. V. Raman, P. Dauby and F. Dehairs, Carbon and Nitrogen Stable Isotope

Ratios of Subtidal Benthic Invertebrates in an Estuarine MangroveEcosystem (Andhra

Pradesh, India), Estuarine, Coastal and Shelf Science 54, pp. 901-913, 2002.

VINATOM-AR 13--23


167

TECHNIQUES FOR INDUCTION OF PREMATURE CHROMOSOME

CONDENSATION (PCC) BY CALYCULIN-A AND MICRONUCLEUS

ASSAY FOR BIODOSIMETRY IN VIETNAM

Pham Ngoc Duy, Tran Que, Hoang Hung Tien, Bui Thi Kim Luyen,

Nguyen Thi Kim Anh and Ha Thi Ngoc Lien

Biotechnology Department, Nuclear Research Institute, Vietnam Atomic Energy Institute

ABSTRACT: The International Atomic Energy Agency (IAEA) and World Health Organization are interested

in biological dosimetry method for radiation emergency medicine currently. Some cytogenetic techniques such

as premature chromosome condensation (PCC) induced by Calyculin-A and micronucleus (MN) assay are

necessary to develop biodosimetry in Vietnam. In this study, we optimized the condition for MN assay with 6

µg/ml Cytochalasin-B concentration and 72.5 hours for peripheral lymphocyte blood culture. The optimization

for PCC method is 50 nM Calyculin-A concentration for 45 minutes peripheral lymphocyte blood treatment.

For samples exposed to 3.0 Gy gamma 60

Co (dose rate 0.0916 Gy/s), the frequency of MN is 19.02 ± 0.38%,

NBP is 1.95 ± 0.28%, dicentric and ring is 41.43 ± 8.12% and frag and min is 63.33 ± 5.16%. For samples

exposed to 6.0 Gy gamma 60

Co (dose rate 0.0916 Gy/s), the frequency of ring-PCC is 17.73 ± 2.46%, extra

unite is 218.91± 7.58%, dicentric is 83.81 ± 1.09%, ring is 10.75 ± 1.74%, fragment and minute is 193.17 ±

13.10%. MN and ring-PCC are specific marker applying for biodosimetry.

Keywords: Chromosome aberrations, biodosimetry, micronuleus assay, premature chromosome condensation.

Introduction

Chromosome aberration analysis technique has been used for biodosimetry over 40 years

and has become the standards method of radiation dosimetry within the framework of radiation

safety assessment. In the radiation incident, biodosimetry methods combined with physical

dosimetry methods, blood formulars and clinical symptoms of the victims would have been a

comprehensive assessment of the incident. Currently, International Atomic Energy Agency (IAEA),

World Health Organization (WHO) focuses on developing biodosimetry by WHO BioDose

Networks. Many laboratorys have developed cytogenetic techniques such as: conventioning

chromosome aberrations technique, MN technique, PCC technique and FISH technique have

confirmed the strength of the biological dosimetry methods. "Biodosimetry in the 21th century"

Conference organized by the IAEA in 2013 driven for biodosimetry with a combination of

biological markers (multiparameter) from cytogenetic techniques. Thus, establishment of MN and

PCC techniques are very nessesary for developing biological dosimetry in Vietnam.

I. EXPERIMENTS

1. Equipments: Nikon Eclipse 80i microscope, thermostatic bath, Hettich Mikro 120

centrifuge, micropipet, culture cabinet, sterilization autoclaves, incubator.


- Code: CS/13/01-04







VINATOM-AR 13--23


168

2. Reagents: Cytochalasin-B (Sigma), Calyculin-A (Sigma), DMSO, RPMI-1640

medium (Sigma Aldrich), Phytohemaglutinin (Sigma Aldrich), Fetal Bovine Serum (Gibco),

Litium Heparine 400U, Kanamycin Sulfate (Gibco), Colcemid (Gibco), acetic acid, methanol,

toluene (Merck), KCl (0.075M), Citrat natri 1% (Merck), KH2PO4, Na2HPO4, ethnol, Giemsa

(Merck), immersion oil.

3. Subjects: lymphocyte peripheral blood from heathy donors.

4. Experiment designs:

- Experiment 1: optimation of Cytochalasin-B for MN technique. Study on the effect

of Cytochalasin-B at 2; 4; 6; 8 µg/ml concentrations combine with 71; 72; 72.5 cuture times to

the binuclei cell.

- Experiment 2: optimation of Calyculin-A for PCC technique. Study on the effect of

Calyculin-A at 10; 30; 50 nM concentrations combine with 30; 45; 60 minutes treatment to the

PCC index.

- Experiment 3: Study on the cell damaged of gamma ray 60

Co at 3 Gy (0.0916 Gy/s

dose rate) by MN and CA techniques, study on the cell damaged of gamma ray 60

Co at 6 Gy

(0.0916 Gy/s dose rate) by PCC and CA (chromosome aberration Giemsa staining) techniques

II. PROCEDURES

1. Method of culturing lymphocytes and making microscopic slides: Venous blood

was collected and kept in 400U heparin. 0.5 ml of blood were cultured in 9.0 ml RPMI 1640

supplied with 15% Fetal bovine serum (Gibco), 1% Kanamicine, 1% L-glutamine, 5%

Phytohemaglutinin (Sigma). Whole blood was cultured at 37o for 48 hours. Cell harvested and

fixed by Carnoy (3 methanol: 1 acetic acid), make and stain microscopy slides by 10% Giemsa.

2. Analysis of the chromosomal aberrations: Identify the mononuclei, binuclei,

trinuclei and tetranulei cells in MN technique, G1, S and G2/M in PCC technique, chromosome

aberration type in CA technique by the microscope at 1000x.

3. Data analysis: Data was analyzed by SPSS 16.0 and Excel software.


1. Experiment 1: optimation of Cytochalasin-B for MN technique

All kinds of cell were obtained as in Figure. 1 A, B, C, D.

Figure 1: mononuclei (A), binuclei (B), trinuclei (C) và tetranuclei (D)

The experiment for investigating the effect of Cytochalasin-B concentration and culture time

to the binuclei cells was based on cell culture technique of the IAEA, the culture conditions and

culture medium were optimized in current laboratory condition. Results of proportion of

mononuclei, binuclei, trinuclei, tetranuclei cells obtained in the combination treatment between

Cytochalasin-B at 2, 4, 6, 8 µg/ml and culture time at 71, 72 , 72.5 hours were shown in Table 1 and

Figure 2.

A B C D

VINATOM-AR 13--23


169

Table 1: The effect of Cytochalasin B concentrations and culture times

to the mononuclei, binuclei, trinuclei and tetranuclei cells.

Treatment Cyt-B (µg/ml) Cuture time

(hours)

Mononuclei

(%) Binuclei (%)

Trinuclei +

tetranuclei (%)

1 2 71 98.51 ± 0.42 1.49 ± 0.42 -

2 2 72 96.52 ± 0.87 3.13 ± 0.92 0.38 ± 0.18

3 2 72.5 92.20 ± 1.55 6.70 ± 0.84 1.10 ± 0.74

4 4 71 89.56 ± 1.85 9.76 ± 1.29 1.03 ± 0.37

5 4 72 87.07 ± 1.89 12.28 ± 2.07 0.65 ± 0.34

6 4 72.5 84.24 ± 2.43 14.66 ± 2.22 1.11 ± 0.27

7 6 71 82.26 ± 1.53 16.60 ± 1.91 1.14 ± 0.42

8 6 72 78.11 ± 3.08 19.58 ± 3.05 2.31 ± 0.27

9 6 72.5 66.75 ± 1.93 30.74 ± 1.36 2.52 ± 0.58

10 8 71 87.49 ± 1.65 16.49 ± 2.07 0.43 ± 0.23

11 8 72 83.74 ± 1.72 15.61 ± 0.85 0.77 ± 0.30

12 8 72.5 83.46 ± 0.52 12.08 ± 1.86 0.93 ± 0.32

0,00

20,00

40,00

60,00

80,00

100,00

1 2 3 4 5 6 7 8 9 101112

Fre

qu

en

cy (

%)

Combinations

Tri + Tetranuclei

Binuclei

Mononuclei

Figure 2: Mononuclei, binuclei, trinuclei and tetranuclei cells.

The percentage of binuclei cells increases from treatment 1 to 9, binuclei cells was highest

(30.74 ± 1.36%) at the treatment 9. While, the percentage of mononuclei cells decreased from

treatment 1 to 9 and in treatment 9 was lowest (66.75 ± 1.93%). The percentage of trinuclei and

tetranuclei cells were not more than 3 % in all treatments. Thus, the treatment 9 was optimized

condition to obtain the highest binuclei cells. Thus, lymphocyte peripheral blood cultured in 72.5

hours at 6 µg/ml concentration of Cytochalasin-B is suitable for MN technique in this study.

2. Experiment 2: optimation of Calyculin-A for PCC technique

All kinds of cell were obtained as in Fig. 3 A, B, C, D.

VINATOM-AR 13--23


170

Figure 3: lymphocyte (A), G1 cell (B), S cell (C), G2/M cell (D).

Results of proportion of lymphocyte, G1 cell, S cell, G2/M cell obtained in the combination

treatment between Calyculin-A at 10, 30, 50 nM and in 30, 45, 60 minutes were shown in table 2

and Figure 4.

The PCC index increases from treatment 1 to 8 and was highest (24.04 ± 2.64%) at the

treatment 8. The treatment 8 was optimized condition to obtain the highest PCC index. Thus,

lymphocyte peripheral blood cultured in 47 hours, treated at 50 nM concentration of Calyculin-A at

45 minutes is suitable for PCC technique in this study.

Table 2: The effect of Calyculin-A concentration and treatment time the lymphocyte,

G1 cell, S cell, G2/M cell and PCC index.

Treatmet Caly-A

(nM)

Time

(minute)

Lymphocyte

(%) G1 cell (%)

S cell

(%)

G2/M cell

(%)

PCC index

(%)

1 10 30 97.39 ± 1.21 1.01 ± 0.64 0.87 ± 0.35 0.73 ± 0.32 2.61 ± 1.21

2 10 45 96.39 ± 0.06 1.39 ± 0.43 1.35 ± 0.35 0.87 ± 0.26 3.61 ± 0.60

3 10 60 94.10 ± 0.99 0.66 ± 0.28 2.57 ± 0.97 2.67 ± 0.32 5.90 ± 0.98

4 30 30 93.40 ± 1.45 0.99 ± 0.27 2.83 ± 0.53 2.79 ± 1.10 6.60 ± 1.45

5 30 45 87.93 ± 1.56 1.08 ± 0.24 6.64 ± 1.11 4.35 ± 0.38 12.07 ± 1.56

6 30 60 85.65 ± 2.81 1.09 ± 0.60 7.98 ± 1.03 5.28 ± 1.61 14.35 ± 2.81

7 50 30 85.05 ± 1.86 1.60 ± 0.45 7.46 ± 1.28 5.89 ± 1.17 14.95 ± 1.86

8 50 45 75.97 ± 2.64 1.99 ± 0.17 10.52 ± 1.21 11.53 ± 1.71 24.04 ± 2.64

9 50 60 89.32 ± 2.33 1.19 ± 0.47 5.36 ± 1.43 4.13 ± 0.83 10.68 ± 2.33

0

20

40

60

80

100

1 2 3 4 5 6 7 8 9

Fre

qu

en

cy (

%)

Combinations

PCC Index = G1 + S +G2/M

Lympho

Figure 4: The distribution of lymphocyte cell and PCC index.

VINATOM-AR 13--23


171

3. Experiment 3

Whole blood exposed to gamma 60

Co at 3.0 Gy (dose rate 0.0916 Gy/s). Cell damages were

analysed by MN and CA techniques.

Table 3: Frequency of MN and nu.bridge in lymphocyte exposed to 3.0 Gy gamma 60

Co.

Radiation

dose

Mononuclei

(%)

Binuclei

(%)

Tri +

tetranuclei (%)

Micronuclei

(%)

Nu.bridge

(%)

0 Gy

59.36 38.37 2.26 1.00 -

64.02 32.88 3.09 0.80 -

61.66 34.48 3.86 1.30 -

Mean 61.68 ± 1.90 35.25 ± 2.13 3.07 ± 0.65 1.03 ± 0.21 -

3.0 Gy

51.25 40.39 8.35 19.28 2.27

68.14 30.64 1.23 19.30 2.00

60.22 35.62 4.17 18.48 1.58

Mean 59.87 ± 6.90 35.55 ± 3.98 4.58 ± 2.92 19.02 ± 0.38 1.95 ± 0.28

The frequency of MN in binuclei cell before irradiation was 1.03 ± 0.21%, there were not

any Nu.bridge. After exposed to 3.0 Gy, MN frequency was 19.02 ± 0.38%, Nu.bridge was 1.95 ±

0.28%, MN and Nu.bridge were increased significantly. According to IAEA (2011), using MN

technique in radiation dose range 0.3 to 4.0 Gy.

Table 4: Frequency of chromosome aberrations in lymphocyte

exposed to 3.0 Gy gamma 60

Co.

Radiation dose No. of

metaphase

Dicentric + ring

(%)

Fragment +

minute (%)

0 Gy

1000 - 0.20

1000 - 0.40

1000 - 0.50

Mean - 0.37 ± 0.12

3.0 Gy

211 47.39 62.16

213 46.95 70.15

334 29.94 57.68

Mean 41.43 ± 8.12 63.33 ± 5.16

In 3000 metaphase of samples before irradiation, there were not any dicentric or ring

chromosome, the frequency of minute and fragments was 0.37 ± 0.12%, at the background level.

For the samples irradiated at 3.0 Gy of 60

Co, the frequency of dicentric and ring chromosome was

41.43 ± 8.12%, the frequency of minute and fragment was 63.33 ± 5.16%, these type of

chromosome aberrations originated from DNA double-stranded break. According to IAEA (2011),

the appropriate dose for using CA technique is 0.1 to 5.0 Gy.

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172

Table 5: Frequency of PCC markers in lymphocyte exposed to 6.0 Gy gamma 60

Co.

Radiation dose G2/M

(%)

PCC index

(%)

Ring

(%)

Extra unit

(%)

0 Gy

13.70 22.37 - 0.20

14.85 25.76 - 0.10

14.04 25.44 - 0.20

Mean 14.19 ± 0.48 24.53 ± 1.53 - 0.17 ± 0.05

6.0 Gy

5.69 10.28 15.15 208.42

5.66 8.36 21.05 226.09

3.54 6.75 17.00 222.22

Mean 4.96 ± 1.01 8.46 ± 1.44 17.73 ± 2.46 218.91± 7.58

PCC index in samples irradiated by 6.0 Gy was lower significantly (p < 0.008), this was due

to high dose irradiation, many lymphocytes could not pass the cell cycle and dead by apoptosis. The

low PCC index also reduced the frequency of G2/M cell (14.19 ± 0.48% before irradiation and 4.96

± 1.01% after irradiation, p < 0.003). Ring chromosomes were not detected in samples before

irradiation, after irradiation, the frequency was 17.73 ± 2.46%. The frequency of extra unit before

irradiation was 0.17 ± 0.05% and after 6.0 Gy irradiation was 218.91 ± 7.58%. Thus, the frequency

of rings and extra units increased very significantly after exposed to 6.0 Gy. However, the

frequency of extra units increased so high, thus this marker was not used for generating the dose

effect calibration curves in biological dosimetry. According to IAEA (2011 ) is the appropriate dose

for using PCC technique is 0.2 to 20.0 Gy .

Table 6: Frequency of chromosome aberrations in lymphocyte exposed to 6.0 Gy gamma 60

Co.

Radiation dose MI index

(%)

Dicentric

(%)

Ring

(%)

Fragment + minute

(%)

0 Gy

7.23 - - 0.2

5.91 - - 0.4

6.74 - - 0.5

Mean 6.63 ± 0.54 - - 0.37 ± 0.12

6.0 Gy

2.20 82.46 9.09 209.09

1.92 85.14 13.16 193.42

4.15 83.84 10.00 177.00

Mean 2.76 ± 0.99 83.81 ± 1.09 10.75 ± 1.74 193.17 ± 13.10

In 6.0 Gy gamma 60

Co, the frequency of dicentric chromosomes was 83.81 ± 1.09%, ring

chromosomes was 10.75 ± 1.74%, fragment and minute was 193.17 ± 13.10%. The frequency of

dicentric, ring, fragment and minute irradiated samples increased significantly compared to control

group.

In this experiment, by the PCC technique, the frequency of ring chromosomes in

lymphocytes after irradiation was 17.73 ± 2.46%, the frequency of fragments and minute was

218.91 ± 7.58%, they are higher than analysing by CA technique (the frequency of ring was 10.75 ±

VINATOM-AR 13--23


173

1.74%, fragments and minute was 193.17 ± 13.10%). In PCC technique by Calyculin-A, the ring

chromosomes is very specify for the effects of ionizing radiation, it can be used for building the

dose effect calibration curves at high dose level.

IV. CONCLUSIONS

This study has identified the appropriate conditions for processing MN technique, lymphocytes

cultured with 6 µg/ml Cytochalasin-B and harvested at 72.5 hours. Processing PCC technique,

lymphocytes cultured with 50 nM Calyculin-A in 45 minutes at last culture time. MN and ring-PCC are

suitable for study on biological dosimetry.

REFERENCES

[1] INTERNATIONAL ATOMIC ENERGY AGENCY, Biological Dosimetry: Chromosomal

Aberration Analysis for Dose Assessment, Technical Reports Series No. 260, IAEA, Vienna,

1986.

[2] INTERNATIONAL ATOMIC ENERGY AGENCY, Cytogenetic Analysis for Radiation Dose

Assessment, Technical Reports Series No. 405, IAEA, Vienna, 2001.

[3] INTERNATIONAL ATOMIC ENERGY AGENCY, Cytogenetic Dosimetry: Applications in

Preparedness for and Response to Radiation Emergencies, EPR-Biodosimetry, WHO, IAEA,

Vienna, 2011.

[4] INTERNATIONAL STANDARD ORGANIZATION, Radiation protection-Performance criteria

for service laboratories performing biological dosimetry by cytogenetics, ISO 19238, Switzeland,

2004.

[5] Kanda, R., Hayata, I., Lloyd, Technical Report. Easy biodosimetry for high-dose radiation

exposures using drug-induced, prematurely condensed chromosomes, Int. J. Radiat. Biol.,

75(4): 441-446, 1999.

[6] M. Durante, Y. Furusawa and E. Gotoh, A simple method for simultaneous interphase–

metaphase chromosome analysis in biodosimetry, Int. J. Radiat. Biol, Vol. 74, No. 4, 457 –

462, 1998.

[7] M. Fenech, M. Kirsch-Volders, A. T. Natarajan, J. Surralles, J. W. Crott, J. Parry, H. Norppa,

D. A. Eastmond, J. D. Tucker and P. Thomas, Molecular mechanisms of micronucleus,

nucleoplasmic bridge and nuclear bud formation in mammalian and human cells,

Mutagenesis, Vol. 26 No. 1, pp. 125-132, 2011.

[8] Michael Fenech, Nina Holland, Errol Zeiger, Wushou P. Chang, Sema Burgaz, Philip

Thomas, Claudia Bolognesi, Siegfried Knasmueller, Micheline Kirsch-Volders and Stefano

Bonassi, The HUMN and HUMNxL international collaboration projects on human

micronucleus assays in lymphocytes and buccal cells-past, present and future, Mutagenesis,

Vol. 26, No. 1, pp. 239–245, 2011.

[9] Michael Fenecha, Nina Holland, Wushou P. Chang, Errol Zeiger, Stefano Bonassi, The

HUman MicroNucleus Project-An international collaborative study on the use of the

micronucleus technique for measuring DNA damage in humans, Mutation Research, 428,

271-283, 1999.

VINATOM-AR 13--24


174

FIELD TEST OF CAPABILITY TO PREVENT CABBAGE CLUBROOT

DISEASE CAUSED BY Plasmodiophora brassicae OF SILVER

NANOPARTICLES SYNTHESIZED BY GAMMA RADIATION

Pham Thi Le Ha, Nguyen Tan Man, Nguyen Duy Hang, Le Hai, Tran Thi Tam,

Pham Thi Sam, Le Huu Tu, Tran Thu Hong, Tran Thi Thuy and Nguyen Tuong Ly Lan

Radiation Technology Department, Dalat Nuclear Research Institute, Vietnam Atomic Energy Institute

ABSTRACT: The effects of four dose rates 0.27; 0.90; 1.80 and 3.60 kGy/h on the solution of silver (Ag+ 10

-2

M, PVP 2%, ethylenglycol 6%) irradiated at 25 kGy were investigated. The results showed that as the dose

rates increased, the absorption peak shifted to blue wavelengths and also the particles decreased in size. For

field test, nano particles were prepared by irradiation of silver solution at 25 kGy with the dose rate of 3.60

kGy/h. The absorption peaks of the synthesized nanoparticles were obtained at wavelengths of 412 nm and

the average diameter of particles were 14 nm. Using two concentrations of 15 and 20 ppm, silver nanoparticles

had not affected the growth and development of cabbage but showed antifungal activity against

Plasmodiophora brassicae cause club root in cabbage. Using nano particles, the clubroot disease index were 9-

10% compared to 5% of nebijin (fungicide), and 12% of control. The yield of cabbage were 55 tons/ha, 63

tons/ha and 70 tons/ha for the control, nanosilver group, and nebijin group, respectively.

I. INTRODUCTION

Today, nanotechnology is topical question and interested by scientists. Various methods

have been reported for the preparation of silver nanopaticles such as: mechanical grinding, co-

precipitation, spraying, electrolysis sol-gel manufacture, irradiation,…These methods are

disadvantageous because the size of the particles formed is difficult to control or high cost. On the

other hand, γ-irradiation method is advantageous because size, shape and size distribution of

particles are easily controlled and the particles may be prepared at the room temperature,..[1,2] First

time, silver nanoparticles were produced for the antimicrobial aim of health care [3]. Nowadays,

nanoparticles made of silver, have special optical properties that particularly harbour promising

applications for medical technology [4]. In agriculture field, nanosilver have ben used for

preservation and treatment of diseases. Nanosilver solution was used for controlling Septoria leaf

blotch, yellow rust, Fusarium, and powdery mildew on wheat which showed that nanosilver

controls wheat disease. [5]. Plasmodiophora brassicae-the casual agent of club root disease of

crucifers. Plants infected have the low yield. This disease occurs all year in Dalat region of Lam

Dong Province [6,7]. Many ways used to controll this disease include liming the soil, using

chemical,…but the results are still restricted [8-10].

Project Information:

- Code: CS/13/01-02



- Implementation Time: 12 months (Jan 2013-Dec 2013)

- Contact Email: [email protected]

- Papers published in relation to the project:

Pham Thi Le Ha, Nguyen Tan Man, Le Hai, Pham Thi Sam, Tran Thu Hong, Tran Thi Tam, Le Huu

Tu, Using silver nano particles prepared by γ irradiation with chitosan as stabilizer to control clubroot

disease on cabbage. The 10th

National Conference on Nuclear Science and Technology, Vung Tau,

8/2013 (in Vietnamese).


VINATOM-AR 13--24


175

In 2009, the project “Radiation induced synthesis of colloidal silver nanoparticles for control

of clubroot disease of cabbage caused by Plasmodiophora brassicae” was carried out and the

results showed that silver nanoparticles prevent Plasmodiophora brassicae in cabbage in the

laboratory. Based on the good results of the project, we continued to evalue capability to prevent

cabbage clubroot disease of silver nanoparticles in field.

II. MATERIALS AND METHODS

Chemical:AgNO3(PA): Merck, Germany

Facilities: Gamma Co-60 radiation source (Issledavachel-Russia), with the dose rate: 27

kGy/h and gamma Co-60 GC-5000 (BRIT,India), with the dose rate: 3.6 kGy/h.

Plant: Cabbage (Shogun)

Fungicide: Nebijin 0.3DP,

The size of the partocles wree determined by transmsstion electron Microscopy (TEM) and

UV-vis spectrophotometer analysis. The solution of nano particles were tested to prevent cabbage

clubroot disease caused by Plasmodiophora brassicae in the field.


III.1. The effect of dose rate on silver nanoparticles

III.1.1. The UV absorbance of silver nanoparticles

The results in fig.1 show that when the dose rates increased, absorption peak shifted to the

blue wavelengths.

Figure 1: Uv-visible absorption spectra of silver nanoparticle solutions.

a) Dose rate: 0.27 kGy/h, λmax = 418.0 nm

b) Dose rate: 0.90 kGy/h, λmax = 411.5 nm

c) Dose rate: 1.80 kGy/h, λmax = 411.5 nm

d) Dose rate: 3.60 kGy/h, λmax = 411.0 nm

VINATOM-AR 13--24


176

III.1.2. TEM image and silver nanopaticle size distribution

0

2

4

6

8

10

12

14

9 11 14 16 18 21 24 26

Size, nm

Fre

qu

ency

, %

a) Dose rate: 0.27 kGy/h (da = 17.85 ± 2.05 nm).

0

2

4

6

8

10

12

14

16

7 9 11 13 20 22 24

Size, nm

Freq

uenc

y, %

b) Dose rate: 0.90 kGy/h (da = 14.74 ± 2.72 nm).

0

4

8

12

16

20

6 9 11 13 17

size, nm

Freq

uenc

y, %

c) Dose rate: 1.80 kGy/h (da = 12.21 ± 1.93 nm).

0

5

10

15

20

25

30

3 5 7 9 11 13 15

Size, nm

Fre

qu

en

cy, %

d) Dose rate: 3.60 kGy/h (da = 7.97 ± 1.85 nm).

Figure 2 (a-d): TEM image and silver nanopaticle size distribution with different dose rates.

The results showed that size of silver nanoparticles decreases with increasing dose rate.

VINATOM-AR 13--24


177

III.2. Some characteristic of field test silver nanoparticle solution

III.2.1. UV absorbance of field test silver nanoparticle solution

0

0,1

0,2

0,3

0,4

0,5

0,6

300 350 400 450 500 550 600

Wavelength (nm)

Op

tica

l D

ensi

ty (

OD

)

The UV/Vis absorption spectrum of the silver nanoparticle solution is shown in Fig.3. The

absorption peak is obtained at the wavelength of 412 nm.

III.2.2. TEM image and silver nanopaticle size distribution

0

5

10

15

20

5 6 7 9 10 11 12 13 14 16 17 18 20

Kích thước hạt, nm

Tần xuất, (%)

Figure 4: TEM image and silver nanopaticle size distribution.

(da = 13.24 ± 2.25 nm)

The average size of silver nanoparticles of field test solution is 13.24 ± 2.25 nm.

III.2.3. Stability of silver nanoparticles with storage time

The silver nanoparticle solution is observed for 3 months and it shows that the absorption

peak shifted to red wavelengths at first 40 days. From the day of 41st, the λmax kept at the same

wavelength. This indicates that the prepared colloidal gold nanoparticles solution is fairly good

stability in 3 months of storage .

III.3. Field testing results

III.3.1. Toxicity of silver nanoparticles on cabbage

Table 2: Toxicity of silver nanoparticle on cabbage.

Variants Dose Toxicity (level)

1(DAT) 3(DAT) 7(DAT)

1. Nano silver 15 ppm 1 1 1

2. Nano silver 20 ppm 1 1 1

3. Nebijin 0.3 DP 300 kg/ha 1 1 1

Figure 3: Uv-visible absorption

spectrum of field test silver

nanoparticle solution.

(λmax = 412 nm, OD = 0.503)

VINATOM-AR 13--24


178

DAT: day after treatment.

Using two concentrations of 15 and 20 ppm, silver nanoparticles has not affected the growth

and development of cabbage.

III.3.2. Effect of silver nanoparticles on percentage of infected cabbage

Table 3: Percentage of infected plants.

Variants Dose

Percentage of infected plants (%)1

20 30 40 50 60 70 80

1. Nano silver 15 ppm 0.0a 0.0a 5.00a 6.67b 11.67b 15.00b 15.00b

2. Nano silver 20 ppm 0.0a 0.0a 3.33a 5.00b 10.00b 13.33b 14.33b

3. Nebijin 300 kg/ha 0.0a 0.0a 1.67a 1.67b 5.00b 6.67b 6.67b

4. Control - 0.0a 1.67a 6.67a 16.67a 23.33a 25.00a 25.00a

1: day after treatment.

The results in table 3 showed that, silver nanoparticles had antifungal activity against

Plasmodiophora brassicae cause club root in cabbage.

III.3.3. Effect of silver nanoparticles on the clubroot disease index

Table 4: Effect of silver nanoparticles on the clubroot disease index.

Variants Dose Disease index (%)

1. Nano silver 15 ppm 10.67 ± 4.04

2. Nano silver 20 ppm 9.00 ± 3.46

3. Nebijin 0.3 DP 300 kg/ha 4.67 ± 2.08

4. Control - 21.33 ± 4.51

Using silver nano particles, the clubroot disease index were 9-10% compared to 5% of

nebijin (fungicide), and 12% of control.

III.3.4. Effect of silver nanoparticles on yield of cabbage

Table 5: Effect of silver nanoparticles on yield of cabbage.

Variants Dose Yield (Ton/ha)

1. Nano silver 15 ppm 63.238

2. Nano silver 20 ppm 63.523

3. Nebijin 0.3DP 300 kg/ha 70.810

4. Control - 55.619

The yield of cabbage were 55 tons/ha, 63 tons/ha and 70 tons/ha for the control, nanosilver

group, and nebijin group, respectively.

VINATOM-AR 13--24


179

IV. CONCLUSIONS

The effects of four dose rates 0.27; 0.90; 1.80 and 3.60 kGy/h on the solution of silver (Ag+

10-2

M, PVP 2%, ethylenglycol 6%) irradiated at 25 kGy were investigated.

The dose rates increased, the absorption peak shifted to blue wavelengths and also the

particles decreased in size.

For field test, nano particles were prepared by irradiation of silver solution at 25 kGy with

the dose rate of 3.60 kGy/h. The absorption peaks of the synthesized nanoparticles were obtained at

wavelengths of 412 nm and the average diameter of particles were 14 nm.

Using two concentrations of 15 and 20 ppm, silver nanoparticles had not affected the growth

and development of cabbage but showed antifungal activity against Plasmodiophora brassicae

cause club root in cabbage.

Using nano particles, the clubroot disease index were 9-10% compared to 5% of nebijin

(fungicide), and 12% of control.

The yield of cabbage were 55 tons/ha, 63 tons/ha and 70 tons/ha for the control, nanosilver

group, and nebijin group, respectively.

REFERENCES

[1] Kumar M., et al., Radiolytic formation of Ag cluster in aqueous polyvinyl alcohol solution

and hydrogel matrix, Rad. Phys. Chem., 73, p. 21-27, 2005.

[2] Meisel D., Radiation effects on Nanoparticles. Emerging applications of radiation in

nanotechnology, 2005, IAEA-TECDOC-1438, p. 125-136.

[3] Steven J. Oldenburg, Ph.D. (President-nanoComposix, Inc), Silver Nanoparticles: Properties

and Applications.

[4] Sotiriou GA et al.: Non-Toxic Dry-Coated Nanosilver for Plasmonic Biosensors, Advanced

Functional Materials (2010), 20, 4209-4399, DOI: 10.1002/adfm.201000985.

[5] Patent (US 20090075818 A1).

[6] www.cals.ncsu.edu/course/pp728/ Plasmodiophora brassicae html.

[7] Dixon G. R., The biology of Plasmodiophora brassicae Wor.-A review of recent advances.

Acta Hort 706: 271-282, 2006.

[8] Shimotori H., et al., Evaluation of benzenesulfonanilide derivatives for the control of

crucifers clubroot. J. Pestic Sci. 21:31-35, 1996.

[9] Donald E.C., et al., Band incorporation of fluazinam (Shirlan) into soil to control clubroot of

vegetable brassica crops. Aust J ExpAgric 41:1223-1226, 2001.

[10] Murakami H., et al., Reduction of resting spore density of Plasmodiophora brassica and

clubroot disease severity by liming, Soil Sci. Plant Nutr. 48:685-691, 2002.

[11] Báo cáo tổng kết đề tài Khoa học Công nghê cấp Cơ sở năm 2009, “Ứng dụng bức xạ để

chế tạo vật liệu nano bạc, thử nghiệm khả năng điều trị bệnh sưng rễ do nấm

Plasmodiophora brassicae trên cây bắp cải”. 2009.

[12] Xia, Y., Halas N. J. Shape-controlled Synthesis and Surface Plasmonic properties of

Metallic Nanostructures. MRS Bulletin 30, pp. 338-343, 2005.

VINATOM-AR 13--25


180

STUDY ON IRRADIATED VIETNAM JAVA RAMBUTAN FRUIT

WHICH WAS POSTHARVESTED TREATMENT TO PROLONG

THE SHELFLIFE FOR EXPORT PURPOSES

Nguyen Thuy Khanh1, Nguyen Thi Ly

1, Doan Thi The

1,

Cao Van Chung1 and Nguyen Van Phong

2

1Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute

202A Street 11, Linh Xuan Ward, Thu Duc District, Ho Chi Minh City

2Southern Horticultural Research Institute

Long Dinh Ward, Chau Thanh District, Tien Giang Province

ABSTRACT: The research:” Study on irradiated Vietnam Java rambutan fruit which was postharvested

treatment to prolong the shelflife for export purposes” was conducted at Research and Development Center for

Radiation Technology and Southern Horticultural Research Institute for 12 months. On the one hand, the

theme was to study the effects of low-dose radiation in the range (200-500 Gy) combined with two types of

packaging: carton boxes and carton boxes + PE perforated cover 0.5% of the area bags. After 13 days

monitoring in 13oC, RH= 85-90% the results showed that Java rambutan fruit which was packed in carton

boxes combined PE bags then irradiated at 300 Gy dose could limit the browning pericarp, dehydration

through the rate of browning, browning level and the percentage of weight loss. Irradiated ramtuban also

remains their pulp quality when testing the soluble solids, the titratable acidity and the ascorbic acid content.

Irradiation did not affect the cell structure of pericarp and pulp by investigating the total ion leakage. On the

other hand, the topics also examined the influence of some postharvest handling and low-dose radiation on

Java rambutan. The results showed that pre-irradiation processing: hot water treatment at 43oC in 6 minuted,

dipping in cloruacalxi 0.4% + citric acid 0.5% solution in 3 minutes, packed in carton boxes + PE bags and

irradiated at 300 Gy dose capable of maintaining the quality which extends the shelflife of Java rambutan more

4 days when kept under conditions of 13oC, RH= 85-90%.

1. INTRODUCTION

Java rambutan (Nephelium lappaceum L) belong to the family Sapindaceae is a tropical fruit

native to Malaysia and Indonesia, which is distributed widely in humid, high rainfall areas of

Southeast Asia. In Vietnam, rambutan is grown in popularity in the province of Dong Nai river

basin or South Central and now Ben Tre, Tien Giang provinces are pioneers in the application

VietGAP and Global GAP for this fruit. Irradiation with an absorbed dose of 400 Gy as quarantine

treatment is approved by U.S. Dept. of Agriculture (USDA/APHIS) for Vietnam rambutan and

dragon fruit [1]. The first Java rambutan treatment was irradiated and export to the United States in


- Code: CS/13/07-04






1. Study on effects of low-dose and package treatment to quality and storage capacity of java rambutan,

The 10th

Natioanl Conference on Nuclear Science and Technology, Vung Tau 15-16 August 2013 (in

Vietnamese).

2. Achieved result of training: A master thesis specialized on the Food Technology, Nong Lam University,

HCM City titled “Study on low-dose irradiation combined with other post-harvest treatments in Java

rambutan for export purposes. Student’s name: Ms. Nguyễn Thụy Khanh, Scientific consultants: Dr.

Nguyen Van Phong, Assosiate Professor, Dr. Bui Van Mien, October 2013 (in Vietnamese).


VINATOM-AR 13--25


181

May 2011 by airport but did not compete with rambutan from other country due to high price. The

problem of competition on the export market have been reviewed and given two solutions: The first

is moving to farming and harvesting Java rambutan in minor season from January to April yearly.

The second is to reduce the costs to sell as well as improve the quality of harvest. The latter solution

is more interested because it can improve the quality and increase the storage time in minor and

major season of rambutan.

The purposes of reasearch were to assess the effects of low-dose radiation combination with

some postharvest treatments to mantain the quality and prolong its shelflife. The outcome of this

research will be a background to improve the quality of rambutan exported to markets approving

irradiation as phytosanitary treatment.

2. EXPERIMENT

2.1. Materials and chemicals

Java rambutan fruits: Were harvested at maturity 90-95 days after blooming from an orchard

in Global GAP model in Phu Phung, Cho Lach district, Ben Tre province during the minor harvest.

Packaging materials: Carton boxes in size of 25×15×5 (cm) and net weight of 2 kg (this is

also the boxes for exporting nowadays in Viet Nam). PE perforated 0.5% bags.

Chemicals: NaOH, phenolphthalein, 2.6 dichlorophenolindophenol, vitamin C, oxalic acid,

CaCl2, manniton, Merk, Germany. 1-MCP, Thailand. Metaphosphoric acid, Chinese.

2.2. Equipment

Irradiation facility: Electron beam accelerator UERL-10-15S2, 10 MeV, supplied by

CORAD Co. Ltd., Russia, at the Research and Development Center for Radiation Technology.

Testing equipment: Handheld refractometer scale 0-320 Brix, Atago, Japan. Colorimeter

Minolta-CR400, Japanese manufactures. Conductivity meter WTW Cond 720 Inlab, Germany.

Other equipments: cold storage, thermor temperature.

2.3. Experimental design and methodology:

a. The effects of packaged treatment and low-dose irradiation to quality and storage

capacity of Java rambutan

Experimental design: The experiment was designed in completely random with two factors:

Factor A was the dose range: 200, 300, 400, 500 Gy and the control (non-irradiated). Factor B was

the type of packing: carton boxes and carton boxes + PE perforated 0.5% bags. The experiment was

repeated two times with 40 fruits of rambutan fruits for each time.

Methodology: The first step, rambutan fruits were taken from Global GAP model farm and

cut the stem leaving 0.5 cm left. The second step, it was packed in carton boxes and carton boxes +

PE perforated 0.5% bags. The last step, rambutan was irradiated by the electron beam facility in a

dose range: 200-500 Gy. Absorbed doses were measured by Fricke dosimeters in each replicate.

b. The effects of post-harvested treatment and low-dose irradiation to quality and

storage capacity of Java rambutan

Experimental design: The experiment was designed in completely random with two factors:

Factor A was the level of radiation: 300 and 400 Gy. Factor B was the postharvest handling that had

done before irradiation. The first was hot water treatment at 43oC in 6 minutes and then steaming 1-

MCP 1.5ppm for 4 hours. The second was hot water treatment at 43oC in 6 minutes and then

dipping in cloruacalxi 0.4% + citric acid 0.5% solution in 3 minutes, and the last was a combination

VINATOM-AR 13--25


182

of them. Rambutan also was packed in cartons and perforated PE 0.5% bags. The experiment was

repeated three times and 40 fruits of rambutan for each time.

Methodology: The first step, rambutan fruits were taken from Global GAP model farm and

cut the stem leaving 0.5 cm left. The second step, it was post-harvested treatment and packed in

carton boxes and carton boxes + PE perforated 0.5% bags. The last one, rambutan was irradiated at

300 and 400 Gy. Absorbed doses were measured by Fricke dosimeters in each replicate.

Quality determination

The sensory qualities:

- The rate of pericarp browning and disease of the skin fruit (%): By counting the number

browning and diseased rambutan fruits each investigation.

- The degree of pericarp browning and disease of inner and outer surface of the pericarp

(0-5 degree): 0 degree = 0%, 1st degree = 1-5%, 2

nd degree = 6-11%, 3

rd degree = 11-25%, 4

th

degree = 25-50% and 5th

degree means more than 50% surface area are browned or diseased.

- Weight loss: Was determined as percentage of the initial weight by Shimadzu weight

UX8200S-8200g (±0.1g), (Japanese manufactures).

- The external color of the pericarp (including spinterns) (L*, a

*): Color values of 40 fruits

per treatment were recorded at three equidistant locations around the backbone of each fruit (by

Minolta-CR400, Japanese manufactures).

The biochemical qualities of pulp:

- The soluble solids (0Brix): Was directly measured using two to three drops of juice

placed on a handheld refractometer (Atago refractometer-Japan 0Brix 0-32 scale).

- The titratable acidity (%): By the titrimetric method with 0.1N NaOH and

phenolphthalein 1% as indicator (AOAC 942.15).

- The ascorbic acid content (mg/100g): By the 2,6-dichlorophenolindophenol titrimetric

method (AOAC 967.21).

The rate of membrane ion leakage (%) (Jang & Chen, 1995):

The ion leakage in the cell (electrolyte leakage) was determined by conductivity meter

WTW Cond 720 Inlab (by German manufacturers) (EC1). The total leakage of intracellular ions

(electrolyte leakage) (EC2) was determined after the samples were boiled for 15 minutes and cooled

to 25oC.

The total ion leakage (%) = EC1*100/EC2


3.1. The effects of packaged treatment and low-dose irradiated to quality and storage

capacity of Java rambutan

3.1.1. The sensory qualities

The rate (%) and degree (score) of pericarp browning:

The Table 1 showed that rambutan fruits after treated, stored at 13oC, RH 85-90% had

begun browning from 5 days. The rate of pericarp browning under 5% on the 5th

day, increased

dramatically around (4.17-62.50)% on the 10th

day and had a strongly increase from 4.25% to 100%

on 13th

day after storage. The degree of pericarp browning under 0.025 on the 5th

day, increased

slightly in the range 0.13 to 2.59 on the 10th

day and had continued from 4 to 0.41 on the last day of

the storage time. Interactions between the method of packaging and irradiation had not significant

VINATOM-AR 13--25


183

difference at 5% on the 5th

day but there were significantly different from the 10th

day of the storage

time. The rate and degree of pericarp browning of the irradiated rambutan fruit were lower than the

control during the storage time. Among the irradiation treatments, the rate and degree of browning

at 300 Gy and packaging carton boxes + PE perforated 0.5% bags were lowest to compare with the

others. Radiation at low doses (<1 kGy) is not likely to affect the enzyme in the cells but have

capable limiting the activity of the enzyme [4] which is included as phenylalanine ammonia-lyase

(PAL), polyphenol oxidase (PPO) and peroxidase (POD) causes the browning by enzymes [5].

Packaging with PE bags was limited the loss of water in fruits, one of the causes of pericarp

browning [6].

The rate (%) and degree (score) of disease in the skin of rambutan fruits:

The Table 1 showed that the rate of disease under 10% on the 5th

days, increased in range

(34,38-95,84)% and (51,81-100)% of the 10th

and 13th

days of storage time, respectively. The

degree of disease also has the same trend, in the range (0-0,15) score on the 5th

days, (1,29-4,37)

score and (2-4,93) score on the 10th

and 13th

days post-treatment, respectively. Interactions between

the method of packaging and irradiation had not significant differences at the level of 5%.

Rambutan fruits were treated by irradiated at 200-500 Gy could not limit the fungal diseases

because the D10 value which dose can kill 90% pathogens in fruits is 1-3 kGy. The disease in the

skin of fruits increased slightly from 5th

to 10th

days in storage time and dramatically from 10th

to

13th

because of the emergence of disease infected in the former period. The high moisture and

nutrient inside containing bags were convenient conditions for disease growing the latter period.

The external color of the pericarp (including spinterns) (L*, a

*):

The external color of the fruit pericarp was not significant difference between all treatments

and decreased in storage time. External appearance for all treatments was acceptable after 5 and 10

days of storage but unacceptable after 13 days because disease and browning pericarp make

brightness (L* value) and red skin color (a

* value) descending. The obtained results were consistent

with studies in comparing two methods: irradiation and hot forced air treatment in R167 and R134

rambutan cultivars showed that irradiation treatment maintained the color outside of the fruits and

not significant differences with untreated fruits [3].

The weight loss (%):

The weight loss in the range (0.76-8.12)% after 5 days, had an increase in the range (0.85-

14,77)% and (1.42-16.66)% after 10 and 13 days of storage time, respectively. The weight loss

values were significant differences between two types of packaging on 5th,

10th

and 13th

of storage

time. These values for carton boxes + PE 0.5% perforated bags were significantly lower (fruit were

less intensely weight loss) than those of only carton boxes because the PE 0.5% perforated bags

could delay the loss of water by respiration of fruits. At 5 days post-treatment carton + PE treatment

had the weight loss more 7.13 times than PE, this value were 8.21 and 7.55 at 10 and 13 days

respectively. Between all treatments, the irradiated at 500 Gy and packed with carton boxes lost

most weight of 14.77% and 16.66% on 10 and 13d in storage time, respectively. The high dose

level and package in carton boxes without PE bags could make the aging process quickly,

increasing the respiration so that the weight loss had a strongly increase.

3.1.2. The biochemical qualities of pulp

The soluble solids (0Brix):

The soluble solids increased slightly during 1-2 days after harvest and storage in the room

temperature because of the dehydration and then decreased gradually due to the respiration of fruits.

Table 2 shows the soluble solids decrease of storage time, in the range of (15.50-18.60)0Brix on the

5th

day to about (15.50-17.00)0Brix on the 10

thday. As recorded data, there were no significant

VINATOM-AR 13--25


184

differences of interaction between packaging factors and irradiation factors. Irradiated at doses less

than 900 Gy did not affect to the nutritional composition of the fruit inside [2]. Packaging in carton

+ PE could limit the respiration and weight loss so that decrease the soluble solid value.

The titratable acidity (TA, %):

Total acid content of all treatments decreased slightly, in the range of (0.74-0,97)% and

(0.60-0.81)% on the 5th

and 10th

day during storage time (Table 2). Among irradiation treatments,

after 5 days storage, the highest total acid content was in control samples (1.06%) and the lowest

was at 300 Gy irradiated fruits (0.76%) and had significant differences. On the 10th

day, the highest

value of TA is at dose of 300 Gy (0.73%) but no significant differences compared to the other

treatments. This result is consistent with studies when comparing quarantine by irradiation at 250

Gy and hot forced air treatment showed rambutan irradiated had the total acid concentration

decreased more slowly than the other [3].

The Table 2 shows the vitamin C content tended to decrease during from (7.05-11.68)

mg.100g-1

on 5th

d and (7.04-9.87)mg.100g-1

on 10th

day in post-treatments. There were significant

differences between two methods packaging and no significant differences between five dose levels

of irradiation. Among all treatments, the highest vitamin C contents were at 300 Gy and packaging

carton + PE perforated bags with 11.68 and 9.16 mg.100g-1

, respectively.

3.1.3. The rate of membrane ion leakage (%)

The rate of membrane ion leakage increased in all treatments during time of preservation,

from the 5th

d in the range (52.03-63.76)%, on the 10th

d in the range (60.55-72.64)% and (65.74-

74.37)% on the last of storage time. This result means that the shelf-life of rambutan did not

maintain its quality as the earliest from the 10th

d of storage time. No significant differences

between the total ion leakage of all treatments because irradiation with a low-dose could not affect

the structure of fruit cell wall.

It was concluded that Java rambutan which was irradiated at 300 Gy by electron beams,

packed in carton boxes + PE 0.5% perforated bags had the rate and degree of browning pericarp

lowest among all treatments. In addition, preservation of carton + PE packaging could reduce the

loss of fruits rather than just packed in carton boxes. Irradiation treatment did not effect to the

quality of rambutan by investigating the pulp changes such as the soluble solids, vitamin C, total

acid content and the rate of membrane ion leakage.

3.2. The effects of post-harvested treatment and low-dose radiation to quality and

storage capacity of Java rambutan

3.2.1. The sensory qualities

The rate (%) and degree (score) of pericarp browning:

The Table 3 showed that treated rambutan (stored at 13oC, RH 85-90%) had begun

browning after 8 days. The rate of pericarp browning under 2.5% on the 8th

day, increased

dramatically less than 4.67% on the 12th

day and increased strongly from 4.94% to 25% on 16th

day

after storage. The method of postharvest and irradiation as well as interactions between them had

not significant difference at 5% on the 8th

and 12th

day but they had significantly different on the

16th

day of the storage time. The rate of browning at 300Gy combined dipping in hot water and then

Ca/A.C solutions had the lowest: 0% on 8th

day and increased slowly to 4.94% on the 16th

. The

highest in the irradiated treatment at 400 Gy: 2.5% on the 8th

day, 4.67% on the 12th

day and 25%

on the 16th

day, respectively.

The degree of pericarp browning under 0.06 score on the 8th

day, increased to 2.43 score on

the 12th

day and had continued from 0.6 to 4.83 score on the last day of the storage time. Among all

treatments, the degree of pericarp browning of the rambutan which is dipping in Ca/A.C lowered

VINATOM-AR 13--25


185

than others. Controls through the storage time and among the irradiation treatments, the 300 Gy

irradiation and packaging carton boxes + PE perforated 0.5% bags gave the lowest rate and degree

of browning. The method of postharvest and irradiation as well as interactions between them had

not significant difference at 5% on the 8th

and 12th

day.

The rate (%) and degree (score) of disease in the skin of rambutan fruits:

The Table 3 showed that the rate of disease in the skin rambutan fruits increased during

storage time. The rate was in the range (8.83-18.43)% on the 8th

days, increased in range (13.27-

40.00)% and (74.17-100)% of the 12th

and 16th

days of storage time, respectively. The method of

packaging and irradiation as well as interactions between them had not significant differences at 5%

on the 8th

and 12th

day. The disease in the skin of rambutan fruits increased slightly from 8th

to 12th

days in storage time and increased dramatically from 12th

to 16th

because of the emergence of the

disease infested in the former period.

The degree of disease in the skin of rambutan less than 0.55 score on the 8th

, in the range

(2.34-3.75) on the 12th

and increased (3.88-4.93) on the last day of storage time. Among all

treatments, the rambutan post-harvested by hot water treatment, dipping in Ca/A.C and irradiated at

300Gy had the lowest degree of disease with 0.16, 2.34 and 3.88 score on the time of evaluation,

respectively. Treatment irradiated at doses 400 Gy had the highest level of disease with 0.55, 3.75

and 4.93 score on the 8th

, 12th

and 16th

day in storage, respectively.

The external color of the pericarp (including spinterns) (L*, a

*):

The external appearance for all treatments tended to decrease during storage time. Treated

with hot water and dipping in Ca/A.C could maintain peel color of fruits through L* and a

* value.

Rambutan that treated in Ca/A.C solutions had the brightest color and keeping the original color of

their pericarp.

The weight loss (%):

The percentage weight loss increased with storage time, in the range (0.64-1.18)% after 8

days, had an increase in the range (1.24-2.22)% and (1.96-4.07)% after 12 and 16 days of storage

time, respectively. Rambutan treated by hot water and dipping in Ca/A.C and irradiated at a dose of

300 Gy had the percentage of weight loss at least (1.96)%, while rambutan irradiated at 400 Gy had

the largest weight loss (4.07)% on the 16th

day of storage time. This can be explained by the

conjunction calcium-pectate when fruits dipped in Ca/A.C solutions; and radiation at 400 Gy

increased respiration of fruits resulted in the loss of weight.

3.2.2. The biochemical qualities of pulp

The soluble solids (0Brix):

Table 4 described the soluble solids of rambutan posttreatment decrease of storage time, in

the range of (16.73-17.47)0Brix on the 8

th day to about (16.00-17.00)

0Brix on the 12

thday,

significant differences between two factors experiment. This is explained by nutrients in the pulp

maintained until the 12th

day preservation. Among all treatments, the rambutan which irradiated at

400 Gy had a strongly decrease of the soluble solids.

The titratable acidity (%):

Total acid content of all treatments fruits decreased slowly in the range (0.81-0.85)% and

(0.73-0.83)% on the 8th

and 12th

day during storage time (Table 4). Among irradiation treatments,

there were not significant differences until 12 days after storage because combining between

postharvest handling and irradiation did not increase the aging process of the fruit itself.

Vitamin C content of Java rambutan also decreased with storage time, in the range

(4.36-5.77) mg.100g-1

on the 8th

day and between (3.29-5.07)mg.100g-1

on the 12th

day post-

VINATOM-AR 13--25


186

treatments. No significant differences between pretreatment methods and their interaction had

significant differences. Among all treatments, the highest vitamin C contents in fruits dipping in

Ca/A.C solutions and irradiated at 300 Gy and packaging carton + PE perforated bags was 5.77 and

5.07 mg.100g-1

on the 12th

and 16th

day, respectively.

3.2.3. The rate of membrane ion leakage (%)

The rate of membrane ion leakage increased in all treatments over time preservation because

of the decrease of cell wall structure. Table 3 showed that this value was in the range (42.50-

48.41)% on the 8th

day, on the 10th

day in the range (53.23-61.50)% and (53.64-64.92)% on the last

of storage time. No significant differences between the total ion leakage of all treatments on the 8th

day but significant difference on others days during storage time. Compared with controls, hot

water treatment and dipping in Ca/A.C solutions were capable of limiting membrane ion leakage

until 16 days.

4. CONCLUSIONS

Combination of post harvested treatments and quarantine irradiation could keep the sensory

and biochemical pulp quality of Java rambutan during storage. Fruits treated by hot water and

dipping in Ca/A.C before irradiated at 300 Gy by electron beams could prolong the its shelf-life

more 4 days in 13oC, RH=85-90% compared to non-treatment.

REFERENCES

[1] [APHIS], Animal and Plant Health Inspection Service, 2008b. Importation of Red

Dragonfruit (redpitaya) (Hylocereus spp.) from Vietnam into the Continental United States.

http://www.regulations.gov/search/Regs/contentSteamerS, 2008.

[2] Fan, X., Niemera, B. A., Mattheis, J. P., Zhuang, H., & Olson, D. W. Quality of fresh-cut

apple slices as affected by low-dose ionizing radiation and calcium ascorbate treatment.

Journal of Food Science, 70(2), 143-148, 2005.

[3] Follet, P. A., and Sanxter, S. Comparison of rambutan quality after hot forced-air and

irridation quarantine treatments. HortScience(7):1315-1318, 2000.

[4] Horak, C. I., Adeil Pietranera, M., Malvicini, M., Narvaiz, P., Gonzalez, M., & Kairiyama,

E. Improvement of hygienic quality of fresh, pre-cut, ready-to-eat vegetables using gamma

irradiation. In Use of irradiation to ensure the hygienic quality of fresh, pre-cut fruits and

vegetables and other minimally processed food of plant origin. Proceedings of a final

research coordination meeting organized by the Joint FAO/IAEA Programme of Nuclear

Techniques in Food and Agriculture and held in Islamabad, Pakistan, 22-30 July 2005 (pp.

23-40). Vienna: International Atomic Energy Agency, 2006.

[5] P. Yingsana, V. Srilaong, S. Kanlayanarat, S. Noichinda, W.B. McGlasson. Relationship

betwwen browning and related enzymes (PAL, PPO and POD) in rambutan fruit

(Nephelium lappaceum Linn,) cv. Rongrien and See-Chompoo. Postharvest Biology and

Technology (50): 164-168, 2008.

[6] T.J. O’Hare. Postharvest physiology and storage of rambutan. Postharvest Biology and

Technology, (6), 189-199, 1995.

http://www.regulations.gov/search/Regs/contentSteamerS

VINATOM-AR 13--25


187

Table 1: The effects of packaged and low-dose irradiated treatment to the rate and degree of pericarp browning, the rate and degree of disease, the

weight loss of rambutan (storaged in 13oC, RH=85-90%).

Packagi

ng (A)

Dose

(B)

The rate of pericarp

browning

(%)

The degree of

pericarp browning

(score)

The rate of disease

(%)

The degree of disease

(score)

The weight loss

(%)

5th

10th

13th

5th

10th

13th

5th

10th

13th

5th

10th

13th

5th

10th

13th

Carton 200 Gy 2.5 37.50 53.13 0.025 0.42 2.56 5 34.38 65.63 c 0.125 1.35 2.66 cd 8.12 12.30 15.63

300 Gy 2.5 11.46 14.59 0.025 0.20 1.88 0 35.42 63.54 c 0 1.29 2.22 d 6.16 10.93 16.26

400 Gy 2.5 16.67 51.05 0.025 1.99 4 2.5 51.05 85.42 ab 0.025 2.26 4.27 ab 6.90 12.29 14.13

500 Gy 2.5 42.71 100 0.025 2.35 4 0 88.54 85.42 ab 0 3.91 4.27 ab 7.61 14.77 16.66

Control 2.5 62.50 100 0.025 2.59 3.90 2.5 75.00 77.08 ab 0.025 2.53 3.24 c 6.54 10.93 15.81

Carton +

PE

200 Gy 0 11.25 11.46 0 0.41 0.41 0 95.84 93.75 a 0 3.70 4.69 a 0.84 2.37 2.71

300 Gy 0 4.17 4.25 0 0.13 0.20 2.5 42.71 51.81 d 0.025 1.66 2.00d 0.76 0.85 1.42

400 Gy 0 7.29 14.58 0 0.25 0.71 10 92.71 100 a 0.15 4.37 4.74 a 1.12 1.05 0.92

500 Gy 0 13.38 19.79 0 0.27 0.66 0 86.63 100 a 0 3.91 4.93 a 0.96 1.40 2.75

Control 0 28.13 54.17 0 2.21 1.41 10 68.75 89.59 ab 0.125 1.61 3.42 bc 1.31 1.82 2.62

CV (%) 27.34 22.22 14.50 23.63 15.26 12.75 33.23 11.12 9.04 37.89 17.77 11.56 29.22 11.57 18.97

A ns * * ns * * ns ns ns ns ns ns * * *

B ns * * ns * * ns ns ns ns ns ns ns * ns

A*B ns * * ns * * ns ns ns ns ns ns ns * ns

ns, *: non significant and significant at p≤ 0.05

VINATOM-AR 13--25


188

Table 2: The effects of packaged and low-dose irradiated treatment to the soluble solids, the titratable acidity, the ascorbic acid content, the external

color of pericarp (L* and a

*) and the rate of membrane ion leakage of rambutan (storaged in 13

0C, RH=85-90%).

Packaging

(A)

Dose

(B)

The soluble

solids (0Brix)

The titratable

acidity

(%)

The ascorbic

acid content

(mg.100g-1

)

L* a

*

The rate of membrane

ion leakage

(%)

5th

10th

13th

5th

10th

13th

5th

10th

13th

5th

10th

13th

5th

10th

13th

Carton 200 Gy 16.50 16.00 0.62 0.92 bc 7.85 7.74 39.18 34.21 32.32 22.04 19.36 19.85 53.81 57.92 60.55

300 Gy 17.50 17.00 0.66 0.85 cde 8.96 8.66 42.66 34.48 31.12 22.79 19.20 19.36 47.94 59.76 60.77

400 Gy 17.00 16.25 0.64 0.89 bcd 7.05 7.04 37.94 32.38 29.87 22.31 21.26 17.93 51.49 54.87 61.95

500 Gy

18.60 16.50 0.81 0.74 ef 8.96 8.86 38.07 30.34 29.80 22.04 16.54 17.52 54.18

54.38

61,53a

61.53

Control 16.90 17.00 0.78 1.15 a 9.77 8.96 37.86 33.29 33.26 20.70 15.58 18.10 53.76 55.16 65.60

Carton +

PE

200 Gy 15.60 17.00 0.66 0.89 bcd 9.87 8.36 38.58 35.74 29.14 21.23 16.43 16.99 47.60 49.27 53.37

300 Gy 18.60 16.50 0.60 0.73 f 11.68 8.86 39.08 34.03 32.07 24.23 21.28 16.96 56.57 54.64 72.74

400 Gy 16.90 16.25 0.63 0.79 def 10.67 9.16 36.87 28.87 30.64 20.85 18.25 15.95 53.90 54.37 79.43

500 Gy 16.25 15.50 0.65 0.78 ef 10.47 9.87 37.08 31.29 30.47 21.23 19.58 16.42 57.01 59.70 62.75

Control 17.25 16.75 0.64 0.97 b 9.46 8.66 38.35 35.09 32.38 19.70 16.11 17.37 52.02 57.17 60.52

CV (%) 4.26 5.66 15.41 5.47 9.15 11.11 4.94 5.07 6.27 7.26 10.08 7.54 6.05 7.28 17.60

A ns ns ns * * * ns ns * ns * * ns ns ns

B ns ns ns * ns ns ns ns ns ns ns ns ns ns ns

A*B ns ns ns * ns ns ns ns * ns * ns ns ns ns

VINATOM-AR 13--25


189

Table 3: The effects of pre-irradiated treatment and low-dose irradiation to the rate and degree of pericarp browning, the rate and degree of disease,

the weight loss of rambutan (storaged in 130C, RH 80-85%)

Dose

(A)

Pre-radiated

(B)

The rate of pericarp

browning

(%)

The degree of

pericarp browning

(score)

The rate of disease

(%)

The degree of disease

(score)

The weight loss

(%)

8th

12th

16th

8th

12th

16th

8th

12th

16th

8th

12th

16th

8th

12th

16th

300 Gy Control 2.50 6.67 15.83ab 0.05 0.8ab 2.7ab 18.43 25.83 98.33 0.33 3.63 4.87a 1.10 2.22 2.89bc

T0 + MCP 0.00 4.17 5.00b 0.00 0.5ab 1.8ab 18.07 21.67 95.83 0.25 3.31 4.42ab 1.15 2.20 3.27ab

T0 + Ca/A.C 0.00 0.00 4.94b 0.00 0b 0.6b 8.83 13.27 74.17 0.16 2.34 3.88b 1.09 1.62 1.96d

T0 + Ca/A.C

+ MCP 0.00 1.67 5.00b 0.00 0b 0.7b 9.93 23.33 87.50 0.20 2.75 4.69a 0.64 1.24 2.08cd

400 Gy Control 2.50 4.17 25.00a 0.06a 2.4a 4.8a 20.23 40 100 0.55 3.75 4.93a 0.78 1.95 3.13b

T0 + MCP 0.83 1.67ab 5.83b 0.00 1ab 2.1ab 18.33 25.83 95.83 0.28 3.21 4.55ab 0.98 1.91 3.23ab

T0 + Ca/A.C 0.00 0.00 5.00b 0.00 0.4b 0.7b 10.87 14.19 98.33 0.17 3.34 4.83a 1.18 2.15 4.07a

T0 + Ca/A.C

+ MCP 0.00 0.00 10.00b 0.00 0.5ab 2.2ab 12.42 17.50 90.83 0.27 2.82 4.89a 0.97 1.53 2.87bc

CV (%) 29.97 27.66 34.74 29.73 27.8

6

19.69 17.75 57.97 6.88 33.65 12.90 9.09 38.18 36.34 17.10

A ns ns ns ns ns ns ns ns ns ns ns ns ns ns *

B ns * * ns * * ns * ns ns * ns ns ns *

A*B ns ns * ns ns * ns * ns ns * ns ns ns *

VINATOM-AR 13--25


190

Table 4: The effects of pre-radiated treatment and low-dose irradiated to the soluble solids, the titratable acidity, the ascorbic acid content, the

external color of pericarp (L* and a

*) and the rate of membrane ion leakage of rambutan (storaged in 13

0C, RH 80-85%).

Dose

(A)

Pre-radiated

(B)

The soluble

solids (0Brix)

The titratable

acidity (%)

The ascorbic acid

content (mg.100g-1

)

L* a

* The rate of membrane

ion leakage (%)

8th

12th

8th

12th

8th

12th

8th

12th

16th

8th

12th

16th

8th

12th

16th

300 Gy Control 16.73 16.00 0.79 0.85 4.70 2.89 34.23 29.26 26.54 22.54 15.77 14.31 48.37 56.69 64,92

T0 + MCP 17.27 16.67 0.81 0.77 4.43 3.56 36.33 32.73 25.02 21.06 19.62 13.53 43.17 54.77 56,49

T0 + Ca/A.C 17.47 17.00 0.84 0.73 5.77 5.07 37.85 34.09 29.77 26.21 20.25 15.99 42.50 53.23 53,64

T0 + Ca/A.C

+ MCP 17.00 16.80 0.83 0.82 4.43 3.59 37.50 32.16 25.99 24.85 19.95 14.12 44.69 55.96 57,03

400 Gy Control 16.93 16.07 0.83 0.85 4.36 3.39 34.39 29.54 25.13 23.32 20.25 13.91 48.12 61.50 63,09

T0 + MCP 16.93 16.47 0.82 0.82 4.43 3.40 37.37 28.53 26.74 22.53 18.20 13.64 48.41 61.33 63,96

T0 + Ca/A.C 17.00 16.60 0.85 0.77 4.36 4.09 36.49 26.82 25.75 22.03 18.47 13.44 45.45 56.59 57,53

T0 + Ca/A.C

+ MCP 16.90 16.40 0.83 0.83 4.70 3.39 35.38 25.91 25.73 21.09 16.02 11.50 45.22 57.33 62,27

CV(%) 1.31 2.55 4.37 4.55 12.01 18.83 4.00 5.81 6.92 6.96 8.30 12.20 7.07 5.87 6.28

A ns ns ns ns ns ns * * * * ns ns ns * *

B * * ns ns ns * ns * * * * ns ns ns *

A*B ns * ns ns ns * * * * * * ns ns * *

VINATOM-AR 13--26


191

RESEARCH AND ESTABLISHMENT OF THE ANALYTICAL

PROCEDURE FOR/OF Sr-90 IN MILK SAMPLES

, , Duong Duc Thang, Nguyen Thi Linh and Bui Thi Anh Duong

Center for Radiation Protection and Environmental Monitoring,



ABSTRACT: Sr-90 is an indicator for the transfer radionuclides from environment to human. This work was

setup to build a procedure for Sr-90 determination in main popular foodstuff and focus to fresh milk. The deal

of this work was establish procedure for Sr-90, assessment for chemical yield and test sample of Vietnam

fresh milk, also in this work, the QA,QC for the procedure was carried out using standard sample of IAEA.

The work has been completed for the procedure of determination Sr-90 in milk. The chemical yield of recovery

for Y- 90 and Sr-90 were at 46.76 % ±1.25% and 0.78 ± 0.086, respectively. The QA & QC program was

carried out using reference material IAEA -373. The result parse is appropriate equally and well agreement

with the certificate value. Three reference samples were analyses with 15 measurements. The results of Sr-90

concentration after processing statistics given a value at 3.69 Bq/kg with uncertainty of 0.23 Bq/kg. The

certificate of IAEA-154 for Sr-90 (half live 28.8 year) is the 6.9 Bq/kg, with the range 95% Confidence

Interval as (6.0-8.0 ) Bq/kg at 31st August 1987. After Adjusting decay, the radioactivity at this time is 3.67

Bq/kg. It means that such the result of this work was perfect matching the value of stock index IAEA. Five

Vietnam fresh milk samples were analyzed for Sr-90, the specific radioactivity of Sr-90 in milk were in a range

from 0.032 to 0.041 Bq/l.

Keyword: Milk, Sr-90, chemical procedure.

1. INTRODUCTION

Approximately 99% of Sr-90 in the environment is due to the nuclear tests (16.8 million

curies to 1980) and the second largest amount is from the Chernobyl nuclear power plant accident

(216 million curies) had spread in atmosphere. Sr-90 enters the human body through the ingestion

and inhalation. Sr-90 is an indicator for the transfer radionuclides from environment to human.

The nations of the world have the radiation monitoring program regularly Sr-90 in various

subjects, such as soil, vegetables, milk and water over the whole country and especially around the

area nuclear power plants. The Sr-90 activity in every monitoring points and stations had been

reports each year to government.

The principle of Sr-90 analysis is determine the activity of 90

Sr through radioactivity of its

daughter isotopes, 90

Y (β-ray), after separation Sr-90 from the components in the sample,

subsequent samples to accumulate until it reaches equilibrium 90

Sr - 90

Y (about two weeks) and

measurement Y-90 in the form of Y2(C2O4)3 using low level Beta counting.

The Sr-90 radioactivity calculated by following equation:


- Code: CS/13/04-04




- Contact email:


Tran Thi Tuyet Mai

VINATOM-AR 13--26


192

Sr

SrSrYE

nnAA90

100100

60

1)(

2

009090

where: n0 n0 : count rate of 90

Y at the time separation from 90

Y/90

Sr (cpm)

E2: efficiency count compared with standard sources (%).

SrY90 : Efficiency separating of

90Sr (%).

2. SAMPLING AND PROCESS ANALYSIS

2.1. Sampling and sample preparation

Fresh milk samples are often preserved with formaldehyde (HCHO) or sodium azide

(NaN3) and stored to obtain 90

Y in the cases where 90

Sr and 89

Sr must be determined. Samples

were ashes at 450oC temperature of about 12 hours to decompose the organic compounds. Add to

form a carrying amount of Sr2+

stable. Carriers, Strontium in the sample were extracted with

concentrated hydrochloric acid solution. Finally SrCO3 precipitate dried weight to determine the

chemical separation of 90

Sr performance. 90

Sr activity was determined by measuring the isotope

separation and its progeny is 90

Y.

2.2. Procedure

A. Prepare:

Chemicals

Carriers Sr2+

10mg/ml

Carriers Y3+

10mg/ml

HCL Solution 6M, 3M, 0.5M

Crystal H2C2O4

The solution (NH4)2C2O4; solution of (NH4)2C2O4 saturation

NH4OH Solution 25%

NaOH Solution 6M

Solution marks isotope 85

Sr (10 Bq/ml)

CH3COONH4 Solution 2M

Methyl alcohol

Solution (NH4)2CO3 saturation

PH indicator paper

Distilled.

Tools

Electric stove

Flask, heat-resistant glass, glass rod

Filter funnels filter paper

Ceramic cup

Desiccators

Ion exchange column (diameter 20mm, h=190mm)

VINATOM-AR 13--26


193

Pipet, micropipette.

Equipment

Analytical balance

pH measuring machine

Drying cabinet, centrifuges, and furnaces.

Total beta measuring machine such as PIC Model 9300, designed to fit the measurements of

low level radiation. Solid Geometry sample, sample tray diameter 50mm, range beta radiation

energy of 50 3000 keV, background count rate for 0.5 channel beta counting pulses/min. Relative

performance of about 50%.

Ion exchange resin: type cation exchange resin DOWEX 50 - X8 (100-200 mesh).

Plastic glasses were soaked in distilled water, stir and let stand, decant water.

Add 1 volume of 6M HCl by volume of resin, and stirred for 15 minutes; then decant the

water.

Wash the resin with water, the process is repeated until pH = 7.

Plastic treated with 6M NaOH, then rinsed with distilled water to pH = 7.

Pour the resin into the column (diameter 10 mm 26cm).

Preparing the form of H +: A volume equal to 10 times the volume of heavy plastic over the

column, then rinse with water. After all of the above procedures, the column can be used to analyze

samples.

Recycling with 6M HCl 500ml and 300ml distilled water; reusable plastic column.

B. Principle analyses:

Take about 10 g ash sample into a 500ml beaker.

Add 5 ml carrier solution SR2+

(10mg Sr2+

/ml). Add 20 ml of concentrated nitric acid

(HNO3); heat to dryness; add acid mixture HCL and HNO3 with a 2:1 ratio.

Heat to dryness the solution to about 1/3 then diluted to 700ml by distilled water, heated at

80oC temperature.

Add 10g H2C2O4, then add little NH4OH and adjust the pH from 4 to 4.2. Heat for a few

hours to complete precipitation; cooling the solution (test by giving one by one drop of (NH4)2C2O4

into filtrate, if there precipitate repeat this procedure).

Filtering the precipitate, wash the precipitate three times with a solution of (NH4)2C2O4

0.02M. Transfer precipitate and filter paper into porcelain cup. Furnace at 6000C for 3 hours.

Dissolve the ash with 3M HCl, transfer the filtrate into a 200ml beaker. Heat the filtrate to

dryness on hot plate. Dissolve the residue in 100 to 150ml 0.5M HCl, this is sample solution.

Pour the sample solution into exchange column; add about 30 ml of distilled water with a

flow rate of 2-3 ml/min. Removed the sample solution after through the exchange column.

Desorption Ca2+

by 250ml (CH3COONH4 2M and CH3OH; volume ratio 1:1) solution with

a flow rate of 2-3 ml/min.

Desorption Sr2+

by 200ml (CH3COONH4 2M) solution with a flow rate 2-3 ml/min.

Evaporating eluent solution SR2+

to about half, adjusting pH = 9 by add NH4OH (no CO2).

VINATOM-AR 13--26


194

Add 10ml saturated (NH4)2CO3 solution, heated on hot plate for a few minutes to form

SrCO3 precipitation.

Filtering the precipitate, record time, washed with a small amount of 0.1M NH4OH solution.

Dissolve the precipitate with 2M HCl. Using Gamma spectrometry to determine the Sr2+

separation

efficiency by measuring 85

Sr . Add 1 ml of Y3+

, and to accumulate for 14 days.

Add NH4OH (no CO2), adjust pH = 8, to form Y(OH)3 precipitate; record time separated Y

from Sr; filter and wash with dilute ammonia.

Add 1ml Sr2+

as a store carrier. Repeat to form Y(OH)3 precipitation.

Dissolve the precipitate with 2M HCl; heat and add H2C2O4 2g (adjust pH = 1-1.5 by

NH4OH to form Y2(C2O4)3 precipitation.

Filter and dry the precipitation.

Measuring and counting on low background beta spectrometry.


After equilibrium, the Y-90 of standard sample was separated from Sr-90 in the form of

Y2(C2O4)3 and the decay of Y-90 by the time (haft live 64h) was checked using low level Beta

counting. The count per minute vs. the time was shown in picture 1.

y = 9.4529e-0.0105x

R2 = 0.9914

1

10

0 20 40 60 80 100 120

Thôøi gian, giôø

So

á ñe

ám/p

hu

ùt

Figure 1: Decay of 90

Y maternal separation.

Efficiency Split Y-90 (chemical yield) is the 46.8% with standard deviation is the 1.2%.

And Chemical separation Efficiency of Sr-90 is the average 78.5% ± 2%. The specific

activities of Sr-90 milk samples were calculated and corrected decay time, the results are described

in Table 1. The parameters of chemical procedure were shown in table 2.

Table 1: Results of milk sample activity measured at the time of measurement.

Sample

name

carrier

Y3+

ml

Measurement sample of date

Date

receipt of

samples

Activity Error

Date,

Month Hour Min

BL* SD

M01 10 11/6/13 10 0 6/30/2013 0.0299 0.0038

M01 10 11/6/13 10 0 6/30/2013 0.0427 0.0034

Count p

er min

ute

Time, h

VINATOM-AR 13--26


195

M02 10 11/6/13 9 29 8/30/2013 0.0428 0.0033

M02 10 11/6/13 9 29 8/30/2013 0.0288 0.0040

M03 10 11/4/13 11 28 6/30/2013 0.0468 0.0034

M03 10 11/4/13 11 28 6/30/2013 0.0359 0.0037

M04 10 11/4/13 13 59 6/30/2013 0.0575 0.0044

M04 10 11/4/13 13 59 6/30/2013 0.0488 0.0035

M05 10 11/6/13 10 4 8/30/2013 0.0349 0.0037

M05 10 11/6/13 10 4 8/30/2013 0.0471 0.0034

* Blank sample.

Table 2: The processing parameters Sr-90 in milk samples.

Sample

name

Volume,

liter

Date

collecting

Mash,

g

Efficiency

of

separation

Error Date

cumulative

The number

of days

accumulated

Equilib

rium

Sr/Y

M01 1.3 30/6/201

3 10.7 0.89 ± 0.02 22/10/2013 129 1

M02 1.35 30/6/201

3 11 0.85 ± 0.02 22/10/2013 68 1

M03 1.35 30/6/201

3 12 0.76 ± 0.02 22/10/2013 127 1

M04 1.5 30/8/201

3 11.5 0.77 ± 0.02 22/10/2013 127 1

M05 1.5 30/8/201

3 13.2 0.66 ± 0.02 22/10/2013 68.00 1

After adjusting the volume of the sample, the measured activity was converted to the

specific activity in Bq/liter with 2σ uncertainties (Table 3).

Table 3: Results of analysis of the average specific activity

of Sr-90 in milk of Vietnam samples.

Sample

name Average activity, Bq Error

Average specific activity

Bq/liter Uncertainty

M01 0.036 0.006 0.032 0.011

M02 0.036 0.007 0.031 0.012

M03 0.041 0.005 0.040 0.011

M04 0.053 0.006 0.046 0.010

M05 0.041 0.006 0.041 0.013

VINATOM-AR 13--26


196

4. CONCLUSION

- The work has been completed for the procedure of determination Sr-90 in milk. The

chemical yield of recovery for Y-90 and Sr-90 were at 46.76 % ±1.25% and 0.78 ± 0.086,

respectively.

- The QA & QC program was carried out using reference material IAEA -373. The result

parse is appropriate equally and well agreement with the certificate value.

- Three reference samples were analyses with 15 measurements. The results of Sr-90

concentration after processing statistics given a value at 3.69 Bq/kg with uncertainty of 0.23 Bq/kg.

The certificate of IAEA-154 for Sr-90 (half live 28.8 year) is the 6.9 Bq/kg, with the range 95%

Confidence Interval as (6.0-8.0) Bq/kg at 31st August 1987. After Adjusting decay, the

radioactivity at this time is 3.67 Bq/kg. It means that such the result of this work was perfect

matching the value of stock index IAEA.

- Five Vietnam fresh milk samples were analyzed for Sr-90, the specific radioactivity of

Sr-90 in milk were in a range from 0.032 to 0.041 Bq/l.

Acknowledgments

The project was completed under the sponsorship of the Institute for Nuclear Science and

Technology, Institute of Atomic Energy, Ministry of Science and Technology, 2013 base level

project.

REFERENCES

[1] [1] VANEY, B., FRIEDLI, C., GEERING, J.J., LERCH, P., Rapid trace determination of

radio strontium in milk and drinking water, J. Radioanal. Nucl.Chem, Articles, 134(1), pp.

87-95, 1989.

[2] [2] BARATTA, E.J., Strontium-89 and strontium-90 in milk, in Horwitz W. (Ed.),Official

methods of analysis of AOAC International, 17th edn. AOAC International, Gaithersburg,

Maryland, USA, chapter 13, 3-6, 2000.

[3] [3] MELIN, J., SUOMELA, J., Rapid determination of 89

Sr and 90

Sr in food and

environmental samples by Cerenkov counting: In Rapid Instrumental and Separation

Methods for Monitoring Radionuclides in Food and Environmental Samples, Final Report on

an IAEA Co-ordinated Research Program, International Atomic Energy Agency,

IAEA/AL/088, Vienna, Austria, 1995.

[4] [4] BRUN, S., KERGADALLAN, Y., BOURSIER, B., FREMY, J., JANIN, F.,

Methodology for determination of radio strontium in milk: a review, Lait 83, pp.1-15, 2003.

[5] [5] BRUN, S., BESSAC, S., URIDAT, D., BOURSIER, B., Rapid method for determination

of radio strontium in milk. Radioanal, Nucl. Chem., 253(2), pp.191-197, 2002.

[6] [6] HONG, K.H., CHO, Y.H., LEE, M.H., CHOI, G.S., LEE, C.W., Simultaneous

measurement of 89Sr and 90Sr in aqueous samples by liquid scintilla counting using the

spectrum unfolding method, Appl. Radiat. Iso., 54, pp. 299-305, 2001.

[7] [7] HEILGEIST, M, Use of extraction chromatography, ion chromatography and liquid

scintillation spectrometry for rapid determination of strontium-89 andstrontium-90 in food in

cases of increased release of radionuclides, Radioanal,Nucl. Chem, 245(2), pp. 249-254,

2000.

[8] [8] CHOBOLA, R., MELL, P., DAROCZI, L., VINCZE, A., Rapid determination of radio

strontium isotopes in sampe of NNP origin, J. Radioanal, Nucl. Chem., 267(2), pp.297-304,

2006.

[9] [9] EIKENBERG, J., BEER, H., RÜTHI, M., ZUMSTEG, I., VETTER, A., Precise

determination of 89Sr and 90Sr/90Y in various matrices: The LSC 3-window approach, in:

Chalupnik, S., Schőnhofer, F., Noakes, J. (Eds), LSC2005, Advances in liquid scintillation

spectrometry, Radiocarbon, Arizona, USA, pp.237-249, 2005.

VINATOM-AR 13--27


197

PRELIMINARY ASSESSMENT ABOUT GENETIC DIVERSITY,

THE STABILITY OF POTENTIAL MUTANTS FROM TWO VARIETIES

OF CHRYSANTHEMUM MORIFOLIUM RAMAT. (BRONZE DOA

AND PURPLE FARM) VIA GAMMA IRRADIATION

Nguyen Tuong Mien, Le Ngoc Trieu, Le Tien Thanh,

Pham Van Nhi and Huynh Thi Trung

Center for Applications of Nuclear Technique in Industry, Vietnam Atomic Energy Institute

ABSTRACT: The objects of radiation breeding were chosen, collected and in vitro propagated. The suitable

modalities for acute and chronic irradiation the materials were determined. Two acute and one chronic

irradiation series were executed. Thus, the irradiated materials were achieved to screening for the mutants. In

this study, on farm, through screening 18 phenotypic mutants of both chrysanthemums were recorded and

collected including 6 potential mutants that selected for next research based on their phenotypic differences to

the originals, their aesthetic and low mosaic. These 6 potential mutants together with their original varieties

were micro-propagated to induce the potential mutant lines for estimation on farm of mutant characteristic

segregation rates. Six potential mutant lines of E2a, E2c, E28, E29, I7, I8 are morphologically and genetically

different to their original varieties, possess the identification markers and aestheticism. They were

morphologically stable on farm through 3 series of growing on farm at M1V3, M1V5 and M1V7 generations.

In the genetic respect, they possessed the high stabilities through in vitro generations. All of these criteria show

that, these mutant lines were already to be registered as temporary cultivars/varieties.

I. INTRODUCTION

Chrysanthemum morifolium Ramat is in great demand and widespread in Vietnam as well as

in the world. Most of current cultivated chrysanthemum varieties in Dalat city were imported from

Holland and other neighboring countries. Therefore, it’s necessary to domestically create new

varieties for chrysanthemum cultivation in Dalat to overcome the commercial barriers related to

copyright and local agriculture improvement. Mutation breeding in general and Radiation breeding

in particular allow to obtain new chrysanthemum varieties/lines that differentiated from the

originals in single or multiple phenotypic characteristics such as the color or shape, which

determine their decorative values in relatively short time. The traditional breeding methods like

crossing, screening from nature have been limited in species scope. In most cases of

chrysanthemum, main effect of mutagens on exposed materials were changing color of the

inflorescence, the changes of plant habit or changes in the shape and size of leaves and

inflorescence or the number and of ligulate florets were observed at less frequently. [Banerji and

Datta 1990, Zalewska 2001, Zalewska 2010].

In mutation radiation breeding, both in vivo materials such as shoots, leaves, cutting and/or

whole plants and in vitro materials such as callus, tissue, suspensions of cells, protoplasts etc. have

been used for irradiation treatment. In this study, artificial seeds were used as material for gamma

irradiation to induce mutant base on previous researches of self-authors with the purpose of genetic

diversity and stability estimation of induced mutant lines subsequently.


- Code: CS/13/06-03



- Implementation time: 14 months (May 2013 - Jun 2014)



VINATOM-AR 13--27


198

In the first phase study, on farm, through screening 18 phenotypic mutants of both

chrysanthemums were recorded and collected including 6 potential mutants that selected for next

research based on their phenotypic differences to the originals, their aesthetic and low mosaic.

These 6 potential mutants together with their original varieties were micro-propagated to induce the

potential mutant lines for estimation on farm of mutant characteristic segregation rates.

II. OVERALL GOAL AND MAIN CONTENTS

The aim of this study was to demonstrate the mutant generation effects of gamma rays on

chrysanthemum artificial seeds to establish the scientific base for application this technique in

similar objects.

Three main activities:

+ Micropropagation to induce the potential mutant lines for estimation on farm of mutant

characteristic segregation rates.

+ Genetic diversity estimation in potential mutant lines, determine the genetic differences

among mutant lines and their original cultivars.

+ Outstanding mutant lines genetic stability estimation through in vitro generations.

III. MATERIAL AND METHOD

The objects of investigation are two varieties of chrysanthemum belong to Chrysanthemum

morifolium Ramat species, which one possesses copper and another possesses purple color

inflorescence, these two varieties are different in structure petals (pictures below).

Bronze chrysanthemum. Purple chrysanthemum.

In the first phase study, on farm, through screening 18 phenotypic mutants of both

chrysanthemums were recorded and collected including 6 potential mutants that selected for next

research based on their phenotypic differences to the originals, their aesthetic and low mosaic.

VINATOM-AR 13--27


199

Table 1: Six potential mutants that seclected in the firsrt phase.

These 6 potential mutants together with their original varieties were micro-propagated to

induce the potential mutant lines for estimation on farm of mutant characteristic segregation rates.

In the third generation, after four weeks for growth, the in vitro plants were injected into the fresh

MS medium for 2 weeks for rooting and complete formed plantlets induction.

The completed in vitro plantlets were transferred to ex vitro condition and injected into foam

trays filled with substrate of treated soil, investigate to screen the arisen phenotypic changes if any

during greenhouse stage and record the survival rate of plantlets after 30 days.

Next to the greenhouse stage, the survival plantlets were transplanted into soil-beds in

plastic house with the modified modality of commercial cultivation protocol for chrysanthemum of

CANTI (plants were only exposed to natural photoperiod, without supplementary illumination).

Planted chrysanthemum in plastic house were followed and recorded for criteria of survival

rate, arisen phenotypic mutant characteristics such as color and shape and structure of

inflorescences and leaves, stem’s height etc. compared to the controls (non-irradiated originals)

during the cultivation until completely blooming. The recorded phenotypic mutants will be

collected for micro-propagation.

Potential phenotypic mutants will be selected from all of screened phenotypic mutants if

they possess the obviously different from the controls about color or structure of inflorescences,

good aestheticism and low mosaic.

In the genetic respect, they possessed the high stabilities through in vitro generations. All of

these criteria show that, these mutant lines were already to be registered as temporary

cultivars/varieties.

No Sign

al

Gamma

Dose (Gy)

Charac-

teristic

The first selection

Picture No Signal

Gamma

Dose (Gy)

Charac-

teristic

The first selection

Picture

1 I8 40

Fresh

yellow,

short and

uncurled

petal

4 E2 20 Quill 2

2 I9 40

Yellow,

appear 1or

2 extra petal

5 E28 40 Light purple

3 I7 30 Fresh

yellow

6 E29 40 White with

light purple

VINATOM-AR 13--27


200

IV. RESULT AND DISCUSSION

1. Micropropagation to induce the potential mutant lines for estimation on farm of

mutant characteristic segregation rates

On the sixth week at thirth generation were done by in vitro microcutting method into the

fresh MS medium. The completed regenerated in vitro plants were planted out into a permanent

place on foam trays filled with substrate of treated soil, estimate the number of survival plantlets

after 30 days. After that, they were transferred into soil-beds, chrysanthemum were growth exposed

to natural photoperiod, applying the standard method.

There was no difference in the development of plants between the mutant/mutant lines and

their original varieties and also no more morphological alteration appeared in the third series of

growing to estimate the mutant morphological stability.

Recorded data indicated that:

- In on farm M1V3 generation, mutant lines of E2a, E2c, E28, E29, I7, I8, E were not

segregated; only 1.2% of individuals in I9 line maintained the mutant forms. Collating to the criteria

to limit the quantity of mutant lines for corresponding to the whole task’s scope, I9 line were not

selected the samples to transfer to in vitro condition for next propagation and breeding. However,

the leaf samples from the individuals that kept mutant morphological characteristic were collected

to extract DNA for genetic analysis.

2. Genetic diversity estimation in potential mutant lines, determine the genetic

differences among mutant lines and their original cultivars

Genomic DNA was isolated from fresh and young leaves of 6 potential mutants with 2

original ones using standard CTAB (Cetyl trimethyl ammonium bromide) method with little

modification. Insoluble polyvinyl polypyrrolidone (PVP) was added to the leaf tissue prior to

grinding. The RNA was removed by giving RNase A (MBI Fermentas, Lithuania) treatment. The

dried DNA was dissolved in minimum amount of dH2O. DNA’s purity degree (OD 260/280) is in

from 1.7 to 2.1 was utilized for RAPD analysis with 22 random decamer oligonucleotide primers as

table below.

Primer Sequence Nu (5’-3’) STT Primer Sequence Nu (5’-3’)

1 BIO27 TGGGCTCGCT 12 OPN6 GAGACGCACA

2 OPC2 GTGAGGCGTG 13 OPN7 CAGCCCAGAG

3 OPA1 CAGGCCCTTC 14 OPN10 ACAACTGGGG

4 OPA2 TGCCGAGCTG 15 OPN13 AGCGTCACTC

5 OPA18 AGGTGACCGT 16 OPM9 GTCTTGCGGA

6 OPA4 AATCGGGCTG 17 S300 AGCCGTGGAA

7 OPA15 TTCCGAACCC 18 S201 GGGCCACTCA

8 OPA6 GGTCCCTGAC 19 UBC728 GTGGGTGGTG

9 OPC10 TGTCTGGGTG 20 OPM9 GTCTTGCGGA

10 OPC11 AAAGTCGCGG 21 OPM18 CACCATCCGT

11 OPC14 TGCGTGCTTG 22 OPN5 ACTGAACGCC

VINATOM-AR 13--27


201

PCR technique: The reaction is observed with cocktail including: DNA sample 25ng, buffer

solution PCR 1X, MgCl2 2mM, dNTP 10µM, Taq polymerase 1U, primer RAPD 1µM and add

dH2O to 15µl for reaction volume.

PCR Cycle:

Stage Reaction Temp (oC) Time Cycle

1 Denaturation 95 5 minute 1

2 Denaturation 95 1 minute

40 3 Annealing 35 1 minute 30 second

4 Polymerization 72 1 minute 45 second

5 Polymerization Final 72 7 minute 1

6 Final 4 1

After the completion of the PCR, 2.5ul of 6x loading dye (MBI Fermentas, Lithuania) was

added to the amplified product and was resolved in 1.5% agarose gel stained with 0.5 ug/mL

ethidium bromide (Sigma,USA).

As the result showed that 11 primes did not give satisfactory amplification, so were not

considered further. Nine primes resulted in the amplification of distinct and producible bands in the

present investigation. All the primers gave wide range of fragments ranging from 200-2000bp. The

highest number of fragments (11) was amplified by primer S201 and OPA 02, the lowest (03) by

the primer BIO 27.

The research results show that among two original cultivars, among each original cultivar

and potential mutant lines induced from it, among all potential mutant lines together with all two

original cultivars were virtually different in genetic. The highest level of genetic difference among 8

investigated samples was 0.902 and the lowest was 0.443.

Although the mutant lines possessed the genetic differences to their original cultivar, these

genetic variations didn’t exceed the genetic limit of group including the original cultivar and the

induced mutant lines from it.

Figure 1: PCR-RAPD primer BIO 27.

VINATOM-AR 13--27


202

Figure 2: PCR-RAPD primer UBC 728.

Table 2: Homologous genetic coefficient among potential

mutants and original ones.

E2a E2c E28 E29 E I7 I8 I

E2a

1.000

E2c

0.738

1.000

E28

0.770

0.836

1.000

E29

0.689

0.721

0.656

1.000

E

0.672

0.902

0.902

0.689

1.000

I7

0.656

0.557

0.590

0.508

0.557

1.000

I8

0.623

0.492

0.557

0.443

0.525

0.803

1.000

I

0.623

0.557

0.525

0.475

0.525

0.803

0.869

1.000

Analysis by the program NTSys 2.1, this is the dendrogram showing homologous genetic

relationship among in vitro generations of potential mutants with their original ones as below.

VINATOM-AR 13--27


203

Figure 3: Dendrogram showing homologous genetic relationship among

in vitro generations of potential mutants with their original ones.

Analyzing DNA fingerprinting induced by RAPD-PCR not only helped to estimate the level

of difference among original cultivars and the potential mutant lines induced from them but could

be used to identify the mutants lines or groups of each original cultivar and the potential mutant

lines induced from it. These data are necessary for protecting and registering the new cultivars in

the future.

3. Outstanding mutant lines genetic stability estimation through in vitro generations

Genomic DNA was isolated from fresh and young leaves of 6 in vitro potential mutants with

2 original ones at M1V3; M1V5, M1V7. DNA fingerprinting from extracted DNA samples were

induced by RAPD-PCR technique, results of genetic analysis by NTSys software indicate that:

The similarity coefficients among 24 investigated samples fluctuated from 0.55 to 1.00. The

highest similarity coefficients appeared in almost samples that were same lines but different in in

vitro generation.

There is no different so much between the results of similarity coefficient when comparing

the nonhomogeneous samples from one potential mutant with samples belong to two original

chrysanthemum.

In general, the genetic stabilities of all six potential mutant lines and original cultivars were

high. However, with E28 the homology in gene between M1V3 and M1V5 generation is absolute, it

means there is the convulsion in gene at M1V7 but no so much (only 2%).

Figure 4: Dendrogram showing stable genetic relationship

among in vitro.

VINATOM-AR 13--27


204

E2a-

a

E2a-

b

E2a-

c

E2c-

a

E2c-

b

E2c-

c

E28-

a

E28-

b

E28-

c

E29-

a

E29-

b

E29-

c

E-

a

E-

b

E-

c

I7-

a

I7-

b

I7-

c

I8-

a

I8-

b

I8-

c

I-

a

I-

b

I-

c

E2a-a

1.00

E2a-b

1.00

1.00

E2a-c

1.00

1.00

1.00

E2c-a

0.74

0.74

0.74

1.00

E2c-b

0.74

0.74

0.74

1.00

1.00

E2c-c

0.74

0.74

0.74

1.00

1.00

1.00

E28-a

0.77

0.77

0.77

0.84

0.84

0.84

1.00

E28-b

0.77

0.77

0.77

0.84

0.84

0.84

1.00

1.00

E28-c

0.79

0.79

0.79

0.85

0.85

0.85

0.98

0.98

1.00

E29-a

0.69

0.69

0.69

0.72

0.72

0.72

0.66

0.66

0.67

1.00

E29-b

0.69

0.69

0.69

0.72

0.72

0.72

0.66

0.66

0.67

1.00

1.00

E29-c

0.69

0.69

0.69

0.72

0.72

0.72

0.66

0.66

0.67

1.00

1.00

1.00

VINATOM-AR 13--27


205

E-a

0.67

0.67

0.67

0.90

0.90

0.90

0.90

0.90

0.89

0.69

0.69

0.69

1.00

E-b

0.67

0.67

0.67

0.90

0.90

0.90

0.90

0.90

0.89

0.69

0.69

0.69

1.00

1.00

E-c

0.67

0.67

0.67

0.90

0.90

0.90

0.90

0.90

0.89

0.69

0.69

0.69

1.00

1.00

1.00

I7-a

0.66

0.66

0.66

0.56

0.56

0.56

0.59

0.59

0.61

0.51

0.51

0.51

0.56

0.56

0.56

1.00

I7-b

0.66

0.66

0.66

0.56

0.56

0.56

0.59

0.59

0.61

0.51

0.51

0.51

0.56

0.56

0.56

1.00

1.00

I7-c

0.66

0.66

0.66

0.56

0.56

0.56

0.59

0.59

0.61

0.51

0.51

0.51

0.56

0.56

0.56

1.00

1.00

1.00

I8-a

0.62

0.62

0.62

0.49

0.49

0.49

0.56

0.56

0.57

0.44

0.44

0.44

0.52

0.52

0.52

0.80

0.80

0.80

1.00

I8-b

0.62

0.62

0.62

0.49

0.49

0.49

0.56

0.56

0.57

0.44

0.44

0.44

0.52

0.52

0.52

0.80

0.80

0.80

1.00

1.00

I8-c

0.62

0.62

0.62

0.49

0.49

0.49

0.56

0.56

0.57

0.44

0.44

0.44

0.52

0.52

0.52

0.80

0.80

0.80

1.00

1.00

1.00

I-a

0.62

0.62

0.62

0.56

0.56

0.56

0.52

0.52

0.54

0.48

0.48

0.48

0.52

0.52

0.52

0.80

0.80

0.80

0.87

0.87

0.87

1.00

I-b

0.62

0.62

0.62

0.56

0.56

0.56

0.52

0.52

0.54

0.48

0.48

0.48

0.52

0.52

0.52

0.80

0.80

0.80

0.87

0.87

0.87

1.00

1.00

I-c

0.62

0.62

0.62

0.56

0.56

0.56

0.52

0.52

0.54

0.48

0.48

0.48

0.52

0.52

0.52

0.80

0.80

0.80

0.87

0.87

0.87

1.00

1.00

1.00

VINATOM-AR 13--27


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I. CONCLUSION

In this study, on farm, through screening 18 phenotypic mutants of both chrysanthemums

were recorded and collected including 6 potential mutants that selected for next research based on

their phenotypic differences to the originals, their aesthetic and low mosaic. These 6 potential

mutants together with their original varieties were micro-propagated to induce the potential mutant

lines for estimation on farm of mutant characteristic segregation rates. 5/6 potential mutant lines

completely kept the mutant phenotype on farm in M1V3 generation.

Among two original varieties, among each original cultivar and potential mutant lines

induced from it, among all potential mutant lines together with all three original cultivars were

virtually different in genetic. Although the mutant lines possessed the genetic differences to their

original cultivars, these genetic variations didn’t exceed the genetic limit of group including each

original cultivar and the induced mutant lines from it.

The genetic stabilities of four outstanding mutant lines and original cultivars through in

vitro generations of M1V3, M1V5, M1V7.

Six potential mutants are morphologically and genetically different to their original

varieties, possess the identification markers and aestheticism. In the genetic respect, they possessed

the high stabilities through in vitro generations. All of these criteria show that, these mutant lines

were already to be registered as temporary cultivars/varieties.

REFERENCES

[1] Harding J., F.Singh, J.N.M. Mol. “Genetics and breeding of Ornamental Spesies”, Kluwer

Academic Publisher, pp. 135-152, 1991.

[2] Harten A.M.V. Mutation breeding in Vegetatively Propagated Crops, Plant breeding and

Genetics section, joint FAO/IAEA, pp.48-53, 1997.

[3] Hitoshi Nakagawa. “Mutation breeding by Gamma Rays”, Presentation about Institute of

Radiation breeding, 2009.

[4] Hitoshi Nakagawa. “Mutation breeding and Biological researchs by the use of Gamma Rays

irradiation in Japan”, Mutation breeding Workshop of FNCA, 2008.

[5] Keichi Takagi, Masanori, Hitashita, Ngoc Trieu Le. “Internal debudding Effects of proton

beams to variegated Petunia”, Annual report, Wakasa Wan Energy Research Centre, 2008.

[6] Kurt Weising, Hilde Nybom, Kirsten Wolff, Gunter Kahl. “DNA fingerprinting-Principles,

methods, and Applications”, CRC Press-Taylor & Francis Group, second edition, 2005.

[7] Watson D.J, Baker T.A., Bell S.P., Gann A., Levine M., Losick R. “Molecular biology of the

gene”. Benjamin/Cummings, San Francisco, USA, 2004.

[8] Zeeshan Abbas, Naheed Ikram, Shahnaz Dawar and Javed Zaki. “Effect of (60 COBALT)

Gamma rays on Growth and root rot diseases in mungbean (Vigna Radiata.L), Pak. J. Bot.,

42(3): 2165-2170, 2010.

[9] Kim, J.H., M.H. Baek, B.Y. Chung, S.G. Wi and J.S. Kim. “Alterations in the

photosynthetic pigments and antioxidant machineries of red pepper (Capsicum annuum .L)

seedlings from Gamma-irradiated seeds”, J. Plant Biol., 47: 314-321. 2004.

[10] Wi, S.G., B.Y. Chung, J.H. Kim, M.H. Baek, D.H. Yang, J.W. Lee and J.S.

Kim..“Ultrastructural changes of cell organelles in Arabidopsis stem after gamma

irradiation”, J. Plant Biol., 48(2): 195-200, 2005.

[11] Barakat M.N., Rania S.A.S. Badr M. and Torky M.G.E. In vitro mutagenesis and

identification of new variants via RAPD markers for improving Chrysanthemum morifolium.

African Journal of Agricultul Research 5 (8): 748-757, 2010.

VINATOM-AR 13--27


207

[12] Bhattacharya A. and Teixeira da Silva J.A. Molecular systematics in

Chrysanthemum × grandiflorum (Ramat.) Kitamura. Scientia Horticulturae 109 (4): 379-384,

2006.

[13] Carmen Martín, Uberhuaga E., Pérez C. Application of RAPD markers in characterisation of

Chrysanthemum varieties and the assessment of somaclonal variation. Euphitica 127: 247-

253, 2002.

[14] Nagatomi. S, Miyahira. E. and Degi. K. Induction of flower mutation comparing with

chronic and acute gamma irradiation using tissue culture techniques in Chrysanthemum

Morifolium Ramat. . Acta Hort. (ISHS) 508:69-74, 2000.

[15] Kurt Weising, Hilde Nybom, Kirsten Wolff, Günter Kahl. DNA Fingerprinting in Plants

Principles, Methods, and applications (second Edition). Cpc press taylor & Fancies group,

2005.

[16] Gamma field symposia Number 1-48. Institute of Radiation Breeding-Nias. Hitachi-Ohmiya,

Ibaraki-ken, Japan. (http://www.nias.affrc.go.jp/eng/gfs) 1962-2009.

http://www.nias.affrc.go.jp/eng/gfs

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208

ESTABLISHMENT OF ILLUMINATION SYSTEM FOR INVESTIGATION

OF MONOCHROMATIC LIGHTS COMBINATION EFFECTS

ON IN VITRO PLANT GROWTH

Le Tien Thanh, Le Ngoc Trieu, Nguyen Tuong Mien, Huynh Thi Trung and Phan Quoc Minh

Centre for Applications of Nuclear Techniques in Industry, Vietnam Atomic Energy Institute


ABSTRACT: Super blue and red light LEDs and other electric, electronic components are used to design and

establish 11 independent illumination systems, each system can arbitrarily control to operate at 55 molarities of

illumination which are different from together in monochromatic lights combination and total illumination

intensity based on the microcontrollers. Programs for loading to microcontrollers were created to base on

theoretical calculation and experimental correction. The illumination cycles can be controlled by setting the

timer. These 11 systems and another fluorescent light illumination were used to execute the experiment for

investigation the effects of monochromatic lights combination on in vitro shoot proliferation stage in

Chrysanthemum and Phalaenopsis orchid. Results from this experiment showed that illumination intensity of

400lux is suitable for chrysanthemum, 750lux is suitable for Phalaenopsis orchid and rate of 70% red light –

30% blue light are suitable for both kinds of these plants.

Keyword: Illumination intensity, single wavelength light illumination system, in vitro, LED.

I. INTRODUCTION

Sunlight is the one of most important ecological factors, it supplies the essential energy for

photosynthesis process of natural plants. Artificial light sources are also used in agriculture and

especially in micro-propagation. Up to now, the most popular artificial light sources for plant tissue

culture are fluorescent tubes with light spectrum of 320-380nm, including many unnecessary areas

of plant photosynthesis. Fluorescent tubes posses a short working time, need a large space to set up

and form the high heat in the in vitro incubation room when operating so that a considerable electric

power to regulate the room temperature. Recent studies for other artificial light sources (compact

bulb, LED…) with the goal of electric saving were executed and achieved results are satisfactory.

Combination of monochromatic lights LEDs seems to be the bester one for micro-propagation with

several advantages as small size, high working time, controlled wavelength of emitted lights, low

electric consumption and released heat. In addition, many published studies showed that the single

wavelength illumination system can cause the many positive physiological activations of both ex

vitro and in vitro plants.

With the desire of increasing the quality, reducing the cost of in vitro seedlings and creating

a monochromatic illumination system for research- and application- oriented activities, the task of

“Establishment of Illumination system for investigation of monochromatic lights combination

effects on in vitro plant growth” were promoted. Time for task execution is 2 years (2013 and

2014), contents of the year of 2013 were approve, in this year, it needs to execute the design,

programming, setting up, correcting the LED illumination systems and using the established 11

systems to carry out experiments about investigation the effects of single wavelength lights

combination on in vitro shoot proliferation stage in chrysanthemum and Phalaenopsis orchid.


- Code: 36/CS/HĐNV







VINATOM-AR 13--28


209

II. RESULTS FROM THE TASK

1. Design and establish the single wavelength light illumination system

After investigating, task execution team chose two kinds out of current commercial LEDs to

establish the illumination systems. The two chosen kinds of LED possess the compatible light

emitting wavelengths for plant photosynthesis and can be used for arranging together to achieve the

suitable total light density in demanded scope illumination for each system. These are two models

of LEDs from Shenzheng Hanhua Company (China) with basic parameter as below:

Blue LED

Power: 3W, Voltage: 3.6-3.8V

Electric intensity: 700mA

Illumination intensity: 45-50lm

Emitting light wavelength: 470-475nm

Red LED

Power: 3W, Voltage: 2.4-2.6V

Electric intensity: 700mA

Illumination intensity: 80-90lm

Emitting light wavelength: 660-665nm

Figure 1: Images and parameter of chosen blue and red LEDs.

By light intensity experimental measurement, task execution team established a configure to

arrange the LEDs for one of illumination system including two parallel troughs, each trough has a

row of blue LEDs and a row of red LEDs. The distance between each LED on the row is 4cm and

the distance between two same LEDs rows is 24cm. This configure can adapt to relatively

homogeneous and maximum illumination of approximate 1100lux in the demanded surface to be

lighted (36 x 50cm).

Figure 2: Outline of blue and red LEDs arrangement for the monochromatic

lights illumination system.

Task execution team designed and established the electronic control board with two

AT89C51 microcontrollers to control the ON/OFF frequencies of 2N3055/ 2SC5200 power

transistors which supply the electricity to LED system, each microcontroller control the

illumination density of one kind of LEDs. The microcontrollers were loaded with a program that

allows them release different pulses depended on received signals from switch board. The diagram

of electronic control boards and the LED power supply diagram described as below figures:

24cm

7cm

3cm

4cm

VINATOM-AR 13--28


210

6+5V

Q2

2SC5200

9

1

+5V

R7

0.5 Ohm/5W

14

6

9

R7

0.5 Ohm/5W

1

14

6

R4R

R6

1K

C

R910K

23456789

+

J3

BLUE LED12

13

5

Q1T IP41

Q4

2N3055

15

S1

Reset

-

+ C6

10u

13

5

15

+

Q3

T IP41

13

5

+5V

Cong tac

12345678

161514131211109

R6

560/1W

15

-

12

U2 AT89C52

9

1819

20

2930

31

40

12345678

2122232425262728

1011121314151617

3938373635343332

RST

XTAL2XTAL1

GND

PSENALE/PROG

EA/VPP

VCC

P1.0/T2P1.1/T2-EXP1.2P1.3P1.4P1.5P1.6P1.7

P2.0/A8P2.1/A9

P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15

P3.0/RXDP3.1/TXDP3.2/INT 0P3.3/INT 1P3.4/T0P3.5/T1P3.6/WRP3.7/RD

P0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7

4

+5V

16

R1350K

C

R810K

23456789

12

+24V

4

+24V

16

12

4

+5V

U2 AT89C52

9

1819

20

2930

31

40

12345678

2122232425262728

1011121314151617

3938373635343332

RST

XTAL2XTAL1

GND

PSENALE/PROG

EA/VPP

VCC

P1.0/T2P1.1/T2-EXP1.2P1.3P1.4P1.5P1.6P1.7

P2.0/A8P2.1/A9

P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15

P3.0/RXDP3.1/TXDP3.2/INT 0P3.3/INT 1P3.4/T0P3.5/T1P3.6/WRP3.7/RD

P0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7

16

R5

1K

+5V

Y4

11.059MHz

C

R9

10K

2 3 4 5 6 7 8 9

11

3

+5V

D2

4148

7

+5V

J4

RED LED12

11

R2

10K

3

C7

33p

7

Cong tac

12345678

161514131211109

C8 33p

+5V

D2

4148

11

S1

Reset

3

8

R2

10K

10

Y4

11.059MHz

2

R5

1K

8

C8

33p

+5V

10

C7 33p

2

8

R10

50K

10

2

7

+5V

R6

560/1W

9

C

R910K

23456789

1

+

C6

10u

14

Figure 3: Diagram of electronic control boards for operation

illumination modalities of LED system.

J4

RED LED12

+

R6

560/1W

-

+

R7

0.5 Ohm/5W

-

R1350K

+24V

R6

560/1W

Q2

2SC5200

Q4

2N3055Q1T IP41

R7

0.5 Ohm/5W

Q3

T IP41

+24V

R10

50K

R5

1K

J3

BLUE LED12

R6

1K

Figure 4: Power supply diagram for blue and red LEDs operation.

The programs for microcontroller operation are based on the linear correlation between

illumination intensities and pulse release frequencies from microcontroller, i.e. time for high level

(t1) and low level (t0) of released signal. By theoretical calculation, the task execution team

established two programs to control the operation of red and blue LESs, each program allows the

microcontroller releases pulses at 55 different frequencies based on t0/(t1+t0) rates in

correspondence with 11 illumination intensities in range of 0, 10, 20…90 and 100% at 5 levels of

400, 575, 750, 925 and 1100lux total illumination . These two programs were established in such a

way that when one of 11 switches for red and blue light combination control is turn on together with

one of 5 switches for total illumination intensity, both microcontrollers will simultaneously release

suitable pulses for desired illumination.

After the preliminary Illumination system were established with LEDs, timer, control

system and power supplier, the correction for whole system were executed by experimental

measurement to identify the actual value of light intensity of each illumination modality, adjust the

VINATOM-AR 13--28


211

impedance of the rheostats and t0/(t1+t0) rates of pulse release from microcontrollers. The system

correction were repeated several times until desire being satisfied. In the result, the suitable two

programs for blue and red LEDs operation control in correspondence with electronic control board

configuration and established LED arrangement were achieved, adapting to the demand for each

light combination rate at each total illumination intensity level.

Figure 5: Control system for LED illumination system.

The corrected preliminary LED illumination system was used as pattern to set up other 10

remains. Each achieved system was operated at each modality of illumination and corrected again

if necessary.

11 LED illumination systems were used to investigate the effect of monochromatic lights on

in vitro plant growth. The demanded illumination space of each system were covered with black

cloth to ensure that it receives the light only from it’s LEDs and avoid the erroneous experiment

results.

Figure 6: 11 LED illumination system were set up on in vitro plant

incubation shelves for experiments.

11 LED illumination systems were set up on 11 shelf blocks and regulated for operation at

11 single wavelength lights combination rates (100% red-0% blue; 90% red-10% blue; …, 10% red

-90% blue and 0% red-100% blue) with highest total illumination intensity level (~1100lux).

Photometer was used to identify the areas that possess the total illumination intensity of ~750lux

and ~ 400lux to arrange the experiments using these two total illumination intensity.

From the top to

bottom:

+ 100% red - 0%

blue;

+ 90% red - 10%

blue;

+ 80% red - 20%

blue;

+ 70% red - 30%

blue;

+ 60% red - 40%

blue;

+ 50% red - 50% blue

From the top to

bottom:

+ 0% red - 100%

blue;

+10% red - 90%

blue;

+ 20% red - 80%

blue;

+ 30% red - 70%

blue;

+ 40% red - 60%

blue

Timer

DC 24V source Electronic control

board

Switches for 5 total

illumination

intensity levels

regulation

Switches for 11

monochromatic

lights combination

rates regulation

VINATOM-AR 13--28


212

2. Investigation of monochromatic lights combination effects on in vitro shoot

proliferation stage

2.1. Effects of monochromatic lights illumination modalities on in vitro shoot

proliferation stage in chrysanthemum

Stem nodes of in vitro chrysanthemum plants belong to “White Farm” cultivar were grown

in shoot proliferation medium according to the previous protocol of Centre for Application nuclear

techniques in industry (CANTI). Cultured samples were arranged in the incubation conditions of 33

monochromatic lights illumination modalities (integral of the two factors of single wavelength

lights combination rate and total illumination intensity: L1R10, L1R9,…, L1R1, L1R0; L2R10,

L2R9,…, L2R1, L2R0; L3R10, L3R9,…, L3R1, L3R0) with the control experiment lot of

fluorescent tubes. Illumination cycle of 16 hour lighting and 8 hour being dark was used for all

experiment lots.

Four weeks after incubation with experiment conditions, achieved results are presented as

below:

Table 1: Shoot proliferation coefficient, shoot height and morphological characteristics of in vitro

chrysanthemum in different lights illumination modalities after 4 weeks incubation.

Experime

nt lot

Shoot

coefficient

(shoot/cluster)_

)

Shoot height

(cm)

Shoot height and morphological characteristics

Control 2.09 ± 0.28 4.77 ± 0.08 Medium shoot stem; Deep green leaves and stems

L1

R10 2.07 ± 0.20 5.20 ± 0.14 Small shoot stem; pale green leaves and stems (weak

shoots)

R9 2.00 ± 0.13 4.88 ± 0.10 Relatively similar to characteristics from control

R8 2.03 ± 0.17 4.64 ± 0.10

Similar to characteristics from control

R7 2.03 ± 0.23 4.62 ± 0.15

R6 2.07 ± 0.24 4.38 ± 0.13

R5 2.02 ± 0.20 4.26 ± 0.14

R4 2.09 ± 0.24 4.06 ± 0.09

R3 2.04 ± 0.13 3.68 ± 0.08

Plump and dwarf shoot stem; dark green and thick leaves R2 1.98 ± 0.09 3.63± 0.11

R1 2.07 ± 0.15 3.09 ± 0.10

R0 1.98 ± 0.16 2.64 ± 0.07

L2

R10 1.99 ± 0.17 5.21± 0.06 Small shoot stem; pale green leaves and stems (weak

shoots)


R8 2.02 ± 0.22 4.76 ± 0.08

R7 2.04 ± 0.18 4.61 ± 0.10

Similar to characteristics from control R6 2.03 ± 0.23 4.33 ± 0.07

R5 2.04 ± 0.13 4.26 ± 0.10

R4 2.06 ± 0.19 4.05 ± 0.09

VINATOM-AR 13--28


213

R3 2.04 ± 0.16 3.73 ± 0.09

Plump and dwarf shoot stem; dark green and thick leaves R2 2.03 ± 0.14 3.67 ± 0.10

R1 2.04 ± 0.16 3.15 ± 0.07

R0 1.98 ± 0.13 2.62 ± 0.05

L3

R10 2.07 ± 0.22 5.54 ± 0.11

Small shoot stem; pale green leaves and stems (weak

shoots) R9 1.98 ± 0.11 5.47 ± 0.08

R8 2.06 ± 0.23 5.20 ± 0.09


R6 2.11 ± 0.19 4.50 ± 0.13

Similar to characteristics from control R5 2.07 ± 0.20 4.37 ± 0.09

R4 2.07 ± 0.15 4.12 ± 0.08

R3 2.07 ± 0.13 4.11 ± 0.06

R2 2.09 ± 0.17 3.68 ± 0.14

Plump and dwarf shoot stem; dark green and thick leaves R1 1.98 ± 0.13 3.42 ± 0.07

R0 1.96 ± 0.16 3.14 ± 0.08

Figure 7: Cultured samples were incubated in different monochromatic

lights combination rates.

From above table and graph, it can be recognized that illumination using single wavelength

lights did not influence the shoot proliferation coefficient of in vitro chrysanthemum; in the same

total illumination intensity of monochromatic lights, it is so clear that the shoot height is inversely

Graph 1: Effects of monochromatic

lights combination rates on in vitro

shoot height in Chrysanthemum at

three total illumination intensities of

L1: 1100lux, L2: 750lux and L3:

400lux.

VINATOM-AR 13--28


214

proportional with blue light rate. The configuration of shoot height and other morphological

characteristics show that the single wavelength lights combination rate of 70% red-30% blue at total

illumination intensity of 400lux is suitable for shoot proliferation of in vitro Chrysanthemum plants.

Figure 8: Morphological characteristics of in vitro Chrysanthemum in different

monochromatic lights combination rates at three total illumination intensities

of L1: 1100lux, L2: 750lux and L3: 400lux.

2.2. Effects of single wavelength lights illumination modalities on in vitro shoot

proliferation stage in Phalaenopsis orchid

Shootlets generated from protocorm like bodies of in vitro Phalaenopsis orchid were

cultured in shoot proliferation medium according to the previous protocol CANTI. Cultured

samples were arranged in the incubation conditions of 33 monochromatic lights illumination

modalities (integral of the two factors of monochromatic lights combination rate and total

illumination intensity: L1R10, L1R9,…, L1R1, L1R0; L2R10, L2R9,…, L2R1, L2R0; L3R10,

L3R9,…, L3R1, L3R0) with the control experiment lot of fluorescent tubes.

9 weeks after incubation with experiment conditions, achieved results are described as

below:

Table 2: Shoot proliferation coefficient and shoot morphological characteristics of in vitro

Phalaenopsis orchid in different lights illumination modalities after 9 weeks incubation.

Experiment lot Shoot coefficient

(shoot/cluster)

Shoot height and morphological

characteristics

Control 3.83 ± 1.06 Deep green leaves and stems

L1

R10 3.77 ± 0.92 Pale green leaves and stems (weak shoots)

R9 3.80 ± 0.88

R8 3.63 ± 0.81

Similar to characteristics from control R7 3.73 ± 0.83

R6 3.77 ± 0.72

R5 3.57 ± 0.77

R4 3.63 ± 0.66

Very deep green and thick leaves R3 3.83 ± 0.75

R2 3.81 ± 0.87

R1 3.67 ± 0.94 Dark green and very thick leaves

R0 3.63 ± 0.84

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215

L2

R10 3.87 ± 1.04

Pale green leaves and stems (weak shoots) R9 3.80 ± 0.81

R8 3.73 ± 0.94


R6 3.73 ± 0.60

R5 3.63 ± 0.84

R4 3.63 ± 0.86


R2 3,81 ± 0,81

R1 3.93 ± 0.92

Dark green and very thick leaves R0 3.67 ± 0.83

L3

R10 1.70 ± 0.68

Pale green leaves and stems (weak shoots) R9 1.57 ± 0.63

R8 1.48 ± 0.50

R7 1.67 ± 0.43


R5 1.47 ± 0.50

R4 1.47 ± 0.50

R3 1.42 ± 0.45


R1 1.46 ± 0.63

R0 1.50 ± 0.54

Graph 2: Effects of

monochromatic lights

combination rates on in

vitro shoot proliferation

coefficient of

Phalaeonopsis orchid at

three total illumination

intensities of L1: 1100lux,

L2: 750lux and L3:

400lux.

VINATOM-AR 13--28


216

From above table and graph, it can be recognized that illumination using monochromatic

lights significantly influenced the shoot proliferation coefficient of in vitro Phalaeonopsis orchid

when comparing the total illumination intensity of 400lux level to other level and the control.

However, data analysis without the results from the 400lux illumination experiment lots show that

illumination using monochromatic lights did not influence the shoot proliferation coefficient of in

vitro Phalaeonopsis orchid, this is the same case with chrysanthemum.

In the same total illumination intensity of monochromatic lights, shoot proliferation

coefficient is not uneven when comparing within different monochromatic light combination rates

and there was no linear rule for increasing or reducing.

In all of total illumination intensity level, the red light percentage is proportional with the

insipidity of the green of shoots and leaves and inversely with blue light percentage increasing.

In the stage of in vitro shoot proliferation, the shoot proliferation coefficient is the most

important but the quantity of shoots is significant, shoot quantity directly influences the

development and the quantity of ex vitro plantlets established from the shoots. Thus, with

Phaleaonopsis orchid in this case, the execution team estimated the shoot quantity and whole

experiment results based on the color of stems and leaves mainly because the color expresses

chlorophyll accumulation level and the vitality of the in vitro plant and it’s organs. From the results

in the table 9 and graph 2, the task execution team realized that the monochromatic lights

combination rate of 70% red-30% blue at both total illumination intensity of 750 and 1100lux is

suitable for shoot proliferation of in vitro Phaleaonopsis orchid. However, when considering about

the electricity usage effect (750lux illumination is less consumptive than 1100 lux illumination) and

also realizing that the single wavelength lights combination rate of 70% red-30% blue at 750lux is

the only experiment lot gave the shoot proliferation coefficient higher than the control lot but still

kept the leaves possess normal morphological characteristics, the task execution team choose this

illumination modality to be the most suitable for in vitro Phaleaonopsis orchid in the stage of shoot

proliferation.

Figure 9: Shoot morphological characteristics

of in vitro Phalaeonopsis orchid at different

monochromatic lights mixing rates.

Figure 10: Leaf morphological

characteristics of in vitro Phalaeonopsis

orchid shoot at different onochromatic

lighs bombination rates.

III. CONCLUSION

Via the document consulting, investigating the theoretical base and executing the

experiments, the task execution team had established 11 independent monochromatic light

illumination systems using chosen red and blue LEDs. These systems can operate according to

arbitrary control from users at 11 monochromatic lights combination rates with 3 total illumination

intensity levels as conventional requirements.

VINATOM-AR 13--28


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These whole facility including these systems was used to investigate the effects of

monochromatic lights on the shoot proliferation stage of plants. Achieved results show that

illumination intensity of 400lux is suitable for chrysanthemum, 750lux is suitable for Phalaenopsis

orchid and monochromatic lights combination rate of 70% red light-30% blue light are suitable for

both kinds of these plants.

REFERENCE

[1] Briggs W.R., Huala E. Blue – light photoreceptors in highter plants. Annu. Rev. Cell Dev.

Biol., 15, pp.33-62, 1999.

[2] Brown C.S., Shuerger A.C. Growth of pepper, lettuce and cucumber under light-emitting

diodes. Plant Physiol., 102, pp.808-813, 1993.

[3] Bula R.J., Morrow T.W., Tibbitt T.W., Barta D.J., Ignatius R.W., Martin T.S. Light-

emiiting diodes as a radiation source for plants. Hort. Sci., 26, pp.203-205, 1991.

[4] C.D’Onofrio, S. Morini & Bellocchi. Plant Cell, Tissue and Organ Culture, 1998.

[5] Nhut D.T., Takamura T., Watanabe H., Okamoto K., Tanaka M. Responses of strawberry

plantlets cultured in vitro under superbright red and blue light-emitting diodes (LEDs).

Plant Cell Tiss, Org. Cult., 73, pp.43-52, 2003.

[6] Hahn E.J., Kozai T., Peak K.Y. Blue and red light- emitting diodes with or without sucrose

and ventilation affects in vitro growth of Rehmannia glutinose plantlets. Plant biol., 43, pp.

247-250, 2000.

[7] Liu C.Z., Wang Y.C., Kang X.Z., Ouyang F. Investigation of light, temperature and

cultivated modes on growth and artemisinin synthesis of Artemisia annua L. shoots. Acta.

Phytophys. Sin., 25, pp.105-109, 1999.

[8] Miyashita Y., Kitaya Y., Kozai T., Kimura T. Effects of red and far-red light on the growth

and morphology of potato plantlets in vitro: Using light emitting diodes (LEDs) as a light

source for micropropagation”. Acta Hortic., 393, pp.189-194, 1995.

[9] Moreira da Silva M.H., Degergh P.C. The effects of light quality on the morphogenesis of in

vitro cultures of Azoria Vidalii (Wats.) Feer. Plant Cell Tiss. Org. Cult., 51, pp.187-198,

1997.

[10] Tanaka M., Takamura T., Watanabe H., Endo M., Yanagi., Okamoto M. In vitro growth of

Cymbidium plantlets cultured under superbright red and blue light-emitting diodes (LEDs).

J. Hortic. Sci. Biotech., 73, pp.39-44, 1998.

[11] Tennesen D.J. Singsaas E.L., Sharkey T.D. Light-emitting diodes as a light source for

photosynthesis research. Photosynthesis Research, 39, pp.85-92, 1994.

[12] Volmaro C., Pontin M., Luna V., Baraldi R. Blue light control of hypocotyl elongation in

etiolated seedings of Lactuca sativa (L.) cv. Grand Rapids related to exogenous growth

regulators and endogenous IAA, GA3, and abscisic acid. Plant Growth Regul., 26, pp.165-

173, 1998.

[13] Wang W.R., Wang Y.D., Ouyang G.C., Xue Y.L. Effects of light quality on differentiation

and itts related enzymes in callus of cucumber and tomato. Acta. Phytophys. Sin.,17,

pp.118-124, 1991.

[14] Yanagi T., Okamoto K. Utilization of supper light-emitting diodes as artificial light source

for plant growth. Ext. Abstr. Annu. Meet. Jap. Soc. Hort. Sci., pp.374-375, 1993.

VINATOM-AR 13--29


218

APPLICATION OF IN VITRO FLOWERING TECHNIQUE

ON EVALUATING OF MUTATION CAPACITY AND COLOR SELECTION

OF TORENIA FOURNIERI L. FOLLOWING IRRADIATION

Le Van Thuc, Le Thi Thuy Linh, Hoang Hung Tien, Dang Thi Dien,

Le Thi Bich Thy and Han Huynh Dien

Department of Biotechnology, Nuclear Research Institute, Vietnam Atomic Energy Institute

ABSTRACT: Gamma irradiation technique combined with tissue culture and in vitro flowering was applied in

this study. The results showed that the frequences of variation in plant regeneration from irradiated leaf

samples were: 0.67% (with 30 Gy dose) and 0.72% (with 40 Gy dose) in MV1 generation; the frequences of

variation in irradiated plantlet samples were: 1.05% (with 30 Gy dose) and 1.15% (with 40 Gy dose) in MV4

generation, the frequences of mosaic were 0.25% and 0.08% in MV3 and MV4 generation, respectively. A total

of 16 mutants were selected based on phenotypic variations going through screening processes of tissue culture

and in vitro flowering. Three promising mutant lines (G40TP1, G40TP2, G30TL1) presented a high genetic

stability through generations cultivated in both in vitro and ex vitro conditions when being compared with the

controls. These mutant lines G40TP1, G40TP2, G30TL1 had a high potential to become new cultivars. This

paper showed that the application of in vitro flowering technique for mutation breeding of Torenia (Torenia

fournieri L.) is a significant complementary and effective model for selecting mutants produced by irradiation.

Introduction

Torenia (Torenia fournieri L.) is Scrophulariaceae dicotyledonous plants, originating from

Southeast Asia, Africa and Madagascar (Yamazaki, 1985). Torenia have sets of chromosomes (2n =

18) and relatively small genome (171 Mbp), it is considered easy to create objects mutation

(Kikuchi et al., 2007). In mutation breeding, the problem in mutation breeding by radiation factors

to consider such as: sample size, selection time, effort, cost, potential mutation miss the big

question posed to the breeders. Therefore, the combination of mutations agent with selective

techniques flowering in vitro is one of the research directions, help us to overcome the weaknesses

of the method traditional selective mutations and mutations found quickly, more efficiently and

thoroughly. In previous studies (2012), in vitro flowering process of Torenia fournieri L. was

completed research. So, use technical coordination gamma irradiation (Co60) with culture

techniques and in vitro flowering to isolate and find the variation in morphology and flower color

Torenia plants even in vitro without taking a lot of time to select on the field.


- Code: CS/13/01-07






1. Le Van Thuc, Le Huu Tu, Tran Que and Duong Tan Nhut. Study on the effects of gamma ray

irradiation on the morphogenesis of Torenia fournieri L. using in vitro flowering technique. Journal of

Biotechnology, 10(4A), 915-922, 2012.

2. Duong Tan Nhut, Le Van Thuc, Tran Trong Tuan, Truong Thi Dieu Hien, Hoang Xuan Chien, Nguyen

Phuc Huy, Nguyen Ba Nam, Vu Quoc Luan. Affects of some factors on in vitro flowering of Torenia

(Torenia fournieri L.). Journal of Science and Technology, 51(6): 689-702, 2013.

3. Le Van Thuc, Le Thi Bich Thy, Le Thi Thuy Linh, Dang Thi Dien, Han Huynh Dien, Hoang Hung

Tien, Tran Trong Tuan, Truong Thi Dieu Hien, Nguyen Phuc Huy, Duong Tan Nhut. Study on

procedure of in vitro flowering of Torenia (Torenia fournieri L.) to applying on mutation selecting by

irradiation. To be published in J. Nuclear Science and Technology, 2014.


VINATOM-AR 13--29


219

I. EXPERIMENTS

1.1. Materials

A population of Torenia fournieri L. (2.000 plants) had been isolated, leaf samples (MV1)

and plantlet samples (MV4), which were made of materials for selected mutations.

1.2. Reagents

Macro minerals, micronutrients, vitamins, hormones are used in all the experiments of Merck;

agar (HaLong Canfoco); sucrose (Bien Hoa Sugar Joint Stock Company).

II. PROCEDURES

Use technical coordination gamma irradiation (Co60) with tissue culture techniques and in

vitro flowering to isolate and find the variation in morphology and flower color Torenia plants even

in vitro.


3.1. Determining the ability of the mutant plant regenerated from leaf samples (MV1) by in

vitro flowering technique

The type of mutation Gamma dose (Gy)

Control 30 Gy 40 Gy

Flower colors 0 16 15

Structural variation 0 3 4

Flower size 2 9 12

Branchers on the plant 0 3 4

Chlorophyl mutations 0 1 3

Irregular shape buds (stunted, slow-growing, multi-body) 0 10 6

Leaf shape (elongated leaves and small leaves) 0 1 2

* Data were recorded in a total of 6,418 (30 Gy) and 6,389 (40 Gy) individuals.

Frequency mutation (MV1) in the dose of 30 Gy and 40 Gy was 0.67% and 0.72%.

3.2. Determining the ability of the mutant plants (MV4) by in vitro flowering technique

The type of mutation Gamma dose (Gy)

Control 30 Gy 40 Gy

Flower colors 0 20 14

Structural variation 0 5 10

Flower size 3 15 12

Branchers on the plant 0 3 4

Chlorophyll mutations 0 5 7

Irregular shape buds (stunted, slow-growing, multi-body) 0 6 11

Leaf shape (elongated leaves and small leaves) 0 4 7

* Data were recorded in a total of 5,742 (30 Gy) and 5,652 (40 Gy) individuals.

VINATOM-AR 13--29


220

Frequency mutation (MV4) in the dose of 30 Gy and 40 Gy was 1.05% and 1.15%.

3.3. Determining the stability of genetic mutations in M1V1 to M1V4 generation

Line of white flower has a very low dissociation rate of only about 1% in M1V4 generation,

while flowers with 4 lips gold-purple dissociation rate is 12.73%. Flowers with 4 lips purple

dissociation rate is very low 0.85% (M1V4), this shows lines flowers with 4 lips purple have a high

genetic stability.

Figure 3.1: Mutation spectrum of flower colors isolated

M1V1 generation (irradiation plantlets).

3.4. Determining the stability of genetic mutations in M1V1 to M1V4 generation

Code Color and structure

of the flower

Dissociation

rate of M1V5

(%)

Dissociation

rate of M1V6

(%)

Dissociation

rate of M1V7

(%)

Dissociation

rate of M1V8

(%)

Control Purple flowers 0 0 0 0

G40TP1 White flowers 0 0 0 0

G40TP2 Purple flowers 0.47 0.20 0 0

G30TP3 Flowers with 4 lips purple 10.25 7.69 5.20 3.06

G40TP4 Yellow body plants 1.9 0.5 0 0

G30TL1 White flower yellow dots 0.50 0.35 0 0

G30TL2 Pale purple flowers 12.60 5.20 3.47 2.00

G30TL3 Flowers with separate

stamen 50.60

35.32 25.09 13.51

Figure 3.2: These mutant line purebred developed into new breeds.

VINATOM-AR 13--29


221

3.5. Comparison of the genetic stability of the mutant lines in in vitro and ex vitro

Code of the mutant lines

Control G40TP1 G40TP2 G30TL1 The monitoring

indicators Conditions

Survival rate (%) In vitro 100±0.0 100±0.0 100±0.0 100±0.0

Ex vitro 87.47 ±1.5a

* 86.41±2.1a 85.31±1.8a 81.15±1.3b

Plant height (cm) In vitro 8.92±1.3a 8.73±1.5

a 6.47±1.3b 8.65±1.8a

Ex vitro 12.35±1.9 a 11.98±2.3

a 9.50±2.1b 12.49±1.6

a

Number of

root/explant

In vitro 18.67±0.7ns

17.23±1.2 ns

19.11±0.9 ns

18.35 ±1.2

ns

Ex vitro 14.25±1.6a 11.79±1.8b 13.08±2.1a 12.73±1.5b

Diameter of leaf

(mm)

In vitro 13.50±0.6a 8.35±0.8a 12.07±0.5b 13.75±0.6a

Ex vitro 15.26±0.7a 11.33±1.4c 14.09±0.9b 15.35±0.9a

Length of leaf (mm) In vitro 24.59±1.4b 27.41±1.3a 23.15±1.5b 25.33±1.8b

Ex vitro 26.19± 1.7b 27.89±1.3a 24.30±1.5c 26.83b ±1.3b

Length of stem (mm) In vitro 10.07±0.2a 11.30±0.5a 5.49±0.1b 10.33±0.6a

Ex vitro 14.58±0.7 16.29±0.5 7.34±0.9c 14.87±0.7b

Number of flower

buds/explant

In vitro 2.76±0.4b 2.50±0.1 3.30±0.1a 2.65±0.4b

Ex vitro 3.48±0.3b 3.65±0.6b 4.29±0.8a 3.19±0.8bc

Flower size (mm) In vitro 19.80±0.3

ns 20.03±0.5

ns 19.69±0.5

ns 19.80±0.7

ns

Ex vitro 20.15±0.6ns

20.46 ±0.7

ns 21.05±0.7

ns 21.11±0.5

ns

Dissociation rate of

flower color (%)

In vitro 0 0 0 0

Ex vitro 0 0 0 0.15

*Different letters within a row indicate significant differences at P = 0.05 by Duncan’s

multiple range test; after ± is the standard deviation of the iteration; G40TP1: white flowers;

G40TP2: purple flowers; G30TL1: white flower yellow dots; ns: non-significant difference. Data

recorded after 45 days of cultivation.

IV. CONCLUSIONS

Total number of individual variation occurs when irradiation leaf samples were 43 plants

(30 Gy) and 46 plants (40 Gy); frequency mutation (MV1) in the dose of 30 Gy and 40 Gy was

0.67% and 0.72%.

Total number of individual variation occurs when irradiation plantlet samples were 58 plants

(30 Gy) and 65 plants (40 Gy); frequency mutation (MV4) in the dose of 30 Gy and 40 Gy was

1.05% and 1.15%, mosaic frequency in MV3 and MV4 respectively 0.25% and 0.08%.

A total of 16 mutants were selected through a screening process in vitro flowering

technique. The genetic stability of three elite breeds (G40TP1, G40TP2, G30TL1) have high genetic

stability through generations in vitro and ex vitro cultivation. The lines G40TP1, G40TP2, G30TL1

mutation are eligible to develop new breeds.

VINATOM-AR 13--29


222

The results showed that the feasibility of the application of in vitro flowering technique for

mutation breeding is really effective, creating the basis for investment and development sectors

mutation breeding in Lam Dong.

REFERENCES

[1] Duncan, D. B. Multiple range and multiple F test. Biometrics, 11, 1-42, 1995.

[2] Kikuchi, S., Kino, H., Tanaka, H., Tsujimoto, H. Pollen tube growth in cross combinations

between Torenia fournieri and fourteen related species. Breed Scinece, 57, 117-122, 2007.

[3] Murashige, T., Skoog, F.A. Revised medium for rapid growth and bioassays with tobacco

tissue culture. Plant Physiology, 15, 473-497, 1962.

[4] Yamazaki, T. A. Revision of the Genera Limnophila and Torenia from Indochina. Journal

Factor Science the University of Tokyo 3(13), 575-624, 1985.

VINATOM-AR 13--30


225

ESTABLISHING THE STANDARD X-RAY BEAM QUALITIES

FOR CALIBRATION OF DOSIMETERS USED IN DIAGNOSTIC

RADIOLOGY FOLLOWING IAEA-TRS457

Duong Van Trieu, Ho Quang Tuan and Bui Duc Ky



ABSTRACT: The determination of the patient dose needs to provide a reference dose for the patient that

reference dose levels to assess the relative risk during X- ray diagnostic. This mission, We had established a

number of standard beam qualities to perform calibrations of diagnostic dosimeters and methods of measuring

patient dose in X-ray diagnostic. At radiation dosimetry room, we had establish RQR2, RQR3, RQR4, RQR5,

RQR6 beam qualities based on IAEA-TRS457 documentation with homogeneity coefficient (h) for each beam

quality in the range 0.7-0.8, and haft-value layers HVL1, HVL2 of experimental and IAEA is different about

10%. Established calibration method for diagnostic dosimeters as KAP meters, UNFORS dosimeters, and the

TLD dosimeters, practical measurements of entrance surface air kerma on Shimadzu X-ray machines used

phantom.

1. INTRODUCTION

The patient dosimetry equipments as dose meter, TLD dosimeters, semiconductor detector

are used to determine patient doses in diagnostic radiology. The standard ionization chambers in X-

rays diagnostic are used to calibrate the patient dosimetry equipment. Standard rooms of the

Institure Nuclear of Sciences and Technology are performed calibration dosemeter equipments. To

meet the requirements of the Atomic Energy Law of radiation protection for patients during

diagnostic radiology, standard room are conducting setting cablibration methods in diagnostic X-

rays according to the IAEA TRS-457 (guidelines, standards and practices to measure the patient

dosimetry in X-ray diagnostic by Agency international Atomic energy Agency launched).

2. ESTABLISHMENT TO PERFORM CALIBRATIONS OF DIAGNOSTIC

DOSIMETERS

Determine of the HVL.

The first HVL (HVL1), is defined as the thickness of the specified material which attenuates

the air kerma or air kerma rate in the beam to one half of its original value measured without any

absorber.

The second HVL (HVL2) is equal to the difference between the thickness of an absorber

necessary to reduce the air kerma (air kerma rate) to one quarter, d1/4, and the value of HVL1:

HVL2 = d1/4 - HVL1. The ratio between HVL1 and HVL2 is termed the homogeneity coefficient, h:

h=HVL1/HVL2.


- Code: 06 /CS/HĐNV







VINATOM-AR 13--30


226

D1

M

A

D2

F

S

Pb house

Detector

25cm

25cm 50cm

X-ray tube

Figure 1: Schematic drawing of the HVL measurement set-up, where: Fo is the focal spot;

S is the shutter; D1, D2 are apertures; F is added filtration; A is the HVL absorber;

M is the monitor chamber; D is the detector.

Table 1: Table practice results measured with the IAEA TRS-457.

Beam

qualities kV

addition

al filter

(mmAl)

HVL

1

HVL

2 h

HVL1

(Practic

e)/HVL1

(IAEA)

HVL2

(Practice)

/HVL1

(IAEA)

h

Practice

/IAEA

RQR2 IAEA 40 2.424 1.411 1.76 0.80

1.05 1.06 0.99 Practice 40 2.4 1.483 1.869 0.79

RQR3 IAEA 50 2.424 1.765 2.328 0.76

1.04 1.06 0.98 Practice 50 2.4 1.835 2.474 0.74

RQR4 IAEA 60 2.67 2.162 3.61 0.60

1.06 0.89 1.20 Practice 60 2.7 2.29 3.197 0.72

RQR5 IAEA 70 2.851 2.553 3.61 0.71

1.02 1.02 1.00 Practice 70 2.55 2.605 3.687 0.71

RQR6 IAEA 80 3.132 3.02 4.369 0.69

1.01 1.03 0.98 Practice 80 2.75 3.06 4.499 0.68

Table 1 shows the values of homogeneity coefficient h in the range of 0.68 to 0.79 and haft-

value layers HVL1, HVL2 of experimental and IAEA is different about 10%.

3. PRACTICE FOR DIAGNOSTIC CALIBRATIONS FOR KAP METER

Calibration of KAP meters in terms of the air kerma–area product for radiation transmitted

through the chamber (96035B ion chamber).

VINATOM-AR 13--30


227

Figure 2: Set-up for KAP meter calibration.

Table 2: The calibration coefficient of KAP meter for radiation

quality DV60, DV70, DV80.

Beam qualities Nk (without MCh) Nk with MCh Different

DV60 1.788 1.792 0.228%

DV70 1.737 1.742 0.281%

DV80 1.713 1.718 0.267%

Nk is the calibration coefficient of the KAP meter

Table 2 shows the calibration factor of KAP meter for beam qualities DV60, DV70, DV80

using monitor chamber different without monitor chamber about 0.5%. Specifically, the beam

quality DV60 is 0.228%, DV70 and DV80 is 0.281%, 0.267%.

4. PRACTICE FOR DIAGNOSTIC CALIBRATIONS FOR UNFORS DOSE METER

The calibration coefficient of the UNFORS dose meter ef

ef ef

70 70

rUN UN UN r rDVDV DV DV DV DVUN

DV

MN N k N k

M

where UN

DVM and efr

DVM are the mean values measured with UNFORS dose meter and the reference

chamber for beam qualities DV. efr

DVk the factor correcting for the difference in response between

beam qualities DV70 and DV. ef

70

r

DVN is calibration factor of reference chamber with beam quality

DV70.

Figure 3: Set-up for UNFORS dose meter calibration.

VINATOM-AR 13--30


228

DET

Phantom tp

d1

dFTD

Table or w all bucky

d2

Table 3: The calibration coefficient of UNFORS dose meter for radiation quality DV60,

DV70, DV80.

Beam qualities Nk (without MCh) Nk with MCh Different

DV60 1.287 1.290 -0.249%

DV70 1.312 1.299 0.975%

DV80 1.329 1.314 1.072%

Table 3 shows the calibration factor of UNFORS dose meter for beam qualities DV60,

DV70, DV80 using monitor chamber different without monitor chamber about 1.0%. Specifically,

the beam quality DV60 is-0.249%, DV70 and DV80 is 0.975%, 1.072%.

5. PRACTICE FOR INCIDENT AIR KERMA AND ENTRANCE SURFACE AIR

KERMA MEASUREMENT

5.1 Incident air kerma and entrance surface air kerma measurement using ion

chamber VICTOREEN (Model: 635; Seri No: 971) and phantom

A detector of the diagnostic dosimeter is positioned at a sufficient distance from the entrance

surface of the phantom to avoid backscatter and the incident air kerma is calculated from the

measurement at the detector position using the inverse square law.

Figure 4: Geometry used for the calculation of incident air kerma and

entrance surface air kerma

for general radio-graphy,

where dFTD=100cm is the

distance between the tube

focus and the patient

support, d1=56cm is the

distance between detector

and the tube focus,

d2=85cm the distance

between detector and the

patient support and tp=15cm

the thickness of the

phantom (30cm x 30cm x

15cm).

Incident air kerma 2

1

2

( )i

dK K d

d

where K(d) is air kerma at the measurement point (at a

distance, d1, from the X ray focus) from the mean value of ion chamber readings.

Entrance surface air kerma Ke=KiB where B is backscatter factor.

Table 4: Results of incident air kerma and entrance surface air kerma measurement using

ion chamber + phantom and KAP.

Filter Field size kV mA ms Backscatter

factor (B)

Ki

mGy

Ke

mGy

KAP

cGy.cm2

2.5mmAl 10cmx10cm 80 200 250 1.41 3.28 4.62 41.0

VINATOM-AR 13--30


229

70 200 250 1.39 2.51 3.49 31.3

60 200 250 1.36 1.74 2.36 21.5

20cmx20cm

80 200 250 1.48 3.58 5.30 171.0

70 200 250 1.41 2.54 3.59 132.2

60 200 250 1.36 1.82 2.48 93.1

25cmx25cm

80 200 250 1.5 3.54 5.31 258.2

70 200 250 1.46 2.69 3.93 198.4

60 200 250 1.36 1.85 2.52 139.6

5.2 Incident air kerma and entrance surface air kerma measurement using UNFORS

dose meter and phantom

Figure 5: Geometry used for the calculation of

incident air kerma and entrance surface air kerma for

general radio-graphy, where dFTD=100cm is the

distance between the tube focus and the patient support

and tp=15cm the thickness of the phantom (30cm x

30cm x 15cm). DET will be attached to the phantom.

Table 5: Results of incident air kerma and entrance surface air kerma measurement using

UNFORS dose meter + phantom and KAP.

Filter Field size kV mA ms Ke UNFORS

(mGy)

KAP

cGy.cm2

2.5 mm Al

10cm x 10cm

80 200 250 5.505 41.0

70 200 250 3.847 31.3

60 200 250 2.844 21.5

20cm x 20cm

80 200 250 5.818 171.0

70 200 250 4.332 132.2

60 200 250 2.983 93.1

25cm x 25cm

80 200 250 5.788 258.2

70 200 250 4.402 198.4

60 200 250 3.001 139.6

VINATOM-AR 13--30


230

Table 6: The comparison of air kerma entrance surface of the IC VICTOREEN, UNFORS.

Figure 6: The graph compares the entrance surface air kerma

of ion chamber Victoreen and UNFORS doser meter.

The graph 6 and table 6 shows, the entrance surface air kerma change depending on field

size and kV, mA and time parameters of the X-ray machine.

- With the same kV, mA and time parameters set on the X-ray, field size increases, the

entrance surface air kerma increases.

- When changing the kV with the same field size, air kerma change respectively.

- The results of air kerma entrance surface measurements of ion chamber VICTOREEN

and UNFORS dose meter difference about 19%.

Field size kV mA ms Ion chamber

VICTOREEN mGy

UNFORS

mGy

10cm x 10cm

80 200 250 4.62 5.505

70 200 250 3.49 3.847

60 200 250 2.36 2.844

20cm x 20cm

80 200 250 5.30 5.818

70 200 250 3.59 4.332

60 200 250 2.48 2.983

25cm x 25cm

80 200 250 5.31 5.788

70 200 250 3.93 4.402

60 200 250 2.52 3.001

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231

6. CONCLUSION

The mission, we had build RQR2 ÷ RQR6 beam qualities in X-ray diagnostic. Established

calibration method for diagnostic dosimeters as KAP meters, UNFORS dosimeters, and the TLD

dosimeters, practical measurements of entrance surface air kerma on Shimadzu X-ray machines

used phantom.

REFERENCES

[1] Technical Reports Series No. 457. Dosimetry in Diagnostic Radiology: An international

code of practice, International Atomic Energy Agency, Vienna, Austria, 2007.

[2] Implementation of the International Code of Practice on Dosimetry in Diagnostic

Dadiology (TRS 457): Review of Test Results, Austria, February 2011.

VINATOM-AR 13--31


232

RESEARCH ON STABILIZATION OF RADIOACTIVE WASTE

BY METHOD OF SYNROCK CERAMIC

Nguyen Hoang Lan, Nguyen Ba Tien, Vuong Huu Anh and Nguyen An Thai

Center for Radioactive Waste Management and Environmental Treatment,

Institute for Technology of Radioactive and Rare Elements, Vietnam Atomic Energy Institute

48-Lang Ha, Dong Da, Ha Noi

- Tên chủ nhiệm đề tài: Nguyễn Hoàng Lân

- Đơn vị: Trung tâm xử lý chất thải phóng xạ và môi trường – VCNXH

ABSTRACT: Separate phases from synroc polyphases ceramic were investigated to fabricate completely

synroc and the distribution of stable isotopes (Sr) in synroc matrix was surveyed simultaneously with leaching

test. The experimental conditions: 13.5 x 11mm pressed pellet synroc with pressure of 2.5-3tons/cm2, sintering

temperature ttk = 1250oC, thermal lifting velocity vt = 20

oC/min with 2 hours prolongation in 1250

oC, Sr

loading amount was 7 % mole, the results showed that pellets contain 3 phases perovskite CaTiO3, zirconolite

CaZr Ti2O7, hollandite BaAl2Ti6O16 with average density of 4.1 g/cm3, leaching rate R (g/m

2.d) of 10

-6, 10

-5 for

Ti, Sr respectively.

I. REQUIREMENTS AND TARGET

- Determining of synroc formular, fabricating of synroc ceramic, evaluating of waste load

and stability of product.

- Investigation on application capacity of synroc to immobilization of radioactive waste.

- Issuing of research results on factors affecting to synthesis of synroc and chemical

stability of synroc by Sr leaching test.

- Fabricate of synroc ceramic comprised 3 phase perovskite CaTiO3, zirconolite

CaZrTi2O7, hollandite CaZrTi2O7.

- Propose the synthesis procedure of synroc ceramic to immobilization of radioactive

waste.

II. METHODOLOGY AND EXPERIMENTAL

Synroc ceramic fabrication techniques: fine powder was mixed with oxides material

composition of 75% (CaO-TiO2-ZrO2 : 25%-65%-10% mole)-25% (15 % Al2O3-10% BaO) then

grinded in agate mortar, fine powder sample was added 3 % PVA as binder agent, then cold pressed

to form pellets with size of 11x13.5 mm, using high hardness mold, the mold diameter of 15mm,

zinc stearate was added as mold lubricant and pellets pressed under pressure about 2.5-3tons/cm2 by

one-dimensional hydraulic pressing machine. Green pellets were placed in high heat resistant boat

and sintered at 1250oC in air, heat rate of 20

oC/min and prolongation at 1250

oC for 2h after


- Code: CS/13/03-03






Nguyen Hoang Lan, Nguyen Ba Tien, Vuong Huu Anh, Nguyen An Thai. Research on immobilization

of radioactive waste by method of synroc ceramic synthesis. To be published in Journal of Nuclear

Science and Technology, VINATOM, 2014.


VINATOM-AR 13--31


233

finishing sintering sample was cooled in furnace to room temperature, analysis results examined by

ICP - MS, SEM, XRD, EDS.

Sr/synroc matrix loading and leaching test: Synroc ceramic pellet loaded 7% Sr was

fabricated similarly, ANSI / ANS 16.1-1986 standard utilized for leaching test.


The tables, graphs and images.

Table 1: Optimal technological parameters for fabrication of synroc loading Sr.

No Parameters Unit Value

1 Material composition of synroc % mole 75% (CaO-TiO2-ZrO2:

25%-65%-10%)-25%

(15% Al2O3-10% BaO)

2 Loading percent of Sr % mole 7

3 Binder (PVA) % weight 3

4 Mold lubricant (zinc stearat/aceton) % weight 0.2-0.3

5 Cylinder size of pellet (DxH) mm 13.5x11

6 Pressure ton /cm2

2.5-3

7 Sintering temperature oC 1250

8 Prolongation at sintering temperature h 2

9 Heat rate oC/min 20

10 Sintering environment -

Air

11 Cooling rate to room temperature -

Turn off furnace and wait

to room temperature

Table 2: Properties of synroc ceramic loaded Sr product.

No Properties Unit Result

1 Loading percent Sr % mole 7

2 Cylinder size of green pellet (DxH) mm 13.5x11

3 Cylinder size of sintered pellet (DxH) mm 12.31x10.55

4 Phases identified by X-ray - Perovskit, zirconolite,

hollandite

5 Average water adsorption % weight 3.26

6 Average density g/cm3

4.1

7 Leaching rate of Sr g/m2.d 10

-5

8 Leaching rate of Ti g/m2.d

10

-6

VINATOM-AR 13--31


234

Figure 1: Sr/synroc ceramic pellet product.

Figure 2: X-ray diffraction of 25% CaO-

65% TiO2-10% ZrO2 system.

Figure 3: SEM image of 25% CaO-65%

TiO2-10% ZrO2 system

Figure 4: X-ray diffraction of complete.

3- phases synroc.

Figure 5: SEM image of complete.

3- phases synroc.

VINATOM-AR 13--31


235

Figure 6: SEM image of synroc

loaded 7% Sr.

Figure 7: Selected areas for EDS analysis

of synroc loaded 7% Sr.

a

b

Figure 9: Relation of leaching rate

with time.

Figure 8: EDS results of synroc loaded

7% Sr (a-area 1, b-area 2).

In this work, we have investigated and fabricated ceramic synroc material application for

stabilization of radioactive isotopes in radioactive waste, this research has determined mole

composition of oxides to form synroc of 75% (CaO-TiO2-ZrO2: 25%-65%-10%, respectively)-25%

(15% Al2O3-10% BaO) and appropriate sintering temperature at 1250oC with 2h prolongation.

Synroc ceramic was fabricated with complete three crystal phases perovskit, zirconolite, hollandite

with high density and homogeneous. The distribution and immobilization of Sr in synroc matrix

was also investigated and examined by ICP-MS, SEM, XRD, EDS as images, tables above showed

high chemical stability of sample. The low leaching rate of synroc had a good ability to immobilize

Sr (10-5

g/m2.d).

IV. CONCLUSION

1. During the experimental section, studying on CaO-TiO2-ZrO2 system of synroc was

established and conducted to evaluate composition in equilibrium formation of perovskite,

zirconolite.The result obtained was sample of (CaO-TiO2-ZrO2: 25%-65%-10% mole, respectively).

2. The results of investigation of complete 3 phases synroc formation was launched. An

appropriate proportion of oxides component in the forming of three-phases synroc perovskite,

VINATOM-AR 13--31


236

zirconolite and hollandite has determined by experiment, the result surveyed was sample of (75%

(CaO-TiO2-ZrO2: 25%-65%-10% mole, respectively) -15% Al2O3-10% BaO).

4. The survey results of loading stable isotope strontrium showed compatibility Sr/synroc

matrix and can be loaded up to 7% mole.

5. Leaching test aimed to survey separation of strontrium from synroc by water to assess

chemical stability of synroc. The results showed that leaching rate decreases over time with very

little separated concentration of elements showing high chemical stability of synroc.

6. Synthesis procedure of synroc ceramic to stabilize radioactive waste has been proposed.

V. RECOMMENDATION

Based on some of results archived of project, respectfully request that the agency is allowed

to invest in more extensive research on project to assessment and application of synroc more

holistically.

REFERENCES

[1] Ringwood, A. E., Kesson, S. E., Ware, N. G., Hibeberson, W.O. and MAJOR, A.

“Immobilization of high level nuclear reactor wastes in SYNROC”. Nature 278, 219-

223.

[2] H. J. Rossell, J. Solid State Chem. 99, pp.38-51, 1992.

[3] ]. I.w. Donald, B.L. Metcalfe, R.N.J. Taylor “The immobilization of high level radioactive

wastes using ceramics and glasses”, Journal of materials science 32, 5851-5887, 1997.

[4] L. W. Coughanour, R S. Roth, S. Marzullo and F. E. Sennett, J. Res. Nat, Bur. Stand. 54,

pp. 191-199, 1955.

[5] J. M. McHale, N. V. Coppa, “Instantaneous Formation of Synroc-B Phases at Ambient

Pressure” Scientific Basis for Nuclear Waste Management XIX, eds.

VINATOM-AR 13--32


237

CALCULATION AND MEASUREMENT DOSE RATE AT THE CONTROL

AREA OF ELECTRON BEAM ACCELERATOR UELR-10-15S2

AT RESEARCH AND DEVELOPMENT CENTER

FOR RADIATION TECHNOLOGY

Nguyen Anh Tuan, Tran Van Hung, Cao Van Chung and Nguyen Hoang Hai

Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute

202 A Sreet 11., Linh Xuan Ward, Thu Duc Dist., HCM City, Vietnam

ABSTRACT: In order to provide data on the dose rate at the control area of electron beam accelerator UELR-

10-15S2 for assessing radiation safety, the approximation method and MCNP simulation were used to

calculate, and then were compared with Fricke dosimetry at high dose area and TLD dosimetry at low dose

area. At the high dose area, inside the irradiation room, accelerator room and along the conveyor, the results of

the calculation methods are good agreed with the results of Fricke dosimeters. At the low dose rate, they were

calculated for the most extreme cases (10 MeV bremsstrahlung energy) by approximation method; the results

are 6.0 Sv/h at the control room and 1.0 Sv/h at the product loading – unloading. MCNP code was applied to

calculation dose rate without natural radioactive background, and the results outside irradiation room are 10-3

Sv/h. TLD dosimeters were used to accumulated measure in a month (including background) and the results

obtained from 0.3 to 0.7 Sv/h, these values are equal to radioactive background.

1. INTRODUCTION

Accelerator UELR-10-15S2 is linear accelerator generation (LINAC) using RF wave [1] to

accelerate the electron beam energy 10 MeV, 15 kW maximum power. The scanning and bending

magnet systems were specifically designed to enable double-sided scanning irradiation products.

The dose rate in areas outside the control room when scanning double-sided irradiation is much

higher than on the upper scan only. In addition, under the scan can cause skyshine effects for the

surrounding area, so the shielding concrete was calculated, designed and built to the best shielding

both transmission and scattering of the bremsstrahlung. The structure of radiation shielding concrete

is shown in Fig.1.


- Code: CS/13/07-02






4

1

2

3 5

6

(1): Loading –

unloading

area

(2): Control

room

(3): Modulator

room

(4):

Irradiation

room

(5):

Accelerator

room

(6): Concrete

Figure 1: the

structure of

radiation shielding

concrete [2].

VINATOM-AR 13--32


238

2. CALCULATION METHOD AND DOSIMETRY

2.1. Approximation theory

Assuming anisotropic photon source, energy of 10 (MeV) is placed in the irradiated head of

the accelerator UELR-10-15S2 with a dose of 1.5 x 109 (Sv/h) at the source position, received

dose rate outside irradiation room by photon transmission and multiple scattering photon along the

conveyor.

2.1.1. Transmission calculation

The dose rate outside irradiation room is calculated by inverse-square law and shielding

material thickness. The dose rate at the target, P0 [Sv.m2kW

-1h

-1], is calculated for electron beam

power of 15 kW:

P0 = 15x104x10

4 = 1.5x10

9 [Sv.m

2/h], with = 90

0 (2.1)

P0 = 15x2,8x105x10

4 = 4.2x10

10 [Sv.m

2/h], with = 0

0 (2.2)

The inverse-square law is applied to calculation dose rate outside irradiation room:

2

0

1 R

P=P (2.3)

Outside irradiation room, the dose rate is also calculated by attenuation factor K:

P2 = P1.K (2.4)

and

TVL

X-

10=K (2.5)

where X is a barrier of thickness;

TVL is tenth-value layer.

The tenth-value layer, TVL, depends on the radiation energy, thickness and characteristic of

shielding materials [3].

2.1.2. Scattering calculation

After the first scattering onto concrete, the energy of photon reduced up to 0.5 MeV and the

second up to 0.3 MeV. The photon scattering schema is shown in Fig. 2.

Figure 2: The multiple scattering schema [4].

VINATOM-AR 13--32


239

After the first scattering, dose rate PS1 [Sv] is calculated by:

PS1 = P(R, ). )E,θ,θ(αs1

.2

1

1

SR

S [Sv/h] (2.6)

where RS1 [m] is distance from scattering surface S1 to S2;

P(R, ) is average dose rate on the scattering surface S1 and is calculated by inverse-square

law;

R [m] is distance from source to the scattering surface;

)E,θ,θ(αs1

is scattering coefficient.

After the second scattering, dose rate PS2 [Sv/h] is calculated by:

PS2 = P(R1, 1θ ).

2

2S22

2

1S11R/S.α.R/S.α [Sv/h] (2.7)

where RS2 [m] is distance from scattering surface S2 to S3;

P(R1, 1θ ) [Sv/h] is average dose rate on the scattering surface S2;

2 = ),,( 22 Es is the second scattering coefficient.

2.2. MCNP simulation [5]

The MCNP origin of coordinates was selected at vertical position of the electron beam on

the floor. The surfaces and the cells are defined by the coordinates of Oxyz axes to escribe the

shielding concrete of the irradiation room. Cross section perpendicular to the axis Oz on the first

and the second floor are shown in Fig. 3.

The error reduction tools which using MCNP code include: increased importance (imp) for

the points calculation, optimization of detector radius which around point calculation and

optimization of physical space.

Figure 3: Perpendicular to Oz cross section of shielding concrete by MCNP.

0,0,120

0,0,300

VINATOM-AR 13--32


240

2.3. Experimental dosimetry

According to the calculation results, the dose rate is very high at the irradiation room (from

10610

8 Sv/h) and very low outside (equal to radioactive background), so dose rate at the

irradiation room was measured by Fricke dosimeters and TLD dosimeters measured at the outside.

2.3.1. Dosimetry at the irradiation room

* Experimental equipment:

- Fricke dosimeter: Solution of (NH4)2 Fe (SO4)2 x 6 H2O, NaCl, H2SO4 and distillated

water was prepared according to ASTM standard [6];

Dose range: 20400 Gy;

Error: 3%.

- Measuring system: JACCO V-630 spectrometer [7]

* Experimental steps:

- Calculation data analysis;

- Setting position and time dosimetry.

2.3.2. Dosimetry outside the irradiation room

* Experimental equipment:

- TLD dosimeter: LiF: MCF crystal, range energy: 410000 keV;

- Model: RE-2000S, serial number: 1502050010;

- Made in Germany;

- Error: 7%

- Lower threshold: 50 nGy

* Experimental steps:

- Calculation data analysis;

- Setting position and time dosimetry.

3. THE RESULTS AND RADIATION SAFETY ASSESSMENT

3.1. Calculation and dosimetry results at the first floor

Dose rate distribution at the first floor of accelerator UELR-10-15S2 is shown in Fig.4.

VINATOM-AR 13--32


241

Figure 4: Distribution dose rate at the first floor.

Calculation and dosimetry results are shown in Table 1.

Table 1: The results of dose rate distribution at the first floor.

Points Theory MCNP calculation Dosimetry

D (Sv/h) D (Sv/h) D (Sv/h)

1 2.6E+08 4.2E+08 0.004 1.3E+08 0.03

2 5.5E+06 6.9E+06 0.050 2.2E+06 0.03

3 1.5E+04 3.2E+04 0.080 3.2E+04 0.03

4 6.4E+00 1.4E-03 0.150 4.9E-01 0.07

5 4.2E+06 4.4E+06 0.020 9.0E+05 0.03

6 2.0E+00 1.3E-03 0.180 4.5E-01 0.07

7 4.3E-03 2.5E-04 0.240 3.5E-01 0.07

In Table 1, dose rate was calculated for photon energy of 10 MeV by equation theory; the

results were calculated by MCNP code without radioactive background; dose rate at points 5, 6 and

7 was measured by TLD dosimeter, other points by Fricke dosimeter.

3.2. Calculation and dosimetry results at the second floor

Distribution dose rate at the second floor is shown in Fig. 5.

VINATOM-AR 13--32


242

Figure 5: Distribution dose rate at the second floor.

The calcultion and dosimetry results at the second floor are shown in Table 2.

Table 2: The calcultion and dosimetry results at the second floor



8 4.3E+07 4.6E+07 0.03 1.1E+07 0.03

9 8.6E+06 6.4E+06 0.04 1.6E+06 0.03

10 2.3E+04 9.4E+03 0.12 2.8E+04 0.03

11 2.5E+00 2.6E-03 0.12 3.5E-01 0.07

12 1.0E+00 5.3E+00 0.06 1.5E+00 0.07

13 - 6.8E-01 0.09 6.2E-01 0.07

At the high dose area (point 8, 9 and 10), the results of calculation methods are good agreed

with the measured. At the low dose area, the outside accelerator room, dose rate was calculated for

photon energy of 10 MeV by equation theory; the results were calculated by MCNP code without

radioactive background; the results were measured by TLD dosimeter including background.

3.3. Calculation and dosimetry results on the top of the irradiation room

On the top of the irradiation room, dose rate was calculated and measured at the ventilation

channel (point 15) and reference position player directly to the electron beam (point 14). The

calculation and dosimetry results were shown in Table 3.

VINATOM-AR 13--32


243

Table 3: The calcultion and dosimetry results on the top of the irradiation room.



14 4.3E+01 8.3E+01 0.10 1.8E+01 0.07

15 6.1E+02 4.2E+02 0.06 2.47E+02 0.07

At points 14 and 15, dose rate is very high so it generates skyshine effect, however, the

calculated dose rate caused by skyshine is very low (10-3

Sv/h).

3.4. The radiation safety assessment

In order to assess radiation safety for groups working outside the irradiation room, it

necessary to compare dose rate at workplaces with dose limit according to ICRP standards.

Table 4: Comparing dose rate with ICRP standards.

Groups Point Dose rate,

Sv/h

ICRP standard,

Sv/h

Occupational exposure 4 0.49 0.07 6.0

6 0.45 0.07 6.0

11 0.35 0.07 6.0

12 1.50 0.07 6.0

13 0.62 0.07 6.0

Public exposure 7 0.35 0.07 0.12

In Table 4, dose rate was accumulate measured including radioactive background by TLD

dosimeter. At the workplaces of radiation workforce, dose rate is less than ICRP standard so

workplaces are safety for radiation workforce. At the public area, dose rate was measured by TLD

dosimeter equals to background and calculated by MCNP code without background 10-3

Sv/h.

3.5. Warning radiation area

On the top of the irradiation room, dose rate is very high; distribution dose and limit

working time are shown in Table 5.

Table 5: Dose and limit working time on the top of the irradiation room.

Point Dose rate

(Sv/h)

Limit working time

(h)

14 18.0 2.7

15 247.0 0.2

Because of very high dose rate on the top of the irradiation room, there should be warning

radiation symbol at the stars to the top. During irradiation, if there is a problem independent of the

control system, the operator must switch off accelerator before troubleshooting.

VINATOM-AR 13--32


244

4. CONCLUSIONS

Dose rate was calculated for the most extreme cases (10 MeV bremsstrahlung energy) by

approximation method, and the results obtained at the control room 6.0 (Sv/h) and 1.0 at the

loading-unloading product.

MCNP code simulated the concrete shielding then was applied to calculation dose rate at the

control area without radioactive background. The results were calculated by MCNP code outside

the irradiation room of 10-4

(Sv/h); these results were less than four levels natural radioactive

background.

In order to assess radiation safety, dose rate was accumulate measured outside the irradiation

room by TLD dosimeter. The results show that dose rate equal to radioactive background (0.4

Sv/h) at the control room and loading - unloading area, so these values are less than ICRP standard

during irradiation.

In addition, dose rate was calculated and measured at the high dose area (inside irradiation

room, along conveyor) so that comparing between calculation and dosimetry results. The

calculation results are good agreed with dosimetry (less than 10 %) at the high dose rate. Dose rate

also was calculated and measured at the top of the irradiation room where radiation can scatter

along ventilation channel to establish radiation warning and recommend working time in the

particularly dangerous area.

REFERENCES

[1] Jean-Luc Biarrotte, RF Cavities for Particle Acceleration, CNRS/IPN Orsay, 2009.

[2] Corad service, Preliminary Calculation of Radiation Shielding for Electron Beam System

Deliverred Under Contract No. 01/12-08-2, St. Petertburg, Russia, 2009.

[3] Philip M.K. Leung, The Physical Basis of Radiotherapy, The Ontario Cancer Institute, 1990.

[4] IAEA, Radiological Safety Aspects of the Operation of Electron Linear Accelerators,

Technical Reports Series 188, 1979.

[5] NCRP, Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator

Facilities, National Council on Radiation and Measurements No.51, 1997.

[6] Los Alamos National Laboratory, Monte Carlo N-Partical Code System, Los Alamos, New

Mexico, 2000.

[7] ASTM, Standards practice for using the Fricke Reference-Standard dosimetry system,

Standards on dosimetry for radiation processing, ASTM (2nd

edition), pp. 261-268, 2004.

[8] www.jascoint.co.jp

[9] ICRP, The 2007 Recommendations of the International Commission on Radiological

Protection, Annals of the ICRP Publication 103, 2007.

VINATOM-AR 13--33


247

STUDY ON IMPROVING ANTIOXYDANT AND ANTIBACTERIAL

ACTIVITIES OF SILK FIBROIN BY IRRADIATION TREATMENT

Tran Bang Diep, Nguyen Van Binh, Hoang Phuong Thao, Pham Duy Duong,

Hoang Dang Sang and Nguyen Thuy Huong Trang

Hanoi Irradiation Centre,Vietnam Atomic Energy Institute

No.5-Minh Khai, Tu Liem, Ha Noi

ABSTRACT: Silk fibroin at dry state and the solution of 3% were irradiated by Co-60 source at dose ranges

0÷1000 kGy and 0÷50 kGy respectively. The results showed that irradiation treatment for fibroin solution have

higher effectiveness for improvement of some bio-activities of silk fibroin compared with dry state irradiation

treatment due to remarkably reducing of irradiation doses. The antioxidant activity of fibroin was significantly

increase by irradiation. The maximum value of DPPH radical scavenging activity was 70.4% when fibroin

solution was irradiated at dose of 10 kGy. Irradiated fibroin solution also shown antibacterial activity against

tested bacteria strains (E. coli, and S. aureus). In order to estimate the applicability of our irradiated fibroin, the

silk fibroin solutions were lyophilized to obtain a pure fibroin powder, then their bio-activities were compared

with those of commercial silk fibroin (Proteines De Soie/ Zijdeproteine, Bioflore, Canada). Our fibroin powder

revealed higher antioxidant and antibacterial activities. The amino acid compositions of our irradiated fibroin

were also higher than that of the commercial product. Thus, the irradiated silk fibroin can be used for further

application in cosmetic and other related fields.

Keyword: Silk, Fibroin Solution, Radiation Treatment, Antioxidant Activity, Antibacterial Activity.

1. INTRODUCTION

Silk derived from the silkworm Bombyx mori is a natural protein that is made mainly of

fibroin and Sericin. The fibroin is a major component of silk fiber (75%), serving as the core. It

contains at least two fibroin protein, light-chain (25 kDa) and heavy-chain (325 kDa). The sericin is

a minor component (25% of the silk fiber), serving as a glue-like protein coated on the two fibroin

cores to conceal a unique luster of fibroin. Both fibroin and sericin contain the same 18 amino

acids, although in different amounts. Another difference between these two proteins is crystalline

repetitive amino acids (-Gly-Ala-Gly-Ala-Gly-Ser-) along its sequence, forming a large number of

β-sheet microcrystallines. This reinforcement contributes the strength and stiffness to the silk fiber

[1].

Silk fibroin has been used as a textile material for thousands years because it has excellent

natures such as lightness and warmth on wearing, beautiful gloss, etc... Recently silk fibroin is also

considered to be natural protein with interesting characters and applications in new diversified

fields, especially medical, cosmetic and pharmaceutical materials [8]. On practical application, it is

necessary to change form of silk fiber in many cases. For example, skin film and block are studied

for artificial skin and for contact lens respectively. Powder has been already used as additions for

food, cosmetic or pharmaceutical materials [4].


- Code: CS/13/08-02







VINATOM-AR 13--33


248

In fact, it is difficult to degrade or dissolve silk fibroin in water because of its crystal

structure. This limitation influenced on the use of silk fibroin, especially for cosmetic and

pharmaceutical applications. The radiation technique has been increasingly used for structural

modification of organic compounds. Gamma radiation can cause the macromolecule chains to

cross-link, graft and degrade. Recently, some authors reported that the conversion efficiency from

fiber to powder of silk fibroin improved by EB treatment, that the solubility in water of silk fibroin

improved while the mechanical properties weakened after treatment with gamma radiation [4, 7, 9].

Despite the mechanisms by which gamma irradiation produce several biological effects on

peptide/protein are still clearly unknown but the latest studies showed the antioxidant and anti-

tumor activities, tyrosinase inhibitory ability, … of silk fibroin were enhanced by gamma irradiation

[2, 3].

In our previous report of 2011, the irradiated fibroin with better degradation and higher

water solubility compared with natural fibroin was produced. Accordingly, this study was

undertaken in order to investigate the effective of gamma irradiation for enhancement of antioxidant

and antibacterial activities of silk fibroin which are among important properties of variety of

cosmetic and pharmaceutical. Process for production of water-soluble silk fibroin powder by

irradiation treatment had been proposed. In the future, the results of this study may be a prerequisite

to expand the applications of radiation technology for using abundant silk fibroin of country as

cosmetic and pharmaceutical materials.

2. EXPERIMENTAL

2.1. Materials

Silk fibroin fiber was purchased from My Duc Commune, Ha Noi. The medium for the

cultivation of microorganism such as Nutrient Broth and Nutrient Agar was supplied by Difco,

USA. The chemicals such as Na2CO3,CaCl2, KBr, DPPH (2, 2-diphenyl-1-picrylhydrazin), CH3OH,

ascorbic acid at analytical grade were supplied by Merck chemical company, Germany, while

C2H5OH was bought from a domestic company.

2.2. Silk fibroin extraction preparation

The raw silk fibers were subjected to removal of the sericin by the method described by

Byun et al. [2].

10g of silk fibroin was dissolved in 100 ml of calcium chloride solution

(CaCl2/C2H5OH/H2O=1:2:8 in mole ratio) at 70 ± 2oC for 1 h. The mixed solution was dialyzed in

distilled water with a molecular weight cutoff of 12-14 kDa for 72 h. The final concentration of the

silk fibroin aqueous solution was 3% (w/v).

2. 3. Irradiation

Silk fibroin at dry state and the solution of 3% were irradiated by Co-60 source of Hanoi

Irradiation Center at dose ranges 0÷1000 kGy and 0÷50 kGy respectively.

2.4. Antioxidant activity

To evaluate the antioxidant of silk fibroin, a radical oxygen species (ROS) scavenging

method (DPPH) was used, according to Lucconi [6]. In particular, silk fibroin solutions were tested

at different concentrations (0.005, 0.0075, 0.01 mg/ml). One milliliter of aqueous silk fibroin

solutions were mixed with 2 milliliter of methanol solution containing DPPH 10 μg/ml. Samples

were incubated in the dark for 1 hour at 25oC and absorbance was measured at 517 nm with UV-

VIS spectrophotometer AV-2450 Shimadzu, Japan. Reaction mixture without fibroin sample was

used as negative control, while ascorbic acid was used as positive control at the same concentration

of fibroin samples.

Radical scavenging activity was calculated by the following formula:

VINATOM-AR 13--33


249

% activity = (A-B)/Ax100

where A is the absorbance of negative control and B is the absorbance of tested solution.

The analyses were performed in three replicates.

2.5. Antibacterial activity

Three kinds of bacteria strains E. coli, B. subtillis and S. aureus were used for antibacterial

activity testing of silk fibroin.

The antimicrobial activities of irradiated fibroin solutions were investigated and compared

with antimicrobial activities of non-irradiated fibroin solution as control. The procedure for testing

was performed as the modified methods of agar disk diffusion and agar dilution methods (AOAC

2000).

2.6. Determination amino acid composition of irradiated silk fibroin

The amino acid components existing in the irradiated silk fibroin was determined using a

high performance liquid chromatography (HPLC, National Institute for Food Control). The results

were also compared to a commercial product in order to estimate the applicability of irradiated silk

fibroin in practice.


3.1. Effects of irradiation conditions and irradiation doses on antioxidant activity of

silk fibroin

The powder and 3% solution of silk fibroin was irradiated at different doses and its DPPH

radical scavenging activity was evaluated and compared with that of ascorbic acid and the

commercialized fibroin powder.

3.1.1. Effect of irradiation treatment at dry state on antioxidant activity of silk fibroin

Antioxidant activity of fibroin irradiated at different doses from 0 to 1000 kGy at dry state

was shown in Table 1 and Fig. 1 presences the UV spectra of the mixed solutions of the irradiated

fibroin in methanol containing DPPH. In the dose range of investigation, the ROS-radical

scavenging activity (%) of irradiated fibroin increases when increasing of irradiation doses. This

value is 50.6% when fibroin was irradiated at dose of 1000 kGy.

Table 1: Antioxidant effect of fibroin irradiated at dry state.

Irradiation dose (kGy) ROS- radical scavenging activity (%)

0.005 mg/ml 0.0075 mg/ml 0.01 mg/ml

0 5.55 ± 0.18 8.43± 0.26 12.05± 0.18

50 5.02 ± 0.16 8.87 ± 0.27 11.08 ± 0.36

100 8.20 ± 0.22 11.46 ± 0.46 14.61 ± 0.41

200 14.40 ± 0.42 17.60 ± 0.43 17.06 ± 0.43

500 15.47 ± 0.39 22.22 ± 0.38 26.14 ± 0.65

750 17.30 ± 0.24 28.90 ± 0.51 36.40 ± 0.54

1000 28.12 ± 0.14 36.20 ± 0.61 50.60 ± 0.36

Commercialized Fibroin 6.20 ± 0.21 7.60 ± 0.35 12.76 ± 0.41

Ascorbic acid 91.07 ± 0.42 - -

(-) No investigated

VINATOM-AR 13--33


250

0

0,02

0,04

0,06

0,08

0,1

0,12

0,14

0,16

0,18

400 450 500 550 600 650 700

Op

tica

l d

en

sity

Wavelenght (nm)

Figure 1: UV absorbency of fibroin (0.01 mg/ml) irradiated at dry state in DPPH solution.

( Negative control, 0 kGy, 50 kGy, 100 kGy, 200 kGy,

500 kGy, 750 kGy and 1000 kGy)

3.1.2. Effect of irradiation doses on antioxidant activity of 3% solution of silk fibroin

A 3% solution of silk fibroin was irradiated at dose range from 0 to 50 kGy and Table 2

shows the antioxidant activity of the fibroin solutions irradiated at different doses. Figure 2

presences the UV spectra of the mixed solutions of the irradiated fibroin in methanol containing

DPPH.

From the these results, we found that 70.04% is maximum value of DPPH radical

scavenging activity obtained with the fibroin solution irradiated at dose of 10 kGy. The antioxidant

activity of the irradiated fibroin solutions also reduced gradually to 32.2% when doses increased

continuously to 50 kGy.

Table 2: Effect of irradiation doses on antioxidant activity of 3% solution of silk fibroin.

Irradiation dose

(kGy)

ROS- radical scavenging activity (%)

0.005 mg/ml 0.0075 mg/ml 0.01 mg/ml

0 5.55 ± 0.18 8.43 ± 0.26 12.05 ± 0.18

5 7.95 ± 0.21 8.65 ± 0.25 32.20 ± 0.63

10 23.80 ± 0.38 27.8 ± 0.66 70.04 ± 0.18

20 14.45 ± 0.18 21.40 ± 0.56 53.60 ± 0.79

30 11.30 ± 0.44 15.38 ± 0.41 48.05 ± 0.74

40 8.30 ± 0.26 12.20 ± 0.45 35.80 ± 0.62

50 5.60 ± 0.17 10.10 ± 0.12 32.20 ± 0.65

Commercialized

Fibroin 6.20 ± 0.21 7.60 ± 0.35 12.76 ± 0.41

Ascorbic acid 91.07± 0.42 - -

(-) No investigated.

VINATOM-AR 13--33


251

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

450 500 550 600 650 700

Op

tica

l d

en

sity

Wavelength (nm)

Figure 2: UV absorbency of fibroin (0.01 mg/ml) derived from 3% irradiated fibroin

solutions in DPPH solution ( Negative control, 0 kGy, 5 kGy, 10 kGy,

20 kGy and 30 kGy).

Similar effect also was observed by some Korean authors when they studied on some

physiological activities of fibroin solution (1 mg/ml). They reported that DPPH radical scavenging

activity of fibroin solution increased to more 80% at irradiation dose of 5 kGy compared with 9% of

unirradiated fibroin solution. DPPH radical scavenging activity slightly reduced to about 53% at

dose of 50 kGy. The authors suggested that the changes of molecular weight of fibroin by

irradiation treatment induced the enhancement of its antioxidant activity [3].

From the these results we found that irradiation treatment for fibroin solution have higher

effectiveness for improvement antioxidant activity of silk fibroin compared with dry state

irradiation treatment due to remarkably reducing of irradiation doses. The dose of 10 kGy is optimal

dose for highest antioxidant activity of silk fibroin.

3.2. Effects of irradiation doses on antibacterial activity of silk fibroin

The antibacterial activity of 3% solution of irradiated silk fibroin against 3 tested bacteria

strains (E. coli, S. aureus , B. subtillis) were investigated through the parameters as width of clear

zone of growth inhibition (Table 3 and Fig. 3) and minimum inhibitory concentration (MIC) (Table

4).

Table 3: Width of clear zone of growth inhibition

of the irradiated fibroin solution for 3 tested bacteria strains.

Irradiation dose

(kGy)

Width of clear zone of growth inhibition (mm)

E.coli S. aureus B. subtillis

0 – – –

5 – – –

10 5.4 ± 0.09 3.6 ± 0.10 –

20 5.6 ± 0.25 3.6 ± 0.12 –

40 5.4 ± 0.11 3.5 ± 0.08 –

* Concentration of fibroin solution using for tested was 1%.

VINATOM-AR 13--33


252

(–) No observed

The results show that, antibacterial activity of fibroin solution had been improved by gamma

irradiation. However, there were no significant differences in antibacterial activity against E. coli

and S. aureus of all samples in dose ranges from 10 to 40 kGy. The 30 mg/ml solution of fibroin

was not enough to inhibit growth of B. subtillis for all investigated doses.

Figure 3: Clear zone of growth inhibition of the irradiated fibroin solution at different

concentrations treated at dose of 10 kGy for (a)-E. coli and (b)-S. aureus.

Table 4: Minimum inhibitory concentration of irradiated silk

fibroin solution at diffident doses.

Irradiation dose

(kGy)

MIC (mg/ml)

E. coli S. aureus B. subtillis

0 30 30 >30

10 4.2 6.5 >30

20 4.5 6.5 >30

40 4.5 7.0 >30

The antibacterial activity of fibroin powder treated at dose of 500 kGy was also reported by

Jindaron [5]. The authors found that the MICs of fibroin powder for E. coli B/r and S. aureus K

were 2.4 mg/l and this concentration was also not enough to inhibit growth of Bacillus subtillis. In

this study, similar activity was obtained for silk fibroin solution irradiated at doses from 10 to 40

kGy.

3.3. Amino acid composition of irradiated silk fibroin

Table 5: Amino acid profile of irradiated fibroin powder and commercial product.

Amino acid Irradiated fibroin

(mg/g)

Commercial fibroin -

bioflore (mg/g)

Aspartic

Serine

Glutamic

9.99

104.96

No observed

No observed

No observed

No observed

b

t

e

s

t

e

d

b

a

c

t

e

r

i

a

s

t

r

a

i

n

s

a

t

e

s

t

e

d

b

a

c

t

e

r

i

a

s

t

r

a

i

n

s

VINATOM-AR 13--33


253

Glycine

Histidine

Threonine

Arginine

Alanine

Proline

Cystine

Tyrosine

Valine

Methionine

Lysine

Isoleucine

Leucine

Phenyalanine

247.24

No observed

3.23

No observed

No observed

No observed

1.40

75.06

42.47

No observed

2.13

6.47

5.19

7.71

0.19

No observed

0.70

No observed

No observed

No observed

0.37

4.03

7.55

3.72

10.61

7.49

11.65

8.46

From the results above, it is evident that the water-soluble yellowish silk fibroin powder can

be prepared by lyophilization of the irradiated silk fibroin solution. The amino acid components of

the irradiated silk fibroin were also analyzed and presented in Table 5. As one can see, the amounts

of some amino acid exsisting in the irradiated fibroin such as serine, glycine, tyrosine and valine

were much higher than those in the commercial product. This might be because the amino acid

compositions of raw materials for silk fibroin production were effected by species of silk. In

addition, the silk protein may be degraded into amino acid during gamma irradiation. The result was

consistent with the experiment done by Vaithanomsat [10] that the chemical compositions of silk

protein could be influenced by silk species and feed and this, therefore would be able to indicate the

amino acid pattern of silk products.

4. CONCLUSIONS

Our results show that gamma irradiation could improved some bioactivity of silk fibroin.

Irradiation treatment for fibroin solution have higher effectiveness for enhancement antioxidant and

antibacterial activities of silk fibroin compared with dry state irradiation treatment.The maximum

antioxidant activity was 70.4% obtained for the fibroin solution that irradiated at dose of 10 kGy.

These irradiated fibroin solution also shown antibacterial activity against the tested bacteria strains

(E. coli and S. aureus).

The water-soluble silk fibroin powder can be prepared by lyophilization of irradiated silk

fibroin solution. The irradiated silk fibroin powder revealed the higher antioxidant and antibacterial

activities in comparision with a commercial silk fibroin (Proteines De Soie/Zijdeproteine, Bioflore,

Canada). The amino acid components of the irradiated fibroin were also higher than those of

commercial product. Thus, the irradiated silk fibroin may potential be used for cosmetic and other

related applications.

REFERENCES

[1] G.H. Altman, F. Diaz , C. Jakuba, T. Calabro, R.L. Horan, J.S. Chen, H. Lu, J. Richmond,

D.L. Kaplan, Biomaterials 24, pp. 40-416, 2003.

[2] E.B. Byun, N.Y. Sung, J.H. Kim, J.I. Choi, T. Matsui, M.W. Byun, J.W. Lee, Chemico-

Biological Interactions 186, pp. 90-95, 2010.

[3] http://www.faqs.org/patents/app/20090286959

VINATOM-AR 13--33


254

[4] K. Ishida, H. Takeshita, Y. Kamiishi, F. Yoshii, T. Kume, JAERI-Conf. 2001-005, pp. 130-

138, 2001.

[5] J. Chvajarernpun, C. Siri-Upathum, JAERI-Conf. 2002-003, pp. 76-81, 2002.

[6] G. Lucconi, Scientifica Acta 6, pp. 3-6, 2012.

[7] W. Pewlong, B. Sudatis, H. Takeshita, F. Yoshii, T. Kume, JAERI-Conf. 2000-003, pp. 146-

152, 2000.

[8] R. M. Reddy, Academic Journal of Entomology 2, pp. 71-75, 2009.

[9] B. Sudatis, S. Pongpat, JAERI-Conf. 2002-003, pp.101-104, 2002.

[10] P. Vaithanomsat, Kasetsart J. (Nat.Sci) 40, pp.152-158, 2006.

VINATOM-AR 13--34


255

STUDY ON PREPARING CARBOXYMETHYL STARCH HYDROGEL

RADIATION-CROSSLINKED ON THE ELECTRON BEAM CCELERATOR

TO DO THE MOISTURIZING MATERIAL IN COSMETIC

Nguyen Thanh Duoc, Doan Binh, Pham Thi Thu Hong and Nguyen Anh Tuan

Research and Develepment Center for Radiation Technology,



ABSTRACT: Hydrogel of carboxymethyl starch (CMS) matrix was prepared by crosslinking of electron beam

(EB) radiation on the EB linear accelerator UERL-10-15S2 (energy of 10 MeV, capacity of 15 kW, Russia)

with support substances such as polyvinyl pyrrolidon (PVP), Kappa-Carragenan and Montmorillonit (MMT).

The characteristic properties of hydrogel membrane such as gel content, degree of swelling, mechanical

strength, adhesion force, water vapor transmission rate (WVTR) and skin allergy were experimented. This

research will be firstly oriented in applications of CMS hydrogel material in cosmetic and personal care field

such as facial mask for skin care, moisturizing membrane for skin and so on.

1. INTRODUCTION

Nowadays, people’s demands of beauty and personal care are very necessary. The more

modern and developed life is, the more necessary demands of cosmetic are. Many developed

countries in this field such as Dutch, Korea, Japan have done a lot of researches [5,6,7,8] and

prepared many kinds of product in the market. In Dutch, O.S Lewal and et prepared CMS hydrogel

crossed by chemical activator axit carboxylic as glutaric, suberic, pimelic and butanetetracarboxylic

[5]. In Japan, group of Nagasawa had a result in radiation crosslinking of carboxymethyl starch [6];

Yoshii and et researched crosslinking CMS at high concentration by irradiation method without

chemical initiator [7]. In Korea, group of Hoon Song resulted in CMS hydrogel used for removing

iron in aqueous Solution [8]. And the products have many different puposes of use such as: facial

mask, moisturizing membrane or scream for skin and so on.

Materials applied in this filed such as gel, hydrgel, nanoparticle and so on have

characteristic properties that satisfy some standard requirements about skin allergy, asepsis,

nontoxic property with people and ability of biodegradation in the environment after used [9].

Radiation crosslinking is the best way to process the products like hydrogel membrane applying to

the cosmetic field.

This research is the basic step of preparation the hydrogel membrane on the CMS matrix by

the method of EB crosslinking. And it will be firstly oriented in applications of CMS hydrogel

material in cosmetic and personal care.


- Code: CS/13/07-03






VINATOM-AR 13--34


256

2. EXPERIMENT

Raw chemical materials

PVP, BASF Kollidone 90, Mw: 1000.000 Da (Dutch); CMS, Emsize CMS 150, MW = 600

kDa, DS=0.85, Emsland-Stärke (Dutch); Kappa-Carragenan, Marcel (Phillipine); Montmorillonite,

Merk (Dutch) and pure water.

Instrument, equipment:

Electron beam accelerator UERL-10-15S2, 10 MeV, CORAD Ser. Ltd, Russia.

DTA, TA-60WS, Shimadzu, Japan

Mechanical analysis, Stograph V10-C, Toyoseiki, Japan

Mechanical analysis QCTech, Taiwan

And other laboratory equipments

Preparation method of sample and irradiation

Weigh 5g CMS, 10g PVP, 1g κ-Carrageenan and 100mg reinforcing phase MMT. Mix the

blend in the glass erlen containing 100g pure water in 4 hours and kept steady over night at the

room temperature. Boil the compound in a bain-marie at 80oC in 3 hours, then decrease the

temperature and keep it at 70oC in 1 hour to remove the bubbles. Pour the blend into the PET mould

with the shape 10cm x 10 cm x 0.3cm at 45oC. Finally, pack it in the PE plastic membrane and then

irradiated on Electron beam accelerator UERL-10-15S2, 10 MeV, Russia.

Analysing the WVTR of hydrogel membrane

Determine the water vapor transmission rate by weighing the lost weight of the cylinder

vase with the diameter 35mm and the height 50mm containing 25ml water that was covered the

hydrogel membrane with diameter 40mm on the its head. The vase was kept in the incubator at

35oC in 24 hours [3,4].

WVTR (g/m2/h) =

24

106

10

Ax

xmm bb

where: mb0: weight of the vase before incubating (g);

mb1: weight of the vase after incubating in 24 hours (g);

A: square of the vase’s surface (mm2).

Analysing the adhesive properties of hydrogel membrane

Sample with the shape 150mm x 20mm covered and rolled with a force about 5N on the

plastic’s surface made of nonwoven PE fiber at the room temperature in 3 hours. Peeling force was

determined in the tensile machine QCTech (Taiwan) and moved at an angle to the direction of the

plastic surface with the peeling velocity 50mm/minute [1,2].

Analysing the degradation of hydrogel membrane in the environment of α-amylase

enzyme

Dry the sample at 65oC until its weight had no change, then grind it into small pieces.

Balance 50mg and put in the glass vases having 4ml buffer solution acetate (pH = 4.6) and 1ml

CaCl2 0.1% and 1ml enzyme -amylaza 0.1%, then keep the vase in the incubator at 400C in 24

hours. After 1 hour, sample was filtered by the filter-paper and cleaned by the pure water

sometimes. Sample was dried at 65oC until its weight had no change again.

VINATOM-AR 13--34


257

3. RESULT AND DISCUSSION

Preparation of the hydrogel membrane with the best ratio of components

From the result of basic experiments, the best ratio of components PVP:CMS:

Kappacarragen = 10g:5g:1g in 100ml pure water with (MT2) and without the reinforcing phase

MMT (MT0) was chosen to determine characteristic properties of sample in the following

experiments in a range of absorbed dose 10-25 kGy.

Characteristic properties

Effect of the absorbed dose on the gel content

50

52.5

55

57.5

60

62.5

65

67.5

70

5 10 15 20 25 30

Absorbed dose (kGy)

Gel

con

ten

t (%

)

3

4

5

6

7

8

9

Deg

ree

of w

ater

sw

ellin

g

(g/g

)

MT0

MT2

Figure 1: Effect of the absorbed doses on the gel content and degree

of water swelling of hydrogel membrane.

In the result of scheme 1, gel content of MT2 is lower than MT0 in range of absorbed doses

10-25 kGy. Both of them increase with the increasing absorbed dose and saturated at the dose 20

kGy. In the opposite, the water swelling of MT2 is higher than MT0 and both of them descrease

with the increasing of absorbed doses. All components are hydrophilic, so in the hightly

crosslinking stage, it prevents the hydration of polymer chains in membrane.

Effect of absorbed dose on the tensile strength and elongation at break

In the studied range of abosorbed doses, tensile force at break of MT2 is higher than MT0

(Figure 2). It show that tensile strength was improved with the reinforcing MMT. Both of samples

increase linearly and get maximum values at dose 20 kGy. In another way, elongation at break of

MT0 and MT2 decrease with the increasing of absorbed doses.

0.07

0.08

0.09

0.10

0.11

0.12

5 10 15 20 25 30

Absorbed dose (kGy)

Ten

sile

fo

rce

at

bre

ak

(MP

a)

120

140

160

180

200

220

240

Elo

ng

ati

on

at

bre

ak

(%

)

MT0

MT2

Figure 2: Effect of the absorbed doses on the tensile force

and elongation at breake of hydrogel membrane.

VINATOM-AR 13--34


258

Adhesive property

0.03

0.04

0.05

0.06

0.07

0.08

0.09

10 12.5 15 17.5 20 22.5Absorbed dose (kGy)

Ad

hesi

ve f

orce (

N/c

m)

.

Figure 3: Effect of the absorbed doses on the the adhesive property

of hydrogel membrane MT2.

Testing the effect of the absorbed doses on the the adhesive property of hydrogel membrane

MT2 shows that adhesive force decreases with the increasing of absorbed doses. It demonstrates

that the adhesive force is opppsite in the gel content or degree of crosslinking. At the optimus

absorbed dose 20 kGy, adhesive force of membrane gets the saturated value and has no change in

over 20 kGy. Comparing the adhesive property of MT0 and MT2 at the absorbed dose 20 kGy

(Figure 4), the result shows that MMT component does not affect to adhesion ability of membrane

because their values of adhesive force have difference in deviation of calculation, alternately 0.04

and 0.043 N/m for MT0 and MT2.

Figure 4: Effect of MMT on the

adhesive property of hydrogel

membrane at the absorbed dose 20

kGy.

Result of thermo gravimetric analysis

Figure 5: Represending

thermogravimetric analysis of

sample.

MT0

MT2

0

0.01

0.02

0.03

0.04

0.05

1

Ad

hes

ive

forc

e (N

/cm

)

VINATOM-AR 13--34


259

In the result, sample MT2 with MMT component has the higher temperature beginning the

decomposition than the control sample MT0 in the same experimented condition. (286oC so với

275oC). At 360

oC, appear a small peak that determined effect of MMT on the change of weight.

Result of the WTVR

Test the WVTR of hydrogel membrane with and without the reinforcer MMT at the

absorbed dose 20 kGy. From the table 1, their WVTR have difference in deviation of calculation

and at low values 23.60 for and MT0 and 24.97 for MT2. The result shows that moisturizing ability

of MT0 and MT2 are the same whether the sample has MMT component or not.

Table 1: WVTR of hydrogel membrane with and without the reinforcer MMT

at the absorbed dose 20 kGy.

WVTR (g/m2/hour)

Control 57.54 ± 4.54

MT0 23.60 ± 3.12

MT2 24.97 ± 2.95

Result of the degradation in the environment of α-amylase enzyme

Test the degradation of sample MT0 and MT2 irradiated at the dose 20 kGy in the

environment of α-amylase enzyme during 24 hours. The result shows that transmission rate of MT2

is lower than MMT. MMT is an inorganic substance, maybe it prevent and moderate the hydrolytic

degradation of enzyme on the CMS polymer chains .

72

74

76

78

80

82

84

86

88

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hour)

Per

cen

t o

f sa

mp

le's

wei

gh

t a

fter

deg

rad

ati

on

(%

)

MT0

MT2

Figure 6: Velocity of sample’s degradation at absorbed dose 20 kGy

in the environment of enzyme following the time.

4. CONCLUSION AND RECOMMENDATIONS

- Hydrogel membrane on the CMS matrix prepared from the compound PVP/CMS/Kappa-

Carragenan with the best ratio 10g/5g/1g/100 ml water and reinforcer MMT about 50-100mg has

good characteristic properties to make the moisturizing membrane for skin in the cosmetic:

+ The optimal range of absorbed doses: 20-25 kGy.

+ Water swelling: 5-6 g/g.

+ Tesile force at break: 0.09-0.10 MPa.

VINATOM-AR 13--34


260

+ Elongation at break: 130-150 %

+ WVTR: 20-25 g/m2/hour.

- Hydrogel membrane on the CMS matrix irradiated in a range dose 20-25 kGy on the EB

accelerator has some restriction such as:

+ Because of the high dose rate, irradiated membrane appears a lot of bubbles and amount

of bubles increases with increasing of absorbed doses.

+ Making shape of product may be processed on the gamma system with the low dose rate,

then step of crosslinking and making asepsis on the EB accelerator.

REFERENCES

[1] Razzak M. T. et al., “Irradiation of polyvinyl alcohol and polyvinyl pyrrolidone blended

hydrogel for wound dressing”, Radiat. Phys. Chem., Vol. 62, pp.101-113, 2001.

[2] Murat Şen*, Esra Nazan Avcı, “Radiation synthesis of poly (N-vinyl-2-pyrrolidone)-κ-

carrageenan hydrogels and their use in wound dressing applications.I. Preliminary laboratory

tests”, Journal of Biomedical Materials Research Part A, Vol. 74A, pp.187-196, 2005.

[3] Jian Ping Gong et at., “Formation of a strong hydrogel-porous solid interface via the double-

network principle”, Acta Biomaterialia, Vol. 6, pp.1353-1359, 2010.

[4] Liudmila Korkina, Vladimir Kostyuk and Liliana Guerra, “Biohydrogels for the In Vitro Re-

construction and Insitu regeneration of human skin”, Hydrogels, Biological Properties and

Applications, pp. 97-109,2009.

[5] Olayide S. Lawal et al., “Hydrogels based on carboxymethyl cassava starch cross-linked with

di- or polyfunctional carboxylic acids: Synthesis, water absorbent behavior and rheological

characterizations, European Polymer Journal, 45, pp.3399-3408, 2009.

[6] Naotsugu Nagasawa*, Toshiaki Yagi, Tamikazu Kume, Fumio Yoshii, “Radiation

crosslinking of carboxymethyl starch”, Carbohydrate Polymers, 58, pp.109-113, 2004.

[7] Fumio Yoshiia,*

, Long Zhaob, Radoslaw A. Wach

b, Naotsugu Nagasawa

a, Hiroshi Mitomo

b,

Tamikazu Kumea, “Hydrogels of polysaccharide derivatives crosslinked with irradiation at

paste-like condition”, Nuclear Instruments and Methods in Physics Research B, 208, pp.320-

324, 2003.

[8] Bhoj Raj Pant†, Hye-Jin Jeon, and Hyun Hoon Song*, “Radiation Cross-linked

Carboxymethylated Starch and Iron Removal Capacity in Aqueous Solution”,

Macromolecular Research, Vol. 19, No. 3, pp.307-312, 2011.

[9] Rafael M. Ottenbrite, Kinam Park, Teruo Okano, Biomedical Applications of Hydrogels

Handbook, Springer, pp.1-15, 2010.

http://onlinelibrary.wiley.com/doi/10.1002/jbm.a.v74a:2/issuetoc

VINATOM-AR 13--35


261

RESEARCH ON DEGRADATION OF SILK FIBROIN

BY COMBINATION OF ELECTRON BEAM IRRADIATION

AND HYDROTHERMAL PROCESSING

Nguyen Thi Kim Lan, Dang Van Phu, Le Anh Quoc and Nguyen Quoc Hien

Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute


ABSTRACT: Silk fibers and silk proteins have been demonstrated to be useful to apply in the textile industry,

biomedical, cosmetics, pharmaceuticals. In this study, the effects of electron beam (EB) irradiation combined

with hydrothermal processing to the solubility of silk fibroin and generation of soluble silk protein were

investigated. The solubility of unirradiated and irradiated fibroin were greater than 80% when hydrothermal

degradation was performed in the sodium hydroxide solution at appropriate concentration of 0.05 M. However,

the solubility of irradiated fibroin was greater than that of unirradiated sample. The protein content increased

from 0.4617 to 0.6530 mg/mg when irradiation doses increased from 0 to 200 kGy, respectively. The

molecular weight of protein was determined by SDS-PAGE method. The characteristics of silk protein were

confirmed by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR),

thermogravimetric analysis (TGA) and X-ray diffraction (XRD).

Keywords: Silk fibroin, silk protein, electron beam irradiation.

I. INTRODUCTION

Silkworm (Bombyx mori) silk is a natural protein consisting of sericin and fibroin protein.

Fibroin has a long history of use as textiles and surgical sutures because of the remarkable

properties such as mechanical strength, elasticity, biocompatibility and controlled biodegradation.

In addition to, fibroin has been potential material for biomedical applications such as enzyme

immobilizing membranes, an oral dosage gel form, scaffolds for tissue engineering and materials

with anti-HIV activity or reducing blood glucose and cholesterol levels [1-4]. Proteins and amino

acids extracted from silk fibroin have been used as additives in soap production, hair conditioners

and body care products because of good moisturizing properties and compatibility with human skin

[2-8]. Many studies have been realized to segment fibroin using proteolytic enzymes. However, the

high cost of enzymes themselve has limited industrial production [9-10]. Another method which has

been used to recover the silk proteins and amino acids is hydrothermal treatment [11]. The results

showed that the use of only water at high temperature and pressure without addition of acid or alkali

catalyst would not get products effectively [8]. Research and application of irradiation technology

for degradation of silk fibroin have attracted considerable interest. Some of research results showed

that gamma or EB irradiation can affect the structures of the fibroin fibers. For example, the high

irradiation doses from 500 to 1000 kGy directly affect the solubility of silk fibroin [6, 12]. Every

year, the silk industry produces tons of silk wastes from broken down or unreeled cocoons. So, the


- Code: CS/13/07-01






Nguyen Thi Kim Lan, Dang Van Phu, Le Anh Quoc, Nguyen Quoc Hien, Research on degradation of

silk fibroin by combination of electron beam irradiation and hydrothermal process, Journal of Nuclear

Science and Technology, VINATOM, 2013.

VINATOM-AR 13--35


262

application of electron beam irradiation method combined with hydrothermal processing to increase

the solubility of fibroin and to create soluble silk proteins from silk wastes is of great interest.

II. EXPERIMENTAL

II.1. Degumming of silk cocoon

Silkworm cocoon was obtained from local silk farm (Di Linh, Vietnam) and degummed

using the hydrothemal degumming method adopted by Yamada et al. [13]. The removal of sericin

by hydrothermal reaction was carried out in a SM200 autoclave (Yamato, Japan) at the temperature

of 120oC in 30 minutes. The reaction products consisted of aqueous solution and remaining fibroin

residue, which was separated from the soluble product using a filter paper (Satorius, Germany). The

fibroin residue was then dried in a forced air oven at 60oC.

II.2. Electron beam irradiation

The irradiation processing of fibroin was done at Research and Development Center for

Radiation Technology using the electron beam accelerator (UERL-10-15S2). The doses delivered to

different samples were measured by Radiochromic film B3000 (GEX) dosimeter. The samples were

subjected to various doses at 0, 50, 100 and 200 kGy.

II.3. Hydrothermal degradation in NaOH solution of irradiated fibroin

II.3.1. Effect of NaOH concentration

In each experiment, the irradiated fibroin and 0-0.1 M NaOH solution (weight ratio = 1:100)

were loaded into the autoclave (and) operated at 120oC for 1 hour. The solution and the remaining

insoluble residue were separated using a filter paper. The insolube residue was then washed with

water until pH=7, dried to get its net weight. The content of soluble fibroin was calculated

following equation (1). The protein content in solution was assayed by Lowry’s method [14] using

bovine serum albumin (BSA) as a standard and from that the protein content obtained per one

weight unit of initial fibroin (mg/mg) was calculated.

The content of soluble fibroin (%) = 100 (mo – mr) / mo (1)

where mo and mr are the weight of initial fibroin and the remaining insoluble fibroin residue,

respectively.

II.3.2. Effect of hydrothemal reaction time

The effect of hydrothemal reaction time of the fibroin samples was determined in the same

manner that described as effect of NaOH concentration. However, the experiments were conducted

in a reaction time interval of 10-30 minutes and NaOH concentration of 0.05 M. The protein

solutions were neutralized to pH = 6-7 by HCl and then dialyzed against deionized water using

cellulose tubings (molecular weight cut off 12 kDa) for 18 h with several changes of water to

remove salts. Protein powders were obtained by a Modullyo free-dryer (Thermo Electron

Corporation) with operating temperature -50oC or a ADL311 spray-dryer (Yamato, Japan) with

inlet and outlet air temperature of 120 and 60oC respectively, and liquid flow rate of 5 ml/minute.

II.4. Analysis of protein characterization

Molecular weight of the protein was determined by sodium dodecyl sulfate polyacrylamide

gel electrophoresis (SDS-PAGE) with 10% acrylamide gel using the Mini-PROTEANR 3-cell

system. A broad range marker (Bio-rad) was run as a molecular weight marker (7.1-209 kDa). Gels

were stained by G250 Coomassie Blue stain and the proteins were detected by dark blue traces on

transparent gel background.

VINATOM-AR 13--35


263

The morphology of particles of the protein powders were observed by SEM images using

S4800 scanning electron microscope, Hitachi, Japan.

The protein powder samples were pelleted with KBr and recorded Fourier Transform

Infrared Spectroscopy (FT-IR) by a FTIR-8400S spectrometer (Shimadzu, Japan).

The protein powder samples were put into aluminum pans. Thermogravimetric analysis

(TGA) of these samples was done by DTG-60 system (Shimadzu, Japan). The temperature range

was scanned from 25oC to 600

oC at a predetermined rate of 10

oC/min.

The X-ray diffraction (XRD) analysis of the protein powders were recorded on D8 Advance

(Brucker) diffractometer using CuK radiation. These samples were scanned in the 2 range of 10-

30o with scan rate of 0.4

o/minute.


III.1. Hydrothermal degradation of irradiated fibroin

Table 1: Effect of NaOH concentration on the solubility and protein content of irradiated

and hydrothermal degraded fibroin.

Irradiation dose

(kGy)

NaOH concentration (M) NaOH concentration (M)

0.025 0.05 0.075 0.025 0.05 0.075

Solubility (%) Protein content (mg/mg)

0 44.5 81.0 89.4 0.2339 0.4617 0.4705

50 51.3 84.6 92.1 0.3297 0.5409 0.5492

100 52.1 86.5 93.0 0.3644 0.5723 0.5760

200 53.9 88.9 94.6 0.4457 0.6530 0.6609

The solubility and protein content of irradiated fibroin that was degraded by hydrothermal

treatment in NaOH solution of 0.025-0.075 M were indicated in table 1. The results showed that the

unirradiated and irradiated fibroin had the solubility more than 80% when NaOH concentration was

0.05 M. The solubility of unirradiated fibroin was 81% while those of fibroin irradiated 50, 100 and

200 kGy were 84.6, 86.5 and 88.9%, respectively. The solubility of 50-200 kGy irradiated fibroin

was larger than that of the unirradiation sample from 2-8%. On the other hand, the solubility of

fibroin at the concentration of 0.075 M NaOH increased in comparison with concentration of 0.05

M NaOH, but protein content did not increase significantly. The protein content of 0-200 kGy

irradiated fibroins obtained from 0.4617 to 0.6530 mg/mg at the concentration of 0.05 M NaOH

while protein content was from 0.4705 to 0.6609 at 0.075 M NaOH. So, the concentration of 0.05

M NaOH was effective to dissolve 1% irradiated fibroin in the hydrothermal degradation reaction.

Table 2: Effect of time of hydrothermal reaction on solubility, protein content of irradiated

fibroin before and after dialysis.

Dose

(kGy)

Time (min.) Time (min.) Time (min.)

10 20 30 10 20 30 10 20 30

Solubility (%) Protein content Before

dialysis (mg/mg)

Protein content After

dialysis (mg/mg)

0 53.8

3.2

62.6

2.8

67.3

2.0

0.390

0.020

0.427

0.030

0.436

0.013

0.233

0.012

0.244

0.011

0.227

0.023

VINATOM-AR 13--35


264

50 56.9

4.0

64.5

2.2

69.2

3.1

0.425

0.028

0.494

0.027

0.533

0.032

0.237

0.010

0.247

0.018

0.231

0.017

100 60.6

2.5

67.3

2.7

71.7

4.5

0.452

0.031

0.539

0.034

0.564

0.015

0.242

0.016

0.254

0.020

0.238

0.017

200 66.4

2.3

72.3

4.1

76.9

4.5

0.498

0.040

0.585

0.093

0.622

0.056

0.251

0.010

0.263

0.008

0.249

0.032

The solubility and the protein content before and after dialysis of irradiated fibroin

according to time of hydrothermal degradation reaction in 0.05 M NaOH solution were presented in

table II. The solubility of unirradiated and irradiated fibroin increased when hydrothermal reaction

time increased. The analysis results of the protein content showed that the protein content obtained

before dialysis also increased with the increase of reaction time. However, after the protein

solutions were dialysed by cellulose membranes with Mw cut off 12 kDa, the remaining protein

content at hydrothemal reaction time of 30 minutes was less than those at reaction time of 10 and 20

minutes. This might be due to lost of protein fragments whose molecular weight was less than 12

kDa were created during the reaction time of 30 minutes and so these fragments were exchanged

against in dialysis process.

III.2. Characteristics of silk protein

III.2.1. Molecular weight measurment

The results of gel electrophoresis analysis of silk protein were showed in Fig.1. The

molecular weight of protein was in range from 13 to 200 kDa and the sizes dominant lied between

34 and 50 Da that indicated the dagradation of peptide linkage. The result here is consistent with

other studies. In the research of effects of gamma irradiation on biodegradation of silk fibroin [6],

the fibroin fibers irradiated in range 0-1000 kGy were hydrolyzed by enzymatic methods in 7 days

to prepare proteins whose molecular sizes were about 33-37 kDa. Meanwhile, the research results of

Lamoolphak et al. [11] showed that the protein obtained after hydrothermal decomposition of

fibroin at temperature over 140oC had molecular weight less than 10 kDa.

Figure 1: SDS-PAGE of the marker (lane TC); spray dried sample: 50 kGy - (lane 1);

free-dried samples: 0 kGy (lane 2), 50 kGy (lane 3), 100 kGy (lane 4), 200 kGy (lane 5).

5 4 3 2 1 TC Da

209,000 124,000 80.000 49.100 34,800 28,900 20,600 7,100

VINATOM-AR 13--35


265

III.2.2. Observation of SEM

(a) (b)

Figure 2: SEM image of protein powder (a) freeze drying, (b) spray drying.

The results on figure 2 showed that the freeze drying process of protein solution created the

protein powder with long flake-like particles while spray drying process formed protein powder

with circular particles whose size was in range between 2 and 5 m.

III.2.3. FTIR characterization

Figure 3: Infrared spectrum (FTIR) of protein powders from 0-200 kGy

irradiated fibroin.

The results of infrared spectra of the protein powders from unirradiated and irradiated

fibroin were indicated in fig. 3. The results showed that, the infrared spectra of irradiated samples

presented characteristic absorption peaks were similar that of unirradiated sample. The absorption

peak of C=O stretching mainly occured at the wavelength of 1652-1654 cm-1

. The vibration of N-H

bonding was at position of 1539-1542 cm-1

. And the phase combinations of C-N stretching and

C=O bending vibration fell in wavelength of about 1242 cm-1

[3, 15]. It was found that there was no

difference in the FT-IR spectral results of the protein powders obtained from fibroin irradiated and

unirradiated.

4000 3750 3500 3250 3000 2750 2500 2250 2000 1750 1500 1250 1000 750 500 (1/cm)

VINATOM-AR 13--35


266

III.2.4. TGA Characterization

The thermogravimetric analysis (TGA) results of the protein powders from fibroin

unirradiated and irradiated 50-200 kGy were presented in fig. 4. The thermogram of all samples

indicated the division into four distinct sections. From room temperature to 100oC, the weight loss

was due to water evaporation of about 9%. In the second, from 100 to 280oC, the samples began to

decompose in range from 20 to 30%. In the third, there was a difference in thermal decomposition

of the irradiated fibroin samples and the original sample. The protein powder of unirradiated fibroin

decomposed 60% at temperature of 520oC. While the protein powder of irradiated samples lost

weight over 70% at the same temperature. At the end, about 70% weight of the protein powder of

unirradiated fibroin and 90% weight of the protein powders of 50-200 kGy irradiated fibroin were

decomposed to volatiles at 600oC. These results showed that the thermal stability of the protein

powders decreased with increasing irradiation dose for silk fibroin. According to the study of

Nogueira et al [16], the thermal decomposition of fibroin membranes is influenced by the internal

structure and physical properties of the sample with the degree of molecular orientation being one

of the most important parameters. Well-oriented silk materials will have decomposition temperature

of above 300oC, no oriented silk fibers with -sheet structure usually decompose in about 290-

295oC and amorphous silk fibroin occurs at a temperature lower than 290

oC. The thermal stability

of the protein powder obtained from the spray drying process was less than that of the free dried

protein powders. The results of TGA in this study showed that the protein powders had dominant

amorphous structure.

Figure 4: TGA thermograms of protein powders.

III.2.5. X-ray diffraction analysis

As well know that, silk fibroin has two regions of structure that are crystalline and

amophous. Tree types of crystal structure are -helix (silk I), -sheet (silk II) and helical structure

(silk III) [2, 11]. The main diffraction peaks of silk I are present at 2 = 12.2o, 19.7

o , 24.3

o and

28.2o while that of silk II are present at about 2 = 9.1

o , 18.9

o , 20.7

o [2]. In addition to, the

amorphous structure displays a broad diffraction peak [11]. XRD spectra of protein powders of

fibroin irradiated 0-200 kGy were recorded in the 2 range of 0o to 30

o (fig. 5 ). A sharp peak at 2

= 13o and a broad peak at 2 = 28

o-31

o were displayed on the XRD spectra of the protein powder

from unirradiated fibroin. This result indicated that there was presence of both crystal and

amorphous structure in the protein powders. On the other hand, XRD of protein powders prepared

of fibroin irradiated 100 and 200 kGy showed two broad peaks which shifted to position of 2 =

19o-22

o and 2 = 28

o-30

o. This could be a result of essential presence of amorphous structure. In

the same condition of irradiation, protein obtained from spray dried solution showed the XRD result

being the same as that of free dried samples.

VINATOM-AR 13--35


267

Figure 5: XRD spectra of protein powders of fibroin unirradiated

and irradiated 100 and 200 kGy.

IV. CONCLUSIONS

Research on degradation of silk fibroin by electron beam irradiation combined with

hydrothermal processing to prepare silk protein were carried out. The solubility of unirradiated and

irradiated fibroin were greater than 80% when hydrothermal reaction was performed in NaOH

solution of 0.05 M. The solubility of irradiated fibroin was higher than that of unirradiated sample.

The protein content increased from 0.4617 to 0.6530 mg/mg when irradiation doses increased from

0 to 200 kGy, respectively. The molecular weight of protein was mainly in the range from 34-50

kDa. The process of freeze-drying or spray-drying formed protein powders whose particle size was

2-5m. It was found that the protein powder had essential amorphous structure and the EB

irradiation process affected the structure of silk fibroin.

REFERENCES

[1] EB. Byun et al.,“Enhancement of anti-tumor activity of gamma-irradiated silk fibroin via

immunomodulatory effects”, Chemico-Biological Interactions, 186, 90-95, 2010.

[2] J. Kundu et al.,“Silk fibroin nanoparticles for cellular uptake and control release”,

International Journal of Pharmaceutics, 388, 242-250, 2010.

[3] A. Sionkowska et al., “The influence of UV radiation on silk fibroin”, Polymer Degradation

and Stability, 96, 523-528, 2011.

[4] R. Rajkhowa et al.,“Ultra-fine silk powder preparation through rotary and ball milling”,

Powder Technology, 185, 87-95, 2008.

[5] GH. Altman et al.,“Silk-based biomaterials”, Biomaterials, 24, 401-416, 2003.

[6] A. Kojthung et al., “Effects of gamma radiation on biodegradation of Bombyx mori silk

fibroin”, International Biodeterioration & Biodegradation, 62, 487-490, 2008.

[7] Q. Lu et al., “Degradation Mechanism and Control of Silk Fibroin”, Biomacromolecules, 12,

1080-1086, 2011.

[8] K. Kang et al.,“Behavior of hydrothermal decomposition of silk fibroin to amino acids in

near-critical water”, Korean Journal of Chemical Engineering, 21 (3), 654-659, 2004.

[9] Y. Suzuki et al.,“Enzymatic degradation of fibroin fiber by a fibroinolytic enzyme of

Brevibacillus thermoruber YAS-1”, Journal of Bioscience and Bioengineering, 108 (3), 211-

215, 2009.

2o

10 20 30

Counts 4000

3000

2000

1000

0

http://www.ncbi.nlm.nih.gov/pubmed?term=Altman%20GH%5BAuthor%5D&cauthor=true&cauthor_uid=12423595

VINATOM-AR 13--35


268

[10] RL. Horan et al., “In vitro degradation of silk fibroin”, Biomaterials, 26, 3385-3393, 2005.

[11] W. Lamoolphak et al., “Hydrothermal production and characterization of protein and amino

acids from silk waste”, Bioresource Technology, 99, 7678-7685, 2008.

[12] H. Takeshita et al.,“Production of fine powder from silk by radiation”, Macromolecular

Materials and Engineering, 283 (1), 126-131, 2000.

[13] H. Yamada et al.,“Preparation of undegraded native molecular fibroin solution from

silkworm cocoons”, Materials Science and Engineering, C 14, 41-46, 2001.

[14] OH. Lowry et al.,“Protein measurement with the folin phenol reagent”, Journal of

Biological Chemistry, 193(1), 265-275, 1951.

[15] S. Halabhavi et al.,“Interaction of 8 MeV Electron Beam with P31 Bombyx mori Silk

Fibers”, Materials Sciences and Application, 2, 827-833, 2011.

[16] GM. Nogueira et al.,“Preparation and characterization of ethanol-treated silk fibroin dense

membranes for biomaterials application using waste silk fibers as raw material”, Bioresource

Technology, 101, 8446-8451, 2010.

VINATOM-AR 13--36


269

SYNTHESIS OF Fe3O4-CHITOSAN MAGNETIC NANOCOMPOSITES

BY GAMMA IRRADIATION FOR ABSORBING OF HEAVY METALS

IN AQUEOUS SOLUTIONS

Tran Minh Quynh, Nguyen Van Binh, Nguyen Quang Long and Hoang Dang Sang

Hanoi Irradiation Center, Vietnam Atomic Energy Institute,


ABSTRACT: Studies on adsorption capacity of the obtained Fe3O4-chitosan nanoparticles for metal ions in

aqueous solutions showed that initial amount of adsorbent and pH have much influenced on their adsorption

capacity. Adsorption rate was quite fast at first, then slower. Maximum adsorption capacity were measured at

25C are 71, 41.4 and 26 mg/g obtained at pH 5, 6 and 7 for Cu(CH3COO)2.H2O, Pb(CH3COO)2.3H2O and

NaH2AsO4.7H2O, respectively. The adsorption capacity increased with adsorbent amount to a certain value,

then leveled off. These results suggested that the Fe3O4-chitosan nanoparticles can be applied as a potential

adsorbent for removal of heavy metals from aqueous solution, but it required further studies including of

adsorption kinetics and desorption in order to control the process in practice.

1. INTRODUCTION

Magnetic nanoparticles (Fe3O4) have been studied and applied in many various fields due to

their superparamagnetic properties as well as their responsibility to surrouding fields [1-3]. Their

application was further improved by incorporating with multi-functional polymers such as chitin,

chitosan, alginate or other bio-polymers [1,4]. Recently, magnetic Fe3O4-chitosan nanoparticles

were prepared by using chitosan as stabilized agent for coating Fe3O4 [5,6]. These magnetic

nanoparticles can be used as adsorbent for removal of some pollutants in the aqueous solutions via

their covalent bonding of chitosan with metal ions or organic compounds. In addition, chitosan can

be modified in order to adsorb certain substance, especially for preparation of the targeted drug

delivery systems, adsorbents, enzymatic or microbial immobilizers, etc.

Several methods have been developed for preparation of magnetic and Fe3O4-chitosan

nanoparticles such as blending, polymerization, co-precipitation, suspension crosslinking... [6-11].

However, the nanoparticles are rather large and inhomogeneous in size, limited their application in

practice. In this study, gamma irradiation treatment has been applied for preparation of the

ferrimagnetic and Fe3O4-chitosan nanoparticles from FeCl3 solutions and the solutions containing

chitosan and Fe3O4, respectively. During irradiation, chitosan can crosslink resulting in the stable

nanoparticles [12].


- Code: CS/13/08-01



- Implementation time: 10 months (Mar 2013- Dec 2013)



Tran Minh Quynh, Nguyen Van Binh, Nguyen Quang Long, Hoang Dang Sang. Characterization of

the magnetic Fe3O4 nanoparticles prepared by gamma irradiation. Nuclear Science and Technology.

2014, xx-xx (Accepted).


VINATOM-AR 13--36


270

The size, structure and magnetic properties of the obtained magnetite and Fe3O4-chitosan

nanoparticles were characterized by SEM, TEM, XRD and vibrating sample magnetometer (VSM).

The Fe3O4-chitosan nanoparticles were applied as an efective absorbents for removal of some metal

ions from aqueous solutions. Their adsorption capacity for heavy metal ions were determined by

UV spectrometer.

2. MATERIALS AND METHODS

2.1. Materials

FeCl2.4H2O, FeCl3.6H2O, Cu(CH3COO)2.H2O, Pb(CH3COO)2.3H2O, AgNO3 were bought

from Xilong Chemical Co. Ltd., China. Zinc in pellet, triallyl isocyanurate (TAIC), sodium

diethyldithiocarbamat (NaDDC) were purchased from Wako Pure Chemical Inc., Japan.

NaH2AsO4.7H2O from BDH Chemical, England. Chloroform, isopropanol, acetic acid, parafin and

other organic solvents from Dae Jung Chemicals and Metals.Co., Ltd. Korea. NaOH, NH3OH, HCl,

and other popular chemicals were bought from Merck, or Guangdong Guanghua Sci-Tech. Co., Ltd.

China.

2.2. Radiation preparation of magnetite and Fe3O4-chitosan nanoparticles.

Gamma irradiation has been used to preparation of magnetite nanoparticles as reported by

Wang et al [11]. Firstly, FeOOH.H2O was precipitated by dropping NH3OH into FeCl3 solution to

the molar ratio about 1.8 for NH3 compared to Fe3+

, the precipitant was collected, washed and dried

at 60C under vacuum for a hour. 20 mL isopropanol was added to each 100 mL of FeOOH 1% for

OH scavenger and differnt mixtures were irradiated at various radiation dose ranging from 10-50

kGy under gamma source of about 60 kCi at Hanoi Irradiation Center. After that, alkaline solution

(NaOH 10%) was added to the irradiated solution for precipitation. The precipitant was separated,

washed and dried under vacuum at 60C for 2 hours. Finally, the obtained products were ground

into small size, the obtained black magnetite nanoparticles were storaged in desiccator in order to

avoid oxidation.

For preparation of Fe3O4-chitosan nanoparticles, magnetite nanoparticles were regularly

dispersed in parafin into 100 mL homogenous emulsion, then 20 mL chitosan solution, 2 mL TAIC

were added, the obtained emulsion were iradiated at various radiation dose. The resulting products

after pricipitation with alkaline solution were ground into fine particles and the effects of radiation

dose and chitosan concentration on the particle size and their structures were determined by

scanning electron microscope SEM), transition electron microscope (TEM), X-ray diffraction

(XRD), and vibrating sample magnetometer (VSM).

2.3. Measurements

Adsorption capacitis of Fe3O4-chitosan nanoparticles for Cu(II), Pb(II) and As(V) ions were

investigated with the Cu(CH3COO)2.H2O, Pb(CH3COO)2.3H2O and NaH2AsO4 solutions. 100 mL

of salt solution was put into each 250 mL flask, a predetermined amount of Fe3O4-chitosan was

added and the solution was shaken in a thermostat at 25C at 120 rpm. The adsorption capacity in

mg of metal ions adsorbed on 1 g of the adsorbent at equilibrium in mg/g (Qe) was calculated as

follow:

Qe = (C0 - Ce) V / m (1)

where C0 and Ce (mg/L) were the metal concentrations at initial and the time of equilibrium,

respectively. V is the volume of solution containing metal ion (in this case 100 mL), and m is

adsorbent mass in gram. The effects of pH, contact time, and initial amount of Fe3O4-chitosan on

the adsorption capacity for metal ion at equilibrium were studied at the same conditions.

VINATOM-AR 13--36


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3. RESULTS AND DISCUSSIONS

3.1. Radiation preparation of magnetite and Fe3O4-chitosan nanoparticles

The results showed both magnetite Fe3O4 and Fe3O4-chitosan nanoparticles can be prepared

by precipitating the irradiated solutions in alkaline solution. Figure1 shows the SEM and TEM

images of these products. From that, average size of the resulting particles can be estimated.

Average diameter of the obtained nanoparticles reduced from 46 to 19 nm with irradiation dose.

Table 1: Preparation of magnetite nanoparticlesby gamma radiation.

Sample Radiation dose (kGy) Reaction yield (%) Average size (nm)

1 10 10.5 46

2 20 27.6 35

3 30 38.9 27

4 40 46.3 21

5 50 42.4 19

However, these reaction yield quickly increased with radiation dose to 40 kGy, then slightly

reduced. These values are much smaller than those compared with copricipitation method, but

similar to the nanoparticles prepared by gamma radiation as reported elsewhere [11]. Therefore, the

dose of 40 kGy was selected as optimal dose for radiation preparation of magnetite nanoparticles.

3.2. Characterization of Fe3O4-chitosan and the effect of chitosan concentration

Table 2: Typical properties of magnetic Fe3O4-chitosan nanoparticles.

Sample Weight ratio of

Fe3O4/Chitosan

Particle size (nm) (s) (emu/g)

1 10/1 25 30.52

2 5/1 26 30.37

3 2/1 31 12.37

4 1/1 35 1.25

Figure 1: SEM microscope of magnetite nanoparticles (a) and

TEM image of Fe3O4-chitosan nanoparticles (b) prepared by gamma radiation.

a b

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Typical properties of magnetic Fe3O4-chitosan have been investigated with chitosan

concentration in the emulsion for radiation preparation. In order to investigate the influences of

chitosan solution on the properties of the resulting magnetic Fe3O4-chitosan nanoparticles, the same

amount of Fe3O4 dispersed in parafin were mixed with the chitosan solutions of different

concentration and iraidated at 40 kGy. The results were presented in Table 2.

Figure 2: TEM images of different magnetic Fe3O4-chitosan nanoparticles.

-60

-40

-20

0

20

40

60

-10000 -5000 0 5000 10000

Magnetic Field (Oe)

Mag

ne

tiza

tio

n (

em

u/g

)

Fe3O410:1/Fe3O4-chitosan

5:1/Fe3O4-chitosan2:1/Fe3O4-chitosan1:1/Fe3O4-chitosan

Figure 3: Hysteresis loop of magnetic Fe3O4 and Fe3O4-chitosan nanoparticles.

VINATOM-AR 13--36


273

As one can see, average diameter of the nanoparticles, which were calculated from their

TEM images increased with chitosan amount in the initial emulsions. The results suggested that the

molar ratio of chitosan and Fe3O4 much influenced on the resulting particles. Average size of the

nanoparticles increased with chitosan content while their saturation magnetization (s) quickly

decreased. The value of (s much reduced with the ratio of chitosan and Fe3O4 higher than 1:2, this

may due to the excessivie chitosan would be absorbed onto the surface of polymer magnetic

nanostructures. Low saturation magnetization may reduced the responsibility of magnetic materials

with surrounding field, then the Fe3O4/chitosan ratio of 5:1 were chosen for further experiments.

The structural properties of Fe3O4 and Fe3O4-chitosan were also analysed by X-ray

difraction. Figure 4 shows XRD patterns of these nanoparticles by compared with the data of

magnetite standard pattern. The diffraction peaks at 2q = 30.2, 35.6, 43.1, 53.4, 57 and 62.6,

correspond to (220), (311), (400), (422), (511) and (440), respectively. There are no impurity peak

suggested that the products contain Fe3O4 with a tiny amount of -Fe2O3.

3.3. Adsorption equilibrium of some metal ions onto the magnetic Fe3O4-chitosan

In this experiment, the magnetic Fe3O4-chitosan nanoparticles were used as absorbent

materials for removel some heavy metal ions in aqueous solutions. Figure 4 showed the equilibrium

adsorption capacity of the material for Cu(II), Pb(II) and As(V) in the aqueous solutions at diferent

pH.

Figure 5 showed the dependance of adsorption capacities of Fe3O4-chitosan for Pb(II) in

aqueous solution of Pb(CH3COO)2 at equilibrium state (Qe). It was obviously that, adsorption

capacity of magnetic Fe3O4-chitosan nanoparticles depended on the pH and initial amount of the

absorbent. Maximum efficiency for removal of Pb(II) was about 41.4 mg/g, which can be observed

at pH 6. The adsorption efficiency increased with the initial amount of the absorbent, it reached to

maximum with 0.05 g of magnetic material for solution containing 100 ppm Pb(II), then leveled off

with further increasing of absorbent content.

Inte

nsity (

a.u

)

2

(deg)

20

30

40

50

60

70

311

440 51

1 400

220

422

XRD patterns of magnetite standard sample,

Magnetic Fe3O4 nanoparticles and

Fe3O4-chitosan nano composites prepared by gamma radiation

Figure 4: XRD patterns of various magnetic nanoparticles with and without chitosan.

VINATOM-AR 13--36


274

4. CONCLUSION

Gamma irradiation treatment has been applied for preparation of the ferrimagnetic and

Fe3O4-chitosan nanoparticles from solutions of FeCl3 and chitosan containing Fe3O4, respectively.

The results showed that the Fe3O4-chitosan nanoparticles can be prepared by precipitating the

irradiated solutions in alkaline solution, but the yield of this reaction was much lower than

compared with preparation of ferromagnetic nanoparticles. Average diameter of the obtained

nanoparticles ranging from 10 to 25 nm depended on the irradiation dose, and it quickly increased

with radiation dose to 40 kGy dose, then slightly decreased. These values also increased with

chitosan amount in solution. Therefore, the 5:1 ratio of Fe3O4 and chitosan, and the dose of 40 kGy

were chosen as the optimal conditions for preparation of Fe3O4 and Fe3O4-chitosan nanoparticles.

Studies on adsorption capacity of the obtained Fe3O4-chitosan nanoparticles for metal ions

in aqueous solutions revealed that the initial amount of the adsorbent and pH have much influenced

on adsorption process. Adsorption rate was quite fast at first, then gradualy slow. Maximum

adsorption capacity were measured at 25C are 71, 57 and 26 mg/g obtained at pH 5, 6 and 7 for

Cu(CH3COO)2.H2O, Pb(CH3COO)2.3H2O and NaH2AsO4.7H2O, respectively. The adsorption

capacity increased with adsorbent amount to a certain value, then leveled off. These results

suggested that the Fe3O4-chitosan nanoparticles can be applied as a potential adsorbent for removal

of heavy metals from aqueous solution, but it required further studies including of adsorption

kinetics and desorption in order to control the process in practice.

REFERENCES

[1] Bin Kang et al. Radiation synthesis and megnetic properties of novel Fe3O4-chitosan

compound nano particles for targeted drug carrier. Radidation Physics and Chemistry 76,

968-973, 2007.

[2] Nhung NT, Thuong NTK. Separation and removal of Pb2+

from aqueous solutions using

Fe3O4 nanopartilces. VNU Journal of Science, Natural Sciences and Technology, Hanoi

National University 24, 305-309, 2008.

[3] M.Faraji et al. Cetytrimethylammonium Bromide-Coated Megnetite Nanoprticles as Highly

Efficient Adsorbent for Rapid Removal of Reactive Dyes from the Textile Companies

Wastewaters. Journal of the Iranian Chemical Society.

[4] Duc NH, Danh TM, Dung TT. Preparation and study on magnetic properties of nanoparticles

Fe3O4 for biomedical applications. VNU Journal of Science, Natural Sciences and

Technology, Hanoi National University 23, 231-237, 2007.

0

10

20

30

40

50

2 3 4 5 6 7 8

pH

Adsorp

tion c

apacity (

mg/g

)

Figure 5: Adsorption capacity of Fe3O4-chitosan for heavy metal ions at equilibrium.

60

65

70

75

80

0 0.05 0.1 0.15 0.2 0.25

Weight of Fe3O4-chitosan material (g)

Adsorp

tion e

ffic

iency (

%)

VINATOM-AR 13--36


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[5] Lian-ying Zang et al. Control synthesis of magnetic Fe3O4-chitosan nanoparticles under UV

irradiation in aqueous system. Current Applied Physics 10, 828-833, 2010.

[6] Gui-yin Li et al. Preparation and properties of megnetic Fe3O4-chitosan nanoparticles.

Journal of Alloys and compounds 466, 451-456, 2008.

[7] Tomohiro Iwasaki, et al. Mechanochemical preparation of magnetite nanoprarticle by

coprecipitation. Material Letters 62, 4155-4157, 2008.

[8] Jing Xu, et al. Preparation and magnetic properties of magnetite nanopracticles by sol-gel

method. Journal of Magnetism and Magnetic Materials 309, 307-311, 2007.

[9] R.Y.Hong et al. Synthesis of Fe3O4 nanoparticles without inert gas protection used as

precursors of magnetic fluids. Journal of Magnetism and Magnetic Materials 320, 1605-

1614, 2008.

[10] Don Keun Lee et al. Preparation and characterization of megnetic nanoparticle by γ-

irradiation. Materials Science Engineering C24, 107-111, 2004.

[11] Wang S, Xin H, Qian Y. Preparation of nanocrystalline Fe3O4 by -ray radiation. Materials

Letters 33; 113-116, 1997.

[12] Jinhua Du et al. Preparation of superparamagnetic γ- Fe2O3 nanoparticles in nanoqueous

medium by γ-irradiation. Journal of Megnetic Materials 302, 263-266, 2006.

VINATOM-AR 13--37


276

STUDIES ON STERILIZATION PROCESS FOR SOMETRADITIONAL

PRODUCTS OF HERBAL MEDICINE BY GAMMA RADIATION

Hoang Phuong Thao, Nguyen Van Binh, Tran Bang Diep, Hoang Dang Sang,

Nguyen Thuy Huong Trang, Pham Duy Duong and Tran Minh Quynh

Hanoi Irradiation Center, Vietnam Atomic Energy Institute


ABSTRACT: Herbal eyebright products and their raw materials have been irradiated with 1, 2, 3 and 5 kGy by

Co-60 gamma radiation source at Hanoi Irradiation Center (VINATOM) for sterilization. Initial bioburdens

were under the limitation levels established for the traditional medicines according to the decree of

16/2011/TT-BYT issued by Vietnam Health Ministry. These values for both bacteria and fungus slightly

increased during storage to three months, reach to about 103 and 10

2 CFU/g for bacteria and mold,

respectively. However, there are no microbial colony could be observed in the samples irradiated with dose

higher than 3 kGy, suggested that the radiation dose of 3 kGy was enough for sterilization of eyebright raw

powders and products. At higher radiation dose of 5 kGy, the moisture and vitamin A content of the samples

were insignificantly changed. These mean the radiation treatment with lower dose did not influenced on the

quality of eyebright products, and radiation treatment can be applied to prolong the storage of not only

eyebright, but also other traditional medicines.

1. INTRODUCTION

The use of eyebright in cultural and traditional settings may differ from concepts accepted

by current Western medicine. Considering the use of herbal supplements, consultation with a

primary health care professional is advisable. Additionally, consultation with a practitioner trained

in the uses of herbal/health supplements may be beneficial, and coordination of treatment among all

health care providers involved may be advantageous.

Food irradiation is a modern technology applied to assure the quality and sanitary safety of

foods. At present, there are more than 30 countries worldwide applied food irradiation technology

for processing of more than 40 different kind of food from fresh fruits, cereals, meat and other

agricultural and seafood products to dehydrated spices. Due to wholesomeness as well as economic

benefit of irradiated food, World Health Organization (WHO), Food and Agriculture Organization

(FAO) and International Atomic Energy Agency (IAEA) approved irradiation as an effective

quarantine method for food similar to the hot and cold temperature treatment [1]. Irradiation is

effective method for quarantine control and prevention of foodborn diseases as well as reducing

economic loss. The herbal medicines have been used in many countries but in Vietnam there is no

adequate scientific and technological base for application development methods on an industrial

scale. So there should be more research applications of radiation technology on medicinal products

for traditional medicine development, while enhancing the applications of nuclear energy in the

economic field.


- Code: CS/13/08-03






Quynh TM et al. Studies on decontamination for herbal eyebright raw material and product by

gamma radiation. To be published in Journal of Nuclear Science and Technology, VINATOM, 2014.

VINATOM-AR 13--37


277

In this project, both eyebright raw materials and commercial products were collected as

samples from Traphaco joint stock company, which has grown into the second largest

pharmaceutical firm in Vietnam. Their initial bioburden as well as their contamination levels during

storage were investigated with radiation dose in order to verify the advantages of radiation

treatment for sterilization and prolong the storage period for the herbal medicine.

2. MATERIALS AND METHODS

2.1. Materials

The eyebright raw materials and commercial products were kindly supported from Traphaco

joint stock company, Vietnam. These samples were divided and packaged into PE bags of about 20

g for each. Meat-pepton agar (MPA) and Sabouraud dextrose agar were purchased from Nihon

Seiyaku, Japan. Other chemicals were bought from Wako Pure Company, Japan.

2.2. Determination of microorganism contamination

Microbial contamination levels in both eyebright raw material and commercial product were

investigated based on number of count forming unit per 1g sample (CFU/g), which can be

developed in MPA and Sauboraud media for bacteria and fungfus, respectively according to TCVN

5165-90 [2,3].

2.3. Radiation treatment and measurements

The samples were irradiated by gamma Co-60 radiation at dose of 0, 1, 2, 3 and 5 kGy as

respective symbol of M1-5 under Co-60 source of Hanoi Irradiation Center with dose rate of about

~1 kGy per hour. Moisture and vitamin A content in the samples were determined by drying and

HPLC [4].

3. RESULTS AND DISCUSSIONS

3.1. Microbial contamination levels of eyebright samples during storage

Table 1: Bioburden of the eyebright samples during storage.

Sample Storage period

(month)

Total number of colony forming unit (CFU/g)

Aerobic bacteria Fungi and molds

Raw materials

0 590 ± 0.22 46 ± 0.21

1 150 ± 0.08 23 ± 0.11

3 600 ± 0.30 13 ± 0.04

Commercial

products

0 26 ± 0.15 13 ± 0.05

1 33 ± 0.20 6 ± 0.01

3 250 ± 0.090 13 ± 0.06

The total number of bacteria and fungi (CFU) observed from the eyebright samples during

storage were presented in Table 1. From the data, we can concluded that contamination levels of

aerobic bacteria in both raw material and commercial products of eyebright increased, but fungal

levels slightly decreased with storage period. These may due to recontamination of bacteria into the

samples during storage. It was very interesting that the contamination level of fungi reduced. It

required further studies for clearify this phenomena. However, we should applied some method to

control the recontamination for eyebright samples during storage, especially for eyebright raw

materials. In this study, gamma radiation has been used to sterilization eyebright and prolong their

VINATOM-AR 13--37


278

storage periods. And the contamination levels of eyebright samples were investigated with radiation

dose.

3.2. Radiation effects on the microbial level of eyebright during storage

Table 2: Total number of microorganisms contaminated

on the eyebright samles with radiation dose after three months storage.

Sample Dose (kGy) Total number of colony forming unit (CFU/g)

Aerobic bacteria Fungi and molds

Raw materials

0 590 ± 0.22 46 ± 0.21

1 66 ± 0.26 (N)

2 12 ± 0.01 (N)

3 (N) (N)

5 (N) (N)

Commercial

products

0 26 ± 0.15 13 ± 0.05

1 21 ± 0.13 6 ± 0.01

2 (N) (N)

3 (N) (N)

5 (N) (N)

None: can not observed

Table 2 showed the existing of aerobic bacteria and fungi on the eyebright storage. The

results suggested that radiation treatment can be used as an effective tool for reduction of total

microorganisms existing in both eyebright raw material and commercial products. The radiation

dose of 3 kGy was enough for prolong the storage period of the eyebright products over three

months without microbial contamination.

3.3. Radiation effect on the quality of eyebright powders and products

0.0

2.0

4.0

6.0

8.0

10.0

0 1 2 3 5Radiation Dose (kGy)

Mo

istu

re c

on

ten

t (%

)

0.0

2.0

4.0

6.0

8.0

10.0

0 1 2 3 5

Radiation Dose (kGy)

Mo

istu

re c

on

ten

t (%

)

Figure 1: Effects of gamma irradiation and storage period on the moisture content

of eyebright powder (a) and products (b).

just after irradiation;; aafftteerr oonnee mmoonntthh aanndd tthhrreeee mmoonntthhss

aa bb

VINATOM-AR 13--37


279

As presented in Figure 1, the mosture content in both eyebright material and product slightly

reduced by radiation, then quickly recovered during storage. For each sample, there are no

significant changes in moisture content during stogare. It may due to the hydrolysis of water during

gamma irradiation, but the sample can absorb the moisture to the saturated content during storage.

Table 3: Vitamin A content (µg/1000g) in the eyebright samples with radiation dose.

Radiation dose

(kGy)

Eyebright Samples

Raw powder

after irradiate

Raw powder

after 1 month

Capsule after

irradiate

Capsule after 1

month storage

0 127.13 113.21 116.1 119.13

1 125.07 116.15 114.08 120.11

2 124.01 111.2 112.05 125.07

3 120.18 115.3 118.08 128.22

5 127.13 118.3 113.09 116.1

Vitamin A was detected with high performance liquid chromatography (HPLC) by

procedure of H.HD.QT.145 at National institute for Food Control. As one can see from the Table 3,

all eyebright samples containing vitamin A. However, the content of vitamin A in powder samples

higher than that in commercial samples (eyebright capsule). It may due to the presence of other

additives in the commercial products, or the degradation of vitamin A during processing. Vitamin A

seemed not to be affected by radiation treatment, and storage in laboratory condition. According to

some studies, radiation treatment did not effected to beta-caroten of herbs or other compounds at

lower radiation dose of 10 kGy [5]. However, other ingredients of the eyebright raw material and

commercial products should be determined for understanding the influence of radiation treatment

on the quality criteria of these oriental drugs.

4. CONCLUSION

Microbial contamination level of eyebright raw powder and commercial product increased

with storage period, but it can be easily controlled by radiation treatment. Radiation dose of 3kGy is

enough for elimination the growth of aerobic bacteria as well as fungi and molds existing on the

eyebright samples. Radiation treatment at higher dose of 5 kGy does not influence on the quality of

eyebright materials. Therefore, gamma irradiation should be considered as an effective method for

sterilization for not only eyebright raw materials and products, but also for other herbal medicines.

REFERENCES

[1] IAEA (International Atomic Energy Agency) Irradiation to ensure the safety and quality of

prepared meals, Vienna, Austria, p.375, 2009.

[2] Dung NL et al. Study methods of microorganisms. Vol 2. Science and technology Publisher,

Hanoi, pp. 7-15, 1982.

[3] Standards of Vietnam TCVN 5104-90, Food and spices products, National Committee of

Science, Hanoi, 1990.

[4] J. Farkas, “Chapter 11 radiation decontami-nation of spices, herbs, condiments and other

dried food ingredients”, Szent Istvan University, Budapest, Hungary, 2000.

[5] Paula M. Koseki, et al. Effects of irradiation in medicinal and eatable herbs. Radiation Physis

and Chemistry; 63: 681-684, 2002.

VINATOM-AR 13--38


283

STUDY ON BENEFICIATION TECHNOLOGY OF DONG PAO RARE-

EARTH-BARITE-FLUORITE WITH TWO PRODUCT PLANS ABOUT

CONTENT AND RECOVERY OF RARE-EARTH FINE ORES

Duong Van Su, Truong Thi Ai, Bui Ba Duy, Bui Thi Bay, Nguyen Hong Ha,

Le Thi Hong Ha, Doan Thi Mo, Doan Dac Ban and Nguyen Hoang Son

Center for Radioactive Ore processing Technology,


48- Lang Ha, Dong Da, Ha Noi

ABSTRACT : The ore sample used in the research was taken from the F3 ore bodies and the sample of the F7,

F9 and F16 ore bodies which contain the average of 5.98% TR2O3; they are multi-metals ore which is difficult

to enrich, highly weather with very complex ingredients. The process of the experiment is the ore is crushed,

grinded, screened and classified reasonably to-0.1mm and divided into 3 particle size with the following

technique: (1)-0.020mm is primary sludge and the rare-earth fine ore; (2) 0.075-1mm is gotten through the

sludge concentrating table with the output is the 2 parts: the heavy part which is dried magnetic separator with

high magnetism to get the rare-earth fine ore and the light one; (3) Light minerals, non-magnetic and

ferromagnetic minerals group are grinded together to 85% of them get size within-0.075 mm then mix it with

0.020-0.075 mm group. Using flotation separator, get barite-rare earth mixture and fluorite. After that, we

separate this mixture by secondary flotation and get refined rare earth, barite and fluorite mineral.

The result of the theme: (1) product plan A-rare-earth fine ore has TR2O3 content archive 42.07% with

recovery is 69.70%; (2) product plan B-rare-earth fine ore has TR2O3 content archive 29.64% with recovery is

80.01%.

1. THE PROJECT OBJECTIVE

The suggestion toward the procedure of the Dong Pao rare-earth enrichment technique to

obtain the fine ore with the quality and the quantity is:

(1) Refined barite with βBaSO4 90% and BaSO4 75% acquired is 50 kg.

(2) Refined fluorite with βCaF2 85% and CaF2 60% acquired is 50 kg.

(3) Refined rare earth minerals we get follow two option:

+ Plan A: Refined rare earth with βTR2O3 42% and TR2O3 75 % acquired is 50 kg.

+ Plan B: Refined rare earth with βTR2O3 30 % and TR2O3 90 % acquired is 50 kg.


- Code: 01/11/VCNXH



- Implementation Time: 24 months (Jan 2012 – Dec 2013)



1. Duong Van Su, Truong Thi Ai, Bui Ba Duy, Le Quang Thai, Trinh Nguyen Quynh, Vu Khac Tuan, Bui

Thi Bay, Nguyen Hong Ha. Summarize some of the results of the research about Lai Chau rare earth's

beneficiation technology was published. 4th

National conference on mineral processing science and

technology, Ha Noi 2014.(in Vietnamese).

2. Duong Van Su, Truong Thi Ai, Bui Ba Duy, Le Quang Thai, Trinh Nguyen Quynh, Vu Khac Tuan, Bui

Thi Bay, Nguyen Hong Ha. Difficults in technology for rare earths milling process on Lai Chau’s ore. 4th

National conference on mineral processing science and technology, Ha Noi 2014. 26th

National

conference on milling science and technology, Vung Tau 2014. (in Vietnamese).

VINATOM-AR 13--38


284

2. THE INTRODUCTION OF THE RESEARCH SAMPLE AND THE PROCESSING

EQUIPMENT, THE MAIN ENRICHMENT METHOD USED IN THE STUDY

2.1. The research sample

The research sample is taken from the F3 ore bodies and the technical sample from the F7,

F9 and F16 ore bodies of “The further probing the Dong Pao fluorite -barite rare-earth project in

Ban Hon, Tam Duong, Lai Chau” in 2010 of Lai Chau rare-earth joint stock. The total of the mixed

sample used to do the research is blended with the weight proportion of F3/F7/F9/F16=1.5/1/1/1,

added up into 1 sample with the weight of 1650kg.

2.2. The processing equipment and the main enrichment method used in the research.

The main equipment of the project is introduced from Fig. 1 to Fig. 6.

Figure 1: Trammel screen, shaking -

spiral classifier-vibrating screen.

Figure 2: Sludge concentration table

BxL = 1.8x4.5 m (Chinese).

Figure 3: Hydrocyclone D = 25.0 mm. Figure 4: Dry magnetic separator 138 T

СЭМ (USSR).

Figure 5: Wet magnetic separator with

high intensity (USA).

Figure 6: Floatation machine DENVER

(USA).

VINATOM-AR 13--38


285

2.3. Reasons for milling methods and equipment selection.

With all the characteristics of ore's material composition, minerals in Dong Pao rare earth

ores; we've chosen milling methods and equipment base on several reasons as follow:

1. Dong Pao rare earth ores are weathered, especially for rare earth minerals. Their form

usually is friable powder, sometime clutching to each other by hydroxide iron gel. Rare earth

minerals have strong bond and well mixed with most of accompany minerals, therefore smashing,

grinding, screening step must be adequate to help release all minerals from stick together. It's

suggested that ore should be smashed to below 1 mm particle size.

2. Rare earth content in primary sludge (with 0.020 mm particle size) is considerably rich;

reach 24.77% TR2O3, so hydrocyclone separator is selected for primary sludge removal to refined

ore. It's also advantage for following milling step.

Rare earths are mostly concentrated in 0.075 mm particle size (Table 13-76.27% and Table

14-78.10%), so smashed ore to 1.0 mm size is separated to 3 smaller size groups: (1) 0.075-1.0 mm;

(2) 0.020-0.075 mm and (3) below 0.020 mm (primary sludge) in order to help later milling

processes.

3. Density of minerals in this ore from heavy to light as follow: hematite 5.0-5.2 >

magnetite 4.9-5.2 > bastnaesite 4.7-5.0 > barite 4.3-4.5 > goethite 4.0-4.4 > limonite 3.3-4.0 >

fluorite 3.0-3.2 > felspate 3.0 > crystal 2.5-2.8 >… dirt. It's realized that bastnaesite belong to group

with very high density, therefore, we can use gravity separator to separate them to 2 groups base on

their density: (1) heavy minerals group contain hematite, magnetite, bastnaesite and barite; (2) light

minerals group contain fluorite, crystal and dirt. The analysis result show that rare earth content in

light group is still high, so we can only use gravity separator right before dry magnetic separator to

save energy for drying step.

4. Magnetism characteristic of minerals fin this ore from strong to weak as follow:

magnetite (very strong) > hematite (strong) > Goethite (weak) > limonite (very weak) > bastnaesite

(very weak) > … > barite (non magnetic) > fluorite (non magnetic) > crystal (non magnetic) > dirt

(non magnetic). With the difference a bout magnetism, we can use magnetic separator to separate

ore to 4 groups: (1) strong magnetic minerals; (2) weak magnetic minerals, (3) very weak magnetic

minerals and (4) non magnetic minerals.

On site experiments of Dong Pao rare earth ore milling reveal that bastnaesite mineral has

very weak magnetism, so we have to use very strong magnetic separator with very high magnetism

flux density, up to 1.5-1.8 millions Tesla. Ore with particle size from 0.075-1 mm is very

susceptible with dry magnetic separator. Particle size of 0.075 mm and below can't be used with dry

magnetic separator at any flux density, wet magnetic separator (American ERIEZ) also ineffective

on this particle size.

5. Water repellency of minerals: Ore sample has 3 useful minerals; among them, barite has

highest natural floatability compare to fluorite and bastnaesite on any collector in the market.

Fluorite and bastnaesite has similar floatability, depent on collector. As a result, in the flotation

separate step, we must figure out most effective reagent with high selective on each minerals and

optimum condition of flotation separate.

2.4. Suggest an enrichment technological layout for Dong Pao rare earth ore.

Base on the research off content, result collected from experiment of each enrichment

method, model and actual condition, we have presented technological layout for enrichment of

Dong Pao rare earth ore, combine several enrichment methods such as,classification, gravity

concentration, magnetic separation with strong magnetic field, selective floation or collective

floation, as shown in figure 7. Enrichment steps in this layout are listed as follow:

VINATOM-AR 13--38


286

1. Properly prepare ore, avoid grind it too fine. Trammel screen, shaking, grinding balls,

vibrating screen and spiral classifier are used together to bring all ore particle below 1.0 mm size.

2. Using particle size classification methods (hydrocyclone, spiral classifier) to separate

processed ore to 3 groups base on their particle size: (1) 0.075-1.0 mm; (2) 0.02-0.075 mm; (3)

below 0.02 mm (primary sludge). Particle size below 0.02 mm are separated will bring advantages

for later steps because it's already very fine rare earth refined ore.

3. Using gravity concentration (sludge concentrating table and multi gravitational separator)

separate ore group with particle size 0.075-1.0 mm to two minor groups: (1) heavy minerals group

and (2) light minerals group.

4. Dry magnetic separator with high magnetic field is use on dried heavy minerals group to

separate it to 3 minor groups: (1) ferromagnetic minerals group (has strong and medium

magnetism); (2) rare earth minerals group (has weak magnetism) and (3) non magnetic minerals

group-contain mostly barite).

5. Light mineral group and non magnetic minerals group and some of ferromagnetic group

are grinded together to 0.075 mm particle size (at least 85%) and mix with 0.02 – 0.075 mm particle

size group. After all, flotation separators are used to separate this mixture to refined rare earth ore,

fluorite ore and barite ore.

Figure 7: Technological layout for enrichment of Dong Pao rare earth

ore in laboratory scale.

VINATOM-AR 13--38


287

3. DONG PAO RARE EARTH MILLING PROCESS WITH TWO PRODUCTS

Base on process has described in figure 7 and probe experiments' result, we has conclude it

to two processes, which lead to two products as described in figure 8 and 9. There're some

differences between these process as listed below:

1. Hydrocyclone separate step: Particle size need to separate are 0.015 mm and 0.020 mm

respectively.

2. Dry magnetic separate under strong magnetic field step: differences between separate

times.

3. Flotation separate step: collector, depressor expenditures, time use on froth skimming,

amount of cleaner circuit step.

3.1. Dong Pao rare earth milling process follow product A.

Dong Pao rare earth milling process follow product A is demonstrate in figure 8. All the

steps of this process are described in table 1 and listed below:

- Run of mine (ROM) is dry screened on screens with 2 aperture size d1 = 5.0 mm and d2

= 10.0 mm to 3 particle size + 10.0 mm; 5.0-10.0 mm; -5.0 mm. Ore with 10.0 mm size are crushed

in smooth-roll crusher to-5.0 mm size. 5.0-10.0 mm particle size ore will go through trammel

screen, shaking and grinding machine, the mix with-5.0 mm particle and proceed through primary

spiral classifier combine with vibrating screen with aperture size = 1 mm. Final product will be ore

with particle size < 1.0 mm. circulation spigot product with size > 1.0 mm will go back to trammel

screen, shaking again.

- The product with particle size < 1.0 mm will go to secondary spiral classifier with

topping threshold particle size 0.075 mm, we'll get 2 products in < 0.075 mm and 0.075-1.0 mm

particle size. 0.075-1.0 mm size is separated on sludge concentration table to 2 groups: heavy and

light.

- Heavy group from concentration table is dried and go through dry magnetic separator

138 T СЭМ (USSR) with field indensity H = 1.000-5.000 gauss and 15.000 gauss. We'll get 3

products after this step as ferromagnetic minerals, refined rare earth minerals 1A and non-magnetic

minerals A.

- -0.075 mm size ore is separated by hydrocyclone with D = 25.0 mm (sand tube diameter

dc = 6 mm and sludge flow pressure H = 2.5-2.8 kg/cm2) to 2 products with particle size-0.015 mm

and 0.015-0.075 mm. Product with-0.015 mm particle size, also called as primary sludge has high

rare earth content and named as refined rare earth minerals 2A.

- Ferromagnetic, non-magnetic minerals and light group products from concentration

tables are grinded to 85%-0.075 mm and mixed together with 0.015-0.075 mm size ore from

cyclone to form a product named assorted product-0.075 mm.

- Assorted product-0.075 mm, barite and rare earth are fed together in primary flotation

separator with reagent’s ingredients as follow: depressor is liquid glass with dosage 2.500 g/t, pH

modifier is sodium bicarbonate with dosage 1.200 g/t to get pH = 10.5, collector S-SDS with dosage

650 g/t with froth skimming time 7 minutes.

- Floating products from flotation separator also go to secondary flotation separate to get

barite with reagent's ingredients as follow: depressor is liquid glass with dosage 2.000 g/t, collector

BEROL 2014 with dosage 650 g/t. Primary refined barite minerals will go through 2-3 milling

process to get refined barite and middlings. Sinking products from process above are separated by

selective flotation one more time to get rare earth minerals with 2.000 g/t liquid glass as depressor

and 550 g/t sodium oleate as collector. Primary refined rare earth mineral will go through 3 milling

VINATOM-AR 13--38


288

processes to get refined rare earth and middlings. All middlings are send back to the primary

flotation separator.

- Sinking products from primary flotation separator will go through secondary flotation

process with 2.000 g/t liquid glass as depressor and 900 g/t acid oleic as collector to get fluorite.

Primary refined fluorite mineral will go through 3 milling process to get refined fluorite and

middlings. Middlings will be sent back to the beginning of this process.

Table 1: Milling process follow product A.

Separate step Milling process and products

Magnetic

separate step

Field intensity, gauss Products

1000-5000 Ferromagnetic ore

15000 Refined rare earth ore 1A

Hydrocyclone

separate step

D = 25.0mm

Sand tube

diameter

db,mm

Sand tube

diameter

dc,mm

Sludge flow

pressure H,

kg/cm2

Products

4.0 6.0 2.5-2.8 - 0.015mm

(refined rare

earth ore 2A)

0.015-

0.075mm

Flotation

separate step

Reagent’s ingredients, Time use on froth

skimming, amount of cleaner circuit.

Reagent

expenditures, g/t

Time,

minute

Collective

flotation step

on barite and

fluorite

- Sodium bicarbonate

- Liquid glass

- S-SDS

- Time use on froth skimming

1200

2500

650

-

4

4

4

7

Flotation

separate step

on barite

- Liquid glass

- BEROL 2014


- Amount of cleaner circuit.

2000

650

-

-

4

4

6

2-3

Flotation

separate step

on rareearth

- Liquid glass

- Sodium oleate



2000

550

-

-

4

4

4

3

Flotation

separate step

on fluorite

- Liquid glass

- Acid oleic



2000

900

-

-

4

4

4

3

The result of milling process follow product A (figure 8) on mixed ore is describe in table 2

and on F3 ore is describe in table 3.

VINATOM-AR 13--38


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Quality of refined product A (DH-A) is evaluated by multi-element analysis at Geology

Analysis and Experiments Center and presented in table 4. Total acquired quantity of DH-A from

project is 50.0 kg.

Figure 8: Dong Pao rare earth milling process follow product A.

VINATOM-AR 13--38


290

Table 2: Result of Dong Pao rare earth ore enrichment follow

product A on mixed ore.

No Products Yield % Content,% Recovery,%

TR2O3 BaSO4 CaF2 TR2O3 BaSO4 CaF2

1 Rare earth

fine ore 1A 0.69 59.21 1.98 1.17 6.83 0.05 0.07

2 Rare earth

fine ore 2A 3.25 25.96 9.28 4.15 14.11 1.17 1.09

3 Rareearth

fine ore 3A 5.97 48.86 18.66 3.22 48.76 4.31 1.55

4

Total Rare

earth fine

ore DH-A

9.91 42.07 14.42 3.38 69.70 5.54 2.71

5 Barite fine

ore 20.25 2.53 92.35 2.63 8.57 72.45 4.31

6 Fluorite

fine ore 8.51 1.59 2.38 85.23 2.26 0.78 58.73

7 Tailings A 61.33 1.90 8.93 6.90 19.47 21.23 34.25

ROM 100.00 5.98 25.81 12.35 100.00 100.00 100.00

Table 3: Result of Dong Pao rareearth ore enrichment follow

product A on F3 ore.

No Products Yield % Content,% Recovery,%


1 Rare earth

fine ore 1A 1.38 51.13 3.65 0.82 5.61 0.09 0.09

2 Rareearth

fine ore 2A 9.92 38.69 22.44 3.08 30.53 4.16 2.54

3 Rareearth

fine ore 3A 10.51 44.24 34.20 5.20 37.00 6.72 4.55

4

Total Rare

earth fine

ore SS-96

21.81 42.15 26.92 3.96 73.15 10.98 7.18

5 Barite fine

ore 43.50 2.96 92.55 5.57 10.24 75.27 20.14

6 Fluorite

fine ore 8.12 4.43 4.33 87.54 2.86 0.66 59.08

7 Tailings A 26.56 6.50 26.37 6.16 13.74 13.09 13.60

ROM 100.00 12.57 53.49 12.03 100.00 100.00 100.00

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Table 4: Result of multi-element analysis of rareearth fine ore DH-A and DH-B.

No Value,

concentration

Barite fine

ore

Fluorite fine

ore

Rare earth

fine ore DH-A

Rare earth

fine ore DH-B

1 TR2O3; % 2.53 1.59 42.07 29.64

2 BaSO4; % 92.35 2.38 14.42 15.56

3 CaF2; % 2.63 85.23 3.38 6.41

4 CaO; % 0.41 1.97 1.30 2.29

5 SiO2; % 1.86 1.38 1.23 4.97

6 Fe; % 0.25 0.36 0.61 2.64

7 U; ppm 3.0 5.0 2.0 5.0

8 Th; ppm 5.0 7.0 5.0 4.0

3.2. Dong Pao rare earth milling process follow product B.

Dong Pao rare earth milling process follow product B is demonstrate in figure 9. All the

steps of this process are described in table 5 and listed below:

- COM is dry screened on screens with 2 aperture size d1 = 5.0 mm and d2 = 10.0 mm to

3 particle size + 10.0 mm; 5.0-10.0 mm; -5.0 mm. Ore with 10.0 mm size are crushed in smooth-

roll crusher to -5.0 mm size. 5.0-10.0 mm particle size ore will go through trammel screen, shaking

and grinding machine, the mix with -5.0 mm particle and proceed through primary spiral classifier

combine with vibrating screen with aperture size = 1 mm. Final product will be ore with particle

size < 1.0 mm. Circulation spigot product with size > 1.0 mm will go back to trammel screen,

shaking again.

- The product with particle size < 1.0 mm will go to secondary spiral classifier with

topping threshold particle size 0.075 mm, we'll get 2 products in < 0.075 mm and 0.075-1.0 mm

particle size. 0.075-1.0 mm size is separated on sludge concentration table to 2 groups: heavy and

light.

- Heavy group from concentration table is dried and go through dry magnetic separator

138 T СЭМ (USSR) with field intensity H = 1.000-5.000 gauss, 14.000 gauss and 15.000 gauss.

We'll get 3 products after this step as ferromagnetic minerals and non-magnetic minerals B. Two

magnetic products acquired from 14.000 and 15.000 gauss condition are mixed together to form

refined rare earth minerals 1B.

- - 0.075 mm size ore is separated by hydrocyclone with D = 25.0 mm (sand tube

diameter dc = 4.0 mm and sludge flow pressure H = 1.5-1.8 kg/cm2) to 2 products with particle size

-0.020 mm and 0.020-0.075 mm. Product with-0.020 mm particle size, also called as primary sludge

has high rare earth content and named as refined rare earth minerals 2B.

- Ferromagnetic, non-magnetic minerals and light group products from concentration

tables are grinded to 85%-0.075 mm and mixed together with 0.020-0.075 mm size ore from

cyclone to form a product named assorted product-0.075 mm.

- Assorted product-0.075 mm, barite and rare earth are fed together in primary flotation

separator with reagent’s ingredients as follow: depressor is liquid glass with dosage 2.500 g/t, pH

modifier is sodium bicarbonate with dosage 1.200 g/t to get pH = 10.5, collector S-SDS with dosage

650 g/t with forth skimming time 8 minutes.

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- Floating products from flotation separator also go to secondary flotation separate to get

barite with agent's ingredients as follow: depressor is liquid glass with dosage 2.000 g/t, collective

BEROL 2014 with dosage 650 g/t. Primary refined barite minerals will go through 2-3 milling

process to get refined barite and middlings. Sinking products from process above are separated by

selective flotation one more time to get rare earth minerals with 2.000 g/t liquid glass as depressor

and 650 g/t sodium oleate as colector. Primary refined rare earth mineral will go through 3 milling

process to get refined rare earth and middlings. All middlings products are send back to the primary

flotation separator.

- Sinking products from primary flotation separator will go through secondary flotation

process with 2.000 g/t liquid glass as depressor and 900 g/t acid oleic as collector to get fluorite.

Primary refined fluorite mineral will go through 3 milling process to get refined fluorite and

middlings. Middlings will be sent back to the beginning of this process.

The result of milling process follow product B (figure 9) on mixed ore is describe in table 6

and on F3 ore is describe in table 7.

Quality of refined product B (DH-B) is evaluated by multi-element analysis at Geology

Analysis and Experiments Center and presented in table 4. Total acquired quantity of DH-B from

project is 50.0 kg.

Figure 9: Dong Pao rare earth milling process follow product B.

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Table 5: Milling process follow product B.

Separate step Milling process and products

Magnetic separate

step

Field intensity, gauss Products

1000-5000 Ferromagnetic ore

14000 Magnetic 2 Refined rare

earth ore 1B 15000 Magnetic 3

Hydrocyclone

separate step

D = 25.0mm

Sand tube

diameter

db,mm

Sand

tube

diameter

dc,mm

Sludge flow

pressure H,

kg/cm2

Products

4.0 4.0 1.5-1.8 -0.020mm

(refined rare

earth ore 2B)

0.020-

0.075mm

Flotation separate

step

Reagent’s ingredients, Time use on

froth skimming, amount of cleaner

circuit

Reagent

expenditures,

g/t

Time,

minute

Collective

flotation

step on

barite and

fluorite

- Sodium bicarbonate,

pH =10,5

- Liquid glass

- S-SDS

- Time use on froth

skimming

1200

2500

650

-

4

4

4

8

Flotation

separate

step on

barite

- Liquid glass

- BEROL 2014

- Time use on froth

skimming

- Amount of cleaner

circuit.

2000

650

-

-

4

4

6

2-3

Flotation

separate

step on

rare earth

- Liquid glass

- Sodium oleate

- Time use on froth

skimming

- Amount of cleaner

circuit.

2000

650

-

-

4

4

6

2

Flotation

separate

step on

fluorite

- Liquid glass

- Acid oleic

- Time use on froth

skimming

- Amount of cleaner

circuit.

2000

900

-

-

4

4

4

3

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Table 6: Result of Dong Pao rare earth ore enrichment follow product B on mixed ore.

No Products Yield

%

Content,% Recovery,%


1 Rareearth fine

ore 1B 1.18 47.73 2.12 1.67 9.42 0.10 0.16

2 Rareearth fine

ore 2B 5.66 23.31 9.31 4.33 22.06 2.04 1.98

3 Rareearth fine

ore 3B 9.30 31.20 21.07 8.28 48.53 7.59 6.23

4 Total Rareearth

fine ore DH-B 16.14 29.64 15.56 6.41 80.01 9.73 8.38

5 Barite fine ore 20.25 2.53 92.35 2.63 8.57 72.45 4.31

6 Fluorite fine

ore 8.51 1.59 2.38 85.23 2.26 0.78 58.73

7 Tailings B 55.10 0.99 7.98 6.41 9.16 17.03 28.58

ROM 100.00 5.98 25.81 12.35 100.00 100.00 100.00

Table 7: Result of Dong Pao rareearth ore enrichment follow product B on F3 ore.

No Products Yield

%

Content,% Recovery,%


1 Rareearth fine

ore 1B 1.89 46.21 4.53 1.07 6.95 0.16 0.17

2 Rareearth fine

ore 2B 16.17 31.59 25.61 3.22 40.64 7.74 4.33

3 Rareearth fine

ore 3B 14.91 29.27 35.80 5.33 34.72 9.98 6.60

4 Total Rareearth

fine ore SS-98 32.97 31.38 29.01 4.05 82.31 17.88 11.10

5 Barite fine ore 43.50 2.96 92.55 5.57 10.24 75.27 20.14

6 Fluorite fine

ore 8.12 4.43 4.33 87.54 2.86 0.66 59.08

7 Tailings B 15.41 3.74 21.49 7.56 4.58 6.19 9.68

ROM 100.00 12.57 53.49 12.03 100.00 100.00 100.00

4. RESULTS, CONCLUSIONS AND SUGGESTION

4.1. Results and conclusions about material composition of Dong Pao rare earth ore.

1. Research samples had very complex material composition, belong to group of "multi-

metals" ore and the ore itself is very hard for milling. Total rare earth oxide is not too high, only

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5.98% Tr2O3. However, barite and fluorite take a large part, for detail: 25.81% BaSO4, 12.35%

CaF2. There're many miscellaneous minerals come together with rare earth with high content of Ca,

Al, Fe, Si, S, Mn, Pb, Mg,... In the samples also contain radioactive elements like uranium and

thorium in low proportion, 18 ppm and 3 ppm respectively. Rare-earth minerals mostly exist in

bastnaesite form. In this kind of ore, barite take a large contain, 4 to 5 times when compare to all of

other rare-earth oxide contain together. Moreover, some of rare-earth element exist in Yttrofuorite

form (Ca,Y)F2-3 and fluorite form CaF2[(CaF2)0.75(YF3)0.25].

2. Dong Pao ore is highly weathered carbonate deposit, mostly rare earth minerals. Their

primary structure mostly destroyed to friable powder, sometime clutching to each other by

hydroxide iron gel. It has strong bond and well mixed with most of accompany minerals.

3. Minerals in Dong Pao ore are diluted or separated in fine and very fine grain.

Orientation and distribution of rare earth and two other assimilate minerals barite and fluorite is

very sharp. The finer grain, the higher content of rare earth and it goes opposite with barite and

fluorite. Rare earth concentrate in fine particle size-0.075 mm. Rare earth content in primary sludge

-0.020 mm is pretty high: 24.77% TR2O3.

4.2. Results and conclusions about material composition of Dong Pao rare earth ore.

We have selected milling technology of Dong Pao rare earth ore as a combination of many

enrichment methods.

- Crude ore is handled properly to grain size-1.0 mm by hydrocyclone and spiral classifier

and separate to 3 sizes: (1) 0.075-1.0 mm; (2) 0.020-0.075 mm and (3)-0.020 mm. Particle size-

0.020 mm is primary sludge, has high content of rare earth elements and can be considered refined

rare earth minerals.

- Separate Dong Pao rare earth ore which sizes 0.075-1.0 mm to 2 sub groups (1) heavy

minerals and (2) light minerals using sludge concentration table. Follow this step, using dry

magnetic enrichment to separate heavy minerals group to 3 sub groups: (1) ferromagnetic minerals,

(2) rare earth minerals (weak magnetism) and (3) non-magnetic minerals.

- Light minerals, non-magnetic and ferromagnetic minerals group are grinded together to

85% of them get size within-0.075 mm then mix it with 0.020-0.075 mm group. Using flotation

separator, get barite-rare earth mixture and fluorite. After that, we separate this mixture by

secondary flotation and get refined rare earth, barite and fluorite mineral.

- Refined minerals have met the follow quality requirements and quantity as follow:

Refined barite with βBaSO4 content = 92.35% and the recovery of BaSO4 72.45% acquired is 50 kg.

Refined fluorite with βCaF2 = 85.23% and the recovery of CaF2 58.73% acquired is 50 kg. Refined

rare earth minerals we get follow two option:

+ Plan A: Refined rare earth with βTR2O3 = 42.07% and the recovery of TR2O3 69.70%

acquired is 50 kg.

+ Plan B: Refined rare earth with βTR2O3 = 29.64% and the recovery of TR2O3 80.01%

acquired is 50 kg.

- Technology diagram for Dong Pao rare earth minerals in laboratory scale has chosen as

figure 9 and technological quality acquired as follow this technology introduced in table 6.

4.3. Suggestions

1. In order to avoid unnecessary risk when design an build a rare earth milling factory in

Lai Chau, it is imperative to run experiments in larger scale (semi-industrial scale) for testing this

technology diagram and collect all the technological and economical parameters which are closest

to real scale operation. It'll serve well for technological design and project initiate of the factory.

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2. Lai Chau rare earth milling technology is “flexible” and “open”; it can adapt to material

composition of various ore bodies.

3. In real industrial scale, in order to has it reasonable from all aspect of technology,

economy and especially guarantee using precious resources in most effective way; it should be

round up the rare earth elements oxide in refined minerals from 30.0-35.0 %.

REFERENCES

[1] Hoàng Trọng Mai, Giáo trình “Khoáng vật học đại cương”, Đại học Mỏ-Địa chất, Hà Nội

năm 1997.

[2] Nguyễn Văn Hạnh, Luận án tiến sỹ kỹ thuật “Nghiên cứu khả năng tuyển tách đất hiếm,

fluorit và barit từ quặng hỗn hợp đất hiếm phong hóa Đông Pao”, Hà Nội năm 2006.

[3] Báo cáo “Nghiên cứu khả thi thân quặng F3 Đông Pao, Lai Châu”, Công ty Toyota Tsusho và

Sojitz Nhật Bản năm 2009.

[4] Nguyễn Thị Hồng Hà, Báo cáo tổng kết đề tài “Nghiên cứu công nghệ tuyển quặng đất hiếm

phong hóa thân quặng F7 Đông Pao, Lai Châu”, Hà Nội năm 2010.

[5] Nguyễn Duy Pháp, Báo cáo tổng kết “Nghiên cứu mẫu công nghệ Đề án thăm dò bổ sung mỏ

đất hiếm-fluorit-barit Đông Pao thuộc xã Bản Hon, xã Bản Giang, huyện Tam Đường, tỉnh

Lai Châu”, Hà Nội năm 2011.

[6] Trần Thị Hiến, Báo cáo sơ bộ “Thí nghiệm mẫu công nghệ quặng đất hiếm mỏ đất hiếm Bắc

Nậm Xe, xã Nậm Xe, huyện Phong Thổ, tỉnh Lai Châu”, Hà Nội năm 2013.

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IMPROVING TECHNOLOGY AND SETTING-UP A PRODUCTION

LINE FOR HIGH QUALITY ZINC OXIDE (99.5%) WITH A CAPACITY

OF 150 TON/YEAR BY REDUCTION-OXIDATION PROCESS

Pham Minh Tuan, Tran The Dinh, Tran Ngoc Vuong, Tuong Duy Nhan, Tran Trung Son,

Le Huu Thiep, Nguyen Trung Dung, Le Thi Hong, Luong Manh Hung and Bui Huy Cuong

Center for Technology Development,



ABSTRACT: Zinc oxide is used not only for the rubber industry, but also in many other industries such as

pigments, ceramics, cosmetics etc. On the basis of references on international scientific researches and

practical activities for the production of zinc oxide in our country, we have carried out additional research and

testing to establish a zinc oxide production line for preparation of high quality (99.5%) product by treating the

industrial zinc containing waste to obtain required composition materials [Zn] >50%; [Pb] < 0.3%; [Cl]/[PbO]

< 0.2 for reduction-oxidation processes using reverberatory furnace.

Keywords: Zinc oxide; reduction oxidation method; american process; direct zinc oxide.

1. OVERVIEW

Reduction-oxidation method (American process) is the most important method for the

highest capacity production of zinc oxide at present. Most industries are using ZnO produced by

this method.

The resulting product by this method is often not of high quality, depending on the type of

raw materials, which can be obtained with a concentration of ZnO 70% to 99%. Along with the

advancement of science and technology today, ZnO produced by this method can reach the higher

quality zinc oxide of 99.5%.

Basically, the method consists of following stages: 1)materials processing; 2)reduction of

zinc oxide in the materials into metallic zinc by using coal, coke; 3) then zinc metal at high

temperature will be evaporated and react with oxygen in the air to form zinc oxide.

Reduction oxidation method is carried out by means of two basic types of devices: the rotary

kiln and reverberatory furnace.

The reverberatory furnace method is currently most commonly used to produce ZnO thanks

to its high quality products. This method has the advantage of a favorable investment due to low

cost, simple device, easily to fabricate. The downside of this method is its rather low recovery

performance compared to the method using a rotary kiln: typical recovery efficiency of zinc is

around 90%.

Technology fundamentals

The chemistry of the production process by reduction-oxidation method can be represented

by the following reaction equation:


- Code: HĐDA. 06/2010/NLNT


- Allocated Fund: 1,700,000,000 VND

- Implementation Time: 42 months (Mar 2010-Aug 2013)


- Papers published in relation to the project: (None)


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ZnO (solid ) + CO = Zn vapor + CO2 (1)

Zn vapor + O2 = ZnO (solid) (2)

During the reduction-oxidation of zinc, lead (Pb) content in the raw material will have a

similar behavior to zinc. Pb content in ZnO product by this method highly depends on the Pb

content in raw materials. In addition, quality of the resulting ZnO product obtained by reduction-

oxidation process depends mainly on two other factors: temperature of reverberatory furnace and

chloride salt content in raw materials.

2. TECHNOLOGY IMPROVEMENT

We have implemented this project with the following specific measures:

1. Research a method of Lead separation, while minimizing Pb and chloride salt

concentrations in raw materials.

2. Change reverberatory furnace design to increase impurity removals efficiency and

improve the furnace performance.

3. Use material pressed pellets instead of powder materials, and design, set-up a dust

handling systems for reduction-oxidation furnace to improve efficiency of reduction-oxidatition

process.

2.1. Lead removal

The reaction of Pb separation process is represented by the following reaction equation :

2NaCl + PbO + 2SiO2 + Al2O3 = PbCl2↑ + 2NaAlSiO4 (1)

2NaCl + PbO + CO2 = PbCl2↑ + Na2CO3 (2)

2NaCl + ZnO + CO2 = ZnCl2↑ + Na2CO3 (3)

According to [19] , the reaction (1) occurs at temperatures of 900-10000C, the reaction time

of about 90 minutes, the activation energy for reaction (1) is 175 kJ/mol, the reactions (2) and (3)

can occur at lower temperatures (800-10000C).

Figure 1: Schema of Lead removal experiment.

The experiment results have been shown in the table 1.

Table 1: Pb removal study by chlorination method.

Sample Con.,% Reaction

temp.,oC

Reaction time, min.

15 30 45 60 75 90 105 120

M1 Zn 67.5

Pb 2.70

850 2.65 2.5 2.2 1.7 1.3 1.1 0.7 0.55

900 2.6 2.4 2.05 1.5 1.1 0.9 0.65 0.55

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299

Cl 6.1

950 2.6 2.2 1.85 1.2 0.85 0.7 0.55 0.4

1000 2.55 2.15 1.75 1.05 0.7 0.55 0.5 0.4

M2

Pb 3.6

Cl 6.2

Zn 67.0

850 3.55 3.3 2.7 2.35 1.55 1.05 0.9 0.85

900 3.55 3.25 2.55 2.2 1.55 1 0.8 0.8

950 3.5 3.2 2.5 2.0 1.4 0.9 0.8 0.7

1000 3.5 3.1 2.4 1.9 0.95 0.85 0.75 0.7

M3

Pb 3.6

Cl 6.2

Zn 67.0

3%NaCl

850 3.55 3.3 2.7 2.35 1.55 0.8 0.55 0.5

900 3.55 3.25 2.55 2.2 1.55 0.8 0.55 0.5

950 3.5 3.2 2.5 2 1.4 0.7 0.5 0.45

1000 3.5 3.1 2.4 1.9 0.95 0.7 0.45 0.45

When the concentration of Pb in raw material is lower (experiment 1), Pb removal process

showed its good efficiency. In the case of high Pb concentrations, although the reaction time

extended to 120 minutes, even at temperatures of 10500C (the highest temperature in the

temperature range survey), amount of Pb remained in the reaction mass was still higher than the

value required (experiment 2).

This phenomenon can be explained that, chlorides containing in the reaction mass was

disintegrated so chloride amount remained could not be enough to transform all Pb containing in the

raw material to lead chloride, therefore chloride salt should be added to the reaction mass to suply

additional chloride for the chlorination reaction (experiment 3, fig.2).

From the experimental results, we could see that, when chloride is added in the form of

sodium chloride, Pb separation efficiency increases even though the amount of chlorine in the

starting material is very large compared with the Pb content in the material.

The additional amount of sodium chloride is calculated according to [19,25]. The

verification experiment showed that NaCl salt should be added so that the total amount of chloride

in the reaction mass was about 3 times larger (in stoichiometric) compared with Pb content in raw

materials.

Figure 2: Lead removal test (Sample tested No.3).

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Through empirical data survey of Pb separation process, following conclusions can be

made:

1) Pb removal process will achieve good efficiency at temperatures in the range 800-

10000C, the time needed to maintain the reaction temperature is 90 minutes.

2) Pb contain in the zinc slag can be reduced to the value of 0.4%.

3) When the concentration of Pb in the zinc slag is high, chloride in the form of sodium

chloride should be added to provide reacting agent for chlorination reaction.

4) This method can simultaneously solve both the most important issues: removal of Pb and

reduction of chloride contained in the raw material.

2.2. Reduction-oxidation furnace set-up

We have changed the design, creating two separate zones in the furnace: Reduction Zone

and oxidation Zone. Air supply for oxidation process is fed into the oxidation chamber through the

intake air (see Fig.3).

Figure 3: Reverberatory Furnace Design Improvement.

Based on additional research, a system of devices are listed below.

1 Reverberatory furnace for Reduction-Oxidation of Zinc: Productivity 600kg/batch;

02 blower power 4 kW; 18000 -20000m3 /h, pressure 250 mmH2O;

Drain system of 10 chambers deposition system made of SUS304 stainless steel.

2 Dust collection system with bag house, filter surface area: 300m2; dust collection

fan of 350mmH2O pressure, flow 12.000m3/h. Working temperature: <100°

3 Ball press machine, Model YBM430: Rolls diameter 430 mm.Capacity: 6-8 t/h.

Motor power: 11 kW.

4 Grinding machine Model ZC-800: Grinding Barrel Diameter: 800 mm.Capacity of

10 ton/h. Motor 30 kW.

5 Mixing Machine, Model YZM-300: Length 3000 mm; Mixing tank 2500x550mm;

Mixing velocity: 40 v/ph.

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3. TRIAL PRODUCTION

Five trials with different composition materials have been done. Each test is carried out by

using 20 tons of zinc slag processed. It has been confirmed:

- The measures applied to improve the quality of materials is a suitable solution to

produce zinc oxide of desired quality.

- The reduction-oxidation furnace system has ability to produce high quality zinc oxide

with the appropriate material.

- Standard input for the production of high quality zinc oxide by reduction-oxidation

method : [Zn]> 50%; [Pb] <0.3%; [Cl] / [PbO] <0.2.

Table 3 below discribes the composition of pretreated material (to reduce Pb and Chloride).

Table 3: Pretreated material composition.

Zn Pb Cl Mass remained,%

X1 76.0 0.36 0.23 100

X2 75.4 0.48 0.22 94

Table 4: Raw (untreated) material composition.

Procedure for high quality inc oxide production.

The production procedure and technical parametters required for each stage have been

shown in the fig.5 below.

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Figure 5: Technology schema for high quality zinc oxide(99.5%) production line.

Table 5: Analysis and assessment of product quality.

No. Species Analysis method Results Examiner

1 ZnO ISO13658(E) 99.52% Analytical Center,

Lab Vilas 143-

Istitute for Mining

and Metallurgy.

2 Pb ISO5889(E) 0.15%

3 Fe ISO5889(E) 0.003%

4 Particles Size LSPSDistribution Analyser

LA-950

5-10µm ITRRE.

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4. CONCLUSIONS

- The Project “Improving technology and setting up a production line for high quality

zinc oxide (99.5%) with a capacity of 150 ton/year by reduction-oxidation method” has been

implemented as registered in the Project Notes. Specifically:

- Technology improvement: The Projects completed all technology items, aimed at the

stages of production of zinc oxide, especially focused on the process of the raw material heat

treatment in a rotary kiln. By using pretreated zinc containing materials, ZnO product meet all

requirements of rubber grade high quality zinc oxide even quality of zinc slag material is not high.

The main technological parameters have been established and a new zinc oxide production line by

reduction-oxidation process has been built.

- Technology equipment: A new Production line equipment mainly focused on the

enhancing process efficiency and increasing product quality. The material pelleting technology is a

key solution in production technology. Dust collection system, gas treatment combined with

material pelleting technology have brought about economic efficiency: increasing product revenue

performance and meeting environmental protection requirements.

- Production: The total amount of product produced during the time of implementing the

project was 455 tons. Zinc oxide products met all the requirements of vulcanized rubber technology.

In fact, the production cost will be reduced at a larger production scale by the depreciation of

equipment and less labor consumption.

REFERENCES

[1] PHẠM QUANG TRUNG, Nghiên cứu quy trình nung phân huỷ ZnCO3 thành ZnO trên

thiết bị nung động, Báo cáo tổng kết đề tài CS-99-13, Viện Công nghệ Xạ-Hiếm, Viện Năng

lượng Nguyên tử Việt Nam, Hà Nội 4/2000.

[2] YUREN JIANG, ET AL, Preparation of High Purity Zinc Oxide from Zinc Metal Scrap,

Akita University and the University of Tokyo-Japan.

[3] G. HEIDEMAN, Reduced zinc oxide levels in sulphur vulcanization of rubber compounds.

Ph.D. Thesis, University of Twente, Enschede, the Netherlands, 2004.

[4] BERGENDORFF O., PERSSON C., HANSSON C., Chemical changes in rubber allergens

during vulcanization.

Department of Dermatology, University Hospital, Lund University, Sweden.

[5] DANIEL L. HERTZ, JR., Theory & Practice Of Vulcanization, Seals Eastern Inc., Red

Bank, NJ 07701.

[6] LUTAO LI, ET AL, Formation of ZnO-containing Dust from Zn-bearing Steel Melts,

Technical University of Claustahl-Germany, July 25, 1994.

[7] HIROYUKI MATSUURA, ET AL, Removal of Zn and Pb from Fe2O3-ZnFe2O4-ZnO- PbO

Mixture by Selective Chlorination and Evaporation Reactions, The University of Tokyo-

Japan, January 30, 2006

[8] www.omnexus.com, Review of vulcanization chemistry.

[9] J.G.KREINER, Method for improving rubber curing rates, US Pat. 4882394, 11/1989.

[10] CHSSR KUMAR, AVINASH M NIJASURE, Vulcanization of rubber, ICI Research and

Technology Center, Thane, India..

[11] Treatment of polyvinylchloride, US patent 5698759.

[12] Treating Lead and Zinc-containing steelmaking by-products, US patent 4765829.

[13] Chloride melt process for the separation and recovery of Zinc, US patent 6931474.

[14] JAE-MIN YOO, BYUNG-SOO KIM, MIN-SEUK KIM AND JINKI JEONG, Separation of

Lead and chlorine from electric arc furnace dust to recover Zinc, Korea Institute of

http://www.omnexus.com/

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Geoscience and Mineral Resouces, 3/2007.

[15] JOHN HENRY CALBECK. Production of Zinc oxide, US patent 2 603 554.

[16] BECKMANN ET AL. Treating Lead and Zinc containing stellmaking byproducts, US

patent 4 765 829.

[17] SHUGARMAN, Lead removal method, US patent 4 704 260, 11/1987.

[18] FRANK G. BREYER, EARL C. GASKILL ET AL. Manufacture of Zinc Oxide, US patent

1522097.

[19] M.P. KIRK. Apparatus for Producing Zinc oxide, US patent 1566103.

[20] DA02/2005. Hoàn thiện công nghệ sản xuất kẽm cacbonat. Viện Công nghệ Xạ-Hiếm, Viện

Năng lượng Nguyên tử Việtnam, 6/2007.

[21] A.M.LASTOTSEV, E.I. GORODNICHEVA, Calcualting power consumption for mixing

high-viscosity newtonian liquids with blade mixers, UDC 66.063.

[22] DAT-NLNT/06-04, Hoàn thiện công nghệ và dây chuyền thiết bị cho sản xuất ZnO 98,5%

quy mô 150tấn/năm, Hà nội 12/2008.

VINATOM-AR 13--40


305

DETERMINATION OF RARE EARTH AND OTHER ELEMENTS

IN YEN-PHU RARE EARTH ORE AND OTHER INTERMEDIATE

PRODUCTS FROM THE FLOATATION AND HYDROMETALLURGICAL

PROCESS ON PORTABLE XRF Si-PIN DETECTOR

Doan Thanh Son, Phung Vu Phong and Nguyen Hanh Phuc



ABSTRACT: The concentration of rare earths elements such as La, Ce, Pr, Nd, Gd... and other elements as Ca,

Fe, U, Th in Yen Phu rare earth ore and other intermediate products from the flotation and hydrometallurgical

process was determined by using Si-PIN detector fluorescence spectrometry. The precision and accuracy of

quantitative analysis was tested by standard reference materials and comparative analysis with different

analytical methods. The analytical procedures were set-up and applied for the determination of rare earth and

other elements in Yen Phu rare earth ore and other intermediate products from the flotation and

hydrometallurgical process with high precision and accuracy.

I. INTRODUCTION

Previously ICP methods were often used to analyze the rare earth elements, however the

disadvantage of this method of analysis was time-consuming because it needed to digest the solid

samples. In published articles written about the identification of rare earth elements by X-ray

fluorescence method, the wavelength dispersion fluorescence systems (WD-XRF) were almost

applied. In ITRRE, there was a report concerning energy dispersion fluorescence system (ED-XRF)

from the year of 2000, in which some rare earth elements belonged to the “light group” was

determined. However, the detector of that (ED-XRF) system was semiconductive Si(Li), and the

number of rare earth elements determined has been limited. The energy dispersion fluorescence

system (ED-XRF) with Si-PIN detector for direct analysis of individual rare earth elements was

thus employed for the study of La, Ce, Pr, Nd, Ca, Fe, Th, U determination in Yen Phu rare earth

ores with the aiming supplying the demands of rare earth ore beneficiation. The procedure was

established with the low error and high precision.

II. EXPERIMENTAL

1. Investigation of the current, voltage of X ray generator to obtain the characteristic X-ray

with highest intensity of elements La, Ce, Pr, Nd, Ca, Fe, Th, U in Yen Phu rare earth ore.


- Code: 23/CS/HĐNV






VINATOM-AR 13--40


306

Table 1: Dependence of characteristic X line intensity on X-ray tube current.

No Elements

Characteristic X-ray intensity at the voltage U = 30 kV

and different X-ray tube current

I=5 μA I=10 μA I=15 μA I=20 μA I=25 μA

1 Ca 4096 5054 5389 4903 4260

2 Fe 336524 461749 471320 434574 384631

3 La 5863 7733 7992 7245 6630

4 Ce 14343 18395 19217 17423 15003

7 Ag-IN 7300 11152 14597 17780 19480

8 Ag-CO 1446 2215 2966 3717 3917

(Dead time )% 16.88 30.56 41.98 51.69 59.29

The voltage of X ray generator by 30 kV and X-ray tube current by 10 μA was chosen when

analyzed of rare earths and other elements in Yen Phu rare earth ore and other intermediate products

from the flotation and hydrometallurgical process on the portable XRF Si-PIN detector.

2. Quantitatively analysis methods for the determination of rare earth and other elements in

Yen Phu rare earth ore and other intermediate products from the flotation and hydrometallurgical

process on the portable XRF Si-PIN detector.

Fundamental parameter method

Fundamental parameter method in QXAS software

Fundamental parameter is the most versatile method for quantification in the QXAS package

and suited even for completely unknown samples. Practically all modes of excitation with

electromagnetic radiation in the range of X-rays can be covered and many more parameters can be

selected to match the assumptions needed for the calculations with the experiment.

The sample self-absorption was corrected by the use of scatter peaks such as Compton and

Rayleigh. The specially characteristic when calculating using fundamental parameters method are

some factors such as absorption and enhancement correction are taken into consideration.

3. Analysis in the comparison with Standard Reference Materials and other methods.

Results received when analyses of the Yen Phu Rare earths ore by X-ray fluorescence Si-

PIN detector using fundamental parameter method compare with the one when analyses by ICP-

MS method.

Table 2: Analysis of Yen Phu Rare earth Ore by XRF and ICP-MS method.

No Element Unit

Results (%)

YA-

XRF

YA-

ICPMS

Relative

Error

(%)

YB-

XRF

YB-

ICPMS

Relative

Error

(%)

YC-

XRF

YC-

ICPMS

Relative

Error

(%)

1 Ca % 0.8 0.77 3.90 0.56 0.51 9.80 0.47 0.43 9.30

VINATOM-AR 13--40


307

2 Fe % 9.72 9.54 1.89 8.78 9.1 3,52 8.08 7.57 6.74

3 Y % 5.794 5.31 9.11 5.94 5.57 6.70 6.834 6.40 6.78

4 La % 1.212 1.13 7.26 1.24 1.13 9.65 1.342 1.23 9.11

5 Ce % 2.468 2.35 5.02 2.57 2.37 8.57 2.824 2.61 8.20

6 Pr % 0.467 0.47 0.64 0.46 0.47 2.34 0.499 0.51 2.16

7 Nd % 2.324 2.12 9.62 2.05 2.10 2.43 2.487 2.26 10.04

8 Sm % 0.577 0.54 6.85 0.61 0.54 12.96 0.616 0.58 6.21

9 Gd % 0.736 0.66 11.52 0.74 0.67 13.28 0.715 0.76 5.92

10 Dy % 0.867 0.84 3.21 0.84 0.87 2.99 1.043 1.01 3.27

11 Er % 0.58 0.54 7.41 0.61 0.55 10.91 0.725 0.66 9.85

12 Yb % 0.48 0.42 14.29 0.47 0.44 6.82 0.565 0.52 8.65

13 Th % 0.286 0.27 5.93 0.41 0.39 5.13 0.37 0.40 7.50

14 U % 0.044 0.04 10.00 0.05 0.04 6.82 0.048 0.044 9.09

From the table, it can be found that resulted analysis is reliable compare with reference

material standard. The Relative Error bethwen compared methods are less then 10%.

Table 3: Analysis of a rare earth samples (M1) by Si-PIN fluorescence

in comparison with results received from Japan laboratory (ICP-OES).

Elements Unit Results (%)

XRF Japan Relative Error (%)

Ca % 4.49 4.4 2.00

Mn % 1.10 1.18 7.27

Fe % 3.04 3.54 9.26

Y % 0.23 0.22 4.35

Ba % 6.18 6.55 5.99

La % 11.20 11.53 2.95

Ce % 14.94 15.8 5.76

Pr % 1.32 1.58 7.48

Nd % 4.50 4.59 2.00

Sm % 0.48 0.47 2.08

Th % 0.1066 0.114 6.94

U % 0.061 0.059 3.28

From the table 3, it can be found that the diffence between analytical result of M1 rare earth

sample, which was done by Si-PIN X-ray fluorescence and that obtained in Japan laboratory (ICP-

MS) are less then 10%.

VINATOM-AR 13--40


308

III. CONCLUSION

Project has solved the following issues

1. The technical parameter of Si-PIN spectrometry was investigated. The studies found

that when the voltage of X ray generator by 30kV and X-ray tube current by 10 μA was chosen

will give the characteristic X-ray with the highest intensity.

2. The selection of X-ray line fluorescence and the fitting of spectrum was performed

when analyzed of rare earths and other elements in Yen Phu rare earth ore and other intermediate

products from the flotation and hydrometallurgical process on the portable XRF Si-PIN detector.

3. Some quantitatively analysis methods used in X-ray fluorescence such as calibration

curve and fundamental parameter was studied. The detection limit of rare earth elements such as La,

Ce, Pr, Nd... was received.

REFERENCES

[1] Ron Jenkins, X-ray Fluorescence Spectrometry.John Wiley and Son, Ed 1988.

[2] IAEA-TECDOC-950, Sampling, storage and sample preparation procedures for X-ray

fluorescence analysis of environmental material. IAEA June 1997.

[3] IAEA-QXAS Quantitative X-ray Analysis System. Ver 1.2 (1995-1996).

[4] Rafal Sitko, Quantification in X-ray Fluorescence analysis theoretical background.

VINATOM-AR 13--41


309

STUDYING OF PREPARATION SILVER NANO-PARTICLES

USING SPINNING DISC REACTOR

Hoang Van Duc, Nguyen Thanh Chung, Tran Ngoc Ha,

Ho Minh Quang and Nguyen Thi Thuc Phuong

Center for Material Science Technology,



ABSTRACT: Preparation of silver nano-particles using spinning disc reactor has been investigated. The effects

of technological factors and experimental conditions such as: concentrations of AgNO3, glucose, PVP,

spinning speed, ect. on quality of nano-silver particles have been studied. With experimental conditions:

rotation speed of 2000 rpm, weight rate of mPVP:mAgNO3=1, AgNO3 concentration of 0.01 M, glucose

concentration of 0.02 M, silver particles of about 12 nm were obtained and the nano-silver solution were stable

for more than 40 days.

Keywords: Spinning disc reactor, silver nano-particles.

1. INTRODUCTION

Based on recently published documentary, nano-silver prevents many kinds of bacterial

from development, destruction of cell membrane of about 650 kinds of dangerous single-celled

bacterial, especially Staphylococcus aureus (Gram+) and Escherichia coli (Gram-). The impact of

nano-silver on baterium is not similar to that of anti-biotic medicine. While anti-biotic medicine

affects on baterium in a long time, nano-silver destroys baterium in a very short time [1].

Nowaday, nano-silver product has many potential applications in many daily fields such as

aquaculture, breeding, farming fields and daily demands.... However, applications of nano-silver are

still limited due to high cost of the product.

Recently, investigation of general nano-sized materials, specially nano-Ag has been paid

much attention in Vietnam. Some initial results has been obtained, especially in applications of

nano-product. However, reported investigations almost use costly resources and are based on

conventional methods, so the product price is high, that limited wide applications of nano-silver [2].

In this work, spinning disc reaction method has been used to prepare nano-silver, in which

reactions take place on the surface of spinning disc, not only causing significantly improved micro-

mixing effection, but also intensifying mass-transfering rate and shortening reaction time [3, 4].

2. EXPERIMENTAL

In this work, the technology applied for preparation nano-silver is precipitation method on

the surface of spinning disc reactor.


- Code: CS/13/03-02






Hoang Van Duc, Ngyen Thi Thuc Phuong. Preparation of nano-silver by reaction method on surface of

spinning disc reactor. (Submitted to Journal of Nuclear Science and Technology, VINATOM).

VINATOM-AR 13--41


310

A schematic diagram of the experimental set-up is shown in Fig.1 in which tank A contained

AgNO3 and protecting reagents (PVP, PVA, PEG...) solution, tank B contained alkali solution

(NaOH, NH4OH, Na2CO3...) and reducing agent (glucose, starch, HCHO, NaBH4....).

The reaction between Ag cations and glucose in NaOH solution is as follows:

2Ag+ + C6H12O6 + H2O 2Ag

0 + C6H11O7

- + 3H

+

At first, tank A contained AgNO3 and protecting agent solutions, tank B contained NaOH

and reducing agent solutions with certain rates. The solutions in tank A and tank B were pumped by

pump C at a specific flow ratio onto the center of the spinning disc with a rotation speed ranging

from 0 to 3000 rpm. The liquid was accelerated due to centrifugal force, causing it to spread over

the disc surface and forming a thin film where the reducing reaction took place. After that, the

slurry of reaction products was shooted out to wall of spinning disc F and then flowed into tank A

to mix with AgNO3 solution. After the solution in tank B was exhausted, solution in tank A was

continuously pumped for a certain time. The recycle operation was adopted to give a high yield

because the retention time on the spinning disc was too short.

Figure 1: Experimental scheme for preparation nano-silver

using spinning disc reactor.

A: Solution of AgNO3 and protecting agent; B: Solution of NaOH and reducing agent;

C: Pump; D: Flowmeter; E: Liquid distributor; F: Spinning disc.

3. RESULTS DISCUSSION

List of tables, graphs and images

Table 1: Optimal technological parameters for preparation of nano-silver.

Rotation speed (rpm) 2000

Liquid flow rate LA (mL/min) 800

Liquid flow rate LB (mL/min) 200

[glucose] (mol/l) 0.02

[NaOH] (mol/l) 0.05

Weight rate: PVP/AgNO3 1

[AgNO3] (mol/l) 0.01

VINATOM-AR 13--41


311

Table 2: Properties of nano-silver solution product.

N0. Property Nano-silver solution

1 Appearace Dark brown

2 Medium Distilled water

3 Mean particle size 12 nm

4 Distribution of particle size 9 – 15 nm

5 Protecting agent PVP K30

6 Concentration 500 ppm

Figure 2: UV-vis absorbtion spectrum of

nano-Ag colloid using protecting agent PVP.

0

10

20

30

40

50

60

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2

Tỷ lệ khối lượng PVP/AgNO3

Kíc

h t

hư

ớc h

ạt

(nm

)

Figure 3: Correlation of nano-Ag particle

size and rate PVP/AgNO3.

10

12

14

16

18

20

22

24

26

28

0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045

Nồng độ gluco (mol/l)

Kíc

h t

hư

ớc h

ạt

(nm

)


size and glucose concentration.

10

15

20

25

30

35

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035

Nồng độ AgNO3 (mol/l)

Kíc

h t

hư

ớc

hạ

t (n

m)


size and AgNO3 concentration.

.

10

12

14

16

18

20

500 1000 1500 2000 2500 3000

Tốc độ quay (v/p)

Kíc

h t

hư

ớc h

ạt

(nm

)

Figure 6: Effect of rotation speed on

nano-Ag particle size.

Figure 7: UV-vis absorbtion spectrum of

sample 16 after reaction and after 42 days.

VINATOM-AR 13--41


312

Figure 8: TEM image of nano-silver colloid

after reaction (M16).

Figure 9: TEM image of nano-silver colloid

after 42 days (M16).

In this work, we have investigated and synthesized sucessfully nano-silver solution with

mean particle size of 12nm, narrow particle size distribution using spinning disc reaction system.

Furthermore, factors such as: selecting protecting agent, effect of initial material concentration,

rotation speed.... on quality of nano-silver product have been studied. The optimal experimental

conditions for preparation of nano-silver particles were: AgNO3 concentration = 0.01M, glucose

concentration = 0.02M, rate of mPVP/mAgNO3 = 1, rotation speed = 2000rpm. Figure 2 is UV-vis

spectrum of nano-silver colloid protected by PVP. Figures 3, 4, 5 and 6 are diagrams of correlation

of technological factors and silver particle size. Figure 7 is UV-vis spectrum of sample 16 (sample

of silver was prepared with optimal experimental conditions) after reaction and after 42 days.

Figures 8 and 9 are TEM images of sample 16 after reaction and after 42 days.

4. CONCLUSION

1. Designed and manufactured sucessfully spinning disc reaction system and employed

this system for preparation of silver nano-particles.

2. Investigated technological factors that affect on particle size of nano-silver product.

3. Suggested optimal experimental conditions for preparation of nano-silver by spinning

disc reaction method.

4. Prepared 5 litres of 500 ppm nano-silver solution with mean size of 12 nm and narrow

size distribution. Stabilized time for nano-silver solution is more than 40 days.

5. Based on researching data, this work released technological process for preparation of

silver nano-particle at experimental scale.

6. The scientific paper “Preparation of nano-silver by reaction method on surface of

spinning disc reactor” has been approved for publishment on VINATOM magazine.

5. PROPOSAL

This work has investigated and released process for preparation of high-quality nano-silver

solution. However, due to limit of investigation time and research grant, the technological process

suggested by this project just reached experimental discontinued scale with small amount of

reactants for each batch run. In order to improve and apply satisfactory results of this project in

daily life, research group give some suggestions as follows:

VINATOM-AR 13--41


313

1. Vietnam Atomic Energy Institute (VINATOM) and Institute for Technology of Rare

Earth and Radioactive Elements (ITRRE) pay attention to allow this project to continue investigate

optimization of technological process and preparation reaction system.

2. Nano-silver particles have potentiality in applications for aquaculture, breeding and

cultivating fields... Therefore, we hope that this project will be scaled up to Ministry-level project in

order to investigate more deeply and comprehensively applications and properties of nano-silver

product.

REFERENCES

[1] Clifford Y. Tai, Yao-Hsuan Wang, Hwai-Shen Liu, “A green process for preparing silver

nanoparticles using spinning disk reactor” Published online December 28, 2007 in Wiley

InterScience Vol. 54, No. 2.

[2] Clifford Y. Tai,* Yao-Hsuan Wang, Chia-Te Tai, and Hwai-Shen Liu “Preparation of Silver

Nanoparticles Using a Spinning Disk Reactor in a Continuous Mode” Ind. Eng. Chem. Res.

2009, 48, 10104-10109.

[3] P. Silvert et al, Preparation of colloidal silver dispersions by the polyol process, J. Mater.

Chem, 1996, 6(4), 573-577.

[4] Hoàng Văn Đức, Nghiên cứu khả năng điều chế canxi cacbonat kích thước nanomet. Luận

văn thạc sỹ khoa học. Hà Nội 2009.

VINATOM-AR 13--42


314

RESEARCH ON TECHNOLOGY OF MAKING RARE EARTH ALLOY

HAVING RARE EARTH CONTENT ≥ 30% FROM ORE ( ≥ 40% REO)

USING ALUMINUM THERMAL TECHNOLOGY IN ARC FURNACE

Ngo Xuan Hung, Ngo Trong Hiep, Tran Duy Hai and Nguyen Huu Phuc

Material Technology Center,



ABSTRACT: Arc furnace was used to smelt materials consisting of rare earth ore having rare earth content of

≥ 40% REO, aluminum as the reducing agent and additives. Rare earth alloy was obtained with rare earth metal

content of more than 30%.

I. INTRODUCTION

Rare earth alloys (FeRE) have been used as an agent to modify physical and mechanical

characteristics of the steel. Rare-earth metals in the molten steel, will reduce the amounts of

phosphor, sulfur, nitrogen, oxygen that are harmful to the properties of steel and have adversely

affect to mechanical properties of steel.

The research team of institutional level scientific project coded CS/13/03-04 proposed one

scientific task that was technology for making rare earth alloy having rare earth content ≥ 30% by

reducing rare earth ore through aluminum thermal technology in arc furnace.

Investigated technological parameters in the arc furnace include: reaction temperature,

reaction time and the actual mass ratio of reducing aluminum to theoretical calculation. From

obtained results, the research team proposes the optimal technical parameters as follows:

- The mass ratio Al(p)/Al(t) =140%.

- Temperature of the reduction: 16000C.

- Time of the reduction: 80 minute.

- The obtained products are FeRE alloys having chemical composition as following: 30-

32% RE, 40%Si, 1-2%Al and remain Fe.

II. EXPERIMENTAL

2.1. Raw materials

Chemicals: REO 40.0%, Al 99.5%, Si 99.0%, CaF2, CaCO3 with exact chemical

compositions. Some of them given in the following pictures.


- Code: CS/13/03-04






VINATOM-AR 13--42


315

Figure 1: Rare earth ore

(40%REO).

Figure 2: Metalic Silicon. Figure 3: Al granules, powder.

2.2. Equipments and product quality assessment method

1. Arc smelting furnace with conditions (15kVA).

2. Spectrum analyzer ICP-MS.

3. Molecular structure analyzer by X-ray diffraction Bruker-D5005.

4. Images of equipments.

Figure 4: The arc smelting furnace (15kVA).


3.1. Study the influence of the mass aluminum ratio on rare earth ore recovery and

product quality

Base on reaction equation: RE2O3 + 2Al + 4Si = 2RESi2 + Al2O3, we will receive 392g

RESi2 + 102g Al2O3 from 328g RE2O3 + 54g Al + 112g Si.

With experimental conditions as follows: 328g rare earth ore (contains ≥40% REO), the

reaction temperature t = 1.600oC and time for reaction = 80 minutes, the obtained results are

showed in table 1.

Table 1: Influence of mass aluminum ratio to the rare earth ore on product quality.

N0

Ratio Al, % Experiment result

RE, % Productivity (RE), %

1 110 4.12 64.0

VINATOM-AR 13--42


316

2 120 31.6 79.5

3 130 32.28 83.3

4 140 32.0 86.5

5 150 26.5 76.9

The optimal reducing Al ratio is chosen: 140%.

3.2. Study the effect of reducing temperature on product recovery efficiency

- Reducing temperature varies from 15000C to 1700

oC.

- Raw material is rare earth ore (containing ≥40% REO) = 328g;

MAl (140%) = 63.18 g; Reaction time: = 80 minutes.

Experiment results are presented in table 2.

Table 2: Effect of reducing temperature on the product recovery.

N0 Temperature,

0C

Experiment results


1 1500 4.12 64.0

2 1550 31.6 79.5

3 1600 32.2 86.5

4 1650 30.0 82.0

5 1700 24.2 77.6

Graphical presentation of the results is showed in Fig. 5:

Figure 5: Influence of reducing temperature on product recovery.

- The maximal recovery of % = 86.5% is achieved at reducing temperature of 1600oC.

- The reducing temperature t = 1600oC is chosen.

Pro

du

cti

vit

y,

%

0 1500 1550 1600 1650 1700 1750

40

50

60

70

80

90

100

Temperature

VINATOM-AR 13--42


317

3.3. Study effects of reducing time on product recovery

Reducing time varies from 60 minutes to 100 minutes.

Experiment results are presented in the table 3.

Table 3: Effects reducing time on product recovery.

N0

, minutes Experiment results


1 60 18.7 66.0

2 70 28.6 76.4

3 80 32.0 86.0

4 90 32.1 86.2

5 100 28.0 76.0

- Maximal product recovery of % = 86.5% is achieved at reducing time of 80 minutes.

- Reducing time of 80 minutes is chosen.

3.4.Product quality assessment

The composition of rare earth alloys obtained from thermal reducing reaction are presented

in the following table.

N0 Sample

Experiment results

RE, % Al, % Si, % Fe, %

1 FeRE.01 4.12 - 67.8 Remain

2 FeRE.02 31.6 - - Remain


4 FeRE.04 32.0 2.0 35.2 Remain

5 FeRE.05 24.2 3.2 - Remain




VINATOM-AR 13--42


318

3.5. Manufacturing process of rare earth alloys

Based on the above experiment results, the research team proposes a manufacturing process

of rare earth alloy (containing RE≥30%):

Figure 6: Diagram of making rare earth alloys containing ≥ 30% RE.

* Preparation for manufacturing rare earth alloys containing ≥ 30% RE as follows:

- CaF2 and CaCO3 are selected as additives because they are good for adjusting the

fluidity of the slag.

- The reducing process is carried out at temperature of 16000C.

- Reaction time is 80.

- Experiments are conducted in arc furnace 15KVA with volume of 600g for each

experiment.

IV. CONCLUSION

The institutional level project coded CS/13/03-04 has been implemented in more than one

year. Some important preliminary results have been achieved as follows:

- Research team proposed one optimal process for manufacturing rare earth alloy having

content of RE ≥ 30%.

Rare earth ore silicon Alumium

Arc melting method

Molten

Themal reaction

Filling the mold, cooled

Casting, pull out product

Rare alloy (30%RE)

product

Waste slag Recovering

product

Additives

VINATOM-AR 13--42


319

- The process is conducted in arc furnace 15 kVA with reaction time of 80 minutes. Raw

materials consist of rare earth ore having content of ≥ 40% REO, aluminum, silicon and additives

that are mixed together and smelted in arc furnace. Melted product is filled into mold and allowed

to cool. Rare earth alloy having content of RE ≥ 30% is recovered after removing slag.

REFERENCES

[1] Bui Van Muu, Nguyen Van Hien, Nguyen Ke Binh, Truong Ngoc Than. Theory of

metallurgical processes. Fire training. Hanoi, 1997.

[2] X-Kh Nguyen Khac Xuong. "Material metal."

[3] Phung Viet Ngu, Pham Kim Dinh, Nguyen Kim Thiet. Theory of metallurgical processes.

Fire practiced 2. Hanoi, 1997

[4] USGS Mineral Commodities Summaries 2011.

[5] Z.L.K. Yasuda et al J alloys and Comp. Vol 193, pp. 26-28, 1993.

VINATOM-AR 13--43


320

A TEST STUDY ON THE RECOVERY OF ZINC OXIDE FROM BAC-KAN

LOW GRADE ZINC ORE

Tran Ngoc Vuong, Pham Minh Tuan, Luong Manh Hung and Bui Huy Cuong

Center for Technology Development,



ABSTRACT: A leaching process of the zinc ore has been carried out by a mixtures of ammonia and

ammonium carbonate under different conditions, then zinc was recovered from the leach liquors in the form of

zinc oxide. Experimental conditions were as the following: A leaching solution containing 80g/l of NH3 and

60g/l of CO2, solid-liquid ratio being 1:1 (200gs of ore and 200ml of solution), crushed zinc ore of particle size

below 0.1 mm, 2 hours of digestion under agitation with a stirring speed of 60-80 rpm/min at room temperature

or at 50°C. The recovery efficiency of zinc could thus be reached 80 to 85%. Purity of obtained product was up

to 99% of ZnO, while Pb content was lower than 0.2% .

I. INTRODUCTION

Zinc ore hydrometallurgy using diluted sulfuric acid is a primary method for zinc recovery

but in this process, many impurities such as Fe, Cu, As, etc. [1, 5] will be dissolved into the leach

solution along with zinc. Zinc ores, especialy Bac Kan low-grade zinc ore contains a large amounts

of impurities (Fe, Pb, Si, etc.) Accordingly, this method is a chemicals consuming and moreover,

the impurities removal from the leach liquors is generally costly and complicated.

Hydrometallurgy method using ammonia and additive reagents such as ammonium

carbonate, sulfate, chloride is based on zinc amphoteric property. In contacting with solutions

containing amonia/amonium salts, zinc oxide or zinc salts will be selectively extracted into solution,

while most of undesirable impurities such as Fe, Pb, etc. generaly retained as precipitate, which can

be removed as insoluble residue. From the obtained leach solution, zinc can be recovered in the

form of 2.ZnCO3 , 3.Zn(OH)2 or ZnCO3.3Zn(OH)2, which is easy to transform to zinc oxide or other

zinc compounds and the recovery of ammonia for its recycling also facilitate [3, 4, 6].

Zinc leaching process and recovery using amonia/amonium salts method can be discribed by

the following reaction equation:

Dissolution step:

ZnO + (NH4)2CO3 + 2NH4OH = Zn(NH3)4CO3 + 3H2O

Solution purification:

Me2+

+ Zn = Me + Zn2+

Hydrolysis and precipitation:

5Zn(NH3)4CO3 + 4H2O = 2ZnCO3.3Zn(OH)2.H2O ↓ + 3CO2 + 20NH3↑


- Code: CS/13/03-01






VINATOM-AR 13--43


321

4Zn(NH3)4CO3 + 4H2O = ZnCO3.3Zn(OH)2.H2O ↓ + 3CO2 + 16NH3↑

Calcination (at 650-700°C)

ZnCO3.3Zn(OH)2.H2O → 4ZnO + CO2 + 7H2O

According to this method, ammonia generaly is used in combination with other reagents

such as ammonium carbonate, or sulphate or chloride. However ammonium carbonate is more

favourable due to creating intermediate compounds such as salts of zinc basic carbonate, which is

easily converted into zinc oxide with a specific surface area of 15-110 m2/g. This value very much

depends on the conditions of calcination (in the atmospheric environment or in a vacuum,

temperature and duration of calcination, etc.)[1, 2, 6].

II. EXPERIMENTAL

Zn content and impurities in the ore samples was determined by chemical method and

Inductively Coupled Plasma Mass Spectrometry (ICP-MS), respectively.

Minerals in the ore sample are determined by XRD at the Testing Center, Institute of

Building Materials.

Zn, Pb in the leach solutions and in ZnO products are determined by titration.

First experimental survey was conducted in the reaction conditions as follows:

Leaching temperature: at room.

Stirring speed: 60-80 r/min.

Concentration of reagents: NH3 80g/l, CO2 60g/l

Time of reaction: 120min.

Weight of ore: 200g.

Volume of reating agents solution: 200ml.

The experiment was then conducted in different reaction conditions by changing the ratio of

raw materials and reagents, reagent concentration, temperature and time of reaction, agitation

condition, etc. to point out the most suitable conditions in terms of maximium for zinc recovery

efficiency.

Zinc in the solution was precipitated in the form of ZnCO3.2Zn(OH)2 by removing NH3

from leach solution at temperature of 70-90°C with air flow contacting. Time of heating and air

contact was 180 minutes. Basic zinc carbonate precipitate was filtered, washed with distilled water

and then dried at a temperature of 100°C. Basic zinc carbonate precipitate ZnCO3.2Zn(OH)2 was

sintered at temperatures of 650-700°C for 120 minutes. The resulting product was analyzed by

chemical analysis and by inductively coupled plasma mass spectrometry (ICP-MS), particle sizes of

ZnO was determined by Lazer Scattering method using Particle Size Analyzer LA-950.


Bac-Kan zinc ore contained about 7.0% of Zn and main impurities as Fe (41.8%), Pb

(5.77%).

X-ray diffraction diagram (Fig. 1) showed that zinc in ore existes in the form of mineral

Zn(ClO3)2.6H2O, Na4Zn2Si3O10/2Na2O.2ZnO.3SiO2. It was also found zinc in the form of

hydroxide Zn(OH)2, ZnCO3. Iron existed mostly in the form of magnetite Fe3O4. Other remaining

substances were mainly in the amorphous phase.

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Figure 1: X-ray diffraction diagram of Bac-Kan Zinc Ore.

The experimental results proved that the selection of ammonia and ammonium carbonate as

reaction agents for zinc recovery fitted perfectly to Bac-Kan zinc ore because of a large amount of

the impurities such as Fe, Pb were retained insoluble. A schematic diagram for zinc oxide recovery

technology from zinc ores by hydro-metallurgical method using ammonia and ammonium

carbonate was shown below.

From the study, it was concluded that the most suitable experimental conditions for Zinc

recovery efficiency up to 85% was as the following.

Leaching temperature: 50°C.

Stirring speed: 60-80 r/min

Concentration of reagents: NH3 80 g/l , CO2 60g/l

Time of reaction: 120min.

Weight of ore: 200g.

Volume of reating agents solution: 200ml.

Crushed ore size: < 0.1mm.

From obtained leach solution, zinc was recovered in the form of basic zinc carbonate

precipitate by hydrolysis reactions. Basic zinc carbonate salts obtained then undergo filtration,

washing and drying. Dried basic zinc carbonate is calcinated in a furnace at 650-700oC for 120

minutes to obtaine ZnO products.

The composition of resulting product was shown in table 1, ZnO purity was up to 99%, and

impurities such as Pb, Fe were very low (<0.1%).

X-ray diffraction diagram confirmed that the formation of ZnO is mainly in obtained

product.

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Table 1:. Chemical composition of zinc oxide product.

No. Species Unit Content

1 ZnO % 99.20

2 Mg % 0.004

3 K % 0.002

4 Ca % 0.006

5 Fe % 0.005

6 Cu % 0.006

7 As % 0.015

8 Cd % 0.002

9 Sn % 0.001

10 Sb % 0.160

11 Ba % 0.002

12 Pb % 0.160

13 Li ppm 0.15

14 Na ppm < 0.001

15 Al ppm 0.53

16 Si ppm 1.14

17 Mn ppm 1.17

The results of particle size determination shows that median size of ZnO particles is 6.9µm

(Figure 2).

Figure 2: Particle size distribution of Zinc Oxide Product.

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SEM images of the obtainned zinc

oxide confirmed this product is very fine with

nanoparticles. It is can be seen by using SEM

image that the median size of particles

increased due to agglomeration of zinc oxide

particles.

Figure 3: SEM image of Zinc Oxide Product.

After the experimental study, we propose a technological process shown below

Figure 4: Technology Schematic Diagram for zinc oxide recovery using reagent

mixture of amonia and amonium carbonate.

Zinc oxide Ore Zn<8%

Leaching (120 min.)

Filtration

Hydrolysis (t0 70-

80oC); 180 min.

Insoluble

residue

Filtration

Basic Zinc Cacbonate

Calcination 650-700oC (120 min.)

ZnO 99%

Solution of NH3 80g/l and

CO2 60g/l

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IV. CONCLUSIONS

Although Bac-Kan zinc oxide ore contained low grade of zinc and very high levels of

impurities, a method using a mixture of amonia and ammonium carbonate shows a great promise in

the recovery of zinc from this ore. Zinc recovery efficiency was up-to 85%. From the leach

solution, a high quality product of ZnO 99% could be obtained.

REFERENCES

[1] Daniel A. D. Boateng, “Method for the solvent extraction of Zinc”, US patent 5135652,

2/1992.

[2] Raymond Lee Nip, “Method for preparing of zinc carbonate”, US patent 6555 075, 4/2003.

[3] W.Herbert Burrows, “Zinc oxide recovery process”, US patent 3849121, 12/1974.

[4] Frank H. Murphy, Matt W. Oleksy, “Recovery of Zinc and ammonium chloride”, US patent

4865831, 09/1989.

[5] Yeonuk Choi, Serge Payant, Joo Kim, “Product of zinc oxide from acid soluble ore using

precipitation method”, US patent 6726889 B2, 04/2004.

[6] Nicholas J. Welham, Garry M. Johnston, Matthew L. Sutclife, “Method for ammoniacal

leaching”, US patent 8388729 B2, 03/2013.

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RESEARCH TO BUILD THE ADVANCED TRAINING PROGRAMS

FOR NUCLEAR POWER PLAN

Nguyen Manh Hung

Nuclear Training Center, Vietnam Atomic Energy Institute

Le Van Hong and Cao Dinh Thanh


Nguyen Ba Tien

Institute for Technology of Radioactive and Elements, Vietnam Atomic Energy Institute

ABSTRACT: The documents use for training of field Nuclear Power at Nuclear Training Center (NTC) is

necessary .On the based analysis, research the current situation and material authors has been to building

specialized Training Programs for Nuclear Training Center (NTC) and to compilation documents use for

training includes is 05 topics: 1. Assessment nuclear power plant technology in the world, 2. Safety analysis of

nuclear reactors, 3.Nuclear fuel cycle, 4. Management technology uses radioactive waste in nuclear power

plants and 5.Nuclear Power Plan.

1. INTRODUCTION

On August 20th

, 2010 the Prime Minister Nguyen Tan ZDung has signed a decree related to

the developing of the education and training programme in the frame of the NPP project in

Vietnam. Several universities in Vietnam are encouraged to participate to such a programme. To

2020, the expected number of experts working in different nuclear field would be around 3000

persons. So that, the Documents about Nuclear Power Plan use for training in NTC is necessary.

The development of a highly skilled human resource is an essential element in the

infrastructure required by a country planning to introduce nuclear power (figure: HRS Development

for NPP Project). As IAEA points out /68/, the principle involved is to identify the human resource

knowledge, skills and abilities needed to implement the nuclear project and to develop the

educational and training institutions to prepare the human resources necessary for the discharge of

their function. This paper describes some of the skills needed, gives some quantitative estimates of

the numbers of experts needed, identifies some possible education and training resources and

concludes with some suggestions for getting started on this important infrastructure element in

Vietnam with regard to the decree just signed by the Prime Minister Nguyen Tan Dung mentioned








1. Strategy and Challenges of Nuclear HRD for Introduction of the 1st Nuclear Power Plant in VIETNAM

Nguyen Manh HUNG NTC-VINATOM-Meeting Coordinator FNCA Tokyo 2013.

2. Challenges in developing HR for Nuclear Education Programmes in Vietnam.

Nguyen Manh HUNG NTC-VINATOM-Meeting Coordinator FNCA 2012.

3. Nuclear Human Resource development in Vietnam Atomic Energy Institute Nguyen Manh Hung NTC-

VINATOM-International Conference on Nuclear Human Resource 29-31 October 2013,Hanoi,Vietnam.

VINATOM-AR 13--44


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above. The problem preparation Human resource for MOST (VINATOM, VARANS and VAEA) is

importance also; because MOST is organization have function: Radiation protection, nuclear safety,

State management of nuclear Energy, Program R/D in nuclear Energy and Consulting for NPP plan.

Figure: HRS Development for NPP Project.


The project “Research to build the advanced training programs for nuclear power plan”

during from 2012 to 2013 with purpose to compile 05 textbooks (1000 pages) and 05 E- learning

lesion (800 slices) is:

1. Assessment nuclear power plant technology in the world;

2. Safety analysis of nuclear reactors;

3. Nuclear fuel cycle;

4. Management technology uses radioactive waste in nuclear power plants;

5. Nuclear Power Plan.

And organize training course “To improve knowledge on Nuclear power Plan for managers

of state agencies”. The report is including 02 parts:

A. To compile Curriculum about Nuclear Power;

B. Organize Training course.

On the part A, the author has to compile Curriculum about:

- The knowledge of nuclear reactors, fabrication technology, the basis of the hydrothermal

reactor and system safety analysis is presented in 02 textbooks and 02 E- learning lesion is

Assessment nuclear power plant technology in the world and Safety analysis of nuclear reactors is

include some problems as:

1. Overview of nuclear reactor technology and nuclear power plants;

2. The basic principles of neutron physics and nuclear fission;

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3. Hydrothermal basis of nuclear reactor;

4. Pressurized water reactor technology-PWR;

5. Boiling water reactor technology-BWR;

6. Heavy water reactor technology pressure-PHWR;

7. Safety design and related issues;

8. Generation nuclear reactors and advanced design;

9. Practical part: Analysis, assessment, technology selection NPP.

and

1. Identify potential risk of radiation in NPP;

2. Design perspective NPP safety;

3. The system safety engineering;

4. Safety Analysis;

5. Analysis of a large number of incidents have occurred;

6. Some orientations enhance safety NPP;

7. The preventive measures and troubleshooting;

8. Introduction of safety analysis calculations RELAP.

- The knowledge of the Nuclear fuel cycle and radioactive waste treatment in nuclear

power plants (NPP) is presented in 02 textbooks and 02 E-learning lesion is Nuclear Fuel Cycle and

Management, technology use radioactive waste in nuclear power plants, so that the contents of the

textbooks should be supply for participants the knowledge about Nuclear fuel cycle and how to

management and technology use radioactive waste in NPP Plan.

1. Fuel for nuclear reactors.

2. System Reactors and corresponding fuel types.

3. Nuclear fuel cycle of the reactor.

4. Technology production Nuclear fuel.

5. Marketing of Nuclear fuel.

and

1. Introduction of radioactive waste.

2. Radioactive Waste.

3. Decontamination of radioactive materials.

4. Assessment safety in the management of radioactive waste.

5. The exercises.

- In addition, the energy problems in the world such as energy demand, energy resources,

environmental issues, as well as issues related to nuclear power development and international

cooperation was the introductory textbook Nuclear Power Plant and E- learning lesion. Its cover

some problems as:

1. Sources of Energy;

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2. Electrical energy today and future;

3. Nuclear Power;

4. Nuclear fuel cycle;

5. Nuclear Waste;

6. Other uses of atomic energy Environmental issues, health and safety;

7. No nuclear proliferation;

8. History Nuclear Energy.

On the part B, Nuclear Training Centre organized a training course to improve knowledge

on nuclear power for managers of state agencies from 6-8 Nov 2013. More than 30 participants

come from the Department of International Cooperation belong the Ministry of Science and

Technology, the Safety Board, the cultural community of the Group electricity of Vietnam;

Department of fire police , College of electricity HCM city, Joint Stock Construction Company,

Consultancy Electrical 1, 2 and 3; and College of Central Power have attend the training course.

3. CONCLUSION

Finally, the authors proposed commendations and measures to promote the Human Resource

Development as:

Continuing the compilation of textbooks on nuclear power technology, radiation safety,

nuclear safety, and system control equipment in nuclear power plants as well as exercises for the

reactor, radiation measurements recorded for documents teaching resources.

Acknowledgements

The authors would like to express their thanks to the Ministry of Science and Technology

and Vietnam Atomic Energy Institute for their great encouragement and financial support for this

work. We also want to express our gratitude to colleagues, which are participation and contribution

on this work.

REFERENCES

[1] “Nuclear Energy in the 21st Century” Ian Hore Lacy-World Nuclear.

[2] TrÞnh Xuân BÒn, Nguyễn Quang Hưng-Cơ sở chọn vùng và đề xuất kế hoạch thăm dò uran

phục vụ chương trình phát triển điện nguyên tử ở nước ta. Hội thảo nguyên nhiên vật liệu hạt

nhân-Hà nội 1999.

[3] Thái Bá Cầu và cs, Báo cáo khoa học đề tài KHCN.09.04/04, Luận cứ và khả năng nội địa

hoá từng phần công nghệ sản xuất nhiên liệu hạt nhân.Hà Nội-1998.

[4] IAEA Technical Document: Minimum Infrastructure for a Nuclear Power Project, Final

draft, 12 January 2006.

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COLLECT, ANALYZE AND DATA BASE FOR BUILDING UP

THE INVESTMENT REPORTS OF CENTER FOR NUCLEAR SCIENCE

AND TECHNOLOGY CONSTRUCTION PROJECT

Pham Quang Minh, Tran Chi Thanh, Cao Dinh Thanh, Mai Dinh Trung,

Hoang Sy Than, Nguyen Nhi Dien, Trinh Van Giap, Le Ba Thuan and Vu Tien Ha


ABSTRACT: Following the Contract No.19/HĐ/NVCB dated July 10, 2013 signed by the President of

Vietnam Atomic Energy Institute (VINATOM), an additional ministerial Project was approval by the Decision

No. 526/QĐ-VNLNT dated July 8, 2013 by the VINATOM’ President in order to implement an important task

for VINATOM. This project was implemented by the Institute for Nuclear Science and Technology (INST) in

Hanoi as management organization and VINATOM as the owner of project’s results. Main objectives of this

Project are to support national budget for implementing to collected the general report from previous projects

which are relevant to CNEST and new research reactor, IAEA guidance documents, documents provided by

ROSATOM in seminars in 2010, 2012 and 2013, report from expert visits of Ministry of Science and

Technology and completed the general report about the construction project of CNEST.

I. INTRODUCTION

The intention for building up the Center of Nuclear Science and Technology (CNEST) was

formed right after the Government Prime Minister of Vietnam had an agreement with Russia

Federation about the construction of the first Nuclear Power Plant of Vietnam (Ninh Thuan 1 NPP)

during the official visit to Russia Federation in 12/2009. The purpose of CNEST is to support the

nuclear power project and nuclear power program of Vietnam. The funding for CNEST will be

provided by Russia Federation to Vietnam through priority credit.

To have the official information for CNEST and to prepare the funds for the project,

Vietnam Atomic Energy Institute (VINATOM) has established the Ministry level project about:

“Collect, Analyze and data base for building up the investment reports of Center for Nuclear

Science and Technology construction project”, and submit to Ministry of Science and

Technology for approvement, and further submit to the Government. This report will be the basis

for Ministry of Finance of Vietnam to start the negotiation with Ministry of Finance of Russia

Federation.

II. CONTENTS

II.1. Data resources for reviewing and analyzing

The investment for CNEST has the purpose of acclerate the research in application of

atomic energy, enhance the abilities of high level human resources in Nuclear science and





- Implementation time: 6 months (Jun 2013-Dec 2013)



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technology and support the nuclear power program as well as application of atomic energy for the

development of the socio-economic.

To prepare for the CNEST project, VINATOM has established some following projects:

- 2010 Ministry level project: “Survey, collect and research the initial data for site

selection of Center for Nuclear Science and Technology”.

- 2011 Ministry level project: “Research and determine design requirement of Center for

Nuclear Science and Technology”.

- 2012 Ministry level: “Research and buildup the criteria set for site selection of new

research reactor and create the initial report for site selection of Center for Nuclear Science and

Technology”.

- B-Branch sub-project: “Building up the argument for new research reactor project of

Vietnam” under the independent National level project: “Builind up the R&D capacity for

supporting the Nuclear power program” Code name: DTDL 2002/17, 2002-2004 period.

- Ministry level project: “Research the plan of building up new research reactor and

perform some calculation about neutron physics and thermal hydraulic to classify research reactor”

Code: BO/06/01-04, 2006-2007 period.

- 2007 Organization level project “Determine the technical mission for new research

reactor and necessary infrastructure investment for this mission as well as human resources

requirement for managing, operating and ultilizing new researc reactor”.

Besides these project reports, a lot of documents from IEAE guidance, technical documents

provided from ROSATOM at the seminars about CNEST in 2010, 2012 and 2013;

recommendations and opinions of scientist during the seminars, results of the discussion between

ROSATOM and experts group of Ministry of Science and Technology during the visit to research

facilities of Russia Federation in 04/2013 are also the documents sources for project establisher to

perform the contents of these project and building up General reports for CNEST.

II.2. Analyzing and reviewing methodology

Inquiring the results of all listed project, guidance documents from IAEA, technical

documents about research reactor, auxiliary system for Nuclear safety research complex, and

Material science complex that ROSATOM provide through all the seminars about CNEST in 2010,

2012 and 2013.

Research, exchange and unify about technical information requirements of the research

reactor, auxiliary system and devices for Nuclear safety research complex, structure of Material

Science complex’s laboratory between ROSATOM’s organizations and send experts group of

Ministry of Science and Technology to visit the research facilities of Russia in 04/2013.

Ultilize the results, design requirement (TOR) for CNEST.

About site selection for the new research reactor: progress the build process of the site

selection review criterial; perform reviewing, analyzing and comparing activites candidate sites by

grading system follow the criteria with the support of Expert Choice software as well as progress

the basic survey for candidate sites.

Establish conference, seminar to gather opinions from senior experts about technical

requirements of research reactor, auxiliary system and devices for Nuclear safety research complex,

structure of Material Science complex.

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III. GENERAL REPORT OF CONSTRUCTION PROJECT OF CNEST

This general report include the following main contents: The need for investment of

CNEST; The progress of of CNEST project; Structure and main sub-division of CNEST;

Construction sites for new research reactor and other research facilities under CNEST; Funding and

funding phases of CNEST; Project establishment plan; and Some recommendation, conclusion.

III.1. The need for investment of CNEST

With the 35 years history of development, VINATOM has played an important role in

forming and developing the atomic energy field in Vietnam, contribute to bring the application of

Nuclear techniques, radiation technology to socio-economic of the country. After the southern

Vietnam was brought back to freedom, the staffs of VINATOM have immediately started to recover

the Dalat Research reactor, and the construction and operation of this research reactor has

contribute largely to acclerate the development of science and technology, application of nuclear

techniques, radiation technology as well as developing the human resources for the atomic energy

field of Vietnam. In this period, when Vietnam is establishing the Nuclear power development

program, acclerating the R&D, technical consultant in nuclear power filed had became a new and

very essential mission of VINATOM.

On 5st March 2012, according to decision No 265/ QD-TTg, the govermental Prime Minister

has approved the project “Enhancing the R&D and technical support capabilities for supporting the

application of atomic energy and ensuring the safety, security” in order to build up and develop

Vietnam Atomic Energy Institute (VINATOM) to an advance level in the region, take role as an

organization for R&D of science and technology; as well as a national technical support

organization, independent in quality assurance and quality control, ensure safety, security and

environment protection for nuclear power development.

With the aim of developing science, technical capabilities and human resources; and in the

framework of collaboration between The social republic of Vietnam and Russia Federation about

nuclear power; establishing Center for Nuclear Science and Technology (CNEST) is well suited

with the collaboration between two countries. In short term, CNEST will support the Ninh Thuan 1

Nuclear power plant process, and for long term CNEST will support the technology receive and

adaptation, moving forward to master the design, technical, operation techniques, maintenance of

the nuclear power plant, make sure that the nuclear power plant will be operated safely and have

good efficient. Beside that, CNEST will create a good condition to establish the modern research,

enhance the application of atomic energy in other socio-economic field and step by step increase the

science and technology capabilities of the country.

III.2. Site selection for new research reactor

The site selection process of the new research reactor will be established by 3 following

phases:

Phase 1: Creation of review criteria to compare sites candidate, from that, determine the

potential region and sites that may be selected and construction location.

Phase 2: Base on the review criteria and basis data collected, perform the the review and

comparison between the potential region and sites to chose 1 or 2 most suited sites that can sastify

all the technical and socio-economic requirements, as well as many advantage as possible to submitt

to te Governmental Prime Minister for approvement.

Phase 3: Perform the detail survey about the location which has been approved by

Governmental Prime Minister to establish investment preparation profile and submitt according to

legal framework.

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Base on the ranking comparison criteria for potential site for new research reactor which has

been approved by Minstry of Science and Technology, Power Consulting Engineering Company I

had cooperate with VINATOM to anlazye, review and ranking 5 potential sites to chose the most

appropriate location that meet the criteria.

And the most potential location is Sub-section 151A (Lam Vien forest management board,

belong to ward 12, Dalat city, Lam Dong Province), on the ground of Center for High level Nuclear

techniques application project.

III.3. Structure of CNEST

According to international experiences, to acclerate and support Nuclear power development

program, VINATOM has determined 15 necessary speciality orientations. VINATOM has

collaborated with ROSATOM scientist to discuss, research the possibility, efficiency of the project

and delivered structurize methodology of CNEST to be 2 part of following components:

a) Construct a new and modern nuclear research facility, gather in one location, include

research reactor with capacity of about 10-20MWt, research laboratories and devices related to

research and application from ultilizing the research reactor.

This nuclear research facility is the main component of CNEST, and its location is expected

to be placed in Dalat city, with the following mission and function: Research and application in

fields of neutron technology, material science, radioisotopes, application of radiation techniques in

healthcare, agriculture and support the nuclear power related field like reactor physics, radioactive

waste management, Instrumentation and Control, environment protection, technical services.

b) Investment for equipages into one of the existing research facility under VINATOM in

Hanoi city, in which are performing research about speciality orientations that is not related to the

new research reactor.

Mission and function of these facilities is to support nuclear power program, including :

Nuclear power safety and technology (mechanical and thermal hydraulic), Material science,

Chemical technology, Nuclear and radiation technology, Radiation protection and environment

monitoring, radioactive waste management, human resources development (simulation devices),

nuclear services (Non-destructive evaluation,..) Center for simulation and calculation, as well as

basic science like Nuclear physics.

After CNEST would be constructed and operated, all the research complex of Northern

Vietnam will be the place for establishing research, human resources development, directly support

for nuclear power. The collaboration between Universities, Research institution (including Vietnam

Academic of Science and Technology) in the Northern Vietnam is necessary to acclerate R&D

activities, creating many research group with high level abilities with fully support to nuclear power

project, and this shall be the basis for education of new generation of experts, human resources for

Nuclear power program.

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Figure 1: Roles and positions of CNEST in Nuclear Power Program of Vietnam.

III.4. Location of the components of CNEST

1) Location of Dalat Nuclear Research Center (DNRC)

The selected construction site of DNRC including new Research reactor and relevant

devices and systems will be at Ward 12, Dalat city, lie inside the 107 Ha project which has been

approved and licensed the document for ultilization of real estate by local goverment of Lam Dong

Province for building the new nuclear research faclity of VINATOM.

This location has sastified almost every criteria to build the CNEST with the new research

reactor with capacity of about 10-20 MWt.

2) Construction location of the Nuclear power safety research Complex (Hanoi city)

The process of selecting the site for the Nuclear power safety research has been established

based on the human resources, research experience and existed space in Institute for Nuclear

Science and Technology. Beside that, the integrity of infrastructure with the project of Center for

environment radiation monitoring of the country will decrease the initial investment and preparation

time related to construction procedure.

3) Construction location of Material science complex (Hanoi city)

The Material sience complex in Hanoi city can be placed at the research facility of Institute

of Radioactive and Rare Earth Elements at 140 Nguyen Tuan street, Thanh Xuan distr, Hanoi. This

location is also the place where Center of Non-destructive Evaluation lie.

4) Construction option for research facility in Hoa Lac high-tech zone

The difficulties of selecting location for 2 center components in Hanoi are very troublesome,

because of the features of individual components. Establishing the project with 2 components in 2

different research units is very challenging.

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Because of that, VINATOM has submitted the option for construct all the components in the

Northern of Vietnam into only one location, appropriate for short term mission and long term

development, we can gather research staff not only from VINATOM but also other research

institution and universities in Northern Vietnam. The most optimum location is inside Hoa Lac

high-tech zone. This zone has a 50000 m2 area.

III.5. Funding and Funding phases of CNEST

1) Total credit funding from Russia Federation

The investment for the construction is from the credit funding of Russia Federation

according to Bilateral government agreement which was signed on 21/11/2012.

Table 1: General description of total investment according to job contents.

Category Borrowed funds (Thousands of USD)

Hanoi Dalat Project

Management

General expense

Construction 91 940

Installation 1 190 29 333

Devices 32 554 165 333

Others 4 286 75 964 49 954 60 965

Back up 4 458 36 718

Total 42 489 399 288 110 919

Total funds 552 696

2) Parallel funding from Vietnam

Investment for facility construction of 2 research components at Hanoi, as well as funding

for all relevant work to the infrastructure are all responsibility of Vietnam.

Table 2: Parallel funding from Vietnam to Northern infrastructure.

No. Categories Expected fund

1 Investment for construction of the facility and

installation research devices and control room for

Nuclear power safety research Complex

41 Billion VND

2 Investment for auxilary construction and technical

infrastructure for Nuclear power safety research

Complex

51 Billion VND

3 Investment for new construction and completion of

the building and infrastructure of the Material

science Complex

90 Billion VND

Total 182 Billion VND

(equal to 9 Millions USD)

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III.6. Human resources development for CNEST

A general human resources development program for entire CNEST has been built in the

feasibility study of CNEST.

Human resources solution for CNEST:

- Consider Dalat Nuclear research institute to be the mini version of CNEST in the future,

and Dalat NRI will be “transition step” to educate and provide human resources for this field;

- Send student abroad for further education (send to Russia Federation);

- Recruit new engineer with good potential and send them for further education abroad

and also on-job training in research organization like GIDROPRESS, VNIIAES or SNITTMASH

institute when experts of these organization perform the design and construction process for

CNEST;

- Educate through research work, mission and projects of VINATOM, collaboration with

universities in Hanoi;

- Educate through performing establishment project inside the framework of CNEST

project (with Russia partners), and may be send experts to research institute in Russia to work with

this project.

IV. CONCLUSION

The main results of this project can be summarize as following:

1. The project has collected the general report from previous projects which are relevant to

CNEST and new research reactor, IAEA guidance documents, documents provided by ROSATOM

in seminars in 2010, 2012 and 2013, report from expert visits of Ministry of Science and

Technology;

2. The project has completed the general report about the construction project of CNEST;

3. Reports about the project which has been approved by Ministry of Science and

Technology in 8/2013. This report will be the supportive material for financial negotiation of

Ministry of Finance and the basis for application for government investment to prepare for the next

stage of the CNEST project in 2014.

REFERENCES

[1] Nguyễn Việt Hùng, Báo cáo tổng kết Nhiệm vụ cấp Bộ năm 2010” Khảo sát, thu thập,

nghiên cứu dữ liệu ban đầu phục vụ cho lựa chọn địa điểm xây dựng Trung tâm Khoa học và

Công nghệ hạt nhân”.

[2] Lê Văn Hồng, Báo cáo tổng kết nhiệm vụ cấp Bộ năm 2011” Nghiên cứu xác lập các yêu cầu

thiết kế (TOR) cho Trung tâm Khoa học và Công nghệ hạt nhân”.

[3] Mai Đình Trung, Báo cáo tổng kết nhiệm vụ cấp Bộ năm 2012 “Nghiên cứu xây dựng bộ tiêu

chí lựa chọn địa điểm xây dựng lò phản ứng nghiên cứu và lập báo cáo sơ bộ lựa chọn địa

điểm dự án Trung tâm Khoa học và Công nghệ hạt nhân”.

[4] Nguyễn Nhị Điền, Báo cáo tổng kết đề tài nhánh B “Xây dựng luận cứ cho đề án Lò phản

ứng nghiên cứu mới ở Việt Nam” thuộc đề tài độc lập cấp Nhà nước “Xây dựng tiềm lực

R&D phục vụ chương trình phát triển Điện hạt nhân” mã số ĐTĐL-2002/17 giai đoạn 2002-

2004.

[5] Nguyễn Nhị Điền, Báo cáo tổng kết đề tài cấp Bộ “Nghiên cứu phương án xây dựng lò phản

ứng nghiên cứu mới và thực hiện một số tính toán neutron và thủy nhiệt để nhân dạng lò

phản ứng” mã số BO/06/01-04 giai đoạn 2006-2007.

VINATOM-AR 13--45


340

[6] Nguyễn Nhị Điền, Báo cáo tổng kết nhiệm vụ cấp cơ sở năm 2007 ” Xác định các nhiệm vụ

kỹ thuật cho LPUNC mới và các đầu tư cơ sở vật chất kỹ thuật cần thiết phục vụ nhiệm vụ

này và nhu cầu nhân lực cho quản lý, vận hành và khai thác sử dụng LPUNC”.

[7] IAEA TEC-DOC-1234, The Applications of Research Reactors, Report of an Advisory

Group Meeting held in Vienna, 4-7 October 1999.

[8] Radioisotope Production in Nuclear Research Reactors. IAEA-TECDOC-2000.

[9] Report of the IAEA Regional Management Workshop on Strategies to Enhance Utilisation of

Local Radiopharmaceuticals, RAS/2/009, Korea, 22-26 October 2001.

[10] Các tài liệu do các đoàn chuyên gia của ROSATOM cung cấp qua các hội thảo, chuyến thăm

và làm việc tại Việt Nam liên quan đến dự án Trung tâm KH&CNHN năm 2010, 2012 và

2013.

VINATOM-AR--13


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2.1. LIST OF VIE PROJECTS 2013

(implemented by VINATOM)

Code Project Title Start

Year

Budget

(USD)

Field

code Project

Counterpart

Institution

VIE2011

Enhancing the Capability

of Uranium and Related

Atomic Mineral

Exploration for Nuclear

Energy

2012 76,913.00 7 Le Ba Thuan

ITRRE

VIE6025

Upgrading the Standard

Dosimetry and Nuclear

Safety Laboratories of the

Institute for Nuclear

Science and Technology

(INST)

2012 76,174.00 29 Vu Manh Khoi

INST

VIE9011

Improving the Capability

for Site Characterization

and Evaluation of New

Nuclear Installations

2009 230,865.59 9F Truong Y

NRI

VINATOM-AR--13


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2.2 LIST OF FNCA PROJECTS 2013

(Implemented by VINATOM and Vietnam other organizations)

Fields Project Tittle Project Coordinators

Radiation

Utilization

Development

Mutation Breeding Dr. Le Huy Ham

Director General

Institute of Agricultural Genetics (AGI)

Ministry of Agriculture and Rural Development (MARD)

Biofertilizer Dr. Pham Van Toan

Director, Postgraduated Department, Vietnam Academy of

Agricultural Sciences (VAAS)

Ministry of Agriculture & Rural Development (MARD)

Electron Accelerator

Application

Dr. Quoc Hien NGUYEN

Principal Scientist

Research and Development Center for Radiation

Technology (VINAGAMMA)

Vietnam Atomic Energy Institute (VINATOM)

Radiation Oncology Dr. Bui Cong Toan

Head of General Radiotherapy Department,

National Cancer Institute (K Hospital)

Research Reactor

Utilization

Developemnt

Research Reactor

Network

Mr.Duong Van Dong Director,

Center for Research and Production of Radioisotope,

Nuclear Research Institute(NRI),


Neutron Activation

Analysis

Mr. Cao Dong Vu Deputy director of Center for Analytical Techniques

(CATech)

Nuclear Research Institute (NRI)


Nuclear Safety

Strengthening

Safety Management

Systems for Nuclear

Facilities Project

Dr. Nguyen Nhi Dien

Director, Nuclear Research Institute,


Radiation Safety and

Radioactive Waste

Management

Dr. Le Ba Thuan

Director

Institute for Technology of Radioactive and rare Elements


Nucclear

Infrastructure

Stecnthening

Human Resources

Development

Ms. CAO Hong Lan Deputy Director

Department of Administration and Personnel


Nuclear Security and

Safeguards

Dr. NGUYEN Nu Hoai Vi Director of Nuclear Control Division

Vietnam Agency for Radiation and Nuclear

Safety(VARANS)

VINATOM-AR 13


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2. 3 List of INT\RAS\ Non RCA Projects 2013

(Implemented by VINATOM)

Code Title Year of

approval

Budget

(USD)

Project

Type Project

Coordinators

INT2014

Supporting Member States to

Evaluate Nuclear Reactor

Technology for Near-Term

Deployment 2012 INT

Tran Chi

Thanh

RAS0060

Enhancing Capacity for Effective

Use and Maintenance of Nuclear

Instrumentation 2012

Footnot A

(FA) Non-RCA

Dang quang

Thieu

RAS0065

Supporting Sustainability and

Networking of National Nuclear

Institutions in Asia and the Pacific

Region 2012 361,418.00 Non-RCA

Nguyen Manh

Hung

RAS0066

Contingency Project for

Institutional Development 2012 188,235.06 Non-RCA

Cao Dinh

Thanh

RAS1012

Characterizing and Optimizing

Process Dynamics in Complex

Industrial Systems Using

Radiotracer and Sealed Source

Techniques 2012 291,348.00 RCA

Nguyen Huu

Quang

RAS1013

Supporting Advanced Non-

Destructive Examination for

Enhanced Industrial Safety,

Product Quality and Productivity 2012 195,000.00 RCA Vu Tien Ha

RAS1014

Supporting Radiation Processing

for the Development of Advanced

Grafted Materials for Industrial

Applications and Environmental

Preservation 2012 262,500.00 RCA Doan Binh

RAS1019

Enhancing Safety and Utilization

of Research Reactors 2012 FA Non-RCA Luong Ba Vien

RAS5055

Improving Soil Fertility, Land

Productivity and Land

Degradation Mitigation 2012 390,211.00 RCA Phan Son Hai

RAS5056

Supporting Mutation Breeding

Approaches to Develop New Crop

Varieties Adaptable to Climate

Change 2012 354,000.00 RCA

Le Quang

Luan

RAS5057

Implementing Best Practices of

Food Irradiation for Sanitary and

Phytosanitary Purposes 2012 268,500.03 RCA

Tran Minh

Quynh

RAS6070

Supporting Quality Assurance

Team for Radiation Oncology

(QUATRO) Training 2012 181,248.01 Non-RCA

Tran Ngoc

Toan

VINATOM-AR 13


346

RAS7021

Marine benchmark study on the

possible impact of the Fukushima

radioactive releases in the Asia-

Pacific Region 2011 763,710.11 RCA Le Nhu Sieu

RAS7022

Applying Isotope Techniques to

Investigate Groundwater

Dynamics and Recharge Rate for

Sustainable Groundwater

Resource Management 2012 236,760.01 RCA

Nguyen Kien

Chinh

RAS7023

Supporting Sustainable Air

Pollution Monitoring Using

Nuclear Analytical Technology 2012 337,388.00 RCA

Vuong Thu

Bac

RAS7024

Supporting Nuclear and Isotopic

Techniques to Assess Climate

Change for Sustainable Marine

Ecosystem Management 2012 240,751.00 RCA

Trinh Van

Giap

RAS8109

Supporting Radiation Processing

of Polymeric Materials for

Agricultural Applications and

Environmental Remediation

(RCA) 2009 410,582.83 RCA Doan Binh

RAS9064

Strengthening the Transfer of

Experience Related to

Occupational Radiation Protection

in the Nuclear Industry and Other

Applications Involving Ionizing

Radiation 2012 119,743.35 Non-RCA Vu Manh Khoi

RAS9065

Strengthening Radiation

Protection of Patients in Medical

Exposure 2012 191,848.96 Non-RCA Ng Huu Quyet

RAS9068

Strengthening and Harmonizing

National Capabilities for

Response to Nuclear and

Radiological Emergencies 2012 236,032.48 Non-RCA

Le Ngoc

Thiem

RAS9071

Establishing a Radioactive Waste

Management Infrastructure 2012 506,948.02 Non-RCA

Nguyen Ba

Tien

VINATOM-AR 13


347

2.4 LIST OF RESEARCH CONTRACTS 2013

(Implemented by VINATOM and Vietnam other organizations)

No CRP

Code Title Programme Start Date

Expected

End Date Closing date

1 D12011 Integrated Isotopic

Approaches for an

Area-wide Precision

Conservation to

Control the Impacts of

Agricultural Practices

on Land Degradation

and Soil Erosion

Food and

Agriculture

2008-12-08 2013-12-07

2 E13031 Role of Nuclear

Cardiology

Techniques in

Ischemia Assessment

with Exercise Imaging

in Asymptomatic

Diabetes

Human Health 2006-03-15 2012-12-31

3 E13037 The Use of Sentinel

Lymph Node in

Breast, Melanoma,

Head & Neck and

Pelvic Cancers

Human Health 2010-10-12 2013-12-31

4 F22046 Development of

Radiation-Processed

Products of Natural

Polymers for

Application in

Agriculture,

Healthcare, Industry

and Environment

Radioisotope

Production and

Radiation

Technology

2007-12-01 2012-12-31

5 F33017 Use of Environmental

Isotope Tracer

Techniques to Improve

Basin-scale Recharge

Estimation

Water

Resources

2009-03-26 2013-03-26

6 I11008 Financing Nuclear

Investments

Capacity

Building and

Nuclear

Knowledge

Maintenance

for Sustainable

Energy

Development

2013-09-05 2016-09-05

http://cra.iaea.org/crp/project/ProjectDetail?projectId=1507&lastActionName=Search



































VINATOM-AR 13


348

7 F31004 Stable Isotopes in

Precipitation and

Paleoclimatic Archives

in Tropical Areas to

Improve Regional

Hydrological and

Climatic Impact

Models

Water

Resources

2013-07-04 2016-07-03

8 F22060 Radiometric Methods

for Measuring and

Modelling Multiphase

Systems Towards

Process Management

Radioisotope

Production and

Radiation

Technology

2012-07-09 2016-07-09

9 F22051 Radiation Curing of

Composites for

Enhancing their

Features and Utility in

Health Care and

Industry

Radioisotope

Production and

Radiation

Technology

2011-03-14 2015-03-14

10 F12024 Utilisation of

Accelerator-Based

Real-time Methods in

the Investigation of

Materials with High

Technological

Importance

Nuclear

Science

2012-03-28 2016-03-28

11 E43023 Stable Isotope

Techniques in the

Development and

Monitoring of

Nutritional

Interventions for

Infants and Children

with Malaria, TB and

other Infectious

Diseases

Human Health 2009-09-08 2014-02-28

12 E35008 Strengthening of

“Biological dosimetry”

in IAEA Member

States: Improvement

of current techniques

and intensification of

collaboration and

networking among the

different institutes.

Human Health 2012-02-10 2016-02-09

13 E13041 Nuclear Cardiology in

Congestive Heart

Failure Value of

intraventricular

synchronism

assessment by gated-

Human Health 2013-09-13 2016-09-13




















































VINATOM-AR 13


349

SPECT myocardial

perfusion imaging in

the management of

heart failure patients

submitted to cardiac

resynchronization

therapy (IAEA-

VISION CRT)

14 D62008 Development of

Generic Irradiation

Doses for Quarantine

Treatments

Food and

Agriculture

2009-06-11 2014-06-11

15 D24012 Enhancing the

Efficiency of Induced

Mutagenesis through

an Integrated

Biotechnology

Pipeline

Food and

Agriculture

2009-02-04 2014-05-20

16 D15013 Approaches to

Improvement of Crop

Genotypes with High

Water and Nutrient use

Efficiency for Water

Scarce Environments

Food and

Agriculture

2011-11-01 2015-11-01

17 D12013 Landscape Salinity

and Water

Management for

Improving

Agricultural

Productivity

Food and

Agriculture

2013-06-04 2018-06-03
























THE ANNUAL REPORT FOR 2013

Responsible for publishing

Publishing editor

Cover designer

: Pham Ngoc Khoi

: Nguyen Quynh Anh

: Nguyen Hoang Anh

SCIENCE AND TECHNICS PUBLISHING HOUSE

70 Tran Hung Dao, Hoan Kiem, Ha Noi, Vietnam

Publishing registration No: 2247-2014/CXB/6-134/KHKT.

Publishing decision No: 182/QĐXB-NXBKHKT dated November 11, 2014

Quantity: 100, size: 21x29.5 cm.

Printed at: Truong Xuan Commercial and Printing Joint Stock Company.

Printing finished and copyright deposited in the 4th

quarter of 2014.

VIỆN NĂNG LƯỢNG NGUYÊN TỬ VIỆT NAM

The ANNUAL REPORT for 2013

Ban biên tập:

TS. Trần Chí Thành, Tổng biên tập

TS. Cao Đình Thanh, Phó tổng biên tập

KS. Nguyễn Hoàng Anh, Ủy viên, Thư ký Ban biên tập

TS. Nguyễn Thị Kim Dung, Ủy viên

ThS. Nguyễn Thị Định, Ủy viên

CN. Nguyễn Thị Phương Lan, Ủy viên.

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