Study On Degradation Of Silk Fibroin By Irradiation Treatment For ...

Vietnam Atomic Energy Institute

Dr. Tran Chi Thanh, Chief EditorDr. Cao Dinh Thanh

Eng. Nguyen Hoang AnhM.Sc. Nguyen Thi DinhB.A. Nguyen Thi Phuong Lan.

Dr. Nguyen Thi Kim Dung

Editorial Board:

Hanoi, August 2013

The VINATOM Annual Report for 2011 has been prepared as an account ofworks carried out at VINATOM for the period 2011. Many results presented inthe report have been obtained in collaboration with scientists from national andoverseas universities and research institutions.

The ANNUAL REPORT for 2011

Edited byVietnam Atomic Energy Institute59 Ly Thuong Kiet, Hanoi, Vietnam

President: Dr. Tran Chi ThanhTel: +84-4-39423434Fax: +84-4-39424133

ThisReport is available from:

Training and Information DivisionDept. of Planning and R&D ManagementVietnam Atomic Energy Institute59 Ly Thuong Kiet, Ha noi,VietnamTel: +84-4-39423591Fax: +84-4-39424133E-mail: [email protected]

[email protected]

mailto:[email protected]

Preface

The research activities of the Vietnam Atomic Energy Institute (VINATOM)during the period from January 1st to 31st December 2011 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, NuclearPower 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 December31st, 2011 was 778 including the clerical service staff. The VINATOM was funded fromthe Government with the amount to 127.027 billion VND for FY 2011. Theinternational support for the VINATOM activities is committed to the operating projectsincluding equipment, staff training and expert services (7 VIE projects, 41 RAS projectsand 18 research contracts with the IAEA).

Main results of fundamental and applied research implemented in the year werepresented in 149 scientific articles, reports and contributions published in manyjournals, proceedings of conferences, etc.

During the time of year 2011, in the VINATOM there were 6 to be graduated inPh.D. courses; about 190 people have been trained abroad in the fields of nuclearscience and technology.

Dr. Tran Chi Thanh

President, VINATOM

7

CONTENTS

Page

Preface 5

1. CONTRIBUTIONS 13

1.1- NUCLEAR PHYSICS, REACTOR PHYSICS 15

Studying Nuclear Matter and Nuclear Scattering Reactions Based on theUnited Nucleon-Nucleon Interaction ModelsLe Xuan Chung, Dao Tien Khoa, Do Cong Cuong, Doan Thi Loan and NgoHai Tan.

17

1.2- RESEARCH REACTOR, NUCLEAR POWER TECHNOLOGY,NUCLEAR SAFETY, NUCLEAR POWER ECONOMY

25

Calculate Some Characteristic Parameters of VVER-1000’s Fuel Assemblyby MCNP4C2 CodeNguyen Van Hien, Nguyen Mai Huong, Hoang Van Khanh.

27

Apply Burnable Poison for Fuel Pebble of PBMR-400 With Otto RefuelingHoang Van Khanh, Nguyen Thi Mai Huong and Nguyen Van Hien.

35

Modeling of Pressurizer of the Pressured Water Reactor (PWR) UsingRelap/Scdapsim CodeLe Thi Thu, Pham Tuan Nam, Nguyen Thi Thanh Thuy and Nguyen ThiTu Oanh.

41

1.3- INSTRUMENTATION, NUCLEAR ELECTRONICS 47

Research and Development of a Pilot First Generation PGNAA Off-beltSystem for Analysing of Composition of Cement and Bauxite RawMaterialTran Thanh Minh, Mai Cong Thanh, Do Trong Vien, Ngo Duc Tin, Le TrongNghia, Phan Quoc Minh and Dang Nguyen The Duy.

49

Application Photodiode to Determine Characteristics of X-rayNguyen Thi Bao My, Nguyen Van Si, Vu Van Tien and Nguyen Thi Thuy Mai.

58

Development of a Fast Parameters Calibration Method for SACP Used inthe Experimental Rerearch of Nuclear Data and StructuresHo Huu Thang, Nguyen Xuan Hai, Tran Tuan Anh, Pham Ngoc Son andNguyen An Son.

63

Re-arrange the Tangential Beam Port of the Dalat Nuclear ResearchReactor for Fundamental Research and Applications with Convenienceand High SafetyNguyen Xuan Hai, Tran Tuan Anh, Nguyen Canh Hai, Pham Ngoc Son, HoHuu Thang, Pham Xuan Phuong, Ho Viet Ngoan, Nguyen Xuan Quy andNguyen An Son.

67

8

1.4- INDUSTRIAL APPLICATIONS 71

Improvement of Procedures for Preparation and Use of Tracers MeBr-82and Ar-41 in Investigation of Petroleum Industry and Study ofEmployment of FBAs (Fluorinated Benzoic Acids) in Interwell TracerTechniqueNguyen Huu Quang, Dang Nguyen The Duy, Tran Tri Hai, Le Thi Thanh Tam,Huynh Thai Kim Ngan, Vo Thi Ngoc Cam, Ho Tran The Huu, To Ba Cuong,Phan Quoc Minh and Le Van Loc.

73

Study of Algorithm for Simulating and Matching of Tracer Breakthroughin the Dipole Flow Geometry by Using Streamtube MethodTo Ba Cuong, Le Van Loc, Le Van Son and Nguyen Pham Quang Vinh.

81

Research to Find out and Exploit about the Features of Eddymax TMTEquipment for Examination of Nonmagnetic Heat Exchanger TubeLuong Thi Hong, Nguyen Nhat Quang, Le Duc Thinh and Ngo Thi Da Huong.

88

Research to Exploit, Utilize Computed Radiography System and BuildSuitable ProcessTran Dang Manh, Nguyen Le Son, Vu Huu Cuong and Kieu Ngoc Dung.

93

Study on Measuring for Component Ratio and Velocity of Fluid in TwoPhases Flow by Application of Gamma Transmission Method and CrossCorrelation AnalysisLe Trong Nghia, Tran Thanh Minh, Mai Cong Thanh, Phan Quoc Minh,Dang Nguyen The Duy, Le Van Loc and Pham Van Dao.

98

1.5- APPLICATIONS IN ECOLOGY, ENVIRONMENT AND GEOLOGY 107

Provenance Research of the Archaeological Earthenware Collected atCattien Relic by Nuclear Analytical Methods and Multivariate StatisticsCao Dong Vu, Nguyen Thi Sy, Nguyen Thi Tho, Pham Ngoc Son,Nguyen Khanh Trung Kien, Luong Nguyen Minh and Ho Sy Dong.

109

Study on the Sources of Oilfield Produced Water Using ChemicalCompositions and Stable Isotope Ratio (2H/1H, 18O/16O)Ho Tran The Huu, Phan Thi Luan and Dương Thi Bich Chi.

117

1.6 - APPLICATIONS IN BIOLOGY, AGRICULTURE AND MEDICINE 123

Cooperative Research on In Vitro and In Vivo Irradiation for MutantFlower Lines Breeding in VietnamLe Ngoc Trieu, Nguyen Tuong Mien, Le Tien Thanh, Khuat Huu Trung,Kieu Thi Dung, Hitoshi Nakagawa, Toshio Takyu and Keiichi Takagi.

125

Quarantine Treatment of Fruit Fly Bactrocera Correcta Infested in NamroiGrapefruits by Gamma Radiation at Hanoi Irradiation CenterNguyen Van Binh, Tran Bang Diep, Pham Duy Duong, Hoang Phuong Thao,Nguyen Thanh Hien and Vu Thi Thuy Trang.

138

9

Study on Chromosome Aberrations in Basedow Patients Following 131ITherapy and Radiation PersonnelPham Ngoc Duy, Tran Que, Hoang Hung Tien, Nguyen Thi Kim Anh and HaThi Ngoc Lien.

145

Study on the Solid Phase Extraction Method for Separation andPreconcentration of Pesticide Multi-residue in Different Vegetable andFruit Matrices by the Gas Chromatography-mass Spectrometry-selectedIon MonitoringNguyen Tien Dat, Le Tat Mua, Ta Thi Tuyet Nhung, Nguyen Thi Hong Thamand Dang TrungTin.

152

Preparation of Kit MIBI for 99mTc Labeling Using in Nuclear MedicalDiagnostic ImagingChu Van Khoa, Duong Van Dong, Bui Van Cuong, Nguyen Thanh Binh,Nguyen Dang Khoa and Nguyen Thi Thu.

158

Finishing Process to Produce Cultured In Vitro Lisianthus Flower Seed(Eustoma Grandiflorum (Raf.) Shinn) Commercial ProductsLe Thi Thuy Linh, Le Van Thuc, Dang Thi Dien, Le Thi Bich Thy and HanHuynh Dien.

164

Study on the Growth Promotion Effect of Grapefruit Oligopectin Preparedby Radiation Processing on Mustard GreensNguyen Huynh Phuong Uyen, Le Quang Luan, Le Thi Thuy Trang and Vo ThiThu Ha.

170

1.7- RADIATION PROTECTION AND RADIOACTIVE WASTEMANAGEMENT

179

A Study for Improving Application of Two TLD Dosimeter Types (CaSO4:Dy and LiF-TLD-100) in Environmental Radiation Dose Rate MonitoringHoang Van Nguyen, Pham Van Dung, Phan Van Toan, Dinh Xuan Hoangand Nguyen Thi Ha.

181

Research on Immobilization of Radioactive Waste Sludge from UraniumMilling Activities by CementationNguyen An Thai, Nguyen Ba Tien, Pham Thi Quynh Lương, Vương Huu Anh,Nguyen Hoang Lan and Nguyen Thi Thu Trang.

186

Determination of Percentage Depth Doses in Water for a Medical LinearAccelerator of 6 MV Photon Energy by EGS5 CodeLe Ngoc Thiem, Nguyen Huu Quyet, Chu Vu Long, Vu Van Cam, Le DinhCuong and Pham Ngoc Diep.

191

1.8 - RADIATION TECHNOLOGY 197

Study on Degradation of Silk Fibroin by Irradiation Treatment forCosmetic and Pharmaceutical ApplicationsTran Bang Diep, Tran Minh Quynh, Nguyen Van Binh, Hoang Phuong Thao,Pham Duy Duong, Hoang Dang Sang, Pham Quan Hieu and Nguyen

199

10

Thuy Huong Trang.

Radiation Polymerization and Crosslinking of Poly (N-isopropylacrylamide) Hydrogels and Their PropertiesPham Duy Duong, Hoang Dang Sang, Hoang Phuong Thao and TranMinh Quynh.

207

Study on Effect of Immune Stimulation of γ-ray Irradiated Chitosan onTilapiaNguyen Ngoc Duy, Nguyen Quoc Hien and Dang Van Phu.

214

Studying on Preparation of Super Water Absorbing Materials byRadiation Modification Techniques Using Bentonite and Water SolubleMonomerLe Hai, Nguyen Tan Man, Tran Thi Thuy, Nguyen Trong Hoanh Phong,Nguyen Tuong Ly Lan, Le Van Toan, Le Thi Tho and Tran Thi Dao.

221

Radiation Synthesis and Application of Absorbent Hydrogels to Enhancethe Quality of BasadieselNguyen Duy Hang, Pham Thi Le Ha, Tran Thi Thuy, Le Hai, Nguyen Tan Man,Le Huu Tu, Nguyen Trong Hoanh Phong, Tran Thi Tam, Tran Thu Hong,Pham Thi Sam and Nguyen Tuong Li Lan.

229

Study on the Immobilization of Silver Nanoparticles onto the Acrylic-grafted Polyethylene Nonwoven Fabric by Gamma Radiation for WaterTreatmentDang Van Phu, Vo Thi Kim Lang, Nguyen Thi Kim Lan, Nguyen Tue Anhand Nguyen Quoc Hien.

235

Establishment of the Sterilization Process by Irradiation in Electron BeamUELR-10-15S2 for Some Medical Devices With Current High DemandDoan Thi The, Nguyen Thuy Khanh, Vo Thi Kim Lang, Pham Thi Thu Hong,Cao Văn Chung and Le Quang Thanh.

242

1.9 - RADIOCHEMISTRY AND MATERIALS SCIENCE 251

The Study on Preparation of UO2 Powder Via AUC Precipitation Routefrom UO2F2 SolutionNguyen Trong Hung, Do Van Khoai, Dang Ngoc Thang, Nguyen Van Tung,Nguyen Thanh Thuy, Dao Truong Giang, Ngo Quang Hien, Ha Dinh Khai,Doan Thi Mo, Tran Thi Thanh Hien, Ta Phuong Mai, Cao Thi Phuong Anhand Tran Thi Hong Thai.

253

Study on the Influence of Pore-forming Substance Ammonium Oxalate onPore Size and Pore Distribution of UO2 Ceramic PelletDao Truong Giang, Nguyen Trong Hung, Dang Ngoc Thang, Ha Dinh Khaiand Ngo Quang Hien.

260

11

Study the Possibility of Preparing Titanium (Ti) Metal from TiCl4 byHeating Magnesium Reconstitution MethodNgo Xuan Hung, Nguyen Van Sinh, Tran Duy Hai, Nguyen Trong Hai and VuThi Loan.

265

Rerearch on Determination of U(IV) and U(VI) in Uranium OreLe Hong Minh, Nguyen Xuan Chien, Do Thi Anh Tuyet and Bui Thi Ngan.

277

Study of the Influential Factors in Ester Preparation of 2, 4, 6-Trifluorobenzoic Acid Survicing to Fba Analysis Process.Huynh Thai Kim Ngan, Vo Thi Ngoc Cam, Dang Nguyen The Duy, Tran TriHai, Ho Tran The Huu, Nguyen Huu Quang and Le Thi Thanh Tam.

283

Determination of U, Fe, V in Uranium Ore and Gross Alpha Beta Throughthe Exploitation, Processing and Handling of Radioactive Ore on thePortable XRF Si-PIN Detector and Device of Alpha Beta MPC-2000Doan Thanh Son, Phung Vu Phong and Nguyen Thi Hanh Phuc.

288

1.10- COMPUTATION AND OTHER RELATED TOPICS 293

Research on the Establishment of Design Requirements (TOR) for Centerfor Nuclear Science and TechnologyLe Van Hong, Nguyen Nhi Dien, Nguyen Kien Cuong, Nguyen Thanh Binh,Pham Van Lam, Nguyen Minh Tuan, Nguyen Canh Hai, Trinh Van Giapand Than Van Lien.

295

Complete the Plans of Training Human Resources in the Nuclear EnergyField for the Ministry Science and Technology to Year 2020 and BuildSpecialized Training Programs at the Nuclear Training CentreNguyen Manh Hung and Cao Đinh Thanh.

302

The Envisagement of Education Program for Development of NuclearScience and Technology in VietnamPham Dinh Khang, Nguyen Xuan Hai, Nguyen Kien Cuong, Than Van Lien,Nguyen An Son, Nguyen Ngoc Anh, Luu Thu Hoa and Nguyen Thuy Linh.

306

Study and Proposal for Solutions on Attracting Human Resources,Technical Support Activities for Atomic Energy Applications andSpecialized & Safe Training for Radiation WorkerCao Hong Lan, Nguyen Trong Trang, Vu Thanh Huyen, Nguyen The Khanh,Bui Dang Hanh, Vu Manh Khoi, Hoang Hoa Mai, Nguyen Trong Hiep,Nguyen Nhi Dien, Nguyen Bich Thu, La Thi Huong and Luu Lam.

315

2. IAEA TC PROJECTS AND RESEARCH CONTRACTS 319

2.1 - List of VIE Projects 2011 321

2.2 - List of Reseach Contract 2011 323

2.3 - List of Active Regional/Interregional Projects 2011 326

2.4 - List of FNCA Projects Operating in 2011 330

VINATOM-AR 11--01

The Annual Report for 2011, VINATOM 17

STUDYING NUCLEAR MATTER AND NUCLEAR SCATTERINGREACTIONS BASED ON THE UNITED NUCLEON-NUCLEON

INTERACTION MODELS

Le Xuan Chung1, Dao Tien Khoa1, Do Cong Cuong1,Doan Thi Loan2 and Ngo Hai Tan2

1Institute for Nuclear Science and Technology, VINATOMNo.179 Hoang Quoc Viet, Nghia Do, Cau Giay, Hanoi, Vietnam

2Hanoi National University of EducationNo.136 Xuan Thuy, Cau Giay, Hanoi, Vietnam

Abstract: The properties of nuclear matter and nuclear scattering reactions werestudied from the same effective nucleon-nucleon interactions. In this project, we usedCDM3Y and M3Y-Pn interaction version as the input to build the nuclear interactionpotential (nuclear optical potential). After that, nuclear scattering reactions were studiedby coupled channel formalism and folding model for scattering potential. Thetheoretical calculated cross sections of (alpha, nucleus) and (nucleon, nucleus)scattering system have been compared with the experimental values. Using the aboveinteractions, the properties of nuclear matter: (i) biding energy, (ii) pressure and (iii)Compressibility were deduced in the Hartree-Fock calculation frame work. From theconsistence between theory and experiment, the information of nuclear structure hasbeen extracted.

RESULT AND DISCUSSION

In the study of nuclear matter and nuclear scattering reactions, nucleon-nucleon(NN) interaction is the first important information. From which, the nuclear opticalpotential can be built. The nuclear potential including of the real, imagine, isoscalar andisospin parts at energy of 43 MeV was calculated using the CDM3Y6 NN interactionversion. The results are shown in figure 1 and are compared to the corresponding partsof JLM potential [1].

Project Information:- Code: CS/11/04-04

- Managerial Level: Institute

- Allocated Fund: 45,000,000 VND

- Implementation Time: 12 months (Jan 2011-Dec 2011)

- Contact Email: [email protected]

- Papers published in relation to the project: (None)


VINATOM-AR 11--01

The Annual Report for 2011, VINATOM18

Figure 1: the real, imagine, isoscalar and isospin parts of nuclear optical potential

The nuclear potential calculated from M3Y-Pn NN interaction version at variousenergy is presented in figure 2. This was obtained with g(E)=1– 0.0020E.

Figure 2: Nucleon optical potential depending on energyin symmetric nuclear matter (δ=0.5).

VINATOM-AR 11--01


The symmetric energy parts using CDM3Y6 and M3Y-Pn versions is shown infigure 3.

Figure 3: The isospin V1 and isoscalar V0 parts of nuclear opticalpotential in symmetric nuclear matter depending on energy

of both NN interaction versions g(E)=(1-0.0026E).

The analysis of nuclear scattering 208Pb(p,p) at energy of 45 MeV usingCDM3Y6 and M3Y-P5 is shown in figure 4. The result shows good agreement with theexperimental data and the optical potential obtained from these above NN interactionversions is appropriate. In the case of 48Ca(p,p), the calculation with CDM3Y6 givesbetter result presented in figure 5.

Figure 4: Elastic scattering of proton on208Pb at energy of 45 MeV.

Figure 5: Elastic scattering of proton on48Ca at energy of 45 MeV

Figure 6 shows the analysis of 208Pb(n, n) at energy of 30.4 MeV.

It is seen that the folding calculations using CDM3Y6 and M3Y-P5 give goodagreements with the experimental data for nucleon-nucleus scattering reactions. Besidesthe study of elastic scatterings, folding potential calculated from these above 2 NNinteraction version can be used to build the optical potential for ingoing channel ofcharge-exchange reactions.

VINATOM-AR 11--01


Figure 6: Elastic scattering of neutron on 208Pb at energy of 45 MeV.

Table 1: Transition strength from ground to excited states of 12C from RGM andAMD models compared with experimental values

Jπ B(EJ)cal. (e2 fmJ+2 ) B(EJ)exp.

(e2 fmJ+2 )

Sρ

RGM AMD

2+1 46.5 42.5 40±0.2 1.00

0+2 6.62a 6.61a 5.4±0.2a 0.55

3-1 749 742 610±90 1.00

2+2 12.4 2.5 2.0b 1.00

0+3 6.32a 2.3a 1.00

aM(EJ) with e fmJ+2 unite of 0+2 and 0+

3 statesbB(E2) extracted from collective model [24]

The cluster structure of 12C nucleus was studied through α inelastic scattering atenergy of 240 MeV. The folding potential with the RGM [2] and ADM [3] densitytransition and the complex CDM3Y6 NN interaction were used. Table 1 shows thetransition strength obtained from RGM and ADM and the experimental values.

VINATOM-AR 11--01


The analysis of inelastic 12C(α,α’) was done in the PWBA frame work withdifferent excited energy Ex=4.44, 0.64, 7.65, 10.3 MeV (figure 7). The results are ingood agreement with experiment.

10-3

10-2

10-1

100

101

102

103

0 10 20 30 40 5010-3

10-2

10-1

100

101

102

0 10 20 30 40 50 60

12C(,')12C', DWBAEx=4.44 MeV, J=2+

1

AMD RGM

12C(,')12C', DWBAEx=9.64 MeV, J=3-

1

AMD RGM

12C(,')12C', DWBAEx=7.65 MeV, J=0+

2

cm. [deg]

d/d

[mb/

sr]

AMD RGM Renormal AMD Renormal RGM

12C(,')12C', DWBAEx=10.3 MeV, J=0+

3

AMD RGM

Figure 7: Inelastic scattering cross section of α+12C at energyElab=240 MeV for 2+

1, 0+

2, 3-1 and 0+

3 states, compared with DWBAresults using RGM [2] and AMD [4] density transitions.

The eigen binding energy of symmetric nuclear matter (NM) was obtained inHartree-Fork (HF) calculation using CDM3Y6 and M3Y-Pn (figure 8). The parametersin NN interaction versions were modified to give the minimum E/A(ρ0)≈ -16 MeV atdensity ρ0≈ 0.17fm-3. When changing from symmetric NM (ρn=ρp) to asymmetricNM, the saturation density of NM decreases quickly with the asymmetry shown infigure 9.

ρ(fm-3)Figure 8: Eigen binding energy of symmetric NM

VINATOM-AR 11--01


Nuclear matter pressure calculated from the above NN interaction versions ispresented in figure 10 comparing with the experimental data.

Figure 9: Eigen binding energy withdifferent asymmetries.

Figure 10: Neutron NM pressure(upper) and symmetric NM (lower)

The information about the asymmetry is very important in study of the structureof neutron rich nuclei and in the problem of astrophysics or in the dynamic of supernovaexplosion, the formation and cooling process of neutron star. In figure 11, we comparecalculating symmetric energy with the results from charge exchange model [5], themodel in [6, 7, 8]. Both NN interaction versions give the good agreement withexperimental data.

From the relation between NM and symmetric energy, the difference betweenAsy-stiff and Asy-soft is in isovector spin K1 of incompressibility K in figure 11.

Figure 11: Isovector spin of incompressibility K

VINATOM-AR 11--01


The obtained results shows the dependence on density of the NM equation ofstate in 2 cases: symmetric NM and neutron matter. In general, HF calculation with theabove 2 NN interaction versions gives appropriate results with symmetric NM in Asy-stiff and Asy-soft calculations. In the case of neutron star, there is the uncertainty in theequation of state at high density.

REFERENCES

[1]. J. P. Jeukenne, A. Lejeune, and C. Mahaux, Phys. Rev. C 16, 80, 1977.[2]. E. Uegaki, Y. Abe, S. Okabe and H. Tanaka, Prog. Theor. Phys. 59, 1031, 1978.[3]. E. Uegaki, S. Okabe, Y. Abe and H. Tanaka, Prog. Theor. Phys. 57, 1262,1977.[4]. Prog. Theor. Phys. 1621, 62,1979.[5]. D.T. Khoa and H.S. Than, Phys. Rev. C 71, 044601, 2005.[6]. A. Akmal, V.R. Pandhanripande, D.G. Ravehall, Phys. Rev. C 58, 1804,1998.[7]. D.V.Shetty, S.J.Yennello, G.A.Souliotis, Nucl. Inst. and Meth. in Phys. Res. B 261,

990, 2007.[8]. P. Danielewicz, R. Lacey, and W. G. Lynch, Science 298, 1592, 2002.

VINATOM-AR 11--02


CALCULATE SOME CHARACTERISTIC PARAMETERS OFVVER-1000’S FUEL ASSEMBLY BY MCNP4C2 CODE

Nguyen Van Hien, Nguyen Mai Huong and Hoang Van Khanh

Institute for Nuclear Science and Technology,VINATOM179 Hoang Quoc Viet, Nghia Do, Ha Noi

Abstract: This report presents the descriptions of parameters characteristics of the LEUand MOX Fuel Assemblies of VVER-1000 reactor, and calculation results such asinfinite neutron multiplication factor kinf, two groups energies constants, neutron fluxdistribution by using Monte Carlo code MCNP.

I. INTRODUCTION

The Monte Carlo N-Particle (MCNP) computer code is a particle transport codewith powerful three dimensional geometry and source modeling capabilities that can beapplied to reactor physics, shielding, criticality, environmental nuclear waste cleanup,medical imaging, and numerous other related areas.

- WWER is an abbreviation for Water-Water Energy Reactor. It is pressurevessel type nuclear reactor with water used both as moderator and coolant, resulting in athermal neutron spectrum.

- In Russia the MOX fuel will be used in both fast (BN-600) and light waterreactors (VVER-1000). Recent work in Russia has focused on the certification of thecalculation codes and the design of MOX fuel assemblies and core configurations. TheExpert’s group has performed several benchmarking efforts to help in the codecertification process by providing experimental data and by sponsoring benchmarkingexercises that provide useful verification of the Russian calculation methods. Whilethese Russian codes and data have been certified for LEU-based fuel, the certificationfor MOX fuel is required because of the essential differences between reactors fuelledwith MOX:

- Reduced worth of the control rods, boric acid and burnable poisons.

- Reduced effective fraction of delayed neutrons.

- Reduced moderator temperature reactivity coefficient at the end of fuelcycle.





- Contact Email: : [email protected]



VINATOM-AR 11--02


- Increased pin power peaking factor at the boundary between MOX andUOX FA’s which makes it necessary to use fuel rods with different contents ofplutonium in fuel assembly.

- Increased quantity of fission neutrons.

- Increased neutron flux sensitivity to local changes of moderator/fuel ratio.

This report describes the detailed results of low-enriched uranium (LEU) andmixed-oxide (MOX) fuel assembly of VVER-1000 reactor.

II. GEOMETRY DESCRIPTION

The VVER-1000 assemblies are hexagonal in design and consist of one centraltube, 312 fuel pin locations (12 of which are U/Gd rods), and 18 guide tubes. The cladand structural material are composed of a Zr-Nb alloy. The UGD assembly is shown inFigure 1.1 and consists of fuel rods with 3.7 wt.% enrichment. The 12 U/Gd pins have a235U enrichment of 3.6 wt.% and a Gd2O3 content of 4.0 wt.%. The MOXGDassembly is shown in Figure 1.2 and contains fuel rods with three different plutoniumloadings. The central region contains MOX pins with 4.2 wt.% fissile plutonium(consisting of 93 wt.% 239Pu), two rings of fuel rods with 3.0 wt.% fissile plutonium,and an outer ring of fuel rods with 2.0 wt.% fissile plutonium. The 12 U/Gd rods are inthe same locations as in the UGD assembly configuration and have the same design.

A uniform LEU fuel assembly with 12 U/Gd rods (UGD variant) and a profiledMOX fuel assembly with 12 U/Gd rods (MOXGD variant).

- Material specification (Table A.1. Material description)

MaterialName

Comment* Isotopic content, (atoms/barn cm3)

Fuel materials

U1 LEU fuel of 3.7 w/o enrichment 235U 8.6264E-4 16O 4.6063E-2238U 2.2169E-2

PU1 MOX fuel with 2.0 w/o of fissile Pu 235U 4.2672E-5 239Pu 4.2414E-4238U 2.1025E-2 240Pu 2.7250E-5

16O 4.3047E-2 241Pu 4.5228E-6

PU2 MOX fuel with 3.0 w/o of fissile Pu 235U 4.2209E-5 239Pu 6.3621E-4

238U 2.0797E-2 240Pu 4.0875E-5

16O 4.3045E-2 241Pu 6.7842E-6

PU3 MOX fuel with 4.2 w/o of fissile Pu 235U 4.1652E-5 239Pu 8.9071E-4238U 2.0522E-2 240Pu 5.7225E-5

16O 4.3043E-2 241Pu 9.4980E-6

VINATOM-AR 11--02


GD1 LEU fuel of 3.6 w/o of 235U

containing 4 w/o of Gd2O3

235U 4.1652E-5 153Gd 1.8541E-4

238U 1.9268E-2 156Gd 2.5602E-4

16O 4.1854E-2 157Gd 1.9480E-4

152

Gd2.5159E-6 158Gd 3.0715E-4

154Gd

2.7303E-5 160Gd 2.6706E-4

Non-fule materals

CL1 Zirconium alloy Zr 4.259E-2 Hf 6.597E-6

Nb 4.225E-4

MOD1 Moderator, 0.6 g/kg of boron, H 4.843E-2 10B 4.794E-6

Tn = 575K, γ = 0.7235 g/cm3 16O 2.422E-2 11B 0.0

MOD2 Moderator, without boron, H 4.843E-2 10B 0.0

Tn = 575K, γ = 0.7235 g/cm3 16O 2.422E-2 11B 0.0

MOD3 Moderator, without boron, H 6.717E-2 10B 0.0

Tn = 300K, γ = 1.0033 g/cm3 16O 3.358E-2 11B 0.0

* The information in this colunm is given only as comments. For calculations it isnecessary to use the data from “Isotopic content” colunm.

UGD – uniform assembly with 12 Gd pins (331 elementary cells of 4 types);

MOXGD – profiled assembly with 12 Gd pins (331 elementary cells of 6 types);

Infinite lattices of LEU and MOX assemblies have assembly pith 23.6 cm. Thecell in assemblies may be as follows: Table A.2. Description of cell types geometry

Cellsname Zones radius (cm)

Fuel cell R1 = 0.386

R2 = 0.4582

Central tube cell R1 = 0.48

R2 = 0.5626

Guide tube cell R1 = 0.545

R2 = 0.6323

VINATOM-AR 11--02


It should be mentioned that all cells of all types have the same outer dimensionsh = 1.275 cm. Fuel cell may contains one of the following materials:

+ Fuel cell in UGD assembly: - U1 or GD1;

+ Fuel cell in MOXGD assembly - PU1, PU2, PU3 or GD1.

Figure 2.1: UGD assembly configuration

Cell types:1. Central tube cell.2. Fuel cell (with U1, 3.7 wt.% LEU).3. Guide tube cell.4. Fuel cell (with GD1, 3.6 wt.% LEUwith 4.0 wt.% Gd2O3).

VINATOM-AR 11--02


Figure 2.2: MOXGD assembly configuration

III. CALCULATION’S MODEL FOR VVER’s FA BY MCNP CODE

Vertical and horizontal cross section view of LEU model calculation by MCNP

Vertical and horizontal cross section view of MOX model calculation by MCNP

IV. RESULTS OF CALCULATION

a) The infinite neutron multiplication factor kinf

+ For the LEU FA: kinf = 1.1360 ± 0.00005 and

+ For the MOX FA: kinf = 1.1601 ± 0.00007

Cell types:1. Central tube cell.2. Fuel cell (with PU3, 4.2 wt.% Pu).3. Guide tube cell.4. Fuel cell (with PU2, 3.0 wt.% Pu).5. Fuel cell (with PU1, 2.0 wt. Pu).6. Fuel cell (with GD1, 3.6 wt. % LEU with 4.0wt.%

Gd2O3).

VINATOM-AR 11--02


The comparison of results in [1] are presented in Tables 4.1 and 4.2

- For LEU FA (Table 4.1)

Code MCU TVSM WIMS8A HELIOS MULTICELL Mean MCNP

k-inf 1.1353 1.1353 1.1328 1.1355 1.1363 1.1350 1.1360

Error 0.000 0.000 -0.002 0.000 0.001 0.0009

- For MOX FA (Table 4.2)

Code MCU TVSM WIMS8A HELIOS MULTICELL Mean MCNP

k-inf 1.1551 1.1585 1.1494 1.1595 1.1606 1.1566 1.1601

Error -0.002 0.002 -0.007 0.003 0.004 0.003

The calculation’s results by MCNP show rather good agreement with the Meanvalue in the report of OECD/NEA [1].

- The calculation’s results of kinf values versus fuel enrichment of U235(weight percent) are presented in Table 4.3.

Fuel enrichment of U235 2.1 % 3.2 % 3.7 % 4.2 % 4.4 %

Result of kinf 1.14777 1.27667 1.31987 1.34854 1.35753

Error 0.00011 0.00011 0.00018 0.00011 0.00013

Remark: The kinf values are proportional with fuel enrichment of U235.

b) Result calculation of two group’s energies constants

For UO2 fuel rod, the result calculation of two group’s energies constants is presentedin Table 4.4.

Group 2 Group 1

2 groups

10MeV 3,0590eV 10 -5eV

Results Group 1 Group 2

f 7.0457E-02 3.8238E-03

Table 4.4 Two group’s energies constants

VINATOM-AR 11--02


For Gd2O3-UO2 fuel rod, the result calculation of two group’s energies constants ispresented in Table 4.5.

For MOX fuel rod, the result calculation of two group’s energies constants is presentedin Table 4.6.

c) Neutron flux distribution

The result calculation of thermal neutron flux is presented in Figure 4.1 and 4.2

Figure 4.1: Thermal neutron flux distribution in LEU FA


∑f 6.3425E-02 6.8519E-03



∑f 9.0903E-02 4.0644E-03


Central tube cell

UO2-Gd2O3 Fuel Rod Cell

Guide tube cell

UO2 Fuel Rod Cell

VINATOM-AR 11--02


Remark: - In the central cell, the thermal neutron flux is higher than in the othercell because there are only water in the central cell and water is good moderator forneutron.

- At the cells in the boundary of fuel assembly, the value of neutron flux ishigher than in the other cell because we use reflective boundary condition in thecalculation.

V. CONCLUSION

MCNP Code can be used in many fields related to protection shieldingcalculation, dose evaluation, kinetics calculation for reactor and others applications.LEU’s and MOX’s models are hexagonal prism with the pitch equal 23.6 cm, includingfour types of cell for LEU FA and six types of cell for MOX FA. Each cell is also smallhexagonal prism with the pitch equal 1.275 cm. The calculation result of kinf of LEU FAis 1.1360, and of MOX FA is 1.1601, very good agreement with the results inOECD/NEA report. The other calculation results are also relatively clear and highlypractical.

REFERENCES

[1]. A VVER1000 LEU and MOX Asembly Computational Benchmark, OECD/NEAJ. Gehin – ORNL – United States; M. Kalugin and D. Shkarovsky – RRC-KI Rusian Fedaration,2002.

[2]. Nguyen Nhi Dien and his staff, Safety Analysis Report for Dalat ResearchReactor, Dalat, 2003.

[3]. Robert Jeraj, Tomaz Zagar and Matjaz Ravnik, “Monte Carlo simulation of theTriga Mark II Benchmark experiment with burned fuel”, Nuclear Technology, VOL 137, March2002.

[4]. Briesmeister, Ed., MCNP -A General Monte Carlo N-Particle Transport Code,Version 4C, LA-13709-M, Los Alamos National Laboratory, April 2000.

Central tube cell

UO2-Gd2O3 Fuel RodCellGuide TubeCell

MOX Fuel Rod Cell with 3.0 w/o ofPu

2.019

MOX Fuel Rod Cell with 4.2 w/o of Pu1.700

MOX Fuel Rod Cell with 2.0 w/o of Pu3.045

Figure 4.2: Thermal neutron flux distribution in MOXFA

VINATOM-AR 11--03


APPLY BURNABLE POISON FOR FUEL PEBBLEOF PBMR-400 WITH OTTO REFUELING

Hoang Van Khanh, Nguyen Thi Mai Huong and Nguyen Van Hien

Institute for Nuclear Science and Technology,VINATOM179 Hoang Quoc Viet, Nghia Do, Hanoi, Vietnam

Abstract: A new fuel pebble was designed by adding spherical Gd2O3 particles forobtaining the minimum reactivity swing. Optimization is done in a lattice model todetermine the combination of radius and number of burnable poison (BP) particles perpebble to obtain the minimum reactivity swing. The numerical calculation so that with740 µm and 13 particles of Gd2O3. The reactivity swing is reduced from 38% to 2.0%,whereas the k∞ is 1.06-1.08 for a fuel lattice with the target burnup of 55 GWd/t.

I. INTRODUCTION

The pebble bed reactor (PBR), a type of the high-temperature gas-cooled reactor(HTGR) which is selected as one of the six Generation-IV nuclear reactor systems, is agraphite-moderated, helium-cooled reactor [1]. The PBR takes all major advantages ofthe HTGR making it a good candidate of next generation nuclear systems such as: highthermal conductivity, inert coolant, inherent safety, and fission product confinementcapability and proliferation resistance. In addition, the PBR has the advantage of onlinecontinuous refueling, allowing it to operate without shutting down periods for refuelingand discharging, and controlling mechanism for excess reactivity.

The fuel pebbles can pass through the core for several times in a multi-passrefueling scheme or for only once in a once-through-then-out (OTTO) refueling scheme.Current PBRs, e.g. the 400 MWt pebble bed modular reactor (PBMR) in South Africaand the small high temperature reactor (HTR-10) in China, operate with the multi-passscheme. After passing through the core, the fuel pebbles are measured for their burnuplevels and reloaded into the core top for next irradiation cycle or discharged to spent-fuel tanks by a fuel handling system. Unlike the multi-pass, no fuel is reloaded in theOTTO scheme [2]. Fresh fuel pebbles are loaded into the core top and discharged from






- Papers published in relation to the project:

Neutronic characteristics of an OTTO refueling PBMR (Đặc trưng nơtron lò phảnứng PBMR với chu trình OTTO), Nuclear Engineering and Design 253(2012), pp.269-276.


VINATOM-AR 11--03


the core bottom after one irradiation cycle. Therefore, the PBR operating with theOTTO scheme takes an additional advantage due to a simplified refueling mechanism.

The biggest challenge of the OTTO scheme is that the fresh fuel pebbles areconcentrated at the core top and the irradiated fuel pebbles are concentrated at the corebottom. This results in a non-uniform axial power profile with an excessively highpower peak at the core top [2]. The problem of the high power peak can be overcome byintroducing so-called spherical burnable poison (BP) particles to control the axial powerprofile [3][4]. However, the appearance of BP causes the decrease of the fuel burnupperformance. This raises a number of further questions regarding the efficiency of fuelutilization and other parameters.

The present study gives a remark on the fuel pebble burnup performance of thePBMR-400 with OTTO scheme. A new fuel pebble has been designed by addingspherical particles of Gd2O3 as BP for controlling the reactivity swing.

II. BURNABLE POISON LOADING PRINCIPLE

In pebble bed HTGR cores using the OTTO refueling scheme, the axial powerprofile is strongly affected by the axial distribution of an infinite multiplication factor,k∞. Because of fuel depletion, k∞ of a fuel pebble decreases linearly with its axialmovement from the core top to the core bottom in the OTTO refueling scheme. Freshfuel pebbles at the core top with a high value of k∞ cause an excessively high axialpower peaking factor.

The axial power profile resembles that in the initial core filled only with freshfuel and a minimum power peaking factor might be obtained if the axially constant k∞distribution is attained. For this study, a BP loading principle was proposed to eliminatethe problem of such an axial high power peaking factor in pebble bed HTGR withOTTO refueling. This principle states that the axial power peaking factor can beminimized when k∞ of the fuel pebbles is kept constant during the pebbles’ axialmovement by adding BP optimally into the fresh pebbles.

Another principle was proposed by Haling for refueling optimization in LWRs.The Haling principle states that if a power distribution is maintained as constant duringthe operating cycle and k∞ at power peak region is lowered through proper managementof soluble poison, solid absorbers, and control rods, then the power peaking factor willbe minimized [3].

III. DESIGN OF THE FUEL PEBBLE WITH Gd2O3

The PBR with a long core height has the large variation of fuel burnup levelsfrom the core top to the core bottom when operating with the OTTO scheme. The largeinfinite multiplication factor, k∞, of the fresh fuel at the core top causes a high powerpeak. Therefore, spherical BP particles are added into the fuel pebble to flatten the axialpower profile through controlling the k∞ during burnup. The idea of using the BPparticles is to take the advantage of a strong geometrical self-shielding effect for long-term reactivity control. If the BP particle radius is large enough in comparison to thethermal neutron mean free path inside it, the particle can be characterized as a black

VINATOM-AR 11--03


absorber. The effective macroscopic absorption cross section of black particles isapproximately given as [5]:

2

00

020 4

)(1)(

Φ−=Σ ∫

RN

dttRnt

t

pa , (1)

where np is the number of BP particles, R0 is the initial radius of the BP particle,and N0 is the initial atomic number density of absorbing nuclides inside the particle. Itcan be seen that the effective macroscopic absorption cross section of the black particlesdepends only on the radius and the number of BP particles, but not on the absorbingnuclide concentration. Application of the BP particles for long-term reactivity controlhas been investigated in several HTGR designs [3][4][6][7].

In previous studies, a proposed optimal BP loading principle stated that the axialpower peaking factor of the OTTO scheme could be minimized when the k∞ of the fuelpebble was maintained constant during its axial movement by adding BP optimally intothe fuel pebble [3][4]. The effectiveness of the principle was confirmed in a 600 MWtPBR design with various BP materials. In that design, the fuel pebble with 9 g uraniumand 16 wt% 235U enrichment was selected for a target burnup of 100 GWd/t.Meanwhile, in the current multi-pass scheme of the PBMR, the target burnup of about90-95 GWd/t can be achieved for the same fuel pebble [8].

It is obvious that using BP will decrease the fuel burnup performance, i.e.decrease the fuel utilization efficiency. The present study estimates quantitatively thefuel burnup performance of the OTTO scheme based on the PBMR design incomparison with the reference multi-pass one. Spherical Gd2O3 particles are used as aBP for controlling the axial power profile. Since reducing the power peak andincreasing the burnup performance are contrary objectives, the BP parameters aredetermined to maximize the fuel burnup performance while maintaining the power peakunder an acceptable limit. For this purpose, the radius and number of Gd2O3 particlesare determined for obtaining a flat k∞ curve in the early burnup stage, e.g. from theinitial burnup to about 57 GWd/t in thiscase. The maximum power density of areference multi-pass scheme is used asthe power limit of the OTTO scheme.

Unit cell lattice calculations havebeen performed for designing the Gd2O3

parameters in the fuel pebble using theMVP code. MVP is a general purpose,continuous energy, Monte Carlo neutrontransport code developed by JapanAtomic Energy Agency [9]. The unit celllattice model consists of one central fuelpebble and a surrounding coolant layer.The TRISO-coated and Gd2O3 particlesare distributed randomly in the free fuel

Helium

Outer graphite skin

Graphite matrix

B4C particle

TRISO-coated fuel particle

Fuel kernelBufferInner PyCSiCOuter PyC

50 mm60 mm

70.7 mm

Figure1: Unit cell lattice model in MVP

VINATOM-AR 11--03


zone using the statistical geometry model of MVP as depicted in Fig. 1. The JENDL-3.3library was used for cross section preparation [10].

For the fuel pebble of the PBMR with 9 g uranium and 9.6 wt% of 235U, the k∞decreases linearly and becomes less than 1.0 after about 80 GWd/t. The objective is toflat the k∞ curve from the initial burnup to about 57 GWd/t by adding Gd2O3 particles,i.e. maintaining the k∞ approximately about 1.06-1.08 in this burnup stage. This is toensure the core criticality when leakage effect is taken into account. In naturalgadolinium, two main BP nuclides of 155Gd and 157Gd comprise about 30% in all. Theirneutron absorption cross-sections and their burning rates differ. Because of the higherabsorption cross-section, 157Gd burns faster and is almost completely depleted beyondburnup of 80 GWd/t. Fig. 2 shows that the total 155Gd and 157Gd burning fraction isgreater than 0.99 at the target burnup of 100 GWd/t. As depicted in Fig. 3, k∞ of the fuelpebble is kept almost constant during burnup and the reactivity swing is reducedrespectively from 38% to about 2% at the optimized radii and quantities of Gd2O3

particles.

The radius and the number of Gd2O3 particles are determined by following twosteps.

1) Determine the particle radius so that the k∞ is controlled up to 57 GWd/t andgadolinium is burnt mostly after this burnup level.

Figure 2: Atomic number density changes of gadolinium with burnup

2) Determine the number of Gd2O3 particles in the fuel pebble to flatten the k∞curve from the initial burnup to 57 GWd/t.

VINATOM-AR 11--03


Figure 3: k∞ changes with the optimal Gd2O3 loading

MWd/tonNoBP R740NUM13

K-inf Error (%) K-inf Error (%)

0.00E+00 1.422 0.027 1.103 0.043

5.00E+01 1.390 0.034 1.084 0.037

5.00E+02 1.380 0.030 1.080 0.036

5.00E+03 1.345 0.027 1.081 0.043

1.00E+04 1.311 0.034 1.081 0.031

2.00E+04 1.247 0.029 1.073 0.041

3.00E+04 1.190 0.031 1.071 0.035

4.00E+04 1.141 0.031 1.073 0.035

5.00E+04 1.099 0.031 1.071 0.032

6.00E+04 1.061 0.032 1.053 0.026

7.00E+04 1.027 0.030 1.024 0.032

8.00E+04 0.996 0.032 0.993 0.032

9.00E+04 0.965 0.045 0.965 0.024

1.00E+05 0.936 0.032 0.938 0.036

VINATOM-AR 11--03


For the requirements that the k∞ is controlled up to 57 GWd/t and gadolinium isburnt mostly after this burnup level, the particle radius of 740 µm is selected in the firststep. Increasing the number of particles will decrease the k∞ curve in the early burnupstage. After about 57 GWd/t, the k∞ decreases with burnup similarly in all cases ofparticle numbers and in case of the original fuel. The parameters of 13 particles and 740µm in radius are selected to satisfy the requirement of flattening the k∞ curve in theearly burnup stage.

IV. CONCLUSIONS

The fuel burnup performance has been analyzed for fuel pebble of the 400 MWtPBMR with the OTTO refueling scheme and compared with that of the current fuel. Anew fuel pebble has been designed by adding spherical Gd2O3 particles for controllingthe k∞ during burnup in order to reduce the axial power peak of the OTTO scheme. TheGd2O3 parameters of 13 particles and 740 µm in radius are selected to obtain a flat k∞curve in the early burnup stage. The results show that k∞ of the fuel pebble is keptalmost constant during burnup and the reactivity swing is reduced respectively from38% to about 2% at the optimized radii and quantities of Gd2O3 particles; the total 155Gdand 157Gd burning fraction is greater than 0.99 at the target burnup of 100 GWd/t.

ACKNOWLEDGEMENT

This work has been conducted using the resources of Institute for NuclearScience & Technology (INST), Hanoi.

REFERENCES

[1]. GIF, A technology roadmap for generation IV nuclear energy systems, GIF-002-00, 2002.

[2]. Hansen, U., Schulten, R., Teuchert, E., Physical properties of the “once throughthen out” pebble-bed reactor. Nucl. Sci. Eng. 47, 132–139,1972.

[3]. Tran, H.N., Kato, Y., Muto, Y. Optimization of burnable poison loading for HTGRcores with OTTO refueling. Nucl. Sci. Eng. 158, 264–271, 2008.

[4]. Tran, H.N., and Kato, Y. An optimal burnable poison loading principle for HTGRcores with OTTO refueling. Nucl. Eng. Des. 158, 264–271, 2009.

[5]. Van Dam, H. Long-term control of excess reactivity by burnable particles. Ann.Nucl. Energy 27, 733–743, 2000.

[6]. Kloosterman, J.L. Application of boron and gadolinium burnable poison particlesin UO2 and PuO2 in HTRs. Ann. Nucl. Energy, 30, 1807–1891, 2003.

[7]. Talamo, A. Effects of burnable poison heterogeneity on the long term control ofexcess of reactivity. Ann. Nucl. Energy, 33, 794–803, 2006.

[8]. Boer, B., Kloosterman, J.L., Lathouwers, D., van der Hagen, T.H.J.J. In-core fuelmanagement optimization of pebble-bed reactors. Ann. Nucl. Energy 36, 1049–1058, 2009.

[9]. Nagaya, Y., Okumura, K., Mori, T., Nakagawa, M. MVP/GMVP II: Generalpurpose Monte Carlo codes for neutron and photon transport calculations based on continuousenergy and multigroup methods. JAERI-1348, 2005.

[10]. Shibata, K., et al. Japanese evaluated nuclear data library version 3 revision-3:JENDL-3.3. J. Nucl. Sci. Tech. 39, 1125, 2002.

VINATOM-AR 11--04


MODELING OF PRESSURIZER OF THE PRESSURED WATERREACTOR (PWR) USING RELAP/SCDAPSIM CODE

Le Thi Thu, Pham Tuan Nam, Nguyen Thi Thanh Thuy and Nguyen Thi Tu Oanh

Institute for Nuclear Science and Technology,VINATOM179 Hoang Quoc Viet, Nghia Do, Cau Giay, Hanoi, Vietnam

Abstract: Nowaday, there are many thermal hydraulics code base on the best estimatemethod such as: CATHARE, TRACE, COBRA, RELAP… RELAP/SCDAPSIM is oneof the thermal hydraulics codes for using the safety analysis of the nuclear power plant(NPP). It is used to modeling for the thermal hydraulics systems in NPP. It can modelthe systems in many different case like steady state, transients and design basicaccidents. The purposes of the study are enhancement of experiences to usingRELAP/SCDAPSIM code and modeling for components in nucler power plant. In thisstudy, the pressurizer has model in the steady state and transients conditions byRELAP/SCDAPSIM code. The scenariors have been built by the pressure changes thatleading operation of safety valves, spray valves and heaters. They have been opened bycontrol trips.

I. STRUCTURES, FUNCTIONS, PRINCIPLES OF THE OPERATIONOF PRESSURIZER

In this part, studied about the structures, the functions, the principles ofoperation and the main parameters of the pressurizer. The main parameters of thepressurizer in AP1000, VVER1000, APR1400 design were mentioned.

Figure 1 illustrates the structures of the pressurizer. The main components, suchas: the pressured tank, the heaters, the safety valves and the spray valves etc. Theoperation of this components is activated by the pressure and the water level changes.







Thermal-Hydraulic analysis of transients in pressurizer of reactor VVER-1000using RELAP/SCDAPSIM Code; Le Thi Thu and Le Dai Dien; Proceeding of the2nd conference on nuclear science and technology of young staff. Ha Noi, October2012.


VINATOM-AR 11--04


Figure 1: Structure of the pressurizer of the pressured water reactor

II. MODELING OF PRESSURIZER BY RELAP/SCDAPSIM CODE

In this part, modeled the pressurizer in VVER1000 design. Figure 2 shows thenodaliztion of the pressurizer in VVER1000 design. The main data of the pressurizer ofVVER1000:

Total volume: 79 m3

Nominal water volume: 55 m3

Water level: 8.77 m

Total height of tank: 12.7 m

Inner diameter: 3.0 m

Outer diameter: 3.3 m

Number of heaters: 28

Total power of heaters: 2520 kW

Working temperature: 346 °C

Working pressure: 15.7 Mpa

Design pressure: 17.7 Mpa

The hydrodynamic components: the surgeline C343, the pressured tank C341and C340, the spray valve V338 and the safety valves V344, V346 and V348. The heatstructures: the wall surgeline HS343-0, the wall pressured tank HS341-0 and HS341-1,the heaters heat structure HS341-2.

VINATOM-AR 11--04


Figure 2: Nodalization of the pressurizer of VVER-1000

III. BUILD THE INPUT FILE

The built structures included the hydrodynamic components, the heat structuresand the control trips. There were four scenarios in this part: the steady state, the pressureincrease transient, the water level increase transient and the pressure decrease transient.

IV. RUN PROGRAME AND ANNALYSE

With the built scenarios in above part, the thermal hydraulic parameters(pressure, temperature, water level) were analyzed. In case one (the steady state), Theresult were compareted with the design data. The errors were less 6 percent. In othercases, the events built corresponding with the transients of the actual pressurizeroperations. In this cases, the some results illustrate from figure 3 to figure 6.

Figure 3: Pressure at the top head, case 2

VINATOM-AR 11--04


-10

0

10

20

30

40

50

60

0 5 10 15 20 25 30

Time, s

Mas

s flo

w ra

te, k

g/s

V344V346V348

Figure 4: Mass flow rate at the single safety valve, case 2

0.2

0.25

0.3

0.35

0.4

0 10 20 30 40 50 60

Time, s

liqui

d vo

id fr

actio

n

Figure 5: Volume liquid fraction at C34106, case 3

500

600

700

800

900

1000

0 10 20 30 40 50 60

Time, s

Tem

pera

ture

, K

httemp-341201httemp-341204

Figure 6: Temperature of the heaters, case 4

In 2 case, the pressure increases to the second set point of the safety valves (18.6Mpa). The safety valves open, the mass flow rate increases to 50 kilogam per second.This value is the design value. And then, the pressure decrease to the first set point ofthe safety valves (17.7 Mpa). The safety valves close, the mass flow rate is equal tozero.

VINATOM-AR 11--04


In 3 case, the pressure increases to the value which is lower than the set point ofthe spray valves and the safety valves. So this valves do not open. The importantphenomena is the water level change. The water level increase.

In last case, the pressure decreased to set point of the heaters. The heaters turnon. The temperature of heaters increase, so the liquid temperature and pressure increase.The pressure increases to 15.34 Mpa then the heaters turn off.

CONCLUSION

This contents of the study studied about the structures, the functions and theprinciple of the pressurizer of the pressured water reactor. Using RELAP/SCDAPSIMcode for modeling of the pressurizer in VVER-1000 design. The results in the last partwere analysed. The productions of the study are the report and one paper. The name ofthe paper: thermal hydraulic analysis of transients in pressurizer of reactor VVER-1000using RELAP/SCDAPSIM code. This paper is preparing to present at the nationalscientific conference of young staff in october 2012.

REFERENCES

[1]. Reactor coolant system, module 2. Doo-Jeong Lee. Principal Researcher PowerReactor System Technology Dept. Korea Atomic Energy Research Institute.

[2]. APR1400 Design Description. Center for Advanced Reactors DevelopmentNuclear Environment Technology Institute. Korea Hydro & Nuclear co., Ltd, 3.2002.

[3]. RELAP5/MOD 3.3 code manual, volume II: Appendix A input requirements.Nuclear Safety Analysis Division. Information systems laboraries, Inc.Rockvill, MarylandIndaho Falls, Idoha, December 2001.

[4]. RELAP5/MOD 3.3 code manual, volume V: User’s guidelines. Nuclear SafetyAnalysis Division. Information systems laboraries, Inc.Rockvill, Maryland Indaho Falls, Idoha,December 2001.

[5]. Pressurized Water Reactor Systems, Reactor concept manual. USNRC TechnicalTraining Center.

[6]. WWER-1000 Reactor Simulator. Material for Training Courses and Workshops,Third Edition. International Atomic Energy Agency, Vienna, 2009.

[7]. The dynamic modeling of the pressurizer surge tank transients in light waterreactor nuclear power plant. R. ZARGHAMI, F.JALALI, N.MOSTOUFI, R.SOTUDEH,K.SEPANLOO, F.DASTJERDI AND N.AHMARI. Dept. of Chemical Engineering, Universityof Tehran, P.O. Box: 11365-4563, I. R. of Iran and Dept. of National Nuclear Safety, AEOI,Tehran, P.O. Box: 14155-1339, I. R. of Iran.

[8]. The Westinghouse AP1000 Advanced Nuclear Plant. Copyright, WestinghouseElectric Co., LLC, 2003.

[9]. VVER-1000 Coolant Transient Benchmark. Nuclear energy agency organizationfor economic co-operation and development.

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RESEARCH AND DEVELOPMENT OF A PILOTFIRST GENERATION PGNAA OFF-BELT SYSTEMFOR ANALYSING OF COMPOSITION OF CEMENT

AND BAUXITE RAW MATERIAL

Tran Thanh Minh1, Mai Cong Thanh1, Do Trong Vien1, Ngo Duc Tin1,Le Trong Nghia1, Phan Quoc Minh1, Dang Nguyen The Duy1 and Dang Quang Thieu2

1Centre for Applications of Nuclear Technique in Industry,VINATOM13 Dinh Tien Hoang, Dalat, Vietnam

2Institute for Nuclear Science and Technology, VINATOM179, Hoang Quoc Viet, Nghia Do, Cau Giay, Hanoi, Vietnam

Abstract: With purpose of development of the PGNAA system which can operate onthe field in the condition of considerably changing of temperature and moisture, a multichannel analyzer-MCA 2k was designed and developed, which can compatibly operatewith BGO detector, connected with computer through USB 2.0 port. Beside that, asoftware for obtaining and displaying the prompt gamma spectrum, with the spectrumstability function and convenience in the data was also designed and developed. Thefirst generation PGNAA system was experimented in the changing condition oftemperature in the laboratory. The result give out that the prompt gamma spectrum wasstability during temperature changing, the peak area of the elements in the sampleschanged about 7%. Besides that, the first generation PGNAA system was alsoexperimented to analyze the cement and bauxite samples. The result was also matchedwith the other analysis methods such as chemistry method and INAA method with thedifference about 10%.

Keywords: PGNAA, MCA, MOCA, DECO

I. MULTI-CHANNEL ANALYSIS-MCA SYSTEM

Based on the characteristics of the BGO detector, research group had built aMCA system which can operate compatibly with it and accordantly with therequirements of the PGNAA analysis.

The parts had been developed in the project

- Amplifier board (Amp);

- Analog to digital convertor board (ADC);

- Multi-channel Analyzer board (MCA);

Project Information:- Code: CS/09/06-02- Managerial Level: Institute- Allocated Fund: 60.000.000 VND- Implementation Time: 12 months (Jun 2009-May 2010)




VINATOM-AR 11--05


- Power supply and battery charger;

- Control program in computer;

Figure 1: Principle diagram of the MCA system

I.1. Amplifier board

Amplifier board is manufactured in accordance with signals from thepreamplifiers of the BGO detector. The board includes: Positive/Negative pulse signalreversing circuit (+/- Signal), amplifier circuits include fine gain and coarse gain circuit,tail (Pole Zero) cancellation circuit, pulse shaping circuit and baseline restorationcircuit.

Figure 2: Block diagram of the Amp board

Pre AMP+/- Signal and Pole-

Zero cancellation

Fine gainBaselinerestoration

Coarse gain Pulseshaping

Buffer

ADC

Power supply

Amp ADC MCA

BGOdetectorPreAmp

Computerwith

controllingprogram

DC supplier

Amplifier ADC Signal processer

BGOdetector

PC

VINATOM-AR 11--05


The input signal from Preamplifier has amplitude about few hundred mV. Itgoes through Positive/Negative pulse signal reversing and tail (Pole Zero), cancellationcircuit. After reducing the pole-zero circuit, signal is amplified by coarse gain amplifier.

After that, the signal continues going through the Pulse shaping to convert to thestandard Gaussian signal and is amplified at fine gain amplifier circuit. The fine gain isadjusted by DAC0808LCN chip and controlled by a program in computer.

The signal continues going through the baseline restoration and a bufferamplifier circuit before going to the ADC board.

I.2. Analog to digital convertor board

Principle of operation: analog signal from the amplifier board goes through acapacitor to store the current from pulse signal. ADC control the discharge current Ilinearly with I0 and the discharge timing of the pulse signal to convert from analog intodigital signal, then save to a memory. The operating process of extending peak pulsecircuit is controlled by a logic circuit. The Logic circuit is responsible for detectingspectral peaks and put the above and below threshold of the pulse signal which ADCcan detect it. The process logic is designed as follows:

At the beginning, the capacitor discharges the current in circuit and the gate inADC is set at the low Gate level to get the input pulse signal. When pulse signal goesthrough ADC, the extending peak pulse circuit can operate and ZLD in ADC changefrom low to high level to control the capacitor charge. When the capacitor C is full, thePD signal changes from high to low and logic control circuit signals the onset of ADCfor ADC start analyzing, and bring forbidden from low to high GATE signal to not getinput pulse signal. After ADC analyzes the signal, it takes an EOC signal to stop theprocess and ready for the next similar process.

Figure 3: Block diagram of ADC

LL

AmplifierLL

Setthreshold

Extending peak(Stretcher)

Discharge

Logic control

Input Data

ST

AR

T

EO

C

GA

TE

ZL

D

PD

UL

ChipADC

Recover(Sliding)

VINATOM-AR 11--05


1

1

2

2

3

3

4

4

5

5

6

6

7

7

8

8

D D

C C

B B

A A

Title

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Date: 9/6/2010 Sheet ofFile: D:\My Protel\USB_MCA\adc_12.SCHDOCDrawn By:

C101N

R933

GND

53

26

74

8

1

U2

LF356AN8R650K

10V

-6V

C6

100N

C8

100N

GND

GND

53

26

74

8

1

U1

LF356AN8

10V

-6V

C7

100N

C5

100N

GND

GND

R5

1K5

2

31

T6C535

GND

R11

1K

GND

D1

1N4148

R1412k

R121k

-6V

K1

K2

12

3

4

56

7

8 U8LM311N

12

3

4

56

7

8

U9

LM311N

12

3

4

56

7

8 U10

LM311N

53

26

74

8

1 U5LF356N8

+10V

-6V

C9

100N

C13100N

GND

GND

R3

2k

R10

2k

GND

+10V

-6V

C15100N

C19

100N

GND

GND

31

2RV4

1k

GND

R20

5k6

R1511k

+10V

R215k6

C21

20pF

C20100N

GND

R175k6

VCC

ThD

+10V

-6V

C24100NGND

C25

100N

GND

GND

C27

20pF

R235k6

VCC

LL

31

2RV51k

R25

5k6

GND

R2211k

+10V

C26100N

GND

R24

5k6

+10VC29

CAP1

C37

CAP1

GND

GND

GND

-6VC43

20pF

R295k6

R31

5k6R32

5k6

VCC

31

2RV6

10k

R335k6

R285k6

+10V

GND

C38100N

GND

C16

10PF

C32

100PF

R181.5K

VCC

1

23

U14A

74HC00

4

CLK3

D2

1

Q 5

Q 6CLR

PRU11A

74HC74

10

CLK11

D 12

13

Q9

Q 8CLR

PRU11B

74HC74

VCC

CS0

CLR

10

CLK11

D12

13

Q 9

Q 8CLR

PRU12B

74HC74

VCC

56

4U14B

74HC00

R301.5K

VCC

PULSE

TH

VCC

UL

VCC 24

I 23

GND12

I/O 22

I/O 21

I/O 20

I/O 19

I/O 18

I/O 17

I/O 16

I/O 15

I 14

I/O 13

I1

I2

I3

I4

I5

I6

I7

I8

I9

I10

I11

G1

*

89

10

U13C

74HC00

CLR

4

CLK3

D2

1

Q 5

Q 6CLR

PRU12A

74HC74

TCGND

CKTHLLULLENPULSEBUSYENATC

K1K2SADCINT0CLR

VCC

GND

1112

13

U13D

74HC00 1

23

U13A

74HC00

56

4U13B

74HC00

1 2Y1

10MHZ

C28

100P

R26

2K2

R27

2K2

C3320PF

C3420PF

GND GND

CK

DB9 1DB10 2DB11 3

AVD4

REF5

VIN6

AGND7

CS8

RD9

CONST10

CLK11

BUSY12 DB0 13DB1 14DB2 15DB3 16DB4 17DB5 18

GND19

VDD20

VD

R21

DB6 22DB7 23DB8 24

U15

AD7472

CSRD

DB11DB10DB9DB8DB7DB6DB5DB4DB3DB2DB1DB0

VCC

U6LM336

53

26

74

8

1

U3

CA3140GND

VCC C3

100N

GND

31

2

RV25K

GND

R71K

C12100N

GND

VCC

VREF

VREF

GND

VCCC22

100NC23

10UF

GND

GND

CSRDSADCCLKIN

CLKIN

A4 8A5 9A6 10A7 11A8 12VDD13

VREF+14 VREF-15

COMP16

A3 7

NC1

GND 2VEE3

IOUT-4

A1 5A2 6

U7

DAC0808LCN

GND

-6V

VCC

53

26

74

8

1

U4LF356N8

10V

-6V

31

2

RV110K

GND

C2

100N

C11

100N

GND

GND

R2

1K

C17100PF

C14

100N

C18

100N

GND

GND

R16

1KGNDR1930KRV3

5K

VREF

1234

JP5

Header 4 GND

C30220UF

C35220UF

C40100N

GND

GND

GND

C41100N

C42100N

C39220UF

C31100N

C36100N

GND

+10V

-6VGND

VCC

GND GND GND

1112

13U14D

74HC00

VCC

C44

470pF

R3410k

VCC

BUSY

BUSY

VCC

CLR

89

10U14C

74HC00

D4

1N4148C60

100PF

C61

20PF

R1310K

GND

3V3C47

100N

GND

IN3

GN

D1

OUT 2

U22 LM1117

VCC

GND

3V3

C50220UF

C51100N

C52100UF

GND GND GND

P1

BNC

GND

R410K

-6V

T2C535

OE 19

T/R1

A1 3B117

A2 4B216

A3 5B315

A4 6B414

A5 7B513

A6 8B612

A7 9B711

A0 2B018

VCC20

GND 10

U20

SN74HCT245N

OE 19

T/R1

A1 3B117

A2 4B216

A3 5B315

A4 6B414

A5 7B513

A6 8B612

A7 9B711

A0 2B018

VCC20

GND 10

U19

SN74HCT245N A0 1

A1 2

A2 3

OE2 4

OE3 5

OE1 6

Y77 GND 8Y69 Y510 Y411 Y312 Y213 Y114 Y015

VDD16U21

MC74HC138AN

1 23 45 67 89 1011 1213 1415 1617 1819 20

JP2

Header 10X2

D7D6D5D4D3D2D1D0

INT0

A0A1A2A3A15WRRDT0T1

GND

OE1

CLK 11

D1 2Q119

D2 3Q218

D3 4Q317

D4 5Q416

D5 6Q515

D6 7Q614

D7 8Q713

D8 9Q812

VCC20

GND 10

U16

SN74HC574N

OE1

CLK 11

D1 2Q119

D2 3Q218

D3 4Q317

D4 5Q416

D5 6Q515

D6 7Q614

D7 8Q713

D8 9Q812

VCC20

GND 10

U17

SN74HC574N

3V3

3V3

C45

100N

C46

100N

GND

GND

123456789

10

JP1

Header 10

GNDGND

GND

GNDGND

GND

D0D1D2D3D4D5D6D7

D0D1D2D3D4D5D6D7

GND

3V3

3V3

C48

100N

C49

100N

GND

GND

GND

GND

GND

DB0DB1DB2DB3DB4DB5DB6DB7

DB8DB9DB10DB11

D0D1D2D3D4D5D6D7

D0D1D2D3D4D5D6D7

R35200

R8

1KGND

CS1

CS2

CS3

CS4

3V3

GND

CS0CS1CS2CS3CS4CS5CS6CS7

A0A1A2

A15A3

56

4U18B

MC74HC00AN

89

10

U18C

MC74HC00AN

1112

13

U18D

MC74HC00AN

A 1

B 2

Y3

VD

D14

GN

D7

U18A

MC74HC00AN

RD

WR

T0

12

JP3

Header 2 GND

3V3 GND

R3622K

C1

10PF

T1

1N4148

Figure 4: Principle diagram of ADC

I.3. Multi-channel analyzer board

The function of MCA board is acquisition, addressing, store the signal in RAMand connect to computer, allowing users to control Fine Gain from the computer.

Data from ADC (12 bit) was taken to BUS data (D0 - D7) through LATCHDATA (8 bits) and LATCH DATA (4 bits). This process is controlled by theDECODER ADDRESS (DATA ports and the DECODER is put in ADC). MEMORYRAM is used to store data. It is addressed from the central processing unit (CPU).Spectral data from the CPU is transferred to the computer via USB. These functions areintegrated on a AN2131 EZUSB chip.

- Some parameters of the AN2131 EZUSB chip is follow :

+ High-speed 8051-based USB Device with Two UARTs;

+ Dual DPTRs, 13 Interrupts / 4 Priority Levels;

+ 24 I/O Lines;

+ 3 Timers/Counters;

+ 3.3V Operation;

+ ROMless;

+ 256 Bytes On-chip RAM;

+ 8K Bytes XRAM 8KB serial EEPROM.

- The ADC controlling program is written and compiled by Keil51 and storedin the EEPROM memory of the processor serial

VINATOM-AR 11--05


- MCA controlling program in the computer was written by LabView. It isresponsible for gathering data from processor chip, and perform the spectral processingon a computer screen. Controlling program also features a universal stability byautomatically adjust Fine Gain of amplifier circuit.

1

1

2

2

3

3

4

4

D D

C C

B B

A A

Title

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VCC02

VCC122

VCC242

VCC362

AVCC21

PA0/T0OUT68

PA1/T1OUT69

PA2/OE70

PA3/CS71

PA4/FWR73

PA5/FRD74

PA6/RD0 OUT75

PA7/RD1 OUT76

PB0/T244

PB1/T2EX45

PB2/RD146

PB3/TD147

PB4/INT452

PB5/INT553

PB6/INT654

PB7/T2OUT55

PC0/RD030

PC1/TD031

PC2/INT032

PC3/INT133

PC4/T038

PC5/T139

PC6/WR40

PC7/RD41

N/C67

WAKEUP66

RESET25

EA24

XOUT20

XIN19

A0 7

A1 8

A2 9

A3 10

A4 11

A5 12

A6 15

A7 16

A8 26

A9 27

A10 28

A11 29

A12 34

A13 35

A14 36

A15 37

D0 48

D1 49

D2 50

D3 51

D4 57

D5 58

D6 59

D7 60

SCL 65

SDA 64

USBD- 77

USBD+ 79

DISCON 1

BKPT 61

CLK24 4

PSEN 80

AGND 18

GND0 3

GND1 5

GND2 6

GND3 13

GND4 14

GND5 17

GND6 23

GND7 43

GND8 56

GND9 63

GND10 72

GND11 78

U4

Y124MHZC10

27pF

C9

27pF

GND

GND

GND

R21

10k

R20

10k

GND

3.3V

R2210k

GND

C81uF

3.3V

1234

JP5

Header 4

VCC

GND

R15

22

R19

1k5

R17

22

E0 1

E1 2

E2 3

GND 4

SDA5 SCL6

WC 7

VCC 8U1

M24C32BN1

GND

R14

10kGND

3.3V

C7

100N

GND

R1110k

R1210k

3.3V3.3V

A0A1A2A3

A15

D0D1D2D3D4D5D6D7

WR

RD

D0D1D2D3D4D5D6D7 A0

A1A2A3A15WRRD

GND

C6100N

C5100N

C4100N

C3100N

C2100N

GND

R110 R2

10 R310 R4

10 R510

C1

1uF

GND

3.3V

2

34

VCC 8

1 6

7

GND5

D

R

A

B

U2

MAX485CSA

2

34

VCC 8

1 6

7

GND5

D

R

A

B

U3

MAX485CSA

GND

GND

VCC

VCC

R18120

GND

VCC

12

J1

CON2

12

J2

CON2

VCC

GND

R13

500

R161k5

GND

R23120

GND

VCC

1 2 3 4 5 6 7 8 9 10

JP1 LCD

GND

LCD

0LC

D1

LCD

2LC

D3

RS_L

CD

EN_L

CD

R6

3kGND

LCD0LCD1LCD2LCD3EN_LCDRS_LCD

12345678

JP4

Header 8GND

R7

10kR8

10kR9

10kR10

10k

3.3V

INT0

INT1

T0 T1

INT0INT1T0T1

PA6PA7

1234567

JP3

Header 7

PA6PA7

12

JP6

Header 2

C13

100NC14

100N

C15100N

C16470uF

VCC

GND

IN3

GND 1OU

T2

U5

LM1117

GND

C12

100N

C11

220UF

VCC

3.3V

GND

1 23 45 67 89 1011 1213 1415 1617 1819 20

JP2

Header 10X2

INT0INT1

T0T1

Figure 5: Principle diagram of MCA board

I.4. Power supply and battery charger

Power supply

The electronics in the MCA operate with 5V - 12V DC voltage, and from100mA to several hundred mA current. So it’s necessary to power supplies:5VDC_300mA, ± 12VDC_150mA, 9VDC_100mA granted to the electronic devices inthe circuit.

1

1

2

2

3

3

4

4

D D

C C

B B

A A

Title

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+IN1

+IN2

-IN3

-IN4 COM 5

+OUT 6

COM 7

-OUT 8*

BWR_DCDC

12

JP7

Header 2C9100N

C10100N

GND

GND

GND

C7100N

C8100N

C11100N

C12100N

GND GND

GND GND

-12V

1234

JP5

Header 4

GND

+12V-12VVCC

12

JP6

Header 2

GNDVCC

ON

/OF

F5

CO

M3

VIN1 FB 4

VOUT 2

U1 LM2575

GNDGND

21TR1

TRAN2

GND

C5100N

C6100N

GND GND

VCC

D1

12

JP8

Header 2

GND

GND

AD

J1

OUT 2VIN3

U3 LM317A

3 1

2

RV15k

R21

RES1

+V

C16470UF

C17470UF

+12V

T6 D438

1 3

2

T5

A1315

R23

10

R25

10

C15100UF R26

1kGND

C14100UF R24

1kGND

C18100N

C19100uF

GND GND

123

JP?

Header 3

GND+12V

-12V

GND+V

C13100N

C14100N

GND GND

Figure 6: Principle diagram of Power supply

VINATOM-AR 11--05


Battery charger

MCA use power from the battery to maintain operation. It’s necessary to makean automatic battery charging circuit with functions: status battery full / empty, whilelower than the battery that allows the interrupt circuit works operational.

1

1

2

2

3

3

4

4

D D

C C

B B

A A

Title

Number RevisionSize

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Date: 1/3/2012 Sheet ofFile: D:\My Data\..\Battery ChargerNew.SCHDOCDrawn By:

IN3

1

OUT 2

ADJ

U1 LM317T

12

JP3Header 2

C9

470uF

R13600

R162.2

RV25k

12

JP1

ACQ

D4

1N4007

GND

R103K3

DS4LED0

T5

C828

T4

C535

GND

R11

3k3

R182k

GND

T3

A564

VCC R7100k

R8100k

VCC

R54K7

R4100K

T2

A564

GND

VCC

GND

VCC

R6100K

K2

K1

12

JP2

Header 2

S2

SW-SPST

C10220uF

GND GND

VCC

C5100N

GND

C11100uF

GND

GND

VCC

VCC

GND

123

RS-1

100nFC8

33pFC6

33pFC7

10uFC3

10uF

C2

1MHzU2*

RA0/AN0 2

RA1/AN1 3

RA2/AN2/VREF- 4

RA3/AN3/VREF+ 5

RA4/T0CKI 6

RA5/AN4/SS 7

RB0/INT21

RB122

RB223

RB3/PGM24

RB425

RB526

RB6/PGC27

RB7/PGD28

RC0/T1OSO/T1CKI11

RC112

RC213

RC3 14

RC4 15

RC5/SDO 16RC6/TX/CK17

RC7/RX/DT18

VSS

8

VSS

19M

CL

R/V

PP1

OSC1/CLKIN9

OSC2/CLKOUT10

VD

D20

U3

PIC16F876-04/P

S1

RESET

1

23

U4A

CD4011BMN

5

64

U4B

CD4011BMN

R17

10kD31N4148

D21N4148

VCC

GND

GND

K1K2

GND

31

2

RV110k

C4100N

GNDGND

VCC

GND

GND

R2

590K

R3

100KGND

C1

100

GND

DS1LED1

R93K3

R15

1K

R14

1K

DS2

LED1DS3

LED1

VCC

D51N4007

D6

1N4007

GND

R12

2/5W

T1

A671

VDD

D1

1N4148R1

120K

2

31

Q1

C828

IN1

4

OUT 3

GND

U5

L78M05CDT

RV31k

T6

A671

R19

680K

R20

100KGND C12

100

GND

GND

R222K

R231K

GND

R21

2K2

GND

Figure 7: Principle diagram of Battery charger

- The completed Multi-channel Analyzer

Figure 8: Multi-channel Analyzer

VINATOM-AR 11--05


II. DESIGN AND DEVELOPMENT OF A PROGRAM FORDISPLAYING THE GAMMA SPECTRUM

The software interface includes Controller block (controls to start/stop receivingdata, clear spectrum, end program and spectrum stabilization), Timer and Amplifierblock (displays Preset time, Elapsed time, position for H0 Channel importing and has abutton controls spectrum stabilization), Parameters block (display some spectrumparameters as the total count, counting rate, region of interest, count in this region andFull Width at Half Maximum), Display Spectrum block (has buttons switch displayingmode channel/energy, linear/log, on/off spectrum smooth mode and save/open button),down side is the chart display spectrum received or opened from an existing file.

Figure 9: MCA’s spectrum receiving and displaying software interface

Controller block: includes buttons Calib used to measure the initial spectrum,which gather position of standard H0 channel used in stabilizing the receiving spectrum;Start button is used to begin getting data from MCA device; Stop button is used in endreceiving data; Clear button is used to erase instant data; Exit button is used to log offthe software).

Timer and Preamplifier block: displays the total counting time set up beforestart counting through Preset time, when the software opened it will be 100 in default;displays real counting time through Elapsed time, this parameter will be given directlyfrom the chip can be integrated in MCA; includes position to import the H0 Channelused in spectrum stabilization; includes Stable Spectrum button used to start receivingspectrum after importing H0 channel, at this time the received spectrum will haveHydrogen peak at position 300 channel.

Parameters block: displays some spectrum basic parameters such as the totalcount Sum; counting rate Rate; two margins of the region of interst L_ROI and R_ROI;count received in this region SCA Cnts; full width at half maximum FWHM(%), thisparameter can be calculate by lots of formulas, but in this software we use:

VINATOM-AR 11--05


Block Parameters: Block Parameters present for the user to observe some basicparameters of the spectrum which is recorded as the total count Sum; total count rateRate; two minutes of the position and interest L_ROI R_ROI Issue counts recorded inthe SCA interested CNTs; thickness half FWHM (%), half the thickness is more but forthe formula program, we use the formula:

Display Spectrum block: includes button switch displaying modechannel/energy; button switch displaying mode linear/log; button switch on/offspectrum smooth mode; besides, it also includes save/open spectrum button.

Chart display: display the received spectrum. When being displayed, thespectrum can be zoomed out/in, shows the spectrum file address if it is opened from ainitial file, add the constant converting between channel and energy. With an accuracyconverting constant, we can get both radiation count and radiation energy without stopcounting.

III. ANALYSIS OF BAUXITE & CEMENT SAMPLE ON PGNAA OFF-BELT SYSTEM

Content of the samples of bauxite, cement compared with the values calculatedby INAA and chemic method are presented in Table III.1:

Table III.1. Concentration of the oxides in the bauxite and cement samplesanalyzed by PGNAA method.

Sample SiO2 (%)Fe2O3

(%)Al2O3

(%)CaO(%)

MgO(%)

TiO2(%)

Bauxite 1 9.2±0.4 23.7±0.9 34.8±0.6 2.3±0.2

Bauxite 2 8.4±0.3 21.2±0.2 37.3±0.7 2.1±0.3

Bauxite 3 3.9±0.3 25.5±0.4 38.1±0.8 2.1±0.4

Bauxite 4 8.6±05 21.1±0.6 38.4±0.2 1.1±0.5

Cement 1 19.6±0.5 7.0±0.7 5.3±0.3 48.0±0.4 2.9±0.4 0.6±0.6

Cement 2 47.5±0.6 5.7±0.3 6.3±0.4 38.7±0.3 2.3±0.5 0.8±0.6

Cement 3 26.1±0.7 5.3±0.5 8.1±0.5 49.7±0.3 3.2±0.5 0.7±0.7

IV. Evaluation results of the analysis

The cement and bauxite samples with different levels of the oxide content wasanalyzed and compared with values analyzed by INAA method and chemical method.The result is quite good match with those methods. But reliability is not high because itwas not comparable to a standard method of analysis.

VINATOM-AR 11--05


ACHIEVEMENTS

- Design and manufacture a 2k MCA channels successfully connected withBGO detector, communicate with computer through USB 2.0 port;

- Design and development of software acquisition and display multi-channelspectrum with spectral gamma function stable and can be accessed easily thegamma spectrum in the desired format for data processing;

- Study of gamma spectrum analysis algorithm to prepare to build a gammaspectrum analysis program for automatically given content component in thesample analysis.

REFERENCES

[1]. Wilde and Herzog, Online analysis of coal by neutron induced gammaspectrometry, J. Radioanal. Chem. 71, 253, 1982.

[2]. Wilde and Herzog, Prompt gamma neutron activation analysis of hard coal, ligniteand raw glass Mixture row, Nucl. Geophys., 3, 467, 1989.

[3]. Yuren et al. Development and application of an on line prompt gamma neutronelement thermal analysis system, J. Radioanal. Nucl. Chem. 151.83, 1991.

[4]. B.D. Sowerby, C.S. Lim, et al. A New On-Belt Elemental Analyzer for the CementIndustry. Proc. 16th Int'l Conf. On the Application of Accelerators in research and industry, AIPconf. Proc. 576, p.1081, 2000.

[5]. M. Bosaru *, Z. Jecny, Application of PGNAA for Bulk Sample Coal in a 4Geomtry.

[6]. Cao Dong Vu, Pham Ngoc Son, Nguyen Nhi Dien, Study and foundation of thechemical components of raw material and powder of cement by PGNAA on neutron filter atDalat reactor, Proceedings of the fifth National Conference on Nuclear Science and Technology,Hochiminh City, 27 - 04/28/2003.

[7]. Pham Ngoc Son, Hai Nguyen Canh, Nguyen Xuan Quy, Tran Tuan Anh, DangLanh, Determination of hydrogen concentration in base rock by PGNAA, Proceedings of thefifth National Conference on Nuclear Science and Technology, Hochiminh City, 27-28 /4/2003.

[8]. Cao Dong Vu, Appling the research methods neutron activation analysis PGNAAinstant-reactor used for quality control problems in the cement production process, master'sthesis.

VINATOM-AR 11--06


APPLICATION PHOTODIODE TO DETERMINECHARACTERISTICS OF X-RAY

Nguyen Thi Bao My, Nguyen Van Si, Vu Van Tien and Nguyen Thi Thuy Mai

Institute for Nuclear Science and Technology,VINATOM179 Hoang Quoc Viet, Nghia Do, Cau Giay, Hanoi, Vietnam







Abstract: This study carried out based on the circuit design using BPW34 photodiodeto measure the attenuation of X-ray beam intensity when passing through the aluminumfilters of different thickness and analyze the results obtained. The instrument includetwo boards: the first board includes 4 x-ray probes(BPW34) with 4 aluminum filters ofdifferent thickness(0.5 mm, 2.5 mm, 5 mm; 10.5 mm) and circuit preamplifiers (TKD);the second board includes 4 amplifier output signals from the probe circuit, acomparator circuit, a PIC16F877A microcontroller with 4-channel analog-to-numberconverter (ADC). Signal after amplification is sent to the microcontroller's ADCconverted to digital, microcontroller calculate this data to for the results of high voltage(HV) current (I), exposure time (T). High voltage ratio linearly with the logarithm of theratio of the two signal channel, the time is equal to the time the signal exceeds thethreshold.

I. INTRODUCTION

Check the quality assessment of X-ray machine on a regular basis is a veryimportant because it directly affects the health of patients, who operate the equipment aswell as increased accuracy in the capture process projection.

At present, the research and manufacture of quality test equipment for X-raymachine has not been conducted in our country, all quality control equipment for X-raymachines are imported from foreign countries with very expensive price and warrantyrepair work very difficult

To reduce the cost of imported equipment and for ease of warranty repair, theresearch equipment, manufacture testing equipment X-ray machine in the country isessential. The results of this study is an important premise for the research andmanufacture test equipment quality evaluation for X-ray machine in the country.


VINATOM-AR 11--06


II. METHOD

II.1. Theoretical Foundations

Determination high-voltage of X-ray machine

High-voltage of X-ray machine proportional linear to the energy of emitted X-ray beam. Penetration of the beam depends on beam energy. So the intensity of X-raybeams when passing through a linear filter with high-voltage of X-ray machine.Analyses of X-ray beam after passing through two filters of different thickness aredetermined high-voltage.

Attenuation of X-ray beam when passing through the thickness of material: X-ray beam passing through the material when they interact with materials so energy, theirintensity decreased. Beam intensity has been reduced by the formula:

I=I0 e-µxBE(hν, Z, µx) (1)

Where:

I, I0: is the radiation intensity before and after passing through the materialthickness x.

µ: linear attenuation coefficient depends on the nature of the material layer

BE: cumulative energy coefficient taking into account the contribution ofscattered radiation. BE depends on the radiation energy (hν=eV), atomic number Z andthickness x of the material.

According to formula (1) the beam intensity after passing through a filter willdepend on the intensity before through the filter (I0), the energy of the beam (hν=eV),the nature and thickness the filter. With the filter is fixed, the intensity after passing thefilter depends on the energy and intensity of X-ray beam before passing through thefilter. Formula (1) can be rewritten as follows:

I=I0 e-µxD(hν) (2)

Where: D(hν)) dependent attenuation coefficient of radiation energy.

So when we take the ratio of the intensity of X-ray beam after passing throughtwo filters of different thickness will be a function that depends only on X-ray energy oraccelerating voltage.

I1/I2 = D(hν) e-µ(x1-x2)= D(eV) e-µ(x1-x2) (3)

Where:

I1,I2: the radiation intensity after passing through the material thickness x1, x2.

From there we can build the function depends of high-voltage on the logarithmof ratio of the beam intensity passing through two different filters.

Determination current of X-ray machine

Current of X-ray machine is proportional to the intensity of X-ray beam, we canbuild a function depends on the intensity of current-ray X-ray beam

VINATOM-AR 11--06


Determination exposure time of X-ray machine

We determined the exposure time by detecting the start signal and end signal.

II.2. Design

Figure 1: Block diagram of the circuit

When flying into the photodiode radiation at the exit of TKD have voltage signalproportional to the radiation intensity recorded photodiode. This voltage signal isamplified and the peak hold circuit is then converted by the ADC of the microcontrollerPIC16F877A. Electrical signal to the ADC has a magnitude proportional to the radiationintensity on photodiode flight. Microcontroller reads the ADC and calculation resultsfor the high-voltage values and current. Signal in channel 1 after amplification is sent tocomparator circuit for detecting the start and end signals.

Microcontroler

PC

Input 3

Input4

Input 2

Input 1

U1

U4

U2

U1

ADC

Amplifiercircuit

Peak holdcircuit

U1Âmplifiercircuit

Peak holdcircuit

U1Amplifiercircuit

Peak holdcircuit

U1Amplifiercircuit

Peak holdcircuit

Comparator circuit

U3

VINATOM-AR 11--06


III.RESULTS

Survey results on high-voltage of X-ray machine is represented by the chart inFigure 3

0

20

40

60

80

100

120

140

160

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Mea suring point

hig

h v

olt

age(

kV)

X-R ay

Measuringc ỉrc uit

Figure 3: Diagram of the measurement resultsof high-voltage measuring circuit with an error of 10%

Survey results on current of X-ray machine is represented by the chart in Figure 4

0

100

200

300

400

500

600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Mea suring point

Cu

rren

t(m

A)

X - R ay

Meas uringc ircuit

Figure 4: Diagram of the measurement resultsof current measuring circuit with an error of 10%

VINATOM-AR 11--06


Survey results on exposure time of X-ray machine is represented by thechart in Figure 5

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Mea suring point

exp

osu

re t

ime

(ms )

X-R ay

Meas uringc irc uit

Figure 5: Diagram of the measurement resultsof exposure time measuring circuit with an error of 10%

IV. CONCLUSION

From the above results show that the photodiode applications to design andmanufacture test equipment evaluate characteristics of X-ray machine is entirelypossible.

REFERENCE

[1]. Nguyễn Văn Đỗ. Các phương pháp phân tích hạt nhân. NXB Đại Học Quốc GiaHà Nội.

[2]. Mauro Gambaccini, Michele Marziani and Otello Rimondi, A fast non-invasivebeam check for mammography x-ray units, universita di Ferrara and Instituto Nazionale diFisica Nucleare (INFN),1994.

[3]. Richard Barnett Larry O’cull Saratt Cox, Embedded C Programming and TheMicrochip Pic.

VINATOM-AR 11--07


DEVELOPMENT OF A FAST PARAMETERSCALIBRATION METHOD FOR SACP USED IN THEEXPERIMENTAL REREARCH OF NUCLEAR DATA

AND STRUCTURES

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

Nuclear Reseach Institute,VINATOMNo.1, Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: The setting up of timing parameters in the experimental rerearch ofnuclear data and structures using SACP (Summation of Amplitutes Coincdent Pulses) orAnticoin is very important,especially for gamma spectrosmeters used large volumeHPGe detectors. If those parameters are not properly determined or incorrect, the relatedexperiments may lose of much significant signals. In this work, a new method for fastsetup of timing parameters for SACP has been developed and applied at NRI (NuclearReseach Institute).

I. INTRODUCTION

The SACP of NRI is specified of two HPGe detectors, a gamma-gammacoincidence spectrosmeter, a reactor base filtered thermal neutron beam and radiationshielding system. The Block diagram of electronic facility system is shown in Figure 1.

Figure 1: The gamma-gamma coincidence electronics.

Project Information:- Code: 26/CS/HĐ/NV- Managerial Level: Institute






VINATOM-AR 11--07


- Two HPGe detector with relative efficiency 20%,

- Two Amplifier 572A, ORTEC,

- Two ADC 8713, CANBERRA,

- Two Timing Filter Amplifier, ORTEC,

- Two Constant-Fraction Discriminator 584, ORTEC,

- Delay cable,

- Time-to-Amplitude Conveter 566, ORTEC,

- High Voltage Power Supply 660, ORTEC,

- NIM Model 4002D, ORTEC,

- An Indor developed Data acquisition interface PCI-7811R and controlprogram,

- Computer.

The characteristics of neutron beam at the tingzental channel No.3 are siliconfiltered thermal neutron, neutron flux th ≈1.4×106 at sample possistion, Cd ratio RCd ≈860 (measured with Au-197 foil, Cd cover 1mm in thickness), beam diameter of 1.2cm.

II. OBJECTIVE

To determine the dependence of the measured results of gamma peak count rateand integrate count rate on the parameters of the spectrometer.

To express an optimal routine for fast determination of SACP timing parameters.Given an exact experimental conditions, and more convenience for young researchersand graduated students.

III. CONTENTS

The proposed contents of project are as follows:

Study on characteristics of electronic function moduls of FFA, CFD, TAC,...Analysis of respond function of those moduls corresponding to different type of inputsignals from HPGe detectors.

Experimental survey of distribution properties of timing channel for the SAPC.

Analysis of experimental data to obtain the optimal respond functioncorresponding to different mode of instruments.

Based on the resulting respond function, an optimal routine for fastdetermination of SACP timing parameters has been compied and valided.

IV. METHODS

Using the experiment method to examine the distribution of functionalcharacteristics of each electronic unit, and building the response functions from themeasesured results of integrate and peak count rate when changing the timingparameters of the SACP instrument.

VINATOM-AR 11--07


V. RESULTS AND DISCUSSTION

The results of parameters set for the each electronic unit of the SACP system atNRI are presented in the Table 1.

Table 1: Optimal parameters for functional electronic units in the SACP system

Electronic Unit Parameter Input 1 Input 2

Aamplifier 572A

Gain 3.0 11.25

Coarse 100 20

Shapping time 3µs 3µs

Input Neg Pos

TFA 474

Coarse gain 20 6

Fine gain Max Max

Integrate Out Out

Diff 200 200

Input Non-Inv Inv

CFD 584Threshold 0.8 1.0

CF Delay (mode SRT) 32ns 32ns

TAC 566Range 50ns

Multiplier 10

Coinc. 414A Resolving time 60ns

Pulse width 1µs

ADC 7072

Gain/ Range: 8K/8K

ADC in pha

Coin/Anti: coin

ADC 8713

Gain/ Range: 16K/16K

ADC in pha

Coin/Anti: coin

Noted: when using different HPGe detectors, the parameters of TFA and CFDalso have to set differently. The determination of parameters of TFA and CFD can onlyby experiment, in which the measurement must be perfomed with the present HPGEdetectors. The using of a common set of parameters is not recomand.

VINATOM-AR 11--07


VI. CONCLUSION

The project has perfomed completely all of the proposed contents with goodresults in comperision with experimental values. The SACP system of NRI is calibratedand optimined with the set of parameters shown in Table 1. The routine for fastcalibration of SACP system has been developed and tested. This routine would beapplied for not only SACP system but also for others gamma spectrosmeters.

VII. PUBLICATION

1. Setting of parameters for timing filter amplifier and constant fractiondiscrimination of gamma-gamma coincidence spectrometer, Ho Huu Thang et al,National Conference on Science and Nuclear Technology VIII, Nha trang, 2009.

2. Gamma-Gamma Coincidence Spectrometer Setup For Neutron ActivationAnalysis And Nuclear Structure Studies, Pham Dinh Khang, N. X. Hai, V. H. Tan, N.N. Dien, Nuclear Instruments and Methods in Physics Research, A 634 (2011), pp. 47-51.

REFERENCES

[1]. “Final report, MOST project implemented in 2005-2006”, Vuong Huu Tan et al,Da lat, 2006.

[2]. “Setting of parameters for timing filter amplifier and constant fractiondiscrimination of gamma-gamma coincidence spectrometer”, Ho Huu Thang et al, NationalConference on Science and Nuclear Technology VIII, Nha trang, 2009.

[3]. Ortec, Constant-Fraction discriminator operating and service manual-584, USA,2002.

[4]. Ortec, Timing filter amplifier operating and service manual-474, USA, 2003.

[5]. “Gamma-Gamma Coincidence Spectrometer Setup For Neutron ActivationAnalysis And Nuclear Structure Studies”, Pham Dinh Khang, N. X. Hai, V. H. Tan, N. N. Dien,Nuclear Instruments and Methods in Physics Research, A 634, pp. 47-51, 2011.

VINATOM-AR 11--08


RE-ARRANGE THE TANGENTIAL BEAM PORT OF THE DALATNUCLEAR RESEARCH REACTOR FOR FUNDAMENTALRESEARCH AND APPLICATIONS WITH CONVENIENCE

AND HIGH SAFETY

Nguyen Xuan Hai, Tran Tuan Anh, Nguyen Canh Hai, Pham Ngoc Son, Ho Huu Thang,Pham Xuan Phuong, Ho Viet Ngoan, Nguyen Xuan Quy and Nguyen An Son.

Nuclear Physics and Electronics Department, Nuclear Research Institute,VINATOMNo.1, Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: This work aims to re-arrange equipments of tangential beam port of the Dalatnuclear research reactor for fundamental research and applications with convenienceand high safety. The project is the next step of serials of research which have beendoing from years of 2009 to 2012.

INTRODUCTION

This report presents results of the task in two phases (from 2010 to 2012). Theyinclude the design and manufacture of shielded and watertight equipments, theequipment installations, dose distribution of the outer space of tangential neutronchannel, evaluation of radiation protection and nuclear safety of new beam guidesystem, and compilation of the new guide for users.

I. CONTENTS

- Release the equipments and shielding wall;

- Install equipments of beam guide, shielding, beam shutter, gammacoincidence spectroscopy;

- Evaluate dose distribution of the outer space of tangential beam port,radiation protection and nuclear safety of new beam guide system;

- Compile the new guide for users.

II. RESULTS

II. 1. Release and Install

Project Information:- Code: 08 /CS/HĐ/NV- Managerial Level: Institute






VINATOM-AR 11--08


Figure 1: Overview of tangential beam port before release.

Figure 2: Overview of tangential beam port after finished project.

For equipments installation, a heavy release and clean beam port works havebeen done. The installation equipments include neutron filters, tight water, neutronbeam shutter, detectors shielding, experiment table and neutron beam stop. Fig. 1 andFig. 2 is overview of tangential beam port before and after re-arrangement respectively.

VINATOM-AR 11--08


II.2. Safety evaluation

Figure 3: Measured gamma dose distribution whenreactor operated at power level 500kW.

Figure 4: Measured neutron dose distribution whenreactor operated at power level 500 kW.

All the positions which are relative to experimenter the dose values are belowlevel of 10 µSv/h. At the positions which are not relative to experimenter the dosevalues are higher level of 10 µSv/h; the results of addition survey shows a reason fromthermal column of reactor. The removed shield wall made effect to dose distribution atthe positions which are near thermal column. This problem could be solve by additionshield around (5 cm of lead) wall of thermal column.

In aspect of nuclear safety, the tight water equipment could be withstood apressures of 15 bar (equivalent of ~ 15 m water column; the water level of Dalat reactoris 6 m in height). That is enough safety for nuclear reactor in case of water leakemergency which happens at tangential beam port.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Positions

Gam

ma

dose

(Mic

ro S

v/h)

Sv/h

)

gamma dose after finished works

gamma dose before release

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Positions

Neu

tron

dose

(Mic

ro S

v/h)

Sv/h

)

neutron dose after finished works

neutron dose before release

VINATOM-AR 11--08


II.3. Compilation of user’s guideThe three user’s guide had been compiled, they read as follows:

1. The user’s guide using of tangential beam port and equipments,

2. The user’s guide using of gamma-gamma coincidence spectroscopy, and

3. The user’s guide using of radiation and protection and emergency.

All of them had been approved and used in the Nuclear physics and electronicsdepartment of Nuclear research institute.

III. CONCLUSION

The all missions of subject had been success. The tangential beam port was re-arranged, that is more safe and convenient for fundamental research and applications.

The authours would like to thanks Ministry of Science for financial support.

REFERENCE

[1]. Trần Tuấn Anh và cộng sự, Tính toán thiết kế cấu hình che chắn phóng xạ kênhnơtron số 3 phục vụ một số nghiên cứu cơ bản và ứng dụng, Đề tài cấp cơ sở CS/09/01-05,2010.

[2]. Vương Hữu Tấn và cộng sự, Nghiên cứu ứng dụng các hiệu ứng tương tác củanơtron, gamma và các hạt mang điện được tạo ra trên các thiết bị đã có sẵn ở Việt Nam, Đề tàicấp nhà nước KC-09-08,1995.

[3]. TCVN 6866:2001, An toàn bức xạ - Giới hạn liều đối với nhân viên bức xạ và dânchúng, 2001.

[4]. Nguyễn Xuân Hải và cộng sự, Qui hoạch không gian kênh nơtron số 3 phục vụ mộtsố nghiên cứu cơ bản và ứng dụng, đảm bảo an toàn bức xạ và thuận tiện trong bố trí thínghiệm, Báo cáo tổng kết thực hiện nhiệm vụ giai đoạn 1, 2011.

VINATOM-AR 11--09


IMPROVEMENT OF PROCEDURES FOR PREPARATIONAND USE OF TRACERS MeBr-82 AND Ar-41 IN INVESTIGATION

OF PETROLEUM INDUSTRY AND STUDY OF EMPLOYMENTOF FBAs (Fluorinated Benzoic Acids) IN INTERWELL

TRACER TECHNIQUE

Nguyen Huu Quang, Dang Nguyen The Duy, Tran Tri Hai, Le Thi Thanh Tam,Huynh Thai Kim Ngan, Vo Thi Ngoc Cam, Ho Tran The Huu, To Ba Cuong,

Phan Quoc Minh and Le Van Loc

Centre for Applications of Nuclear Technique in Industry,VINATOM13 Dinh Tien Hoang, Dalat, Vietnam

Abstract: With aim at improvement of capability of applications of tracer techniques inpetroleum industry for the Centre for Applications of Nuclear Technique in Industry(CANTI) in order to meet the national requirement and to extend to the internationalmarket, the Project 07/HĐ/NV-NLNT was implemented in the cycle of 2010-2012. TheProject includes two separated components: 1) Improvement of procedures ofpreparation of radiotracers MeBr-82 and Ar-41 for tracing gas phase and 2)Development of method for use of Fluorinated Benzoic Acids (FBAs) as chemicaltracers in interwell water injection study. Basing on the procedures of preparation ofMeBr-82 and Ar-41 which were established in the previous Project, the kits forsynthesis of those radiotracers in the field were designed and fabricated duringimplementation of this Project. The synthesis protocols for working with the kits werealso established with regards to quality of products, facilities and safety in operation.Particularly, the procedure of synthesis of Ar clathrate – a form of solid cage to entrapAr for activation in the nuclear reactor was established. Owing to high concentration ofAr in clathrate cage (6,9% wt) the obstacles of irradiation of gas in the reactor areovercome and thus the method improved possibility of production of large activity up toCi of Ar-41 to enable the field experiment. In the second component of project theapproaches for development of use of Fluorinated Benzoic Acids (FBAs) as thechemical tracers in interwell water injection studies were carried out. The procedures ofanalysis of FBAs by GC/MS in produced water having saltinity concentrations rangedfrom low to high (25%) level were developed. The tests of thermal stability,hydrodynamics of FBAs in water tracing were implemented with aim at understandingtracer behaviors in reservoir conditions. The Minimum Detection Limit was determinedfrom 0.2 to 1.0 ppb for 250 ml of sample. The achievements obtained from the projectimproved the capability of application of tracers for CANTI in investigation ofpetroleum process industry and oil production.

Project Information:- Code: 07/HĐ/NV-NLNT

- Managerial Level: Ministry


- Implementation Time: 30 months (Mar 2010-Sep 2012)




VINATOM-AR 11--09


PROJECT ELEMENT TASKS

Component 1. Improvement of procedures of synthesis and use of radioactivegas tracer MeBr-82 and Ar-41 for gas phase tracing.

- Improvement of procedures of synthesis MeBr-82 and Ar-41 in regard tofield condition, safety and facilities;

- Improvement of procedures of use of MeBr-82 and Ar-41 in regard to gasprocessing production (pressure ~70 atm);

- Estabilishment of protocols of operation on the kits and related assessment.

- Component 2. Establishment of the methods on use of Fluorinated BenzoicAcids (FBAs) as non-radioactive chemical tracer for interwell water tracing in the oilfield.

- Establishment of analytical procedures for FBAs by GC/MS in producedwater having high salinity;

- Laboratory test of thermal stability and hydrodynamics of FBAs in sedimentand carbonate formation;

- Establishment of protocols of FBAs injection in to reservoir.

RESULTS

With the aims of strengthening and improvement of capability of tracerapplications in petroleum industries for the Tracer Laboratory of the Centre forApplications of Nuclear Technique in Industry (CANTI) in order to meet the nationalrequirement and to extend to the international market, the Project 07/HĐ/NV-NLNTwas implemented in the cycle of 2010-2012. The Project includes two separatedcomponents: 1) Improvement of procedures of preparation of radiotracers MeBr-82 andAr-41 for tracing gas phase and 2) Development of method for use of FluorinatedBenzoic Acids (FBAs) as chemical tracers in interwell water injection study. The mainresults achieved through implementation of the project are as followings.

I. DESIGN AND FABRICATION OF THE KITS FOR SYNTHESIS OFMEBR-82 AND AR-41

Basing on the procedures of preparation of MeBr-82 and Ar-41 which wereestablished in the last Project, the kits for synthesis of those radiotracers in the fieldwere designed and fabricated during implementation of this Project. The synthesisprotocols for working with the kits were also established with regards to quality ofproducts, facilities and safety in operation. Particularly, the procedure of synthesis of Arclathrate – a form of solid cage to entrap Ar for activation in the nuclear reactor wasestablished. Owing to high concentration of Ar in clathrate cage (6,9% wt) the obstaclesof irradiation of gas in the reactor are overcome and thus the method has improvedpossibility of production of large activity up to Ci of Ar-41 to enable the fieldexperiment.

VINATOM-AR 11--09


I.1. MeBr-82

a) Study of MeBr-82 synthesis parameters for kit designing

Radioactive gas tracer MeBr-82 is synthesised from KBr-82 which was activatedfrom KBr by neutron in the nuclear reactor by the following reaction:

(CH3)2SO4 + 2KBr (H2SO4)→ K2SO4 + 2 CH3Br ↑

The synthesis parameters which were determined through a number ofexperiments for designing the kits are as followings:

- Amount of KBr: 3 g

- Irradiation time (max): 15 min

- Neutron flux: 1012 n/cm2s

- Maximum Br-82 activity: 0.5 Ci (cooling time ~ 24h)

- Dimethyl Sulphate: 20 ml

- H2SO4 10%: 30 ml

- Reaction temperature: 70oC

- Condensation temperature: -10oC

- Volume of gas product: 950 ml (std)

- Reaction time: 60 min

- Efficiency of MeBr-82gas production: 90-98%

b) Fabrication of the kit

The kit was designed and fabricated with the following specifications:

- Net weight 80 kg

- Cover SS 304L

- Leashielding 10 cm

- Reaction house volume 86 ml

- Condensation house volume 93 ml

- Reaction house material SS 316 L

- Max. surface dose rate 100 uSv/h (in accordance with respectiveprotocols)

Sketch and photo of the Kit for synthesis of MeBr-82 is shown in the figure 1and figure 2, respectively.

VINATOM-AR 11--09


Figure 2: The kit for synthesis of MeBr-82 and Ar-41.

1: Lead shield2: Reaction house3: Ampoule break rod4: Ampoule of KBr-825,6,7,9: Covers

Figure 1: Sketch of the kit for synthesis of MeBr-82.

8: Condensation house10: Tube 316 ¼” for gas injection11: Tools for open/close12: Tool for rod#3

Vacumn pump

Pres

suriz

ed N

2Regulator

VINATOM-AR 11--09


I.2 Ar-41

a) Synthesis of Ar clathrate

The approach to Ar clathrate in this context came from the need to turn Ar gasinto solid phase (non-pressure) for safety issue required by regulation of nuclear reactoroperation as well as from demand of increasing the amount of Ar gas to be activated intight space of irradiation channel in reactor without imposing additional pressure. Dueto inert chemical properties of Ar gas it is almost impossible to make an argoncompound. However, the stable argon molecular complexes can be formed undercertain conditions where argon atoms are constrained in a cage like structure formed bythree molecules of hydro-quinone (Davies, 1977; Evans and Richards, 1954; Santikaryet al., 1992). The basic structure of this material is therefore (C6H6O2)3_xAr, wherex<1 is the number of Ar atom.

The Ar clathrate was firstly studied by McLain and Diethorn in 1963 forpreparation of solid crystal to irradiate in nuclear reactor. In form of p-hydroquinonecrystal the clathrate can capture Ar at concentration up to 7.02% wt in comparison with10.8% wt in theory.

Figure 3: Cage like tructure of the guest atomin clathrate of hydroquinone.

VINATOM-AR 11--09


Figure 4: Crystal of Ar clathrate (left) and product bags (right).

In this project, the condition of forming Ar clathrate such as pressure,temperature program, drying … was studied to establish the procedure. Thespecifications of produced clathrate were determined such as thermal stability,concentration of Ar. The results showed that Ar concentration level of product is 6,9%wt, maximum temperature for stability (no gas release) is 1000C which is enough forirradiation in the reactor. Figure 4 shows crystal of Ar clathrate product.

b) Procedures for release of radioactive Ar-41gas.

The procedures for releasing radioactive Ar-41gas based on the kit which is alsoused for MeBr-82 metioned in the above sections, were established. Ethanol was usedas the solvent to dissolve clathrate for release Ar. The pressurized Ar cylinder was usedfor flushing Ar-41 from the solvent to recover cylinder. The efficiency of Ar-41recovery is 91%.

II. DEVELOPMENT OF METHOD FOR USE OF FLUORINATEDBENZOIC ACIDS (FBAS) AS CHEMICAL TRACERS IN INTERWELLWATER INJECTION STUDY

Fluorinated Benzoic Acids (FBAs) have been used as chemical tracer in groundwater and interwell water injection studies over years in many advanced tracerlaboratories owing to the stability, insignificant adsorption in to the soil and rock andvery low detection limit by GC/MS. In this project, development of use of FBAs as thechemical tracers to extend the selectivity among available tracers in CANTI forapplications in interwell water injection in the oil field was implemented. The tasksinclude development of analytical procedures, tests of thermal stability andhydrodynamics under reservoir conditions.

The procedures of analysis of FBAs by GC/MS in produced water havingsalinity concentrations ranged from low to high (25%) level were developed. TheMinimum Detection Limit was determined from 0.2 to 1.0 ppb for 250 ml of sample,which is as the same as the common achieved level. Other QA/QC indicators anduncertainty of analytical method were also evaluated.

VINATOM-AR 11--09


The thermal stability tests showed the different degredation levels of FBAscompounds under formation condition which are useful in tracer compound selectionduring field experiment design (Figure 5). The results showed the following compoundsare remaining above 90% after 100 days of test: 4TFMBA, 2FBA, 2TFMBA,2345TFBA and 234TFBA.

The dynamic tests showed the suitability of FBAs for interwell water tracingpurposes in comparison with the ideal tracer HTO with regrads to mean residence timeand dispersivity (Figure 6). All 5 FBAs compounds 4TFMBA, 2FBA, 2TFMBA,2345TFBA and 234TFBA are in good match of transport behaviors in comparison withideal tracer HTO.

Figure 5: Results of thermal stability test of FBAs in carbonate formation.

Figure 6: Results of Hydrodynamic test of FBAs in carbonate formation.

VINATOM-AR 11--09


III. CONCLUSIONS

Two components of the Project 07/HĐ/NV-NLNT were implementedsuccessfully that reached the goals of improvement and strengthening of the capabilityof applications of tracer techniques of CANTI in petroleum industries. The radioactivegas tracers MeBr-82 and Ar-41 with on-the-site synthesis procedures enable tracerexperiment to be conducted advantageously in the industrial processing lines. Thesuccess of development of FBA chemical tracer contributes selectivities of availabletracers both radioactive and non-radioactive in deployment in the oil field to meet thedistinguish demands of the companies that improves obviously competency of CANTIin the international market.

REFERENCES

[1]. Đề tài cấp Bộ 2006-2009 BO/06-03-01“ Thiết lập công nghệ đánh dấu pha khí”,Nguyễn Hữu Quang, Viện NCHN, Đà lạt.

[2]. Contract “Radioisotope Investigation of Condensate Stabilizer in Nam Con SonPipeline Terminal”, Contract Report, 2005.

[3]. “Radioisotope Techniques in Industry”, IAEA TECDOC No. 316, Vienna, 1995.[4]. IAEA Technical Report Series No. 423, Radiotracer Applications in Industry – A

Guide Book, IAEA, Vienna, 2004.[5]. Radiotracers and Labelling Compounds for Applications in Industry and

Environment, IAEA Report for CM, Poland, 16-19 June, 2004.[6]. Radiotracer Technology as Applied to Industry, IAEA TECDOC-1262, 2001.[7]. Yelgaonkar V.N., Isotope Tracer Techniques in Studies on Flow Dynamics, Ph.D

thesis, University of Mumbai, India, 1997.[8]. Candeiro R.E.M., Crispim V., Brandao L.B., Compact Unit Procedures of the

Radiotracer CH382Br for Measurement of Flowrate Applying Transient of Time Method, INAC

2007, Brazil, 2007.[9]. McLain J.W, Diethorn W.S. A molecular capsule for the production of AR-41. Int.

J. Appl. Radiat, Isot 14, 527, 1963.[10].Mercer J.R, Duke M.J, McQuarie S.A. Practical reactor production of 41Ar from

argon clathrate, Aplied Radiation and Isotopes 52, 1413-1417, 2000.[11]. R.S., Gibbens, J.F., Difluorobenzoates as nonreactive tracers in soil and

groundwater. Groundwater 30, 8-14, 1992.[12]. Carl F. Benson, Evaluation of tri-and tetrafluorobenzoate as soil and groundwater

tracers, July 1993.[13]. Claus Ulrich Galdiga, Tyge Greibtokk, Ultra-trace determination of fluorinated

aromatic carboxylic acid in aqueous reservoir fluids using solid-phase extraction in combinationwith gas chromatography-mass spectrometry, 29 April 1997.

[14]. Colin F. Poole and Sheila A. Schuette, Contemporay practice of chromatography,Elsevier Science, 1984.

[15]. John Wiley and Sons, Fluorobanzoate and halide tracers in groundwater, Ltd.Hydrol. Process. 19, 2671–2687, 2005.

[16]. Regis Technologies, Inc., GC derivatization, June 2000[17]. Stanley N. Davis, Glenn M. Thompson, Harold W. Bentley and Gary Stiles,

Ground-water tracer-A short review, Vol. 18, No. 1-Ground water, January February 1980.

[18]. Tonya Dombrowski, Kluas Stetzenbach, Identification and characterization ofconserve organic tracers for use as hydrologic tracers for the Yucca mountain, 1993.

VINATOM-AR 11--10


STUDY OF ALGORITHM FOR SIMULATING AND MATCHINGOF TRACER BREAKTHROUGH IN THE DIPOLE FLOW

GEOMETRY BY USING STREAMTUBE METHOD

To Ba Cuong, Le Van Loc, Le Van Son and Nguyen Pham Quang Vinh


Abstract: Reservoir is always heterogeneous. Those heterogeneities may affect thetracer profile at different levels and can be extracted by analyzing of tracerbreakthrough with an appropriate technique. This study has introduced an algorithm foranalyzing of tracer breakthrough in the dipole flow geometry of fracture basementreservoirs (FBRs) in attempt to estimate the porous characteristics of fractured zoneswhich contribute to the overall tracer profile. Firstly, tracer flow in the dipole modelwas simulated by streamtube method of Abbaszadeh-Brigham for predicting of tracerbreakthrough; then a non-linear regression was applied for decomposing and matchingof tracer profile in order to estimate the contributions (kh/Σkh) and storage capacities(φh) of fractured zones connecting between injector and producer. A computer programwas developed for performing this algorithm and a physical model was built to validatethe program. Validating of physical experiments and numerical simulations shows thatthe program yields a good match for almost cases of medium heterogeneity and it canbe used for interpreting of tracer in real reservoirs.

I. OVERALL GOAL AND MAIN TASKS

Overall goal of this project is to find an algorithm for decomposing andmatching of tracer breakthrough cuves in a multi-plane dipole model; for reasonabllydescribing of tracer flow in fractured basement reservoirs.

Major tasks of the project are as follow:

1. Study of decomposition algorithm of Abbaszadeh-Brigham and apply it formatching of tracer breakthrough cuves in multi-plane dipole model.

2. Develop a computer program for performing that algorithm and matching oftracer in heterogeneous cases of dipole model

Project Information:- Code: CS/11/06-04- Managerial Level: Institute- Allocated Fund: 60,000,000 VND- Implementation Time: 12 months (Feb 2011-Feb 2012)

- Contact Email: [email protected] Papers published in relation to the project: (None)


VINATOM-AR 11--10


3. Building of physical experiment and numerical simulation for validating ofprogram.

II. TRACER DECOMPOSITION ALGORITHM OF ABBASZADEH-BRIGHAM

For studying of tracer flow in layering (sedimentary) reservoirs, Abbaszadeh andBrigham have proposed the following algorithm for matching of overall tracer profile:with a multi-layer system, the injected tracer and displacing water can be divided intolayer proportional to the flowing capacity (kh) of each layer. If VT is the total volume ofwater injected into the reservoir, then the pore volume injected into layer j is:

( ) ( ) ( ) ASw

V

hK

K

SwAh

V

hK

hKV T

jjjj

j

jj

T

jjj

jj

jPD ∑∑==

(1)

VT: total volume of water injected [L3]

hj: thickness of layer j [L]

Kj: permeability of layer j [permeability unit]

A: area of the model [L2]

Sw: water saturation in model [%]

The overall tracer concentration being produced at producing well is the sum oftracer concentration being supplied by each layer:

( ) j

n

jj

jj

jj ChK

hKC ∑ ∑=

=1

(2)

( ) ( ) jDjj

Tr

jjj

jjj C

SwAh

V

hK

hKaCC

∑= 0

(3)

C0: initial concentration of injected tracer [concentration unit]

C: tracer concentration at producing well [concentration unit]

j: layer index (j = 1,… , n = number of layers)

a: width of the model [L]

α: dispersivity of porous media [L]

VTr: total volume of tracer [L3]

CD: dimensionless concentration of tracer at producing well. (CD)j is calculatedas a function of pore volume (VPD)j injected into layer j

VINATOM-AR 11--10


( ) ( )( ) ( )

Γ=Γ=

∑ T

jjjj

j

jPDjD VhK

KVC ,

(4)

From (2), (3) and (4), concentration of tracer at producing well can be describedas a function of 3 variables:

( )∑j

jjj

j

hK

K

,

( ) ( )∑∑j

jj

jj

jjjj

j

hK

hK

hK

K

and VT

( ) ( ) ( )∑ ∑∑∑=

Γ=

n

jT

jjjj

j

jjj

jj

jjjj

jV

hK

K

hK

hK

hK

KC

1

,

(5)

Where, Γ is a function given by analytical solution of tracer in homogeneouspatterns. Denoting:

( )∑=

jjjj

jj hK

KA

and

( ) ( )∑∑=

jjj

jj

jjjj

jj hK

hK

hK

KB

(6)

Equation (5) becomes

( )∑=

Γ=n

jTjj VABC

1

, (7)

The tracer concentration C in (7) is a linear combination of the non-linearfunctions Γ, with VT is variable and Aj is parameter. For matching of equation (7) withexperimental data, the linear parameters B1, B2, …, Bn and non-linear parameters A1,A2,…,An can be found by a non-linear regression technique.

III. DEVELOPING OF COMPUTER PROGRAM FOR DECOMPOSINGAND MATCHING OF TRACER IN MULTI-PLANE DIPOLE MODEL

Dipole model is a conceptual pattern for reasonable describing of flow anddisplacement of water in fractured basement reservoirs. The model is expressed as a 2Dfractured plane in which water is injected at the bottom and produced at the upper partof the plane.

In case of more than one plane exists between injector and producer, overalltracer profile can be described as the summation of individual planes. And this profilecan be decomposed for estimating of the contributions and storage capacities of eachplane by matching with experimental profile.

VINATOM-AR 11--10


A computer program was developed for simulating and matching of tracer inmulti-plane dipole model. The program was written in Fortran 90 in combination withMatfor GUI libraries.

Figure 1: Tracer response in multi-plane dipole model.

Tracer response ofindividual planes

Figure 2: Tracer matching program for multi-plane dipole model.

VINATOM-AR 11--10


FLOWCHART OF THE PROGRAM

BEGIN INPUT: d, a, α, Sw, VTr,Nlayer, (Aj)est, Tobs, Cobs

PRE-CALCULATIONCalculate d/a, A, VPD,max

Solving for mCalculate K(m), K(m1)

REGRESSION USING VARPRO- Read non linear Aj

- Calculate NORM-

CALCULATE Calculate VpDbt(ψ) of each streamtubeCalculate Y(ψ) of each streamtubeCalculate CD according to VPD

Calculate Γ

CALCULATE DCALCULATE ΓCalculate derivatives of Γ with respect toAjALGORITHM IN CORE OF VARPROCalculate Bj, Aj

Compare NORMwith Tolerance

Update Aj

Export Bj, Aj

CALCULATE OVERALLTRACER PROFILE (C)

FINISH

Note:d: heigh of the modela: width of the model: dispersivity of porous mediaSw: water saturationVTr: tracer volume(Aj)est: initial estimation value of AjTobs: time axis in observation profileCobs: tracr concentration in observationprofileVPD,max: location of peaks in analyticalsolution

NORM > Tolerance

NORM < ToleranceorIterations exceeded

VINATOM-AR 11--10


IV. VALIDATING OF PROGRAM BY PHYSICAL EXPERIMENT ANDNUMERICAL SIMULATION

For validating of the program, a physical model was build in term of 2 glassbead filled boxes, in which water is injected at the bottom and produced at top of theboxes. The two injectors and two producers are connected together and thus tracer canbe injected and produced simultaneously from 2 planes.

Figure 3: Physical model of two parallel planes.

Experimental data from the model was then matched by the program forcomparing of calculated and designed parameters.

Figure 4: Matching of experimental data from physical model.

Injectors

Producers

Designed Calculatedkh h kh h

Plane1

0.485 0.8 0.45 0.839

Plane2

0.515 1.2 0.508 1.234

VINATOM-AR 11--10


In addition, some numerical models were built by UTCHEM simulationprogram to investigate the effluence of heterogeneity (cause by differences inpermeability) on the tracer breakthrough profiles. Below is an example of tracermatching in a 10 planes model. A small result is: with its Dykstra-parsons number of0.35, the tracer can only be matched with a higher effective dispersivity (0.16) than theone was used to input in the numerical model (0.1)

Figure 5: An example of tracer matching in 10-planes model.

V. CONCLUSION

The decomposition algorithm of Abbaszadeh-Brigham was well studied andsuccessfully applied for matching of tracer in the multi-plane dipole model. Theprogram has been validated by numerical models and physical experiments; indicates itcan be used to interpret of real tracer data in fracture basement reservoirs.

REFERENCES

[1]. Abbaszadeh Dehgani, W.E Brigham, Analysis of unit mobility ratio well to welltracer flow to determine reservoir heterogeneity, Stanford University Petroleum ResearchInstitute, 1982.

[2]. B.Zemel, Tracer in the oil fields, Elsevier Science, 1995.

[3]. Brigham W.E & Smith Jr, Prediction of Tracer Behavior in Five-Spot Flow, SPE1130-MS,1965.

[4]. Mishra. S, On the use of pressure and tracer test data for reservoir description,Petroleum Research Institute, Stanford University, 1989.

[5]. Yuen D.L, Brigham W.E, Cinco L.H, Analysis of five-spot tracer tests to determinereservoir layering, Petroleum Research Institute, Stanford University, 1979.

[6]. Deng .X, Description of heterogeneous reservoirs using pressure and tracer data,Dissertation of Department of Petroleum Engineering, Stanford university, 1996.

VINATOM-AR 11--11


RESEARCH TO FIND OUT AND EXPLOIT ABOUT THEFEATURES OF EDDYMAX TMT EQUIPMENT FOR

EXAMINATION OF NONMAGNETIC HEAT EXCHANGER TUBE

Luong Thi Hong1, Nguyen Nhat Quang1, Le Duc Thinh1,Ngo Thi Da Huong1 and Pham Van Nam2.

1Center for Non-Destructive Evaluation, VINATOMNo.140 Nguyen Tuan, Thanh Xuan, Hanoi, Vietnam

2Setin Company

Abstract: Electromagnetic (Eddy-Current) test is an important and widely used methodwithin the broad field of nondestructive material testing. Applications of eddy current inindustry are numerous and widespread. It’s also used for no contacting measurement ofthe thickness of metallic foils, sheets plates, tube walls and machined parts from oneside, it’s also detecting material discontinuities that lie in planes transverse to the eddycurrent such as the cracks, seams, laps, score mark and plug cuts, drilles and the otherholes. However, in Vietnam, the application of this method is still not popular. Base onthe IAEA- funded project VIE 8/020, Center for Non- destructive Evaluation (NDE) hasbeen invested Eddy current instrument system named Eddymax TMT. This instrumentis used to inspect the heat exchanger tubes. This system has fully features to inspect thetubes, but now it has not been working because of no manual instruction and standardtubes to calibrate the eddy current instrument. This subject focuses to find out andexploit about the features of Eddymax TMT, to compile the using instruction for thisequipment, to manufacture the experiment tube comply with ASTM standard, butfirstly to get the result about how to use and run the system Eddymax TMT.

CONTENT OF THE SUBJECT

Eddy-current testing is a nondestructive method of locating discontinuities intubing made of materials that conduct electricity. Signals can be produced bydiscontinuities located either on the inner or outer surfaces of the tube, or bydiscontinuities totally contained within the tube wall. When using an internal probe, thedensity of eddy currents in the tube wall decreases very rapidly as the distance from theinternal surface increases; thus the amplitude of the response to outer surfacediscontinuities decreases correspondingly. When you use Eddy current instrument, allthe signal from the probe which go through a tube will be analyzed and get the result.








VINATOM-AR 11--11


In this report we also use the Eddymax TMT system as figure 1. This system isdigital system which has multi-channel and multi-frequency allow setup of calibrationcurves constructed from stored data and automated analysis of signals as compared tothese curve.

Figure 1: Eddy Max TMT system

To compile the using instruction for Eddy Max TMT equipment of NDE centerand using this equipment to practice in the Experiment tube (which has manufacturedcomply with ASME standard section 5 artical 8 – figure 2) building the calibrationcurve:

Figure 2: The Experiment Tube

75 50 50 50

300±1

A B

∅19

1,2

4 hole ∅0,83 spaceddeg apart90°

C

FBH∅ 2,7 : 0.72

D

4 FBH∅ 5 : 0,24

spaced 90 degapart

0,5x45°

hole ∅ 1,7defects

VINATOM-AR 11--11


PRACTICE IN THE STAINLESS STEEL 304 TUBE AND COPPERTUBE

Caculated frequency following the function: f90 = 3ρ/t2 , kHz. With theresistivity and conductivity from Table 1-Electromagnetic Testing-Handbook Volume5-ASNT we have frequency f90:

Table1: Frequency f90 for Stainless steel 304 (SS) and Copper 90%

Experimenttube

Resistivity(µΩ/cm)

Conductivity(%IACS)

Thicknesswall (t)

InternalDiameter

f 90 = 3ρ/t2

(kHz)

Stainless steel304 (SS)

72 2.39 1.2 16.6 150

Copper 90% 18.95 9.10 2.0 21 14.2

Use two bobbin probe with the diameter 16mm and 19mm which has frequencyfrom 10kHz to 200kHz. Setup the analysis system in the Eddymax TMT with theparameter like table 2:

Table 2: The parameter setup for analysis system in the Eddymax TMT

CH Source Pre-gain Gain Phase LP filter HP filter Spread X Spread Y

1 0.0 dB 6.0 dB 20.9 dB 257.9o 1 kHz off 3 dB 0 dB

2 0.0 dB 6.0 dB 19.6 dB 351.5.9o 1 kHz off 0 dB 0 dB

3 0.0 dB 6.0 dB 22.0 dB 0o 1 kHz 100 mHz 0 dB 0 dB

To pull the probe through the experiment tube and the signal will be displayedand recorded. Analyze this signal we get the calibration curve below:

Figure 3: Calibration curve for SS 304

VINATOM-AR 11--11


After getting the calibration curve, we take some examinations with SS304 andget signal like the figure 4:

Figure 4: The signal from SS 304 Tube

Base on the result of practical for two tube SS 304 and Copper we also havebuilt 02 procedures to examination (using an internal, probe type - bobbin, EddymaxTMT system) of nonmagnetic tubing that made from Copper and Stainless steel. Theseprocedures base on the ASTM E-690-98: Standard practice for In Situ Electromagnetic(Eddy - Current) Examination of Nonmagnetic Heat Exchanger Tube

In the scope of project at grassroots level, the project team have some results asabove, complying with the objectives of the project: focus to find out and exploit aboutthe features of Eddymax TMT which already has in NDE center. We also apply thisresult to examine the long straight tube similar with Heat exchanger tube system ofThermal Power plant. In the future, we expect NDE center as well as VINATOM tocreate favorable conditions and support for project team to develop more features ofEddymax TMT system – it is the Remote field testing to expand the scope of activitiesof Eddymax TMT system.

REFERENCES

Vietnameses[1]. Nguyễn Lê Sơn, Nguyễn Nhật Quang… Tài liệu đào tạo Kiểm tra dòng điện xoáy

bậc II, Kết quả nghiên cứu đề tài “Xây dựng chương trình huấn luyện , đào tạo kỹ thuật kiểmtra bằng dòng điện xoáy cấp I và cấp II cho vật liệu kim loại phù hợp theo tiêu chuẩn Iso 9712và tiêu chuẩn 5868-1995”.

[2]. Donald I. Hagemaier, Trương Thành Chung dịch và biên soạn. “Những nguyên lýcơ bản của phương pháp kiểm tra dòng điện xoáy”.

[3]. Nguyễn Công Hân, Nguyễn Quốc Trung, Đỗ Anh Tuấn, “Giáo trình Nhà máy nhiệtđiện” Trường ĐHBK Hà Nội, tập 2.

[4]. PGS.TS Hoàng Ngọc Đồng - Giáo trình Nhà máy nhiệt điện.

[5]. Công ty CP nhiệt điện Cẩm Phả-Nhà máy nhiệt điện Cẩm Phả-Quy trình vận hànhvà bảo dưỡng lò hơi.

VINATOM-AR 11--11


English[6]. Patrick O. Moore, Satish S.Udpa - American Society for Nondestructive Testing –

Handbook Volume 5 “Electromagnetic Testing” Chapter 3, part 3: Eddy Current testing - Tàiliệu tra cứu – phương pháp kiểm tra điện từ - Chương 3 phần 3 phương pháp kiểm tra dòng điệnxoáy, 2004.

[7]. Patrick O. Moore, Satish S.Udpa - American Society for Nondestructive Testing –Handbook “Electromagnetic Testing” Chapter 6, Eddy current Instrumentation – Tài liệu tracứu – phương pháp kiểm tra điện từ- chương 6- các thiết bị cho kiểm tra dòng điện xoáy, 2004.

[8]. TubeMaxTMT, Instruction manual TMT eddyMax® Documentation, TestMaschinen Technik GmbH- Tài liệu hướng dẫn sử dụng thiết bị Eddymax TMT, 2009.

[9]. TubeMaxTMT, Instruction manual - First Steps with TubeMax, 2009. Hướng dẫnsử dụng thiết bị - Các bước đầu tiên với Tube Max.

[10]. ASTM – E 690-1998. Standard practice for In Situ Electromagnetic (Eddy -Current) Examination of Nonmagnetic Heat Exxchanger Tube.

[11]. ASTM – E 243- 97. Standard Practice for Electromagnetic (Eddy - Current)Examination of Copper and Copper-Alloy Tube.

[12]. ASTM – E 426- 98. Standard Practice for Electromagnetic (Eddy - Current)Examination of Seamless ans Welded Tubular Products, Austenitic Stainless Steel and SimilarAlloys.

[13]. ASTM – E 1316-02a. Standard Terminology for Nondestructive Examinations.

VINATOM-AR 11--12


RESEARCH TO EXPLOIT, UTILIZE COMPUTEDRADIOGRAPHY SYSTEM AND BUILD SUITABLE PROCESS

Tran Dang Manh, Nguyen Le Son, Vu Huu Cuong and Kieu Ngoc Dung1Center for Non-Destructive Evaluation, VINATOMNo.140 Nguyen Tuan, Thanh Xuan, Hanoi, Vietnam

Abstract: CR is computed radiography method. CR35 is digital radiography equipmentwhich has just equipped in Viet Nam at the end of 2009 by VIE8020 project. Thesystem include image plate (IPs) to change for film, CR35 equipment which scans andrecords IP’s signal by laser light and converts to digital image. This system can replacesof film radiography at any where has possible infrastructure like stable power supply,flat… The research’s purpose is to use the CR35 system, own equipment andtechnology, compile technical documents and process guide for practice computedradiography.

I. CONTENT OF SUBJECT

a. Request: Research to use the CR35 system, compile technical documentsand process guides for practice computed radiography.

b. Assignment

- Compile user manual for CR35 system in Vietnamese;

- Study to use specialized software;

- Practice on some standard samples to evaluate optimal computedradiography regulations;

- Research on specifications with impact on image quality;

- Compile procedure for computed radiography in industrials according toASTM E2007-00 and ASTM E 2033-99.

c. Process and technique

Base on training documents of IAEA’s experts, compile and research CR35’stechnical documents, practice experiences and experiment research results on standardsamples, analyses the results and repeat experiment research we had summarized and








VINATOM-AR 11--12


processed guides for practice computed radiography industrial according to ASTME2007-00 and ASTM E 2033-99.

II. THE RESULT

II.1. Overview research: Theresearch overview of computedradiography’s principle, characteristics,focus on computed radiography method,image plate structure and scan equipment(CR35), classification, factors influencethe image’s quality in radiography,specifications, image’s quality when scanimage plates and study to use imageinterpreted software.

Figure 1. CR35 system

II..2 Evaluate optimal computed radiography regulation: In experimentresearch, we investigate to evaluate the optimal computed radiography regulation whenreplaces film by image plate (IP); investigate factors influence the image’s quality andused this result in fact with some of standards specimens. IPs use in this experimentresearch are white IPs.

To determine the optimal computed radiography regulation when replaces filmby image plate, we use step sample made of carbon steel with different step’s thickness,calculate radiography’s regime step by step by using D7 film which is determine sameclass of White IP, but change the dose by other rate.

The result indicates that, the radiography’s regime helps to get best imagequality is about 30% dose compare with dose of D7 film is used, so that the radiographydiagram for white IP can uses D7 film diagram but reduce 70% dose is applied for D7film.

Figure 2: Best image quality at 30% dose which is applied for D7 film

VINATOM-AR 11--12


II.3. Research on specifications with impact on image quality

Specifications have to consider when scan an image place, they include: Laserpower (change from 1 to 8 mW), high voltage (change from 600-1200V), rotation perminute of laser light (change from 3000-5000 rpm), scan resolution (set at 16, 25, 50and 100µm) and time to keep IP is exposed before scanned (the signal reduces time bytime).

For this purpose, we use computed radiography phantom which accords withASTM E2445 – 05 standard. Research on specifications with impact on image qualityexperiment research indicate that: laser power at 5 to 6 mW, high voltage at 600-800Vand rotation per minute at 3000rpm are help to get best image quality when scan IP. Thescan resolution, of cause the more lower scan resolution, the better image quality; but isdepends on computer system, requires of evaluation object because the better imagequality, the slower system speed and more store memory.

Time to keep IP is exposed before scanned is very important, the signal reducesis continuous, the first hour is reduced about 50%, next hourly is about 30%, so that wehave to scan IP is exposed to get image as soon as possible. Figure 3 show how thesignal reduces by time.

Figure 3: Signal reduces by time

There research results apply to evaluation in fact, we choose some standardssamples which have advance defects like flaws. Images achieving have baserequirements include sensitivity, space resolution, grey value, signal noise ratio areaccordance with ASTM and EN 462-5 standards, defects are determined accordancewith manufacturer’s information.

Time(hours)

VINATOM-AR 11--12


Figure 4: Image achieve by CR35 with good quality

II. RESULTS AND CONCLUSION

By this assignment, we have known deeply how to confidence, effect operate theCR35 system; it was proved in fact when we tested some of standards specimens.Thought by, we compiled used manual documents, guided line for CR scan system andprocess guide for practice computed radiography

Some matter is needed to deeply research was found, such as the appearance ofstrange lines in image, the images accumulation after takes a high dose radiography ornew filed applications of CR method, such as testing the pipe line corrosion, testing thethickness of subjects with cannot do by film radiography testing etc…

REFERENCES

[1]. U. Ewert, BAM Berlin, U. Zscherpel, BAM Berlin, K. Bavendiek, YXLONInternational X-Ray, Hamburg, REPLACEMENT OF FILM RADIOGRAPHY BY DIGITALTECHNIQUES AND ENHANCEMENT OF IMAGE QUALITY, annual conference of IndianNDT society, Kalkutta. V.S. Jain-Lecture, Proceedings, S. 3-15.4, 6.12.2005.

[2]. U. Ewert, U. Zscherpel, BAM Berlin, K. Bavendiek, YXLON International,Hamburg, Film Replacement by Digital X-ray Detectors – The Correct Procedure andEquipment, oral presentation of U. Ewert at the 16th WCNDT 2004. Montreal, Canada and,30.8. – 3.9.2004

[3]. ASTM E 07 Committee Meeting, Kansas City, USA,13. June 2005.

[4]. Uwe Ewert, Uwe Zscherpel, Klaus Bavendiek …: “Strategies for FilmReplacement in Radiography - a comparative study”, IAEA Coordinated Research Project -Buenos Aires, 2007.

[5]. P. Willems, B. Vaessen, W. Hueck, U. Ewert, U. Zscherpel “Applicability of CRfor corrosion and Wall Thickness Measurements”, proceedings of the 7th ECNDT, Copenhagen,1998.

[6]. ASTM- E94 Guide for Radiographic Testing.

[7]. ASTM- E747 Practice for Design, Manufacture, and Material GroupingClassification of Wire Image Quality Indicators (IQI) Used for Radiology.

VINATOM-AR 11--12


[8]. ASTM- E1025 Practice for Design, Manufacture, and Material GroupingClassification of Hole-Type Image Quality Indicators (IQI) Used for Radiology.

[9]. ASTM- E1316 Terminology for Nondestructive Examinations.

[10]. ASTM-E1453 Guide for Storage of Media That Contains Analog or DigitalRadioscopic Data.

[11]. ASTM-E1475 Guide for Data Fields for Computerized Transfer of DigitalRadiological Test Data.

[12]. ASTM-E1817 Practice for Controlling Quality of Radiological Examination byUsing Representative Quality Indicators (RQIs).

[13]. ASTM-E2007 Guide for Computed Radiology- Photostimulable LuminescenceMethod.

[14]. ASTM-E2033 Standard Practice for Computed Radiology (PhotostimulableLuminescence Method).

[15]. ASTM-E2002 Standard Practice for Determining Total Image Unsharpness inRadiology.

[16]. EN 14784-1 Non-destructive testing - Industrial computed radiography withstorage phosphor imaging plates - Part 1: Classification of systems.

[17]. EN 14784-2 Nondestructive testing- Industrial computed radiography withstorage phosphor imaging plates - Part 2: General principles for testing of metallic materialsusing X-rays and gamma rays.

[18]. ASME V- Article 2, Radiographic examination, 2007.

VINATOM-AR 11--13


STUDY ON MEASURING FOR COMPONENT RATIOAND VELOCITY OF FLUID IN TWO PHASES FLOW BYAPPLICATION OF GAMMA TRANSMISSION METHOD

AND CROSS CORRELATION ANALYSIS

Le Trong Nghia, Tran Thanh Minh, Mai Cong Thanh, Phan Quoc Minh,Dang Nguyen The Duy, Le Van Loc and Pham Van Dao

Center for Applications of Nuclear Technique in Industry,VINATOM13 Dinh Tien Hoang, Dalat, Vietnam. Email: [email protected]

Abstract: Gamma transmission method and cross-correlation analysis techniques wereapplied to determine the gas flow and component ratio in two-phase flow in a laboratorymodel. The velocity was determined by cross-correlation analysis of transit time ofdisturbance through two detectors placed at a fixed distance; ratio of gas in the pipecross section was determined by attenuation intensity of gamma transmission. However,because equipment is limited, we could only measure a gas velocity in two phase flow.The maximum gas velocity was measured 100cm/s, with lower than 8cm/s of absoluteerror. The component ratio was measured from 15% to 50% with lower than 5% for gas– liquid phase and 7% for liquid – liquid phase of absolute error.

Key words: Cross correlation, dual phase flow, multiphase flow meter, turbulence …

I. INTRODUCTION

The flow meter is usually used for measuring single phase flow, if there aremixed components of liquid and gas phases, the measured result will be meet significanterror. Gamma transmission method associated with cross-correlation technique can beapplied to measure flow rate of gas in two-phase flow. From that, the measured resultby this method can be used to validate the result obtained by flow meter normal. Theadvantages of this method are portable, no implant in the pipe and no affect theproduction process.

Gamma radiation cross-correlation method was applied to experiment modelwhich includes a vertical pipe with gas and liquid flow inside; gas bubble createddisturbances which could be recorded by gamma transmission system; the recorded datawas analyzed by cross-correlation function.







Determination of flow rate of gas of vertical flow in dual phase pipe by gammatransmission method and cross correlation analysis, 2nd Conference on NuclearScience and Technology of Youth Officers in Atomic Energy branch – Hanoi,10/2012.



VINATOM-AR 11--13


II. PRINCIPLE OF METHOD

As we know the gas flow rate in two phase flow is calculated by formula (1),where Qg is the flow rate of gas, αg is volume fractions, S is inside area of the pipe, v isaverage velocity of the gas. v and αg are calculated in the next section.

ggg SvQ = (1)

II.1. Principles of determining the gas velocity in dual-phase gas-liquid flow

The block diagram of data processing shows in Figure 1. Suppose that the gasflow component in the pipe is smaller than liquid flow component and the disturbancesappear random. If there is a disturbance of gas bubbles passing through first detector attime t1, the measured data of first detector will increase; with a fixed distance, thedisturbance which is passing through second detector at time t2, still preserved. Theperiod between t1 and t2 is τ that the transit time of the bubble between two detectors.

The experimental data recorded from two detectors are transformed through thediscrete Fourier transform which is defined as in Eq. (2) converted to time domainsignal into frequency domain data to be applied with the low-pass filter for removingnoise.

∑−

=

−=

1

0

2^ N

n

knN

i

nkexx

(2)

The filtered data was input to the cross-correlation function that evaluates thesimilarity of two sets of data. The cross-correlation function for two signals of x(t), y(t)is defined as in Eq. (3)

dttytxT

RT

xy ∫ +=0

*^

)()(1

)( (3)

Where, Rxy is value of cross-correlation function, signal x(t) fromthe first detector, signal y(t) from thesecond detector, x*(t) is the complexconjugate of the function x(t).

The transit time of the bubblesbetween two detectors is found by thesurvey delay time τm at which cross-correlation function reaches themaximum value. The average velocityof the gas derived from the formula (4):

m

Lv

= (4) Figure 1: The cross-correlation principle of

component velocity measurement in amultiphase flow

Where L is distance between two detectors.

VINATOM-AR 11--13


II.2. Principles of determining flow rate of gas component in cross section ofthe pipeline

Radiation attenuation coefficient for mixture system can be described as Eq.(5)where mmix is the attenuation coefficient of a homogeneous mixture of two components,µg and µl are linear attenuation coefficients of the gas and the liquid, respectively. αg andαl are the corresponding volume fractions. The sum of αg and αl is unity in a pipe. Thegas fraction is expressed as Eq. (6) where IE is the beam intensity with an empty pipeand Bmix, Bl and Bg are the build-up factors of corresponding phase. Eq. (6) was derivedon conditions that the build-up factors are almost the same due to the maintaineddetection geometry.

llggmix −= (5)

[ ] [ ][ ] [ ]

]/ln[

]/ln[

)ln()ln(

)ln()ln(

/ln/ln

/ln/ln /

lg

lmix

lg

lmix

EllEgg

EllEmixmix

lg

lmixg

II

II

II

II

IBIIBI

IBIIBI

=−−

≈

−−

=−−

=

(6)

III. EXPERIMENT SET UP

A diagram layout experiment was showed in Figure 2. Gas and liquid flow weredrained in the vertical pipe which was made by acrylic resin with dimension of 10.4cmof diameter and 1.2 m of length. Air was injected by air compressors; the air flow rate isadjusted by a valve. The flow rate of liquid was monitored with two turbine currentmeters (one for water and one for oil). Gas and liquid was through a horizontal pipe tobe mixed together prior to coming the vertical pipe. The recorded value obtained fromgamma radiation cross-correlation was compared with the results of flow meters.

Figure 2: Diagram layout experiments

VINATOM-AR 11--13


The gamma radiation sources are 8mCi and 3mCi of 137Cs (0.662MeV,0.326Rm2h-1Ci-1) and the radiation intensity transmitting the pipe was measured withtwo scintillation detectors of 2x2 inch NaI(Tl) (Ludlum model: 44-10). The radiationdetectors were mounted on metal brackets separately so that the distance between themcan be adjusted. Sources and detectors are put in collimators.

Cross-correlation technique for analyzing the data requires high speed of signalsampling rate about µs or ms. The experiment couldn't be performed at a lowerthreshold of 10ms due to have no specialized equipment. Two Ludlum model 2200Scaler Ratemeter which were improved TTL pulse output connected with GSN Serial 3Portable Datalogger. Data from

Portable Datalogger arerecorded by Datalog 99software which was set up aPalmtop PC HP 360 LX. Themeasured data was processedby Mathematica 8.0 software.And result of gas velocity wascompared with average gasvelocity measured by ParticleImage Velocimetry (PIV)method which images wererecorded by a camera CMOSwith frequency 120Hz and240Hz.

Figure 3: Radiometer system

IV. RESULT AND DISCUSSION

IV.1. Equipment calibrations

Table 1: Calibration coefficients of flow meters

CalibrationsReal flow rate

(l/m)Flow rate ofmeter (l/m)

Calibrationcoefficients

Flowmeter 1 with water 68.33 65.99 1.04

Flowmeter 2 with water 68.78 68.65 1.00

Flowmeter 2 with oil 63.39 61.67 1.03

Flowmeter 3 with air 11.50 5.00 2.30

Calibration coefficients of flow meter 1 and flow meter 2 are used for watercorresponding 1.04 and 1.00. Calibration coefficient of flow meter 2 for diesel oil is1.03. Calibration coefficient of flow meter 3 using for air at 240C is 2.30. Result ofcalibration coefficients of flow meters were showed in Table 1.

VINATOM-AR 11--13


IV.2. Measurement of gas velocity in a dual-phase pipe

In accordance with the purpose of this experiment, radiation measurementexperiments were performed with air and water mixed flow for bubble velocitymeasurement. An example of the experimental result shown in Figure 4 where Sx andSy are signals acquired from two detectors and the maximum correlation function wasobserved at τm= 0.28s. By applying the experimental condition that two detectors wereseparated by two times of the diameter (2D), the bubble velocity was calculated as74.3cm/s.

(a)

(b)

Figure 4: (a) Example signals from two detectors (NaI (Tl) – 2”)(b) Cross-correlation result with τm=0.28s.

VINATOM-AR 11--13


Apply this method, experiments dual phase flow with gas/water and gas/oil wereperformed and repeated under the same condition for every type experiments. The inputparameters are controlled by the flow meters and the result was summarized in Table 2.

These results of gas velocities were compared with average bubble velocity ofPIV method show the relevant differences between two methods maximum of around6.7 cm/s and standard deviation is approximately (2.7% of gas/oil and 4.7% of gas/water). Source of errors is due to counting statistical error and the nature of thedistribution of gas velocity dual-phase flow. However, average values of two methodsare approximate.

Table 2: Measurements of gas velocity of dual-phase flow by application ofcross-correlation function to radiation counts produced by two sealed gammaradioisotopes (137Cs) with a distance of 2D (D = 10.4 cm) and sampling time 10ms

No.Experiments

Gas in Oil Gas in water

Transittime(s)

Measuredvelocity(cm/s)

Averagevelocityby PIV(cm/s)

Differ-ences

Transittime(s)

Measuredvelocity(cm/s)

Averagevelocityby PIV(cm/s)

Differ-ences

1 0.270 77.0 81.4 -4.4 0.320 65.6 63.3 2.3

2 0.260 80.0 81.4 -1.4 0.320 65.6 63.3 2.3

3 0.250 83.2 81.4 1.8 0.340 61.8 63.3 -1.5

4 0.260 80.0 81.4 -1.4 0.340 61.8 63.3 -1.5

5 0.250 83.2 81.4 1.8 0.340 61.8 63.3 -1.5

6 0.260 80.0 81.4 -1.4 0.300 70.0 63.3 6.7

Average 0.258 80.6 81.4 0.327 64.4 63.3

IV.3. Measurement of component ratio in a dual-phase pipe

In experiment gas – water, a unit count was sum counts in duration time 30seconds. Input gas and water flow rates were maintained at 16.5 (l/min) and 134.8(l/min). Data measured from a scintillation detector was calculated by Eq. (6). Averagegas contents was 33.6 liter/m where absolute was 3.4%. There are differences betweenthe measured result and gas flow rate input; besides random error, the differencesincluded systematic error which were caused by gas velocity faster than liquid velocityand many small bubbles slow moving in water phase but they contribute to increasingthe value of αg. Detail was summarized in Table 3.

VINATOM-AR 11--13


Table 2: Measurements of gas content in a dual-phase pipe(unit: counts per 30s)

Counts in anemty pipe (Io)

Counts in afull water (Iw)

Counts in adual phasepipe (Imix)

Measured gascontents (αg)

Input gascontents (Qg)

428920 328260 338430 12.9% 10.9%

428810 328620 339060 13.3% 10.9%

428000 328680 339690 14.3% 10.9%

428550 328590 337620 11.4% 10.9%

429120 327810 336330 10.5% 10.9%

IV.4. The influence of the distance between detectorsThe experiments surveyed the influence of the distance between detectors on the

air velocity values was conducted as follows: water flow was maintained at 134.8 l/min;gas flow was 22.2l/min. Each experiment was repeated 05 times. The resultsdistribution at the distance between the two detector equal 2 times the tube diameter(2D) was near the reference value the most, when the distance increases, the distributionis more discrete. When the distance between detectors equal 5D is not hardly valuemeasure. Disturbance pass through the second detector was distinct shape compared tothe pass through the first detector.

Figure 5: Relative variations of velocity of gas in water was calculatedwith cross-correlation method by using a sealed radioisotope asa function of the distance between two sealed gamma sources;

the velocity reference was measured by PIV

VINATOM-AR 11--13


V. CONCLUSION

Gamma radiation cross-correlation method was applied to measure the gas flowrate in experiment model which includes a vertical pipe with gas and liquid flow inside.The velocity was determined by cross-correlation analysis of transit time of disturbancethrough two detectors placed at a fixed distance; ratio of gas in the pipe cross sectionwas determined by attenuation intensity of gamma transmission. The maximum gasvelocity was measured 100cm/s, with lower than 8cm/s of absolute error. Thecomponent ratio was measured from 15% to 50% with lower than 5% for gas – liquidphase and 7% for liquid – liquid phase of absolute error.

Gamma radiation cross-correlation method can be applied to validate the resultobtained by flow meter normal which is influenced by gas phase. The advantages of thismethod are portable, no implant in the pipe and no affect the production process.Requires about proper equipment of this method are high sensitive detector, small dealtime of detectors, small sampling time (about µs) of datalogger, data processingsoftware online and in accordance of type energies of radioactive sources withcomponents of flow. Then this method will be increased performance and accuracy.

REFERENCE

[1]. S. H. Jung, J. S. Kim, J. B. Kim, T. Y. Kwon, Flow-rate measurements of a dual-phase pipe flow by cross-correlation technique of transmitted radiation signals, ScienceDirect,67, 1254–1258, 2009.

[2]. Marek Dziubinski, Henryk Fidos, Marek Sosno, The flow pattern map of a two-phase non-Newtonian liquid–gas flow in the vertical pipe, ScienceDirect, 30, 551–563, 2004.

[3]. Gioia Falcone, G. F. Hewitt, Claudio Alimonti, Multiphase Flow Metering –Principle and Applications, Elsevier, 2009.

[4]. W. Chenga, YuichiMurai, Toshio Sasaki, FujioYamamotod, Bubble velocitymeasurement with a recursive cross correlation PIV technique, ScienceDirec, 16, 35–46, 2005.

[5]. A.K. Janaa, G.Dasa, P.K. Dasb, Flowregime identification of two-phase liquid–liquid upflow through vertical pipe, ScienceDirect, 61, 1500 – 1515, 2006.

[6]. Samir Teniou, Mahmoud Meribout, Multiphase Flow Meters Principles andApplications: A Review, Canadian Journal on Scientific and Industrial Research Vol. 2, No. 8,November 2011.

[7]. B.J. Azzopardi, Multiphase Flow, Chemical Engineering and Chemical ProcessTechnology, Vol. 1.

[8]. John R. Thome, Engineering Data Book III, Wolverine Tube, Inc, 2007.

VINATOM-AR 11--14


PROVENANCE RESEARCH OF THE ARCHAEOLOGICALEARTHENW ARE COLLECTED AT CATTIEN RELIC BY

NUCLEAR ANALYTICAL METHODS AND MULTIVARIATE STATISTICS

Cao Dong Vu1, Nguyen Thi Sy1, Nguyen Thi Tho1, Pham Ngoc Son2

Nguyen Khanh Trung Kien,3Luong Nguyen Minh4 and Ho Sy Dong5

1Center for Analytical Techniques, Nuclear Research Institute,VINATOM2Nuclear Physics and Electronics Department, Nuclear Research Institute

3Center for Archaeology, Southern Institute of Sustainable Development4Cattien Archaeological Site Management

5Lamdong Building Materials and Mineral joint Company

Abstract: In this research, methods of INAA, XRF, AAS combined with themultivariate statistics have been applied for provenance search of the earthenware at theCattien relic. About 34 elements in 363 samples have been characterized. Number ofsamples are 111; 16; 158; 65; 10 and 3 for clay; sand; ancient brick; ancient ceramic;ancient tile and agglutinative substance, respectively. The sampling area was 12,600 ha,30 km in length along Dongnai river belonging to Dateh, Cattien districts of Lamdongprovince and Tanphu district of Dongnai province. Three reference clay sources witharea of approximately 500 ha at Quangngai town, Cattien have been localized andclassified. Multivariate statistics such as CA, PCA, CD, MD were applied to analyze setof data. The results showed that: The C2 field is a combination of 3 different sources ofclay that are the riverside, the field center and the hill base rather than a homogenoussource; These three sources are characterized by indicator elements such as Mn (PC1,PC4), As (PC1, PC3), Ba (PC2) and Tb (PC2), in which pair of Mn - As is the mostimportant. Through multivariate analysis, clay from riverside of the C2 field wasidentified to be the source of 93% of the ancient brick used to build twelve towers 2A,2B, 2C, 2D (2D1, 2D2), 3, 4, 6A, 6B, 7, 8A, 8B and C out of 14 towers at Cattien relic.On the other hand, it is found that there is no clear relation between the bricks collectedat the relic and those at Bay-Mau field. Distribution of ancient pottery and tile is quitediverse, therefore, their source has not been found in this study.

INTRODUCTION

In period 2007 – 2008, a research topic named “Study for application of NAAand multivariate statistics analysis for provenance study of the earthenware

Project Information:- Code: ĐT.01/10/NLNT



- Implementation Time: 24 months (Mar 2010-Feb 2012)




VINATOM-AR 11--14


archaeological objects collected at some relic sites of Vietnam” was carried out. Themain obtained results were:

A NAA analytical procedure for archaeological pottery was established

A multivariate statistics routine for analyzing data to get the information ofprovenance of the research objects was studied

Investigation, collection and analysis of 29 elements in 278 samples includingraw clay material, ancient brick, ancient pottery at three archaeological site which arethe Cattien site, the My-Son relic and the Emperor rampart were done to test thefeasibility of the procedures.

Through the research, some initial information about the provenance of theresearch objects at investigated sites. These results prove the feasibility of naturalsciences methods in provenance study of the ancient earthenware in Vietnam and havebeen accepted by domestic archaeologists.

However, this research also has some limit as follow:

In order to study on methodology, the research was carried out in 3 areas(Cattien, My-Son and Emperor Rampart). This means that the number of sample at eachsite is small, so that the results are not statistically assured.

With each studied site, there is only one reference clay source. However, asprinciple, every local source need to be clearly investigated.

The procedure for clay samples collection was not optimal.

The computer program and analytical processes were not completed.

Adequate and explicit information on the provenance of the pottery has not beengiven, so, the result did not contribute to the archaeology of Vietnam.

The research has been enlarged for (i) completion of the analytical methods(XRFA, NAA), (ii) improvement of the clay raw material sampling and (iii)Quantification of the output data etc. In addition, this method should be implementedfor a certain site for to get persuadable and applicable results.

Cattien archaeological relic was chosen for this study with three reasons as: (i)Cattien archaeological relic was one of three archaeological sites that were investigatedin the first phase of this project; (ii) Cattien archaeological relic is a large-scalearchaeological site with unclear architecture style and owner undefined; (iii) This studywill contribute to the documentation of Cattien relic that will be submitted to UNESCOfor consideration for becoming the World Heritage.

I. EXPERIMENTS

I.1. Elemental analytical methods

a. Neutron Activation Analysis - NAA

b. X-ray Fluorescence Analysis – XRFA

c. Atomic Absorption Spectrophotometer - AAS

VINATOM-AR 11--14


I.2. Multivariate statistic methods

a. Cluster Analysis - CA

b. Principal Component Analysis - PCA

c. Canonical Discriminant Analysis – CDA

d. Mahalanobis Distances – MD

II. PROCEDURES

Provenance study of the archeology pottery consist of different tasks such asinvestigation of the area where pottery was found; Chemical characterization of thesample by nuclear related methods; Statistical analysis; and Discussion andcommendation on the results. The procedure can be divided into 10 steps as following:(Fig. 1)

Step 1: Documentation of thearchaeological items.

In this step, information related to thestudied objects is collected such asclassification, taking picture, drawing,encoding, description of sample. Thisnormally was carried by the archaeologists.

Step 2: Investigation of the researcharea.

After having initial information ofthe research objects, reference materialsrelated to them including papers, geologymaps, etc. are picked up. Next steps areinvestigation on location, dividing ofresearch areas, planning of the samplecollection points and collection of the testsamples.

Step 3: Sample collection

- With the archaeological samples,collect the representative for each classifiedgroup depending on the number of sample.

- With the raw material (clay), thesamples are

collected after initial testing andreviewing the detail planned map of theresearch area.

Figure 1: Provenance study of theearthenware

VINATOM-AR 11--14


Step 4: Documentation and encoding of the samples

After transferred from site to laboratory, samples are documented and encodedby the standard laboratory procedures to avoid mismatching or corruption duringtransportation, preserve and storage.

Step 5: Sample preparation and storage

Sample preparation is carried out with the standard laboratory procedure foreach analytical method. The remains are stored.

Step 6: Sample analysis

Characterization of the samples by the standard laboratory analytical proceduresof INAA (30 elements) and XRFA (6 elements)

Step 7: Compilation of the input data including chemical concentration of theelements

Chemical concentration of 30 elements is compiled into input data for themanagement and statistical analysis.

Step 8: Statistical analysis

Analysis of the input data (step 7) statistically by computer program MURRAP,MSAP, v.v.. and others multivariate statistics methods.

Step 9: Edit, arrangement and storage of the data

Output of the statistical analysis such as table, figure is used for provenancesearch of the sample and/or group of samples.

Step 10: Discussion and commendation of the results

Discussion and commendation on the output of statistics analysis combined withthe samples information to find out their source.

III. RESULTS AND DISCUSSION

III.1. Investigation of the C2 clay source

The C2 field is a combination of 3 different sources of clay that are the riverside,the field center and the hill base rather than a homogenous source (Fig.2). These threesources are characterized by indicator elements such as Mn (PC1, PC4), As (PC1, PC3),Ba (PC2) and Tb (PC2), in which pair of Mn - As is the most important (Fig. 3). Thismeans that most of the remain components are equivalent. From this result and samplemapping on location, the geographical space between sources are relatively identified(Fig. 4). Fig. 5 shows the interpolation of Mn concentration at C2 field whichdetermines the bound between sources. This three clay areas are used as the referencesources for the pottery objects at Cattien site.

VINATOM-AR 11--14


Figure 2: 3D PCA analysis (PC1- PC2- PC3) for the C2 clay source

Figure 3: Element vectors (PC1-PC2)

Figure 4: Map of the C2 field’s clay groups based onmutivariance statistics and sample mapping on location

Figure 5: Distribution of Mnconcentration at C2 field

III.2. Provenance study of the brick at Cattien site

Figure 6: PCA analysis (2 first maincomponents) of the bricks from mounds of2ABCD, 3, 4, 6AB, 7 and 8ABC with the

C2 clay sources

Figure 7: PCA analysis of the Cattienpottery

VINATOM-AR 11--14


PCA analysis for mounds of 2 ABCD, 3, 4, 6AB, 7 and 8 ABC with the C2 claysource is given in Fig. 6. The results show that distributions of the brick collected atthese mounds almost coincide in the space of the main component and belong to theriverside clay source of the C2 field. In Table 1, sauces for sample collected at theabove mounds are following: (i) the riverside clay source: 121/130 samples (93%); (ii)the Bay-Mau clay source: 4/130 samples (3%); (iii) the unidentified source: 4/130samples (3%); and 1 sample may belong to the C2 source. On the other hand, bricks atmounds of 1A, 5, and tomb tower dispersedly distribute with 22/35 samples (62.8%),7/35 samples (20%) and 6/35 samples (17.1%) belong to the riverside clay source, C2field center source and unidentified source, respectively. Through multivariate analysis,clay from riverside of the C2 field was identified to be the source of 93% of the ancientbrick used to build twelve towers 2A, 2B, 2C, 2D (2D1, 2D2), 3, 4, 6A, 6B, 7, 8A, 8Band C out of 14 towers at Cattien relic. It is found that there is no clear relation betweenthe bricks collected at the relic and those at Bay-Mau field.

Table 1: Group classification using Mahalanobis distance results are based onthe following variables: PC1, PC2, PC3, PC4, PC5

PlaceBayMauclay

Riversideclay

Hillbaseclay

C2clay

Unidentified Total

Mound 1A - 8 - 6 1 15Mound2ABCD

1 46 - - 3 50

Mound 3 - 10 - - - 10Mound 4 - 10 - - - 10Mound 5 - 9 - - 1 10Mound6AB

2 16 - 1 1 20

Mound 7 - 10 - - - 10Mound8ABC

1 29 - - - 30

Tomb tower - 5 - 1 4 10Brick kiln

N0.16 - - 3 1 10

Brick kilnN0.2

2 2 - - 6 10

Brick kilnN0.3

6 1 - 3 - 10

Brick kilnN0.4

7 - - 3 - 10

Total 25 146 0 17 17 205Ratio % 12.2 71.2 0 8.3 8.3 100

VINATOM-AR 11--14


IV. CONCLUSIONS

After 2 years, most of the initial planned contents have been carried out. Theachieved results are as following:

- Investigation and collection of 1,496 samples in an area of 12,600 ha, 30 kmin length along Dongnai river belonging to 3 Towns of Lamdong and Dongnaiprovinces. There are 783 clay samples in depth of 1.0 m – 4.7 m, 324 ancient bricksfrom 19 towers at Cattien relic; 305 ancient pottery from 6 positions; 62 ancient tile; 19sand sample located at 12 points along riverside and 3 agglutinative substance samples

- The effect of burn and mix process on chemical content during ceramicmaking procedure was studied. The results showed that content of most elementincreases 8% after burning. This change, however, does not affect the staticticalanalysis. Mixing process, on the other hand, made the concentration alter regarding tothe mix ratio. This made the provenance search for ceramic sample difficult.

- After two phases (2008-2009 and 2010-2011) of the research, set of data for15,500 analytes (phase 1: 3,422, phase 2: 12,342) of more than 30 elements in 481samples (phase 1: 118, phase 2: 363) including 205 ancient bricks, 147 clay samples, 95ancient pottery, 16 sand samples, 15 ancient tile and 3 agglutinative substance sampleshas been complied. This is an important data base for Cattien relic and can be used foranother study with other purposes in the future.

- A computer progam for multivariance statistics analysis named MSAP 1.0has been developed. Toghether with MURRAP (written and distributed by M.D.Glascock, MURR), MSAP 1.0 was employed to analyze the analitical data of 481samples. However, MSAP has some weakness such as: time consuming in preparationof input data, difficult in use and need to be improved in the future.

Multivariate statistics such as CA, PCA, CD, MD were applied to analyze set ofdata. The results showed that:

- The C2 field is a combination of 3 different sources of clay that are theriverside, the field center and the hill base rather than a homogenous source. These threesources are characterized by indicator elements such as Mn (PC1, PC4), As (PC1, PC3),Ba (PC2) and Tb (PC2), in which pair of Mn - As is the most important.

- Through multivariate analysis, clay from riverside of the C2 field wasidentified to be the source of 93% of the ancient brick used to build twelve towers 2A,2B, 2C, 2D (2D1, 2D2), 3, 4, 6A, 6B, 7, 8A, 8B and C out of 14 towers at Cattien relic.On the other hand, it is found that there is no clear relation between the bricks collectedat the relic and those at Bay-Mau field.

- Distribution of ancient pottery and tile is quite diverse, therefore, theirsource has not been found in this study.

- Methods for provenance search for acheological pottery, including nuclearrelated analysis and statistical analysis are quite complete and can be used for realityapplication.

VINATOM-AR 11--14


REFERENCES

English[1]. Glascock M. D. Characterization of archaeological ceramics at MURR by neutron

activation analysis and multivariate statistics, Chemical Characterization of Ceramic Pastes InArchaeology, pp. 11-26, 1992.

[2]. Glascock M. D. and Neff H. Neutron activation analysis and provenance researchin archaeology, Meas. Sci. Technol. 14, pp. 1516–1526, 2003.

[3]. IAEA-TecDoc (2003) Technical Report series N0. 416.

[4]. Johannes H. Sterba et. Al. The influence of different tempers on the composition ofpottery, J. Archaeol. Sci., 36, 1582-1589, 2009.

[5]. Neff H. Neutron activation analysis for provenance determination in archaeology,Modern Analytical Methods in Art and Archaeology (Chemical Analysis Series) 135, NewYork: Wiley, 2000.

[6]. Sayre, E.V. Brookhaven Procedures for Statistical Analyses of MultivariateArchaeometric Data, Brookhaven National Laboratory Report BNL-23128. New York(unpublished), 1975.

[7]. Weigand, P.C., Harbottle, G., Sayre, E.V. (Eds.) Turquoise Sources and SourceAnalysis: Mesoamerica and the Southwestern USA, Academic Press, New York, 1977.

Vietnamese[8]. B. C. Hoàng, P. Q. Sơn. Điều tra khảo cổ học ở huyện Đạ Huoai tỉnh Lâm Đồng.

Tài liệu lưu Trung tâm Nghiên cứu Khảo cổ, 1986.

[9]. C. Đ. Vũ và cộng sự (2009) a Báo cáo tổng kết đề tài nghiên cứu cấp Bộ 2007-2009, MS: ĐT.06/07-09/NLNT, Bộ Khoa học và Công nghệ.

[10]. Đ. L. Côn và cộng sự (2004) Điều tra cơ bản và khai quật di chỉ khảo cổ học CátTiên (Lâm Đồng), Báo cáo kết quả thực hiện dự án, Viện Khoa học Xã hội Việt Nam, 2002-2004.

[11]. N. T. Đông. Khu di tích Cát Tiên (Lâm Đồng), Luận án Tiến sỹ Lịch sử, ViệnKhảo cổ học Việt Nam, 2002.

[12]. Sở Văn hoá thông tin tỉnh Lâm Đồng. Kỷ yếu hội thảo khoa học di tích khảo cổhọc Cát Tiên, 2001.

VINATOM-AR 11--15


STUDY ON THE SOURCES OF OILFIELD PRODUCED WATERUSING CHEMICAL COMPOSITIONS AND STABLE ISOTOPE

RATIO (2H/1H, 18O/16O)

Ho Tran The Huu, Phan Thi Luan, Dương Thi Bich Chi,Pham Thi Hoang Ha and Tran Tri Hai

Centre for Applications of Nuclear Technique in Industry, VINATOM13 Dinh Tien Hoang, Dalat, Vietnam

Abstract: Produced water samples from basement of Su Tu Den reservoir – Cuu Longbasin were collected from wellhead of producing wells. Results on hydrogeochemicalanalysis show that all water samples are of chloride calcium type following Sulin’sclassification method. The metamorphic degree of water is affected by mixing processwith injected seawater. Research on stable isotopes (2H/1H, 18O/16O) of 24W-well’ssamples show that the origin of water was the result of mixing process betweenformation water and fresher water that is increased in heavy oxygen isotope fraction dueto rock interaction. It is also show that the water has a lightly certain relationship withthermal water because of its little higher than normal in boron and lithiumconcentration.

I. INTRODUCTION

Su Tu Den is one of the five major oil fields produce predominantly from thebasement of Cuu Long basin, which was formed during the rifting in Early Oligocene.Late Oligocene to Early Miocene inversion intensified the fracturing of granitebasement and made it become an excellent reservoir. Research on petrology shows thatthere are two main types of mineral in the basement of Su Tu Den: granite andgranodiorite – diorite. In spite of some discoveries in the Oligocene-Miocene clasticsand volcanic sections, fractured granite basement is still the main target of the area.Tectonic activities play a key role in creating and enhancing the fractures in thebasement. Oil was discovered in both basement and Oligocene and Miocene clastics,but it is mainly found in the basement, over 70% of the total reserve.[1, 2]

The basement reservoirs have relatively low natural reservoir energy providedby fluid and rock expansion. In order to supplement this energy, water injection is








VINATOM-AR 11--15


applied to maintain reservoir pressure and increase oil recover factor. In recent years,however, there was increase in water cut to very high ratio in many wells. Therefore,understanding the sources of water is crucial to having a proper production anddevelopment strategy. The sources of produced water include formation water, aquifer,injected water (seawater), water infiltration from technical solutions (chemical solution,drilling fluids) which could be identified base on chemical compositions and some othertools.

II. METHODOLOGY

Produced water and injected water samples were collected for hydrogeochemicalcompositions and stable isotopes ratio (2H/1H and 18O/16O) analysis. More analysis dataof water produced from the basement was also collected and processed. Characteristicof water was determined by Sulin’s method, in which waters related to petroleum wereclassified into two main types. The “chloride-calcium” type was defined by the ratio(rCl--rNa+)/rMg2+>1, which is water in deep subsurface conditions within the earth’scrust. The “bicarbonate-sodium” type was defined by the ratio (rNa+-rCl-)/rSO4

2->l,promoted by continental conditions. Injected water (seawater) is classified as chloridemagnesium type. It is usually found in hydrodynamic area, with rNa+/rCl- < 1 and (rCl--rNa+)/rMg2+< 1. [4]

Some criteria are also applied for culling erroneous data in the analyses [6]. Inrespect to pH value, contents of OH-, CO3

2- in the result, ionic balance and value of(K/Na)×103, sources of the contaminated factors could be found. Abnormal in pHvalues (pH <5.0 or> 10.0) shows the impact of technical solutions. The report of OH- orCO3

2- could be result of wash job, contamination from drilling fluid or bad sampling.The sample is contaminated with KCl drilling fluid when (K/Na)×103 >100. Ionicbalance is used to evaluate if the analysis is good or not.

Ionic balance (%) = 100zΣzΣ

ii

ii ×C

C< 10% (1)

where Ci, zi are molar concentration and ionic charge of ion i, alternately.

Stable isotope analysis (2H/1H and 18O/16O) is an important tool in hydrologyinvestigation because it is very sensitive in change of temperature, water rockinteraction, mixing process and steam separation. Most natural processes, likeevaporation, isotope exchange with rock minerals under high-temperature conditions,and mixing with seawater or sedimentary brines shift the isotopic compositions ofmeteoric waters towards a position to the right of or under the meteoric water line(MWL). Deviation from the MWL is mainly reported in oil-field brines and geothermalwaters, and has been explained by a variety of processes. One of these processes isevaporative enrichment of D and 18O, which results in a line on the δD vs. δ18O diagrambelow the MWL, with a slope lower than that of Craig's (1961) equation. [3]

δD = 8δ18O+10 (2)

VINATOM-AR 11--15



Culling criteria are applied to the analysis data. Results show that there is onlyone sample is contaminated by KCl drilling fluid as (K/Na)×103 reach the value of1484. Applying Sulin’s method for classification of water samples, results show that allof them are classified as Ca-Cl type which is specific for water in deep buried condition.

According to rNa+/Cl- ratio, samples are classified into 2 groups. The one withrNa+/rCl- > 0.75 shows strong relationship to water in hydrodynamic area (includesamples of 3W, 6W, 7W, 21W, 25W and NE2W wells – Fig.2). In combination withmetamorphic indicato`r (rCl--rNa+)/rMg2+ and TDS values, it could be seen from Figure1, 2 and 3 that the more the water is high in rNa+/rCl- ratio and TDS, the lessmetamorphic it is (decrease in (rCl--rNa+)/rMg2+ value). It means that water is muchaffected by the other water type, which is less metamorphic and has high salinity. It issuggested here that the increase in salinity of produced water is due to the mixing offormation water with injected seawater since rNa+/rCl- approach the value of 0.85(Figure 2).

Further concerning on chemical components of 24W samples, no significantvariations were observed throughout the year (Table 1). The metamorphic degree ofwater is high, the effect of seawater mixing is not clear. Water is significantly enrichedin B (11 - 14.4 mg/L), Li (10.6 – 11.7 mg/L) and Sr (63.6 – 80.4 mg/L) compared toseawater (5.0, 0.2 and 7.0 mg/L, approximately) (Table 1). It is reported that Li, Srconcentration in water depends on the contact time between water and rock. Thus, theycan be used as an indicator for the residence time of water in the aquifer [5]. Both B andLi concentrations can be attributed to the presence of deep waters (formation water) inproduced solution. Otherwise, as indicators for thermal solution, B and Li just show alightly certain relationship with thermal water because of its not so high inconcentration compare to values that thermal water usually has.

Figure 1: The comparision of TDS dataof produced water samples

Figure 2: The comparision of calculatedrNa+/rCl- ratio of produced water samples

VINATOM-AR 11--15


Figure 3: The comparision of calculated (rCl--rNa+)/rMg2+

ratio of produced water samples

Figure 4: δD versus δ18O for produced water from 24W well

Determination of stable isotopes of 24W water samples, results from Table 1and Figure 4 show that water in 24W well is increased in heavy oxygen isotope and hasthe characteristic of deep buried water that have the origin from mixing process betweensalty formation water and local fresher water. The evidence for that is δD of samplesvary from -43% to -54%, compare to that of fresh groundwater (from -42% to -65 %).Moreover, the water has low TDS and the ratio Cl/Br is similar to seawater value.

No. SampleTDS

(g/l)pH

mg/l δ2HV-

SMOW

(‰)

δ18OV-

SMOW

(‰)Li+ K+ Na+ Ca2+ Mg2

+ Sr2+ Cl- SO42- HCO3

- Br- I- B

1. 10-Feb 16.3 7.00 10.9 216 3851 1971 7.53 65.1 9784 225 73.2 25.4 0.20 11.5 -53.63 -2.58

2. 11-Mar 15.8 7.00 11.4 184 3627 2081 6.00 79.2 9508 152 83.0 30.0 0.11 13.3 -53.81 -2.70

3. 25-Mar 16.9 7.07 11.6 235 3971 2079 4.54 71.7 10168 215 56.1 24.5 0.05 12.5 -43.57 -1.02

4. 15-Apr 16.7 7.11 11.1 212 3982 2000 6.13 65.8 10033 212 79.3 38.2 0.20 11.3 -52.63 -2.42

5. 15-Jun 17.3 7.13 10.9 177 4289 1962 5.43 73.9 10372 194 80.5 26.2 0.20 11.8 -51.45 -2.61

6. 27-Jun 16.3 6.93 11.7 212 4037 1863 4.03 87.0 9668 229 61.0 35.6 0.64 14.4 -48.44 -1.38

7. 15-Aug 15.2 6.80 11.1 212 3732 1718 3.98 80.4 9053 243 61.0 22.6 0.72 14.1 -50.03 -0.65

8. 5-Nov 15.0 6.95 10.6 191 3555 1827 4.58 61.6 8980 195 68.3 25.9 0.78 11.0 -47.79 -2.04

9. 17-Nov 15.6 6.72 11.6 210 3899 1978 5.48 63.6 9230 169 89.8 22.2 0.20 12.4 -51.90 -2.63

10. 19-Nov 15.8 6.32 11.7 236 3951 2071 6.55 72.4 9240 165 83.0 22.0 0.70 12.5 -50.36 -2.00

11. IW-Jul 33.8 8.09 0.2* 484 10609 384 1212 7.0* 18396 2514 136.6 53.0 0.05* 4.8 - -

12. IW-Nov 33.4 8.02 0.2* 378 10090 474 1183 7.0* 18512 2462 131.8 48.2 0.05* 5.0 - -

Table 1: Analytical results of produced water from 24W well

(*) Standard seawater - Collins A.G., Geochemistry of oilfield waters [4]

VINATOM-AR 11--15


IV. CONCLUSIONS

Produced water from the basement formation usually have the medium level ofsalinity (lower than seawater). Increase in salinity and decrease in metamorphic degreeof water are the indications of mixing process with other water in the reservoir. Thesewaters could be injected seawater, water from drilling fluids, technical solution.

According to Sulin classification method, all produced water samples here are ofchloride calcium type, the one that is found in most petroleum reservoir.

Research on stable isotopes of 24W-well’s samples shows that the origin ofwater was the result of mixing process between formation water and fresher water and isincreased in heavy oxygen isotope fraction due to rock interaction. It is also show thatthe water has a lightly certain relationship with thermal water because of its little higherthan normal in boron and lithium concentration.

REFERENCES

[1]. Nguyễn Hiệp (Chief editor), Địa chất và tài nguyên Dầu khí Việt Nam, Tập đoànDầu Khí Việt Nam , trang 265-306, 2010.

[2]. Phạm Vũ Chương, “Đặc điểm thạch học trầm tích cát kết MIOXEN hạ bể CửuLong”, Tạp chí dầu khí, Số 9, trang 14-23, 2009.

[3]. Arnórsson, S., Isotopic and chemical techniques in geothermal exploration,development and use, International Atomic Energy Agency, pp. 25-26; 35-36; 53-61, 2000.

[4]. Collins A. G., Geochemistry of oilfield waters, Bureau of Mines - United StatesDepartment of the Interior, pp. 1-4; 14-17; 133-173; 192-262; 293-306, 1975.

[5]. Edmunds W. M., Smedley P. L., “Residence time indicators in groundwater: theEast Midlands Triassic sandstone aquifer”, Applied Geochemistry 15, pp.737-752, 2000.

[6]. Hitchon B. and Brulotte M., “Culling Criteria for “Standard” Formation Water”,Applied Geochemistry, Vol. 9, pp. 637-645, 1994.

[7]. Ostroff A. G., “Subsurface Water - Tool for Petroleum Exploration”, Society ofPetroleum Engineers journal (SPE-4225), pp. 50-64, 1975.

VINATOM-AR 11--16


COOPERATIVE RESEARCH ON IN VITRO AND IN VIVOIRRADIATION FOR MUTANT FLOWER LINES BREEDING

IN VIETNAM

Le Ngoc Trieu1, Nguyen Tuong Mien1, Le Tien Thanh1, Khuat Huu Trung2,Kieu Thi Dung2, Hitoshi Nakagawa3, Toshio Takyu3 and Keiichi Takagi4

1 Centre for Applications Nuclear Techniques in Industry,VINATOMNo.13 Dinh Tien Hoang, Dalat, Lam Dong, Vietnam

2Agricultural Genetics Institute3Institute of Radiation Breeding (Japan)

4Wakasa Wan Energy Research Centre (Japan)

Abstract: The objects of radiation breeding were chosen, collected and in vitropropagated. The suitable modalities for acute and chronic irradiation the materials weredetermined. Two acute and one chronic irradiation series were executed. Thus, theirradiated materials were achieved to screening for the mutants. 164 mutants including12 potential mutants were indicated and collected from chrysanthemum irradiatedmaterials. Four outstanding mutant lines of A4, A34, B3 and B14 are morphologicallyand genetically different to their original varieties, possess the identification markersand aestheticism. They were morphologically stable on farm through 3 series ofgrowing on farm at M1V3, M1V5 and M1V7 generations. In the genetic respect, theypossessed the high stabilities through in vitro generations. All of these criteria showthat, these mutant lines were already to be registered as temporary cultivars/varieties.The knowledge and experience from the Japanese experts were recorded andsystematized to synthesize the process for irradiation with the purpose of breeding.

I. INTRODUTION

Radiation Breeding is a bundle of proven technologies with significantachievements that contribute to global agriculture to satisfy humankind’s increasing

Project Information:- Code:

- Managerial Level: Government

- Allocated Fund: 1.910,000,000 VND

- Implementation Time: 42 months (Jan 2009-Jun 2012)



1. Trieu Le Ngoc, Mien Nguyen Tuong, Trung Khuat Huu, Dung Kieu Thi; Studyon the genetic differences between chrysanthemum mutant lines and their originalvarieties by RADP marker. Science activities review. ISSN 1859-4794. No 640:82-85, 2012.

2. Trieu Le Ngoc, Mien Nguyen Tuong, Trung Khuat Huu, Ham Le Huy; Effectsof X ray, Gamma ray 60Co and proton beam on survival and genesis of somephenotypic mutants in chrysanthemum (Chrysanthemum morifolium Ramat.).Science and Technology Journal of Agriculture & Rural Development. ISSN8066-7020. No 173: 16-21, 2011.


VINATOM-AR 11--16


demands, and which has become one of the fastest developing scientific research fieldswith practical applications in the world.

To implement the “Application of Atomic Energy for Peaceful Purposes to theYear 2020” strategy approved by the Prime Minister, the Centre for Application ofNuclear Techniques in Industry (CANTI) has begun a scientific program of radiationbreeding in 2007 with the project of establishing Vietnam’s premier National RadiationBreeding Complex under the auspices of CANTI.

Pursuant to the cooperation agreement between CANTI and the Institute ofRadiation Breeding (IRB-Japan), CANTI has proposed, registered and implemented theInternational Co-operative Research Task via protocol: “Cooperative research on invitro and in vivo irradiation for mutant flower lines breeding in Vietnam”.

The purposes of this task are to create convenient conditions for CANTI’sresearchers to achieve the methods by (1) acquiring knowledge and experience fromJapanese experts, and (2) applying such knowledge to the tasks of radiation breeding incircumstances with minimal irradiation facilities.

Demanded scientific and technological products of the task include the basicprocess for irradiation for plant breeding purposes, one to three mutant flower lines thatmight be applied to reality. Beside that, by executing the task some the researcher canget the level of master and specialist.

Thanks to the efforts of the execution team who performed this challenging task,the disadvantages were overcome, and the scientific and technological products of thistask have been quite satisfactory at registration:

- 04 mutant lines of chrysanthemum were induced versus 01-03 mutant lines ofchrysanthemum at registration.

- Basic processes for irradiation for plant breeding purpose were synthesized forapplying in future with Gamma ray, X-ray and ion beam. Methods and approaches forthe irradiation, and experimental arrangement were described in detail in this process.

II. METHODS

II.1. Investigation and choosing the objects for radiation breeding

Investigation into chrysanthemum cultivation and business in Da Lat city tochoose the cultivars that are needed to improve the characteristics, cultivated with largearea and possess high commercial ability; choose potential cover flower cultivars;popular, specific to Da Lat city flowers species and potential fragrant flower species inDa Lat city to be the research objects.

II.2. Sample sterilization, callus/shoot induction, in vitro propagation

Experimentally investigate HgCl2 concentrations and time for sample treatmentto sterilize samples; effects of plant growth regulators concentrations on shoot inductionaccording to different complexes of BAP, NAA, and TDZ; effects of differentcomplexes of BAP and NAA on coefficient of shoot multiplication; effects of differentNAA concentrations on in vitro root induction in chrysanthemum and Wedelia toestablish the protocol/process in in vitro propagation of chrysanthemum and Wedelia.Apply the achieved process to induce in vitro materials for next investigations.

VINATOM-AR 11--16


II.3. Investigate the artificial seed making process and apply the achievedprocess

Base on published protocols, a common process was sumarised and used forseparate investigation effect of each factor on result of process. Experimentalinvestigation for age and size of shoot used as “embryo”; sodium alginate and CaCl2

concentration; soaking time to establish the protocol for artificial seed making inchrysanthemum and Wedelia. Apply the achieved process to induce in vitro materialsfor in vitro irradiation.

II.4. Investigate to determine types of materials and suitable doses forirradiation:

II.4.1. In vitro materials for acute irradiation: Investigate the survival rate ofartificial seeds at 9, 18, 27, 36, and 45 days after making to determine/choose suitableperiod time for germinate. Based on the experiments to determine LD50, choose doses of1/5; 2/5; 3/5; 4/5 and 1 LD50 for irradiation with purpose of mutation induction.

II.4.2. In vivo materials for acute irradiation: With chamomile seeds,investigation of modalities for acute irradiation was executed in two types of materials:dry seeds and bloat seeds. Investigate LD50 by experimental tests. Choose doses that thematerials still alive to irradiate with purpose of mutation induction.

II.4.3. In vivo materials for chronic irradiation: With both chamomile andTithonia, investigate types of cutting (tender, medium, and old) in combination withdifferent concentrations of NAA and IBA; investigate 3 concentration of Atonik usingin seed treatment to choose the advantageous modality for plantlet induction. Base ondata of genetic variation in Matricaria recutita (L.) Rauschert and Helianthus annuuswhich are close-related with research objectives and the consultantship fromIRB’experts to set up experimental lots on gamma field with different doses/dose rates.

II.5. Carry out chronic and acute irradiation series

Base on the results of investigation in choosing material types and irradiationdose.

II.6. Systemize the knowledge and experiences to synthesise of generalprocess for irradiation with breeding purpose using in vitro and in vivo materials

The basic process for irradiation with breeding purpose using in vitro and in vivomaterials was established by training, gathering knowledge and experience onirradiation and radiation/mutation breeding from books, scientific articles, technicalreports/papers/documents from specific organization with radiation breeding function.

II.7. Quick multiplication of irradiated materials

Apply the achieved process from the investigation protocol for micro-propagation, using micro-cutting if necessary.

II.8. Experimental test of irradiated materials’ growth on farmII.8.1. Experimental growing: Process of experimental growing was

implemented through two stages: in nursery and in plastic house according to themodalities to commercially cultivate chrysanthemum, chamomile and modalities toplant Wedelia and Tithonia that applied in Dalat city by farmers.

VINATOM-AR 11--16


II.8.2. Mutants screening

In chrysanthemum: followed-up and recorded criteria were concentrated ongiven characteristics, in concrete as: Quantitative criteria; Plant height,; Number ofcapitules; Size of capitule; Size of stem; Shape and structure of leaf/leaves; Color ofleaf/stem; Color of petal; Structure of capitule.

In chamomile: concentrated on criterions of petal stability.

In Wedelia: size, structure of capitule and color of petal

In Thithonia: concentrated on criterions of plant height, flower color

II.9. Sterilization of the samples from mutants, in vitro propagation toinduce potential mutant lines

Apply the investigated processes for in vitro propagation.

II.10. On-farm morphological stability estimation

Record and determine mutant morphological phenotypes’ segregation:observation and data recording were done with the concentration on segregation rate ofexpected mutant characteristics.

II.11. Genetic diversity estimation in potential mutant lines, determine thegenetic differences among mutant lines and their original cultivars

DNA from leaves are extracted by CTAB protocol (Weising et al., DNAfingerprinting, 2005) with modification of adding 10% SDS to isolation buffer. DNAfrom the potential mutant lines and original cultivars as controls are used to induceDNA fingerprinting by RAPD-PCR technique. 33 RAPD primers belonged to primergroups of BIO, OPA, OPC, OPM, OPN, S, and UBC supplied by Operon and Bioneercorporations were used. RAPD bands are recorded for their appearance or absence toestablish the binary matrix. These data are processed by NTSYS-pc2.1.1(F.J Rohlf.,2000) to determine similarity coefficient and establish genetic relationship tree amongsamples.

II.12. Outstanding mutant lines genetic stability estimation through in vitrogenerations

In vitro materials for DNA extraction are leaves from plantlets. RAPD-PCRtechnique were applied to induce the DNA fingerprinting with 14 RADP decamerprimers. Compare the similarity coefficients among in vitro samples belong to M1V6,M1V8, M1V10 and M1V12 to estimate the genetic stability.

II.13. Select Chrysanthemum outstanding mutant lines

Base on following criteria: a) Morphologic differences to its original cultivar,aestheticism; b) Molecular/genetic difference(s) comparing to its original cultivar andmolecular marker(s) for recognition; c) Mutant morphologic stability through on farmM1V3, M1V5 and M1V7 generations; d) Genetic stability through in vitro generationsto select Chrysanthemum outstanding mutant lines as task result/products.

III. RESULTS

III.1. Choosing the objects for radiation breeding according to the task:Following chrysanthemum cut flower cultivar to be objects of the task: White Artfarm,

VINATOM-AR 11--16


signed as C1; White Doa, signed as C6; White Saphia, signed as C21; Yellow Saphia,signed as C29 and Green Tassel, signed as C26.

Other chosen flower to be objects of the task were Wedelia, signed as SĐ;Tithonia (Mexican sunflower), signed as DQ and chamomile, signed as DCC.

III.2. Sample sterilization, callus and shoot induction, in vitro propagationwith collected materials to prepare in vitro materials for irradiation

Based on experimental results, execution team had established the processes forpropagation with Chrysanthemum and Wedelia as follows:

With Chrysanthemum: Sterilize the petals by 1‰HgCl2 solution for 2 minutes.Medium for shoot generation from petals is MS + 1mg/l BA + 0.3mg/l NAA + 0.3mg/lTDZ + 30g/l succrose + 7.5g/l agar. Medium for quick multiplication of shoot: MS +1mg/l BA + 0.3mg/l NAA + 30g/l succrose + 7.5g/l agar. Medium for rooting: MS +0.5mg/l NAA + 30g/l succrose + 7.5g/l agar.

With Wedelia: Sterilize the apex shoots by 1‰ HgCl2 solution for 4 minutes.Medium for transferring sterilized shoots is: MS + 1mg/l BA + 0.3mg/l NAA + 30g/lsuccrose + 7.5g/l agar. Medium for quick multiplication of shoot: MS + 1mg/l BA +0.3mg/l NAA + 30g/l succrose + 7.5g/l agar. Medium for rooting: MS + 0.5mg/l NAA+ succrose 30g/l + agar 7.5g

Application of achieved processes to induce 44,700 in vitro plants/shoots ofchrysanthemum and Wedelia as materials for next investigation.

III.3. Investigate the artificial seed making process and apply it to preparematerials for irradiation

The processes for artificial seed making in chrysanthemum and Wedelia weresummarized as described on following table:

Table 3.1: Advantageous modalities for artificial seed making

Factor Chrysanthemum Wedelia

Material for “embryo” Apical Shoot Apical Shoot

Chamomile Tithonia Wedelia White Doa

Green Tassel White Artfarm White Saphia Yellow Saphia

Figure 3.1: The chosen object for radiation breeding

VINATOM-AR 11--16


Age of in vitro plant to separate the apical shoot 3-week age 3-week age

Na-Alginate concentration 3% 3%

CaCl2 solution concentration 100mM 100mM

Time for soaking in CaCl2.2H2O solution 10 minutes 10 minutes

According to these results, processes of making artificial seed withchrysanthemum and with Wedelia were the same.

Investigated process was applied to induce 36,060 artificial seeds for testingmaintainable time, irradiation doses estimation and irradiation to induce the mutants.

III.4. Experimental research to identify types of materials and suitabledoses of irradiation by different facilities

From the results of investigation on LD50 by experimental tests, base on factsituation of transportation, storage, irradiation, plant generating and consultative ideasfrom Japanese radiation breeding experts, modalities for irradiations were determined:

a. In vitro materials for acute irradiation were artificial seeds and suitable totaltime for storage, irradiation and transportation were 18 to 27 days after inducing, dosesto apply in actual irradiation with purpose of mutant induction were 10, 20, 30, 40 and50Gy.

b. In vivo materials for acute irradiation were chamomile dry and bloat seeds,irradiation modalities were as follows:

- Directly irradiate the chamomile dry seeds with doses of 100, 200, 300, 400,500Gy by gamma ray and 100, 200, 300, 400, 500, 600 Gy by X ray, irradiated dryseeds were brought back to Vietnam for experimental arrangement in nursery withtreatment of 0.3‰ Atonik 1.8 DD solution before sowing.

- Irradiate bloat seeds: LD50 was approximately 55 Gy by X ray from X raymachine. Based on fact condition of task’s execution, we chose dose of 10, 20…, 90,100Gy for irradiation with purpose of mutants induction. Seeds were treated with 0.3‰Atonik 1.8 DD solution 2 days before irradiation and brought back to Vietnam forarranging in nursery.

c. In vivo materials for chronic irradiation: chamomile dry seeds are transportedto Japan, treated with 0.3‰ Atonik 1.8 DD solution before sown in nursery. Generatedplantlets were transplant on gamma field at positions that have the distances to radiationsource of 10.5; 12; 14; 16; 18; 20 and 22m, approximately equal to expected dose forwhole chronic irradiation of 209.75; 155.87; 110.64; 82.22; 63.27; 50.06 and 40.5Gy.Tithonia medium age cuttings are treated with 500ppm IBA solution to induce thecomplete plantlets. These plantlets are transplanted on gamma field with distances toradiation source of 10.5; 12; 14; 16; 18; 20 and 22m, approximately equal to expecteddose of 271.14; 201.48; 143.02; 106.28; 81.8; 64.71 and 52.35Gy

VINATOM-AR 11--16


III.5. Carry out one chronic and two acute series of materials irradiation bydifferent facilities with purpose of mutant induction

III.5.1. Acute irradiation

Two series of acute irradiation were executed in May to June and in November,2009.

Table 3.2: Acute irradiation executing

Time Irradiation executing Quantity of material

27th May Artificial seeds of C1, C29; using Carbon beam 100 artificial seeds

15th June Artificial seeds of C1, C26, C29; using Gammaray

360 artificial seeds

Dry seeds of chamomile; using Gamma ray 5,000 seeds

17th June Artificial seeds of C1, C6, C29 and Wedelia;using X ray

1,000 artificial seeds

Dry seeds of chamomile; using X ray 6,000 seeds

15th Nov. Artificial seeds of C1, C6, C21,C26, C29 andWedelia; using Gamma ray


17th Nov. Artificial seeds of C1, C6, C21 and Wedelia;using X ray


19th Nov. Artificial seeds of C1, C6, C21,C26, C29 andWedelia; using Proton beam


23rd Nov. Bloat seeds of chamomile; using X ray 12,000 seeds

III.5.2. Chronic irradiation

Materials for chronic irradiation were plantlets as follows:

- Chamomile: plantlets were transplanted on Gamma field from 25th May to 23rd

November, 2009. There were 7 doses from 40.5 to 209.75Gy were applied. 10g ofseed/dose were collected.

- Tithonia: plantlets were transplanted on Gamma field from 25th May to 18th

November, 2010. There were 7 doses from 88.98 to 460.79Gy were applied. 20 cuttings/irradiation dose were collected.

III.6. Establishment of general process for irradiation with breedingpurpose using in vitro and in vivo materials

This basic process includes following parts:

- Basic principles for irradiation to induce the mutants.

VINATOM-AR 11--16


- General process to estimate/calculate suitable/advantageous/optimal dose rangefor irradiation with purpose of mutant induction.

- Method to determine suitable dose rate for regular irradiation with a certainmaterial. This part mentions about modalities of irradiation in large program of breedingthat irradiation is required to repeat many time and regularly with a given material.

- Process for acute irradiation. The process includes basic steps to executeirradiation with purpose of mutant induction, modalities for experimental arrangement,operate facilities.

- Process for chronic irradiation (only applied with Gamma field facility). Thispart mentions to general steps for chronic irradiation,

III.7. Quick multiplication of irradiated materials

Irradiated in vitro materials (artificial seeds) were in vitro propagated to induce112,669 in vitro complete plants of chrysanthemum varieties and Wedelia species forgrowing to screen the mutants. Results in in vitro stage show that the survival rate ofirradiated in vitro materials is inversely proportional to irradiated dose in all irradiationmodalities.

Quantity of induced in vitro plantlets from each type of survival material afterstorage, irradiation, transportation was more than 600.

III.8. Experimental test of irradiated materials’ growth on farm andmutants screening

Irradiated and propagated materials were grown on farm. In nursery stage,survival rate of irradiated materials is inversely proportional to irradiated dose in allirradiation modalities with all kinds of materials. After transplanted on farm or plastichouse, the survival rate of irradiated material almost same to the control. There were164 mutants including 12 potential mutants were indicated and collected fromchrysanthemum irradiated material. There some morphological alterations appeared inirradiated materials of Tithonia and chamomile were recorded, however they are similartogether and might be caused from seed embryo injured by irradiation and were notconsidered as real mutants.

III.9. In vitro propagation of mutants to induce potential mutant lines asmaterials for on farm planting to estimate stability of mutative phenotype

Three series of transferring the ex vitro samples to in vitro condition forpropagation. In first series, the materials were petals from 164 achieved mutantsincluding 12 potential mutants and 15,000 in vitro complete plantlets of potentialmutant lines were induced. In second series, the materials were petals from 11 potentialmutant lines and 10,500 in vitro complete plantlets were induced. In the third series, thematerials were petals from 4 outstanding mutant lines and 10,500 in vitro completeplantlets were induced. These induced in vitro complete plantlets were used as materialsfor growing on farm to estimate the segregation of chosen mutant characteristicsthrough on-farm M1V3, M1V5 and M1V7 generations. There were no difference insurvival rates, in multiplication coefficients and in other characteristics of in vitropropagation process between original varieties and the induced mutant/mutant linesfrom them.

VINATOM-AR 11--16


C1 –original variety

A34 A4 A14 A15

C6 –original variety

B3 B13 B14 B29

C29-original variety

F3 F7 F9 F29

Figure 3.3: 12 chosen potential mutants and their original varieties

III.10. On-farm morphological stability estimation

There was no difference in the development of plants between themutant/mutant lines and their original varieties and also no more morphologicalalteration appeared in the third series of growing to estimate the mutant morphologicalstability.

Recorded data indicated that:

- In on farm M1V3 generation, mutant lines of A4, A34, A14, A15, B3, B13,B14, B22, F29 were not segregated; 68% of individuals in F3 line; 21% of individualsin F9 line and only 1.4% of individuals un F7 line maintained the mutant forms.Collating to the criteria to limit the quantity of mutant lines for corresponding to thewhole task’s scope, F7 line were not selected the samples to transfer to in vitrocondition for next propagation and breeding. However, the leaf samples from theindividuals that kept mutant morphological characteristic were collected to extract DNAfor genetic analysis.

- In on farm M1V5 generation, mutant lines of A4, A34, A14, A15, B3, B13,B14, B22, F3, F9, F29 were not segregated.

- In on farm M1V7 generation, four outstanding mutant lines of A4, A34, B3and B14 were not segregated.

These were the base to conclude that four outstanding mutant lines A4, A34, B3and B14 were stable in mutant phenotype on farm.

VINATOM-AR 11--16


III.11. Genetic diversity estimation in potential mutant lines, determine thegenetic differences among mutant lines and their original cultivars

The research results show that among three original cultivars, among eachoriginal cultivar and potential mutant lines induced from it, among all potential mutantlines together with all three original cultivars were virtually different in genetic. Thehighest level of genetic difference among 15 investigated samples was 0.37 (similaritycoefficient was 0.63) and the lowest was 0.04 (similarity coefficient was 0.96).

Although the mutant lines possessed the genetic differences to their originalcultivar, these genetic variations didn’t exceed the genetic limit of group including theoriginal cultivar and the induced mutant lines from it.

Analyzing DNA fingerprinting induced by RAPD-PCR not only helped toestimate the level of difference among original cultivars and the potential mutant linesinduced from them but could be used to identify the mutants lines or groups of eachoriginal cultivar and the potential mutant lines induced from it. In this research, 41markers for such mutant lines identification and 56 markers for such groups’identification. These data are necessary for protecting and registering the new cultivarsin the future.

III.12. Outstanding mutant lines genetic stability estimation through in vitrogenerations

Leaf samples of in vitro lines of A4, A34, B3, B14 and their original (C1 andC6) at M1V6; M1V8, M1V10 and M1V12 were extracted to achieve DNA samples.DNA fingerprinting from extracted DNA samples were induced by RAPD-PCRtechnique, results of genetic analysis by NTSys software indicate that:

- The similarity coefficients among 24 investigated samples fluctuated from 0,66to 1.00. The highest similarity coefficients appeared in almost samples that were samelines but different in in vitro generation. However, similarity coefficient between twopairs of M1V6 -M1V8 and M1V10-M1V12 generation in A34 was 0.99 and similaritycoefficients between M1V10 and each other generation in B3 were also 0.99. Theseshow that the genetic variations through in vitro generations were very low. In total ofinvestigated samples, the lowest similarity coefficient was 0.66 and recorded betweenM1V10/M1V11 generations of A34 and generations of C6 or B14. Low similaritycoefficient was 0.67 also recorded between M1V6/M1V8 generations of A34 andgenerations of C6 or B14.

- The two original cultivars and the two mutant lines of A4 and B14 possessedthe absolute genetic stability through 7 in vitro generations.

- In mutant line A34, there was the genetic variation that appeared in M1V10 invitro generation and maintained to M1V12 in vitro generation. But this variation werevery small: around 1%. In mutant line B3, there was the genetic variation that appearedin M1V12 in vitro generation but disappeared in M1V12 in vitro generation. Thisphenomenon may due to the genetic self correction in plants.

In general, the genetic stabilities of all four potential mutant lines and originalcultivars were high.

VINATOM-AR 11--16


III.13. Selection the mutant lines as task’s resultThrough the execution of the special subjects, we recognized the four

chrysanthemum mutant lines A4, A34, B3 and B14 possessed the characteristics asfollows:

- In phenotype: The four mutant lines are different to their original cultivarsand possess aestheticism.

Possessing these phenotypes, these mutant lines can be accepted by the market.During on farm experimental growing of mutant lines, the execution team had contactedand introduced these lines to the farmer and flower businesses and received the goodfeedbacks/supports.

- In genetic characteristic: The results in genetic diversity analysis andidentifying the genetic differences among the mutant lines and their original cultivarsindicated that the mutant lines are actually different together and to their correlativeoriginal cultivars in genetics, namely as follows:

+ The genetic difference between A4 mutant line and its original cultivar were4%

+ The genetic difference between A34 mutant line and its original cultivar were14%

+ The genetic difference between B3 mutant line and its original cultivar were9%

+ The genetic difference between B14 mutant line and its original cultivar were10%

These mutant lines can be identified by RAPD markers

- In on farm mutant morphological stability: All of four mutants of A4, A34,B3 and B14 were sampled, sterilized, transferred to in vitro condition to propagate and

A34 line White Artfarm original cultivar A4 line

B3 line White Doa original cultivar B14 line

Figure 3.4: Mutant lines and their original cultivar

VINATOM-AR 11--16


grown on farm at M1V3, M1V5 and M1V7 generations. All of them showed non-segregation from the very first series of experimental growing and absolutely kept themutant phenotypes in the two later series of growing.

- In genetic stability through in vitro micro-propagation: the genetic stabilityamong in vitro generations of the four mutant lines were high, namely A4 and B14 lineswere absolutely stable through 7 in vitro generation, and the genetic differences on A34and B4 were very low, limited in 1%.

Thus, four outstanding mutant lines of A4, A34, B3 and B14 were chosen tobe the products of the task as registration.

IV. CONCLUSION

1. 05 Chrysanthemum cut flower cultivars and the species of Tithonia,Chamomile, Wedelia were chosen as objects of radiation breeding.

2. The protocols for sample sterilization, quick multiplication and complete invitro plant induction and artificial seeds making for the chrysanthemum and Wedeliawere established by experimental investigations. These protocols were applied to induce36,060 artificial seeds for testing maintainable time, irradiation doses estimation andirradiation to induce the mutants.

3. The suitable modalities for acute and chronic irradiation the materials weredetermined. Two acute and one chronic irradiation series were executed. In the results,irradiated artificial seeds, dry and bloat Chamomile seeds, Tithonia cuttings werecollected. Thus, the irradiated materials were achieved to screening for the mutants.

4. The knowledge and experience from the Japanese experts were recorded andsystematized to synthesize the process for irradiation with the purpose of breeding. Theprocess includes 5 sections related to principles in radiation breeding, the steps forchoosing the suitable dose(s) for irradiation, the steps for choosing the suitable doserate(s) for irradiation, the steps for acute irradiation executing and the steps for acuteirradiation executing.

5. Irradiated and propagated materials were grown on farm. In nursery stage,survival rate of irradiated materials is inversely proportional to irradiated dose in allirradiation modalities with all kinds of materials. After transplanted on farm or plastichouse, the survival rate of irradiated material almost same to the control. There were164 mutants including 12 potential mutants were indicated and collected fromchrysanthemum irradiated materials.

6. Three series of transferring the ex vitro samples to in vitro condition forpropagation were executed. The induced in vitro complete plantlets were used asmaterials for growing on farm to estimate the segregation of chosen mutantcharacteristics through on-farm M1V3, M1V5 and M1V7 generations.

7. 9/12 potential mutant lines completely kept the mutant phenotype on farm inM1V3 generation; 11/11potential mutant lines completely kept the mutant phenotype onfarm in M1V5. Four chosen outstanding mutant lines completely kept the mutantphenotype on farm in M1V7. Thus, these outstanding mutant lines were stable in mutantphenotype on farm.

VINATOM-AR 11--16


8. Among three original varieties/cultivars, among each original cultivar andpotential mutant lines induced from it, among all potential mutant lines together with allthree original cultivars were virtually different in genetic. Although the mutant linespossessed the genetic differences to their original cultivars, these genetic variationsdidn’t exceed the genetic limit of group including each original cultivar and the inducedmutant lines from it. 41 markers for such mutant lines identification and 56 markers forsuch groups’ identification were indicated.

9. The genetic stabilities of four outstanding mutant lines and original cultivarsthrough in vitro generations of M1V6, M1V8, M1V10 and M1V12 were high.

10. Four outstanding mutant lines of A4, A34, B3 and B14 are morphologicallyand genetically different to their original varieties, possess the identification markersand aestheticism. They were morphologically stable on farm through 3 series ofgrowing on farm at M1V3, M1V5 and M1V7 generations. In the genetic respect, theypossessed the high stabilities through in vitro generations. All of these criteria showthat, these mutant lines were already to be registered as temporary cultivars/varieties.

REFERENCE

[1]. Barakat M.N., Rania S.A.S. Badr M. and Torky M.G.E. In vitro mutagenesis andidentification of new variants via RAPD markers for improving Chrysanthemum morifolium.African Journal of Agricultul Research 5 (8): 748-757, 2010.

[2]. Bhattacharya A. and Teixeira da Silva J.A. Molecular systematics inChrysanthemum × grandiflorum (Ramat.) Kitamura. Scientia Horticulturae 109 (4): 379-384,2006.

[3]. Broertjes C., Roest S. and Bokelmam G.S. Mutation breeding of chrysanthemummorifolium Ram. Using in vivo and in vitro adventitious techniques. Euphytica 25: 11-19, 1976.

[4]. Carmen Martín, Uberhuaga E., Pérez C. Application of RAPD markers incharacterisation of Chrysanthemum varieties and the assessment of somaclonal variation.Euphitica 127: 247- 253, 2002.

[5]. Nagatomi. S, Miyahira. E. and Degi. K. Induction of flower mutation comparingwith chronic and acute gamma irradiation using tissue culture techniques in ChrysanthemumMorifolium Ramat. . Acta Hort. (ISHS) 508:69-74, 2000.

[6]. Kurt Weising, Hilde Nybom, Kirsten Wolff, Günter Kahl. DNA Fingerprinting inPlants Principles, Methods, and applications (second Edition). Cpc press taylor & Fanciesgroup, 2005.

[7]. Gamma field symposia Number 1-48, 1962-2009. Institute of Radiation Breeding –Nias. Hitachi-Ohmiya, Ibaraki-ken, Japan. (http://www.nias.affrc.go.jp/eng/gfs).

[8]. Technical News. Institute of Radiation Breeding – Nias, No. 1 – 69, 1969 – 2003.

[9]. Etsuo Amano. Practical suggestions for Mutation breeding, Fukui PrefecturalUniversity, 2004.

[10]. Hitoshi Nakagawa. Mutation breesing and Biological researches by the use ofGamma ray irradiation in Japan. Mutation breeding project Workshop of FNCA, 2008.

[11]. Van Harten A.M. Mutation breeding in vegetatively propagated Crops, Plantbreeding section, Joint FAO/IAEA, 1997.

[12]. Etsuo Amano, Shigemitsu Tano. Mutation breeding manual. FNCA, 2004.

http://www.nias.affrc.go.jp/eng/gfs

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QUARANTINE TREATMENT OF FRUIT FLYBACTROCERA CORRECTA INFESTED IN NAMROI

GRAPEFRUITS BY GAMMA RADIATION AT HANOIIRRADIATION CENTER

Nguyen Van Binh1, Tran Bang Diep1, Pham Duy Duong1, Hoang Phuong Thao1,Nguyen Thanh Hien2 and Vu Thi Thuy Trang2.

1Hanoi Irradiation Center, VINATOMMinh Khai, Tu Liem, Hanoi

2Plant Protection Research Institute

Abstract: In this study, the gamma irradiation was investigated as an effectivequarantine treatment of fruit fly infested on Namroi grapefruit. The grapefruit infectedwith the eggs and larva of Bactrocera correcta were irradiated with gamma radiation.Egg hatching mortality of pupa and larva, maturation of adults flies, as well as sensoryand nutrient qualities of the irradiated grapefruits were investigated with radiationdoses. Results revealed the radiation dose of 250 Gy is enough for quarantine treatmentof these fruit flies. Though small amount of larva can become pupa, but no adultemergence could be observed. The dose of 250 Gy or at this dose, but it is enough (until850 Gy) did not significantly affect the quality grapefruit. As a result, the dose of 250Gy can be applied to radiation quarantine treatment of Bactrocera correcta infected onNamroi grapefruits. The results also suggested an effective quarantine radiationprocedure for the grapefruits infecting with Bactrocera correcta fruit flies by gammaradiation at Hanoi Irradiation Center.

Keywords: Irradiation, quarantine treatment, Bactrocera correcta.

I. INTRODUCTION

The purpose of quarantine treatment is to prevent the migration of potentiallyharmful insects, wild grass to new areas within and between countries. Traditionaltreatments, which most commonly involved the fumigation with chemicals such asethylene bromide, methylene bromide and both heating (43-48°C) and cooling (0-3°C)for complete killing all stages of quarantined pests that might be present in thecommodities have been applied for a long time. However, the quality of treatedcommodities was more or less reduced. Alternative quarantine treatments for freshcommodities are required because the chemical fumigants are being prohibited to healthand environment problems, heat damages also occurred for a lot of commodities,especially for fresh fruits.








VINATOM-AR 11--17


Radiation technology has been studied as a quarantine treatment for over 50years, and paid much attention from development countries since 80’s of the lastcentury, but has rarely applied for exportation of fresh fruits. Unlike traditionaltreatments, the objective of radiation quarantine treatment is not acute mortality. Thedose need to kill larva of fruit flies before they can be encountered by inspectors oremerge from the fruit would damage most fresh fruits, therefore, the quarantine doseshould be lower than the dose for killing all insects at various growing states. Thoughradiation treatment has been accepted as an effective quarantine measure in manydeveloped countries, radiation quarantine has been studied to control the spreading ofseveral fruit flies infecting in the tropical fruits such as dragon fruits since the end oflast century in our country. Up to now, only the dragon fruits that quarantined bygamma irradiation with dose of about 400 Gy was overcome the quarantine barriers forexportation to developed countries.

Grapefruit is the tropical fruits not only rich in nutrients, but also high values ineconomics. Up to now, there are many kinds of grapefruits in Vietnam such as DoanHung, Phuc Trach, Da Xanh, Nam Roi, and Dien. However, their exportation stilllimited to some developed countries because of the strict requirements on food hygieneand phytosanitary treatment. In this study, the NamRoi grapefruits have been infectedwith the fly Bactrocera correcta were irradiated with gamma Co-60 source at HanoiIrradiation Center (HIC) for quarantine purpose. The minimum radiation dose to control100% of all growing stages of Bactrocera correcta was estimated as a quarantine dose,and the nutrient quality of the grapefruits that irradiated with dose higher than thequarantine dose, consisting of sensory quality, morphology, sugar and vitamin Ccontents were also investigated.

II. EXPERIMENTS

NamRoi grapefruits were bought from the fruits market with the same sensoryquality. Mature flies of Bactrocera correcta were isolated from the fruits infected withthe flies and reared in the laboratory (Plant Protection Institute) with controlledtemperature (26-28°C), humidity (70-80%). Eggs and larva at different stages wereinfected on the grapefruits shell, and the infected fruits were irradiated with 0, 150, 250,350 and 850 Gy at a dose rate of about 10 Gy per min in 60Co gamma source (HIC).After irradiation, egg hatching, pupation and maturation of the irradiated eggs and larvawere investigated with radiation doses. Sensory quality as well as nutrient quality suchas sugar and vitamin C contents of the irradiated grapefruits were also investigated.


III.1. Radiation effects on egg hatching and pupation of Bactrocera correcta

As presented in Table1, about 87.7% eggs can hatch and develop into the larvaat different states for non-irradiated sample, but the egg hatching quickly decreased withradiation dose. There are no larva can be observed in the grapefruits irradiated with dosehigher than 250 Gy, namely the eggs, which irradiated with dose higher than 250 Gycould not hatch. The results also indicated that the irradiated insects can not becomenymphs, even 23.3% eggs can hatch to the larva. These results suggested that the doseof about 150 Gy is enough for killing all larval stages of B.correcta.

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Table 1: Egg hatching and pupation of B.correcta with radiation dose

2.1. Dose (Gy) 2.2. Hatching rate (%) 2.3. Percentage of nymphs (%)

2.4. 0 2.5. 87.67 ± 0.42 2.6. 83.52 ± 0.38

2.7. 150 2.8. 23.2 ± 0.53 2.9. 0

2.10. 250 2.11. 0 2.12. 0

2.13. 350 2.14. 0 2.15. 0

III.2. Radiation effects on development of larvae to nymphs

Table 2 showed the pupation of B.correcta from the larva in different growingstages consisting of 1st, 2nd and 3rd instars. The results revealed that percentage ofpupation was significantly decreased with increasing of the absorbed dose. At the dosesof 350 Gy, no nymphs can be observed, namely the larva could not develop to pupa.However, lower doses will prevent the fruit fly immatures reaching the adult stage, andthis lower dose has been recommended as the radiation dose for quarantine.

Table 2: Effect of gamma irradiation on development to nymphs

Developmentstage

Percentage of nymphs (%)

Non-irradiated 150 Gy 250 Gy 350 Gy

1st instars 79.33 ± 0.25 25.0 ± 0.12 12.33 ± 0.11 0

2nd instars 82.67 ± 0.19 29.0 ± 0.15 16.0 ± 0.1 0

3rd instars 84.33 ± 0.28 40.67 ± 0.21 20.0 ± 0.14 0

III.3. Effect of gamma irradiation on mature pupae

To determine the quarantine dose for B.correcta, the development of irradiatednymphs should be recorded with time. Table 3 showed the numbers of adult emergingafter irradiation of the mature pupae at different radiation dose. Regarding to thedevelopment of nymph, adult emerging and adult deformation were not significantlydifferent from non-irradiated or one another. After irradiation, there was a significantdifference in ratio of adult insects at the stages of 1st, 2nd and 3rd instars. Ratio of adultemerging decreased with radiation dose, and no adult can be emerged in the grapefruitsirradiated at 250 Gy. Therefore, the dose of 250 Gy was suggested as the quarantinedose for B.correcta.

VINATOM-AR 11--17


Table 3: Radiation effects on mature nymphs

2.16. Developmentstage

2.17. Percentage of adults (%)

2.18. Non-irradiated 2.19. 150Gy 2.20. 250Gy

2.21. 1st instars 2.22. 94.35 ± 0.27 2.23. 16.8 ± 0.22 2.24. 0

2.25. 2nd instars 2.26. 92.32 ± 0.21 2.27. 42.6 ± 0.31 2.28. 0

2.29. 3rd instars 2.30. 96.15 ± 0.23 2.31. 59.5 ± 0.25 2.32. 0

Figure 1: Infection procedures of B.correctaat different stages on the grapefruit shell

III.4. Optimal dose for radiation quarantine of B.correcta

Table 4 showed the maximum absorbed doses for irradiated grapefruits affectedwith the insects at several growing stages. Comparing with the quarantine dosedetermined from the experiments for egg hatching, development of pupa at differentgrowing states and adult emerging, we can conclude that the dose of 250 Gy is enoughfor radiation quarantine treatment of the B. correcta fruit fly infected in Namroigrapefruit.

Table 4: The absorbed doses for irradiated samples

2.33. Sample No. 2.34. Dose (Gy)

2.35. 1 2.36. 149 ± 7

2.37. 2 2.38. 245 ± 12

2.39. 3 2.40. 348 ± 14

2.41. 4 2.42. 850 ± 12

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III.5. Quality of irradiated grapefruits with radiation dose

III.5.1. Sensory quality evaluation

Sensorial quality of irradiated fruits is one of the important indicators for theconsumer acceptability. Sensory qualities such as color and taste of the NamRoigrapefruits irradiated with gamma radiation at 850Gy were indicated in Table 5. Thereare insignificant differences between non-irradiated and irradiated grapefruits, mean theradiation treatment with dose lower than 850 Gy does not influence on the sensoryquality of grapefruits.

Table 5: Sensory evaluation results

Dose (Gy) Color Taste Other taste

0 Yellow Naturally sweet not detected

250 Light Yellow Naturally sweet not detected

850 Yellow Naturally sweet not detected

Figure 2: Color and morphology of grapefruit shell and inside sections

III.5.2. Total sugar

Nutrient quality of the irradiated grapefruits was investigated with radiationdose. Table 6 showed that total sugar contents of irradiated grapefruits as a function ofradiation dose. There are no significant differences of total sugar contents betweencontrol and irradiated grapefruits.

Table 6: Effect of irradiation treatment to the total sugar

Dose (Gy) Total sugar (%)

Non-irradiated 9.68 ± 0.15

250 9.76 ± 0.18

850 9.63 ± 0.21

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III.5.3. Vitamin C content

Because grapefruit has such a high vitamin C content, the vitamin C is one of themost important criteria for identification of the nutrient quality of the grapefruit. Table 7showed the vitamin C contents with radiation dose for experimental grapefruits. Theresults revealed that no differences of vitamin C contents between control and irradiatedgrapefruits. Manoto and Shaw have also reported that the gamma irradiation with doseof 1000 Gy had no effect on vitamin C content of grapefruits.

Table 7: Vitamin C contents of different grapefruit samples

Dose (Gy) Vitamin C (mg%)

non-irradiated 57.14 ± 0.2

250 56.98 ± 0.18

850 57.22 ± 0.16

III.6. Gamma irradiation process quarantine treatment of Namroigrapefruit infested by fruit fly Bactrocera correcta on irradiation facility of HanoiIrradiation Center

Figure 3: Gamma irradiation process quarantine treatment

IV. Conclusions

The ratios of egg hatching, development of larva and pupa at different growingstages were prevented by irradiation treatment with gamma radiation source at HanoiIrradiation Center. The dose of 250 Gy was regarded as a necessary minimum radiationdose for quarantine treatment of B.correcta fruit flies infected on NamRoi grapefruits.

Sensory and nutrient qualities of the grapefruits were insignificantly affected bygamma irradiation at the quarantine radiation dose of 250 Gy or higher up to 850 Gy.

Grapefruit

Packaging Put up container

IrradiatedGrapefruit has been

radiated

VINATOM-AR 11--17


REFERENCES

[1]. Nguyen Thi Chat, Huynh Tri Đuc, Nong Lam University. Some morphologicbiologic characters and host of fruit flies Bactrocera correcta Bezz. On several south provicesin 2001-2002. Tại địa bàn một số tỉnh phía nam năm 2001-2002. Science and TechnologyMagazine Agriculture Forest, 3.2004.

[2]. Benschoter C.A., Spalding. D.H., Reeder. W.F., Toxility of atmospheric gases toimmature stages of Anastrepha suspensa. Fla. Etomol., 64, 543, 1981.

[3]. Drew R.A.I., S.Vijaysegaran and M.C.Romig, 2002. Fruit fly biology. In:Morphology, taxonomy and Management of fruit flies. R.A.I.Drew, S.Vijaysegaran andM.C.Romig, 7. 2002.

[4]. IAEA (1999). Irradiation as a quarantine treatment of arthropod pests. Proceedingof a final Research Co-ordination Meeting organized by the Joint FAO/IAEA Division ofNuclear Techniques in Food and Agriculture and held in honolulu, Hawaii, 3-7 November 1997.

[5]. Ladaniya M. S. (2008). Citrus Fruit Biology, Technology and Evalution. Ela, OldGoa 403-402 Goa India. Academic Press is an imprint of Elsevier.

[6]. Manoto E.C., Reselva S.s., Delrosario S.E., Casubha L.C., Lizada C.C., EsguerraE.B., Brena S.R., Fuentes R.A., Effects of gamma radiation on the insect mortality and fruitquality of Philippine ‘Carabao’ mangoes. Use if irradiation as a quarantine treatment ofagricultural commodities, IAEA, Techdoc, 91-115, 1991.

[7]. Soe . S.T., Akamine. E.K., Goo. T.T.S., Harris. E.J., Lee. C.Y.L Oriental andMediterranean fruit flies fumigation of papaya, avocado, tomato, bell pepper, egg plant, andbanana with phosphine. J. Econ. Entomol., 7, 354, 1979.

[8]. White, I.M and Elson- Harris,M.M. Fruit flies of economic significance: Theiridentification and Bionomics. In: International Institute of Entomology. Australian center forInternational Agricultural Research, 1992.

VINATOM-AR 11--18


STUDY ON CHROMOSOME ABERRATIONS IN BASEDOWPATIENTS FOLLOWING 131I THERAPY

AND RADIATION PERSONNEL

Pham Ngoc Duy, Tran Que, Hoang Hung Tien,Nguyen Thi Kim Anh and Ha Thi Ngoc Lien

Biotechnology Department, Nuclear Research Institute,VINATOMNo1. Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: To study the chromosome aberrations of the Basedow patients treated with131I and radiation personnel, 14 patients were selected for the analysis of chromosomalaberrations in 3 period of time: before treatment, 1 day after treatment and 90 days aftertreatment. Analysis results obtained showed the frequency of dicentrics + rings,fragments + minutes, chromatid breaks in pre-treatment turn is 0.02 ± 0.05%, 0.20 ±0.08%, 0.18 ± 0.08%; after 1 day of treatment was 0.08 ± 0.06%, 0.39 ± 0.10% and 0.32± 0.19% respectively; after 90 days treatment 0.18 ± 0.10%, 0.51 ± 0.15%, 0.35 ±0.14% respectively. Recognizing the cumulative frequency of chromosome aberrationscaused by 131I. Biological dosimetry was estimated for patients in the range 100-272mGy, the data showed that the effects of 131I on different patients are different. For thegroup of 4 radiation personnel who produce radioisotope, there is no significantdifference in frequency of chromosomal aberrations compared to the control group, itshould be able to conclude this group of personnel were not effected of radiation in thedetectable level (10 mSv).

Keywords: Chromosome aberrations, Basedow, biodosimetry, radiation personnel, 131I.

INTRODUCTION

For over 60 years, radioiodine has been widely used in the treatment of thyroiddiseases such as hyperthyroidism, differentiation thyroid cancer,... this is known as asafety and effective method. 131I can cause side effects to patients by other normaltissues may be exposed to radiation [3]. Ionizing radiation is known as a mutagen cancause the stable and unstable chromosome aberrations. Chromosome aberrations is oneof the biological indicator of the persons affected by ionizing radiation or other toxins.Many epidemiological studies show that people with the high frequency of chromosomeaberrations in the peripheral lymphocytes increase the risk of cancer [6, 8]. Therefore,the reduction of damage in the genetic material of cells contributing to a safe level ofradiation and reduce the risk of cancer due to radiation.








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Another object is a group of employees working in environment related toradiation as X-rays, nuclear medicine, radiation workers ... routine exposure to ionizingradiation at low doses. The cytogenetic studies demonstrated an increased frequency ofchromosomal aberrations in the dose and low dose rate radiation [1, 7]. Many studies onradiation personnel that have received radiation doses below the annual dose limits haverecorded an increased frequency of chromosomal aberrations in the lymphocytes(Evans, 1979; Lloyd, 1980; Bauchinger, 1980; Tawn and Binks, 1989; Kubelka, 1992).So, the monitoring of radiation workers working in the long period of time is essential.

To make the sufficient radiation safety and reduce hazards to human health, it isimportant to have a study of chromosome damage by estimate ionizing radiationabsorbed dose for patients and individuals who relevant occupational radiation. For themanagement of health, the detection of the damage in cytogenetic material may allowmaking some supporting things such as sanitation, upgrading work, reducing the timebeing occupational radiation exposure.

I. EXPERIMENTS

I.1. Equipments: micropipet, Pasteur pipette, cell culture vessels, culturecabinet, thermostatic bath, sterilization autoclaves, ovens, microscope.

I.2. Reagents: medium F10 (Difco), Lithium Heparin (Gifco),Phytohemaglutinin (Sigma), L-Glutamine (Gifco), Kanamicine, Fetal calf serum(Difco), colchicine (Gifco).

I.3. Subjects

- Patients: 14 Basedow patients from 22 to 61 years old received 5.85 ± 0.99mCi (from 5.0 to 8.3 mCi) 131I at the Department of Nuclear Medicine, Lam DongHospital. Samples were taken from three period of time: Before treatment, after 1 day oftreatment and after 90 days of treatment.

- Radiation personnel: 4 persons produce radiation isotope at the Center forRadioisotope Research and Modulation, Nuclear Research Institute and the controlgroup of 4 people make are the similar with the radiation personnel in age, gender andsmoking habits, with no history of radiation effects.

II. PROCEDURES

II.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 in9.0 ml F10 (Difco) supplemented with 15% Fetal calf serum (Gibco), 1% antibioticKanamicine, 1% L-glutamine, 5% Phytohemaglutinin (Sigma ). Samples were culturedat 37o for 48 hours, add Colchicine at 46 hours. Samples harvested and fixed withCarnoy (3 methanol: 1 acetic acid), make and stain microscopy slides with 10% Giemsa[5].

II.2. Analysis of the chromosomal aberrations: Identify the damagechromosome by the microscope at x1000 observations.

VINATOM-AR 11--18


II.3. Biological dosimetry methods: Based on the frequency of dicentrics inlymphocytes irradiated by 60Co source (9/1985), 592 Ci activity, dose rate 125 mGy / hwith the combination of different doses of irradiated 0.1, 0.2, 0.3, 0.4, 0.5 Gy. On thatbasis, the dose – effect curve y = 0.492 D + 3.054 D2 + C is built and applied in thisstudy [10], where y is the frequency of dicentrics, C is the background of frequency ofdicentrics, D is the absorbed dose (Gy).

II.4. Data analysis: Data were analyzed by SPSS 16.0 and Excel software.

III. RESULTS AND DISCUSSIONS

Analysis 13213 metaphases at the time of before treatment, the frequency ofdicentrics + rings is 0.02 ± 0.05% (0.00% ÷ 0.11%), fragments + minutes is 0.20 ±0.08% (0.10% ÷ 0.36%), considered as the frequency of background chromosomeaberrations under the influence of natural factors and this is control group forcomparison with group 1 day, and 90 days after treatment.

In 14043 metaphases of patients at 1 day after treatment, the frequency ofdicentrics + rings within 0.08 ± 0.06% (0.00 ÷ 0.21%), fragments + minutes is 0.39 ±0.10% (0.20 ÷ 0.51%). 10/14 patients has the dicentric chromosomes. When absorbedthrough the intestines, the blood is circulating 131I throughout the body. Thus,accumulation of 131I in the thyroid gland also takes time to put our blood circulation to thethyroid gland and is retained here. 1 day after treatment, 131I had a period of time existsand evenly distributed in the circulatory system. So, the biological effects of 131I is allover the body.

Table 1: Frequency of chromosome aberrationsin Basedow patients after 131I therapy

Time oftreatment

(day)

Numberof

patients

Number ofmetaphases

Frequency of chromosome aberrations (%)

Dicentrics +rings

Fragments +minutes

Chromatidbreaks

A (0) 14 132130.02 ± 0.05

(0.00 ÷ 0.11)

0.20 ± 0.08

(0.10 ÷ 0.36)

0.18 ± 0.08

(0.10 ÷ 0.40)

B (1) 14 140430.08 ± 0.06

(0.00 ÷ 0.21)

0.39 ± 0.10

(0.20 ÷ 0.51)

0.32 ± 0.19

(0.10 ÷ 0.68)

C (90) 12 113110.18 ± 0.10

(0.10 ÷ 0.40)

0.51 ± 0.15

(0.30 ÷ 0.78)

0.35 ± 0.14

(0.20 ÷ 0.63)

VINATOM-AR 11--18


Figure 1: Distribution of the chromosome aberrationsthe time before and after treatment.

Analysis 11311 metaphases at 90 days post-treatment, 12/12 samples havedicentrics or rings, the frequencies of dicentrics + rings is 0.18 ± 0.10% (0,10 ÷ 0.40%),fragments + minutes is 0.51 ± 0.15% (0.30 ÷ 0.78%). In figure 1, we can see that thefrequency of dicentrics + rings at this time was higher compare with the time 1 day aftertreatment, whereas the frequency of fragments + minutes did not increase significantly.Thus, in this period, the ionizing radiation of 131I continue to impact caused doublestrand breaks of DNA and dicentrics chromosome was accumulated more. On the otherhand, 2/12 samples with more than one dicentrics per cell, this is an evidence show thelocal impact of 131I in the thyroid gland, suggesting that during this time, 131I has beenconcentrated in the thyroid gland. The samples taken at 90 days after treatment reflectthe realities of the process of accumulation 131I exists in the body.

For nonspecific types of chromosome aberrations caused by ionizing radiation: Dataanalysis with the frequencies of chromatid breaks at the time after treatment 1 day was 0.32± 0.19 % (0.10 ÷ 0.68), 90 days was 0.35 ± 0.14% (0.20 ÷ 0.63%). The data is notsignificant difference in time of 1 day after treatment and 90 days after treatment seems todepend on the role of adjuvants, adjuvants added in 131I when entering in the body, existsonly in a short time then metabolized and excreted from the body through which no longeraffects the physiological processes of the cell. This significant distinction between cases ofsuspected environmental contamination with the cases affected by radiation.

Figure 1 show that the frequencies of chromosome aberrations was increased onlyafter 1 day of treatment and after 90 days of treatment, the chromosome aberrations notless than 1 day after treatment. This result agree with the studies on cytogenetic by SaraGutiérrez, Elisabet Carbonell (1999) by micronuclei analysis methods, the authorsconcluded the micronucleus frequency of patients with hyperthyroidism following 131Iincreased up to 3 months after treatment . This can be explained by the fact that in patientswith hyperthyroidism, the thyroid works much more so it could increase the levels ofthyroid hormone synthesis, this hormone will be circulation in the circulatory system, andthe survival time of 131I in the thyroid gland should be long term effects on lymphocytescontinuously with time they are present. Data analysis showed low dose 131I can alsocause damage the chromosome of treated Basedow patients. Ramirez MJ, Puerto S,Galofre P, Parry EM, Parry JM (2000) found out the frequency of chromosome

VINATOM-AR 11--18


aberrations increased 1.8 times in patients with hyperthyroidism after treatment with 131I,confirming the values of in vivo indicator by chromosome aberrations for the individualaffected by ionizing radiation.

Table 2: Absorbed dose of the patient after 90 days of treatment

Number Samples Dose of 131I(mCi) Dicentrics + rings (%) Absorbed dose

(mGy)

1 1C 5.0 0.21 182

2 2C 5.0 0.10 100

3 3C 5.1 0.10 100

4 4C 5.2 0.10 100

5 5C 5.4 0.16 148

6 6C 5.5 0.10 100

7 7C 5.5 0.11 109

8 8C 5.6 - -

9 9C 5.6 0.40 272

10 10C 5.7 - -

11 11C 5.7 0.20 175

12 12C 6.8 0.25 205

13 13C 7.5 0.10 100

14 14C 8.3 0.30 222

The group of Basedow patients in this study were treated with doses range 5.0 -8.3 mCi, mean 5.85 ± 0.99 mCi, the therapeutic dose is relatively low and still make thechromosome damage, but with low frequency, biological dose in this group is calculatedfrom 100-272 mGy. Results Table 2 showed the absorbed dose in this patients with isdifferent, this can be explained by the treatment with 131I, the ionization radiation of 131Iexposed from internal of the body, the physiological elements of each patient isdifferent, so will dominate the digestibility, concentration and duration of excretion of131I. Thus, the ability of 131I effects on different individuals is not the same. Research byAdriana T. Ramalho (1998) points out, the existence of the stable chromosomeaberrations depend on the dose, with the high absorbed dose (> 0.2 Gy), the frequencywill decrease with time, whereas with the low absorbed dose (<0.2 Gy), the frequencywill fall slowly and may remain for a long time. Chandrasekhar Bal, Ajay Kumar,

VINATOM-AR 11--18


Madhavi Tripathi, Gauri S., Pant. (2005) suggested that biological effects due toirradiation of 131I through absorbed dose are very specific in each organ, very littlerelated to the therapeutic dose. Ability to use the biological dosimetry for patientstreated with 131I as well as other pharmaceutical isotopes depends heavily on identifyingthe biological mechanisms of pharmaceutical substances in the body, this must be goodsby the biodosimetry in vivo studies.

To study on the effects of ionizing radiation for radiation workers group, weexamined four employees directly involved in the production of radioactive isotop suchas 131I, 32P , 99mTc in working time from 2 to 25 years. The results in Table 3.

Table 3: Frequency of chromosome aberrations in the radiation personnel

Samples GenderAge

(year)Smoking

habit

Period ofworking(year)

Numberof

metaphase

Frequency of chromosomeaberrations (%)

Fragments +minutes

Chromatidbreaks

ĐV1 Male 50 Yes 25 1048 0.57 0.48

ĐC1 Male 51 Yes - 1012 0.20 0.10

ĐV2 Male 29 No 6 1004 0.30 0.10

ĐC2 Male 28 No - 994 0.20 0.20

ĐV3 Male 29 No 2 965 0.31 0.21

ĐC3 Male 29 No - 998 0.30 0.10

ĐV4 Male 26 Yes 4 980 0.10 0.51

ĐC4 Male 27 Yes - 1007 0.20 0.30

Mean of radiation personnel 0.32 ± 0.19 0.33 ± 0.20

Mean of control groups 0.23 ± 0.05 0.18 ± 0.10

ĐV: Radiation persoonel, ĐC: Control groupsTable 3 shows the dicentrics or rings were not detected within in both groups, the

frequency of fragments + minutes and chromatid breaks among radiation workersrespectively 0.32 ± 0.19% and 0.33 ± 0.20%, in the control group was 0.23 ± 0.05% and0.18 ± 0.10%. Thus, the chromosome damage between the radiation workers and controlgroup was not significantly different. Compared with some other studies, RS Cardoso, S.Takahashi-Hyodo, P. Peitl Jr. (2001) studied eight radiation workers working on mean of19.8 years (8-26 years), total cumulative dose mean of 63.2 mSv (9.5 to 209.4 mSv)found out that the frequency of chromosome aberrations is 3.2% compared with controlswas 2.4%, most of the damage type is the Gap and Break, no dicentrics and ringsreported. Alfredo H. Hagelstrom, Nora B. Gorla, Irene B. Larripa (1995) surveyed a

VINATOM-AR 11--18


group of 10 workers producing radioactive substances, detected the frequency ofchromosome aberrant average 13.6 ± 1.5% compared to controls of 3.6 ± 0.5%, but notfound the dicentrics and rings. Status analysis results did not record dicentrics and ringswhich characterized the effects of ionizing radiation, the frequency of fragments, minutesand chromatid breaks remained at background. With the sensitivity of this analysistechnique at 1000 metaphases analysed, this group of subjects were not affected ofradiation at detected level (10 mSv). The results are consistent with the reality of personaldose is measured in 1 year before sampling.

IV. CONCLUSIONS

Frequency of the specifics frequencies of chromosome aberrations reflect thecumulative impacts of ionizing radiation caused by 131I. The presence of the nonspecificchromosome aberrations effected by radiation are explained by the ability to inhibit therepair of DNA damage of drug excipients. No dicentrics or rings detected in blood samplesof radiation personnel groups working with radioactive isotopes, the results showed theradiation impacted at low degree of sensitivity of this methods with limited analysing 1000metaphase/sample.

REFERENCES

[1]. Bouchter S, Haas T., External radiation doses to nuclear medicine technologists fromprocedures using 99mTc radiopharmaceuticals, Can J Radiogr Radiother Nucl Med, 16: 161–165,1985.

[2]. Gutierrez S, Carbonell E, Galofrd A, Creus A, and Marcos R., Micronuclei inductionby 1311 exposure: study in hyperthyroidism patients, Mut Res, 373:39-45, 1997.

[3]. Haynie TP, Vassilopoulou-Sellin R., How safe for the patient is iodine-131 therapy fordifferentiated thyroid carcinoma? (Editorial). J Nucl Med, 36: 27–28, 1995.

[4]. Hossein Mozdarani, Ashkan Hejazi, Peyman Hejazi, Chromosomal Aberrations inLymphocytes of Individuals With Chronic Exposure to Gamma Radiation, Arch Irn Med, 5 (1): 32-36, 2002.

[5]. INTERNATIONAL ATOMIC ENERGY AGENCY, Cytogenetic Analysis forRadiation Dose Assessment, Technical Reports Series No. 405, IAEA, Vienna, 2001.

[6]. L. Hagmar, S. Bonassi, U. Stromberg, A. Brogger, L.E. Knudsen, H. Norppa, C.Reuterwall, Chromosomal aberrations in lymphocytes predict human cancer: a report from theEuropean Study Group on Cytogenetic Biomarkers and Health (ESCH), Cancer Res, 58: 4117–4121, 1998.

[7]. Nowak B, Jankowiski J., Occupational exposure in operational radiology, Pol J OccupMed, 1991; 4: 169–174.

[8]. S. Bonassi, A. Abbondandolo, L. Camurri, L. Dal Pra, M. De Ferrari, F. Degrassi, A.Forni, L. Lamberti, C. Lando, P. Padovani, Are chromosome aberrations in circulating lymphocytespredictive of future cancer onset in humans? Preliminary results of an Italian cohort study, CancerGenet – Cytogenet, 79: 133–135, 1995.

[9]. Sara Gutiérrez, Elisabet Carbonell, Pere Galofré, Amadeu Creus, Ricardo Marcos,Cytogenetic damage after 131-iodine treatment for hyperthyroidism and thyroid cancer, Eur J NuclMed, 26:1589–1596, 1999.

[10]. Trần Quế, Phạm Ngọc Duy, Nguyễn Thị Kim Anh, Nguyễn Văn Kính, Xây dựngđường phân bố thực nghiệm liều – hiệu ứng sai hình nhiễm sắc thể ở tế bào lympho người chiếu bứcxạ gamma suất liều thấp, Đề tài khoa học công nghệ cấp cơ sở 2007.

VINATOM-AR 11--19


STUDY ON THE SOLID PHASE EXTRACTION METHODFOR SEPARATION AND PRECONCENTRATION OF PESTICIDE

MULTI-RESIDUE IN DIFFERENT VEGETABLE AND FRUITMATRICES BY THE GAS CHROMATOGRAPHY-MASS

SPECTROMETRY-SELECTED ION MONITORING

Nguyen Tien Dat, Le Tat Mua, Ta Thi Tuyet Nhung,Nguyen Thi Hong Tham and Dang TrungTin

Center for Analytical Techniques, Nuclear Research Institute,VINATOMNo.1 Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: The Solid phase extraction (SPE) method has been optimized forsimultaneous determination of herbicides in the different matrices by the gaschromatography-mass spectrometry-selected ion monitoring (GC-MS-SIM). Theseherbicides belong to the following different families: carbamate, neonicotinoid,pyrroles, benzoylure, organophosphorus, azole, pyrazole and oxadiazines. Differentsolid substrates have been applied (LC-NH2, LC-C18, and activated charcoal). Thetypes of conditioning and elution solvents, and their volumes have been considered asvariables affecting the recovery yields of the herbicides. The MgSO4.7H2O has beeninvestigated for removing the fat in the matrices that contain high lipid content. Thismethod which gives efficient separation of pesticides from fat and removal ofcoextracted substances is better than use of a time-consuming freeze-out step. In arecovery test, 10 pesticides were spiked and average recoveries ranged from 84.8% -93.2%. The method detection limits (MDLs) were calculated by multiplying thestandard deviation with student t-value for n-1 (6) degree of freedom at 99% confidentlevel. Repeatability studies yielded relative standard deviations (RSD) ranging 7.9% -13.8% in all cases, fully in agreement with the Horwitz empirical equation. The methodwas applied to real samples to demonstrate its use in routine analysis.





- Contact Email: : [email protected]


1. Nguyen Ngoc Tuan, Nguyen Tien Dat, Le Tat Mua, Pham Thi Lan Phi. Study onthe mix of graphitized carbon and silica gel solid phase extraction cartridge methodfor separation and pre-concentration of pesticide multi-residue in vegetable cropswith gas chromatographic method . Journal of Analytical Sciences. T-17, 3, 2010.

2. Nguyen Tien Dat, Le Tat Mua, Nguyen Ngoc Tuan, Ho Van Quoc, Huynh ThienDiem. Determination of pesticide residues – acetamiprid, thiamethoxam andchlorfenapyr in tea leaf samples by GC-MS. Journal of Analytical Sciences. T-16,3, 2011.


VINATOM-AR 11--19


I. INTRODUCTION

Many kind of pesticides have been applied to improve agricultural productivity.The residues resulting from the misuse of pesticides on vegetables and fruits is a majorconcern. And much attention has been made in pesticide analysis to control thesecompounds in food and environmental samples. Despite employing powerfulinstrumental techniques, the risk of interference increases with the complexity of thematrix. So sample preparation prior to instrumental analysis is necessary

In the past decades, great advancement has been made in order to achieveefficient separation of analytes from a sample matrix with high selectivity andsensitivity. Different extraction methods are employed, consisting of solvent extractionfrom solids and liquid – liquid extraction from solutions. The solvents may be organicliquids, or supercritical fluids. Alternatively, the liquid extraction may be bonded tosupport material. Selectivity can be achieved by the suitable choice of extraction solventor liquid. The purpose of the sample preparation method is to convert a real matrix intoa form that would be appropriate for analysis. The recent trends for sample preparationmethods have ben towards: The capacity to use smaller initial sample sizes; greaterselectivity in extraction; a more environmentally responsive approach by using a smallamount of organic wastes; and improved potential for automation.

All extraction mainly focus on concentrating the analytes selectivity in onephase, whereas an analytes will be distributed between two phases according to itsdistribution coefficient, temperature and the relative volumes of the phases. However,the extraction rates are based on the migration kinetics and hence are governed bytemperature and diffusion rates in the two phases. So solid samples are usually preparedby grinding, chopping up or crushing up by solvent or liquid extraction. After theextraction steps, the analytes of interest are obtained in an aqueous solution, which thenrequires concentration or additional clean-up by solvent – solvent extraction, or sorptionmethods such as solid phase extraction [8], solid phase microextraction [9].

Vegetable matrix is a complex non-homogeneous mixture of a wide range ofchemical substances, especially processed samples with lipids. These matrices maketheir hard to isolate and determine the analytes of interest. Analyzing of pesticideresidues in these samples always suffer from interferences present in the matrix. Toovercome this problem, it is necessary to use appropriate extraction method and clean-up process.

Based on the principles of the QuEChERS procedure - Quick, Easy, Cheap,Effective, Rugged and Safe, This work is focused on the development and evaluation ofa simple sample preparation strategy based on solid phase extraction using aminopropylC18 and activated charcoal as sorbent material, followed by mass spectrometricidentification and quantitation of the selected group of insecticides and herbicides,typically found in non-fatty vegetables and fruits and in matrices that contain high lipidcontent, using gas chromatography–mass spectrometry (GC–MS) in selected ionmonitoring (SIM) mode.

II. RESULTS AND DISCUSSION

II.1. Effect of matrices

VINATOM-AR 11--19


II.1.1. The matrices contain high pigment

The results in fig 1 showed almost the entire spectral range from 330nmwavelength - 800nm of crude extract was removed completely (Fig 2). The result showsthe ability to remove the pigments of activated charcoal is very high. So activatedcarbon will be stuffed adding LC-NH2 column extraction or LC-C18 extraction columnto remove noise effects and/or to support the separation on the second phase (LC-NH2

or LC-C18)

Figure 1: Spectrum of crude extract

II.1.2. Fruit matrix containing essential oil

The results in Fig 3 showed that some constituents have not been completelyeliminated yet, but the background has decreased significantly. It is necessary to removethe background in chromatography analysis because the interferences can completelycover the peaks of interest or can increase the area of the peak.

Figure 2: Spectrum of cleaned up extract

VINATOM-AR 11--19


Figure 3: Orange extract before and after clean-up

II.1.3 Matrices contain high lipid content

The results in Fig 4 and 5 showed that the approximately 20-25g ofMgSO4.7H2O can be used for removing fat and the periods of removal fat should

be set up in approximately 2-3 hours (including 45’ shaking).

II.2. Method validation

The recoveries ranged from 84.8% - 93.2%. The method detection limits(MDLs) were calculated by multiplying the standard deviation with student t-value forn-1 (6) degree of freedom at 99% confident level. Repeatability studies yielded relativestandard deviations (RSD) ranging 7.9% - 13.8% in all cases, fully in agreement withthe Horwitz empirical.

Figure 4: Effect of MgSO4.7H2O onremoving fat in 2h

0,020,040,060,0 %

Figure 5: Effect time on removing fat

VINATOM-AR 11--19


II.3. Application to real samples

Based on the results analyzed, in comparing with other selected pesticides,metalaxyl is the most frequent residues. May be due to a broad spectrum effects,adsorption and translocation of which make metalaxyl is used not only on thevegetables, but also be used on fruits such as strawberries and grapes. Chlorprifos wasfound in the second frequent. But chlorprifos mainly be used on all kinds of leafvegetables. Fipronil were found in low frequent. But the level of fipronil detected inchinese cabbage was higher than the Maximun residal limit (MRL) by a factor of 5.2.

III. CONCLUSION

1. LC-NH2 are universal than LC-C18 using n-hexane solvent conditions ofthe column. Especially polar compounds were best recovered on LC-NH2. If mobilephase is acetone, it is recommanded to combine LC-NH2 and LC-C18 for increasing theyield. In this case, conditioning solvent should CH2Cl2: acetone: ethylacetate = 4:4:1(v/v/v).

2. 20ml of eluate was divided that 10ml of B- CH2Cl2 : CH3COCH3 : C6H5CH3

: CH3COOC2H5 (20:15:6:1) was used for elution of slight or non-polar compounds andthen 10ml of D- CH2Cl2 : CH3COCH3 : C6H5CH3 : CH3OH (10:8:2:2) for polarcompounds

3. It is strong recommended to apply activated charcoal for rising up theefficiency of solid phase extraction procedures.

4. It is strong recommended to use MgSO4.7H2O for reducing the fat inmatrices in which contain high lipid content prior to solid phase extraction.

5. Based on the basic of the matrices, we will be strategizing appropriately forreusing solid phase extraction cartridges.

6. The recoveries ranged from 84.8% - 93.2%. The repeatability ranged 7.9% -13.8% in all cases, fully in agreement with the Horwitz empirical.

7. In comparing with other selected pesticides, metalaxyl is the most frequentresidues.

REFERENCES

[1]. Analytical detection limit guidance & Laboratory guide for determination methoddetection limits. Wisconsin Department of Natural Resources Laboratory Certification Program.PUBL-TS-056-96, April 1996.

[2]. Anastassiades, M., S.J. Lehotay, D. Štajnbaher and F.J. Schenk. Fast and easymulti-residue method employing acetonitrile extraction/partitioning and dispersive solid phaseextraction for the determination pesticide residues in produce. Journal of AOAC Int, 86, 412-431, 2003.

[3]. Banerje, K., D.P. Oular, S Dasgupta, S.B. Patil, S.H. Patil,R. Savant and P.G.Adsule. Validation and uncertainty analysis of a multi-residue method for pesticides in grapesusing ethyl acetate extraction and liquid chromatography – tandem mass spectrometry. Journalof Chromatography A, 1173, 98-109, 2007.

VINATOM-AR 11--19


[4]. Barrek, S., O. Paisse and M.F. Grenier-Loustatol. Analysis of pesticide residues inessential oils of citrus fruit by GC-MS and HPLC-MS after solid-phase extraction. Journal ofAnal Bioanal. Chem., 376, 157-161, 2003.

[5]. Chen, S., X. Yu, X.He, D. Xie, Y. Fan and J. Peng. Simplified pesticide multi-residue analysis in fish by low-temperature cleanup and solid phase extraction coupled with gaschromatography/mass spectrometry. Journal of Food Chemistry, 113, 1287-1300, 2007.

[6]. Díez, C., W.A. Traag, P. Zommer and P. Marinero and Atienza. Comparison of anacetonitrile extraction/partitioning and “Dispersive solid phase extraction” method withclassical multi-residue methods for the extraction of herbicides residues in barley samples.Journal of Chromatography A, 131, 11-23, 2006.

[7]. Ferrer, I. and E. Michael Thurman. Multi-residue method for the analysis of 101pesticides and their degradates in food and water samples by liquid chromatography/time-of-flight mass spectrometry. Journal of Chromatography A. 1175, 24-37, 2007.

[8]. Hernández-Borges, J., J. cabrera, M. Ángel Rodríguez-Delgado, E.M. Hernández-Suárez and J. Víctor Galán Saúco. Analysis of pesticides residues in bananas harvested in theCanary Islands (Spain). Journal of Food Chemistry, 13, 313-319, 2009.

[9]. James N. Miler and Jane C. Miler. Statistic and chemometrics for analyticalchemistry. Pearson Education Limited, England, Fifth edition, page 90-93, 2005.

[10]. Lucio F.C.Melo, Carol H.Collins, Isabel C.S.F.Jardim. Newmaterials for solidphase extraction and multiclass high-performance liquid chromatographic analysis of pesticidesin grapes.

[11]. Melo, L.F.C., Carol H. Colins and I.C.S.F. Jardim. High performance liquidchromatographic determination of pesticides in tomatoes using laboratory-made NH2 and C18solid phase extraction materials. Journal of Chromatography A. 1073, 75-81, 2005.

[12]. Raposo J’unior, J.L. and N. R’e-Poppi. Determination of organochlorinepesticides in ground water samples using solid phase microextraction by gas chromatography-electron capture detection. Journal of Talanta, 72, 1833-1841, 2007.

[13]. Sanusi, A., V. Guillet and M.J. Montury. Advanced method using microwavesand solid phase microextraction coupled with gas chromatography-mass spectrometry for thedetermination of pyrethroid residue in strawberries. Journal of Chromatography A, 1046, 35-40,2004.

[14]. Shim, J.H., M.H. Lee, M.R. Kim, C.J. Lee and I.S. Kim Simultaneousmeasurement of fluorouinolones in eggs by a combination of supercritical fluid extraction andhigh pressure liquid chromatography. Journal of Biosci. Biotechnol. Biochem, 67(6), 1342-1348, 2003.

[15]. Zeng, J., J. Chen, Z. Lin, W. Chen, X. Chen and X. Wang. Development ofpolymethylphenylsiloxane-coated fiber for solid phase microextraction and its analyticalapplication of qualitative and semi-quantitative of organochlorine and pyrethroid pesticides invegetables. Journal of Anal. Chim. Acta. 619, 59-66.

[16]. Zhang, Z., M.J. Yang and J. Pawliszyn. Solid phase microextraction. Journal ofAnalytical Chemistry. 66, 844-853, 1994.

[17]. Zhou, Q., J. Xiao, Wang, G. Liu, Qizeng Shi and J. Wang. Enrichment ofPyrethroid Residues in Environment Waters Using a Multiwalled Carbon Nanotubes cartridgeand Analysis in combination with High performance liquid chromatography. Journal of Talanta,68, 1309 – 1315, 2006.

VINATOM-AR 11--20

The Annual Report for 2011, ViNATOM158

PREPARATION OF KIT MIBI FOR 99mTc LABELING USING INNUCLEAR MEDICAL DIAGNOSTIC IMAGING

Chu Van Khoa, Duong Van Dong, Bui Van Cuong, Nguyen Thanh Binh,Nguyen Dang Khoa and Nguyen Thi Thu

Center for research and production of radioisotopes,Nuclear Research Institute,VINATOM

No.1 Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: 99mTc-MIBI is the cation complex of 99mTc of oxidation states +1 with ligandmethoxy-isobutyl-isonitrile using diagnotic imaging of many illnesses especially use inmyocardial perfusion studies. Coronary artery disease present is quite common in ourcountry so that need to use kit MIBI for labelling with Tc-99m is great. Therefore weimplement studies of preparation of kit MIBI and find the labelling procedure with Tc-99m of labelling yield or the highest radiochemical purity. In this annual report presentsthe results of researches made be like finding the optimal conditions for the labellingprocedure, preparation procedure of kit MIBI and SnCl2.H2O content. This report alsodescribes studies of the optimization of the preparation of 99mTc-MIBI. Stability studiesof these complexes are also described. The comparative results between our kit andCardiolite® kit are reported. Also the results of srterilty test and bacterial endotoxin testare presented.

I. INTRODUCTION

Nuclear medicine had a great development in the 1980s, when new classes ofcompounds, such as the tetraamines, aminethiols and isonitriles, were synthesized andevaluated as possible new [99mTc] radio-pharmaceuticals. In the isonitrile classprepared, 1-isociane-2-methoxy-2-methyl-propane, currently named MIBI, exhibitedexcellent characteristics for use in myocardial perfusion studies. Also, it was indicatedfor use in breast cancer detection and parathyroid scanning. Because of these importantapplications and the high cost of the commercial products, our laboratory has introducedroutines to make the product cost-effective for supplying to the nuclear medicinedepartments of hospitals in our country.[1]

II. EXPERIMENTAL

II.1. Equipment








VINATOM-AR 11--20


- MINIGAMA counter;

- BIOSCAN counter;

- Gamma spectroscopy system;

- Thermostat.

II.2. Reagents

- All the chemicals used in experiments is kind of analytical purity and notrefined.

II.3. Procedure

The empirical survey of the dependence of performance marked on pH,temperature reaction, reaction time, concentration, SnCl2.H2O content, in vitro stabilit,expiration of kit MIBI and comparison experiments are used thin layer chromatographicTLC-SG system and solution of chloroform: propanol (90: 10) as mobile phase todetermine labelling yield or radiochemical purity.

MIBI[Tc-99m] was obtained from Cardiolite kit following the manufacture'sinstructions. Chromatographic analyses of the radioactive preparations were performedin chromatographic support (strips 1x 10 cm) and developed over 8 cm using defollowing systems: ITLC-SG and chloroform:propanol solution (90:10) as mobilephase. After the chromatographic development, the strips were cut in tree segments,origin (3 cm), medium (2 cm) and front (3 cm), in relation to length of the strip, and thereaction was measured for radiation in a NaI(Tl) well counter.

The studied chromatographic system provided an alternative, rapid andreproducible method to MIBI[Tc-99m] quality control, with advantages that it can useless expensive TLC-SG strips. We are chosen this system to MIBI[Tc-99m] qualitycontrol.


III.1. Prepation of MIBI

The kit includes a lyophilized mixture of a copper complex of MIBI (tetrakis(2-metho-xyisobutyl-isonitrile) copper(I) tetrafluoroborate ([Cu(MIBI)4]BF4)) as the activeingredient, sodium citrate dihydrate as a buffer, L-cysteine hydrochloride monohydrateas a stabilization aid, mannitol as a lyophilization aid, and stannous chloride dihydrateas a reducing agent.

Chemical composition of kit

- MIBI: 1.0 mg;

- Stannous chloride dihydrate: 0.05 mg;

- L-cysteine hydrochloride monohydrate: 1.0 mg;

- Sodium citrate dihydrate: 2.6 mg;

VINATOM-AR 11--20


- D-mannitol: 20 mg.

The solutions were sterilized by membrane filtration (0.22for 24 – 48 hours. Store refrigerated at 2–8ºC.

III.2. Labelling studies

- Reconstitute the freeze-dried kit using 5 ml of 99mTcO4 solution containing amaximum of 400 mCi (14.8 MBq) of activity.

- Stir for 1 min; heat the vial in a boiling water bath for 15 min and leave tocool at room temperature[2].

III.3. The dependence of labelling yield on pH

The labelling yields of 99mTc-MIBI as a function of pH is presented in Tables 1.From table 1 we see that high labelling yield obtained in pH from 5-6.

III.4. The dependence of labelling yield on temperature

Practical results recorded in table 2. The results showed at temperatures from70-90oC the highest labelling yield achieved.

III.5. The dependence of labelling yield on reaction time

From the results obtained in table 3, we see that the reaction time of 15 minutesis enough.

III.6. Survey of SnCl2.2H2O

From the results obtained in table 4 and to avoid the reduction of Sn2+ inpreparation process of kit and kit storage, we select the optimum SnCl2.H2O content is0.05 mg per bottle of MIBI kit.

Table 1: The dependence of labelling yield on pH (15min, incubation at 90°C)

pH Labeling yield (%)

4 58.9

5 96.9

6 97.6

7 92.5

8 78.7

Table 2: The dependence of labelling yield on temperature (30 min, pH 6)

Temperature (oC) Labeling yield (%)

20 88.4

30 94.2

VINATOM-AR 11--20


40 96.1

60 96.5

70 97.3

90 97.6

Table 3: The dependence of labelling yield on reaction time (at 90°C, pH 6.0)

Reaction time (mint) Labeling yield (%)

5 74.7

10 88.9

15 97.3

20 97.3

25 97.3

30 97.8

35 97.7

Table 4: The dependence of labelling yield on content of SnCl2.2H2O

Conten of Sn2+(mg) Labeling yield (%)

0.010 92.1

0.025 96.8

0.050 97.5

0.075 97.4

0.100 97.3

0.125 96.6

III.7. In vitro stability of MIBI-99mTc

VINATOM-AR 11--20


Table 5: The dependence of labelling yield on reaction time after labelling

Time after lalelling (h) Radiochemical purity (%)

1 97.3

2 97.3

3 97.3

4 97.4

5 97.4

6 97.3

From the results obtained in table 5, we see that the in vitro stability of MIBI-99mTc complex is more than 6 hours.

III.8. Expiration date of kit MIBI

Practical results in table 6 were show that within 6 months quality guarantee stillMIBI kit.

Table 6: The dependence of labelling yield on storage time of kit MIBI

Storage time (month) Labeling yield (%)

1 97.2

2 97.2

3 97.3

4 97.3

5 97.2

6 97.2

III.9. Test of sterility and bacterial endotoxins

Table 7: Test results of sterility and LAL test

Test Specification Method Results

Sterility Sterile Direct inoculation sterile

Bacterial endotoxins <0.62 IU/ml LAL test (Ph. Eur.) < 0.125 IU/ml

From the experimental results show that our products meet the requirements.

VINATOM-AR 11--20


III.10. Comparative quality with foreign importted kit of Cardiolite

The results of comparisons of quality between the kit Cardiolite and our kitMIBI produced are presented in table 8.

Table 8: Test results of radiochemical purity of kit MIBI and kit Cardiolite

Test Specification (%) Method Results

Radiochemicalpurity

> 95% TLC Cardiolite MIBI-TTĐV

97.7 ± 0.3 97.6 ± 0.4

From the results obtained we concluded that our kit MIBI by quality equivalentto imported kit.

IV. CONCLUSION

We have fulfilled the goals of theses propounded to find the optimal conditionsin preparation of kit MBI and labelled with 99mTc for nuclear medicine imaging are asfollows:

1. Content of 0.05 mg SnCl2.H2O.

2. pH = 5-6.

3. Reaction temperature 90oC

4. Reaction time 15 minutes.

5. In vitro stability of the product more than 6 hours after the labelled

6. Expiration data of kit MIBI than 6 months.

7. Sterile product and bacterial endotoxins requirements according to thepharmacopoeia.

8. Radiochemical purity is more than 97% and the quality of the imported kitequivalent.

REFERENCES

[1]. IAEA Technical Reports Series No. 458, Vienna, 2007.

[2]. Delmon-Moingeon L, Piwnica-Worms D, et al. Uptake of cation hexakis (2-methoxyisobutylisonitrile)-technetium-99m by human carcinoma cell line in vitro. Cancer Res50 : 2198-202, 1990.

[3]. Shankar Vallabhajosula, et al. Altered Biodistribution of Radiopharmaceuticals:Role of Radiochemical/Pharmaceutical Purity, Physiological, and Pharmacologic Factors.Semin Nucl Med 40 : 220-241 © 2010 Elsevier Inc.

VINATOM-AR 11--21


FINISHING PROCESS TO PRODUCE CULTURED IN VITROLISIANTHUS FLOWER SEED (EUSTOMA GRANDIFLORUM

(RAF.) SHINN) COMMERCIAL PRODUCTS

Le Thi Thuy Linh, Le Van Thuc, Dang Thi Dien,Le Thi Bich Thy and Han Huynh Dien

Room Biotechnology, Nuclear Research Institute,VINATOMNo.1 Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: Lisianthus (Eustoma grandiflorum. Gentianaceae) originated fromNorth America. It has been grown in Dalat since 1995, with various varieties.However, seed sources are dependent on foreign seed (planted by seed). Thecomplete process in vitro breeding lilacs Lisianthus is to serve the needs ofproduction. In this study, experiments comprised four stages: the sample, shootproliferation, plantlets and greenhouse trials. The results showed that the periodof rapid on MS medium supplemented NAA (0.3 mg/l) in combination with BA(0.5 mg/l) for best results. The experiment produces complete plants on MSmedium supplemented NAA (0.3 mg/l) for best results. Greenhouse trials alsoshow result on par with trees planted by seed (seed imported). Using in vitroseedling cultivation will bring efficiency to growers and seed sources areactively serving the domestic flower market, is not dependent on foreign sourcesof seed.

INTRODUCTION

Lisianthus is a wild flower, native to North American, the original color is blueand has appeared on many different colors such as pink, white tinged with violet, pinkand white mixed, with branches,…beautiful flowers, can be considered as varieties ofcut flowers is relatively complete, as well as flower varieties are avid consumers andflowers are being produced commercially, Lisianthus are produced more in Dalatbecause climate and soil here is well suited to the characteristics of its growth.








VINATOM-AR 11--21


Picture 1: Some Lisianthus grown in DaLat

I. EXPERIMENTS

I.1. Materials

Lisianthus is commercially cultivated in Dalat. Buds Lisianthus obtained aftercoal burning sterile sample are used as material for further experiments.

I.2. Reagents

Salt macro, micro salt, MS vitamins, sugar, agar, quality standard pH (HCl,NaOH), substances of plant growth regulators (NAA, BA).

II. PROCEDURES: The experimental layout style single factor completelyrandomized among treatments. The data recorded will be handle by MSTATC statistics,the variable results of ANOVA analysis allows assessment of the treatments of theexperiment. If the treatments differ, use the LSD test for classifying and evaluating theresults of the treatments.

Contents 1: Construction and finishing processes in vitro seed cultureLisianthus

- Sterilized sample: Conduct sterile shoots with Ca(OCl)2 7%, HgCl2 0.1 % andHgCl2 0.2 % in the period 5, 7, 10, 15 minutes.

VINATOM-AR 11--21


- Shoot proliferation (Staff quick): Examined the effect of Naphthalene aceticacid (NAA) and Benzyl adenine (BA) at different concentrations on the growth of buds.

- Plantlets (Create a full-grown plant): Exploring the effects of NAA in differentconcentrations on the rooting process Lisianthus after 4 weeks of culture.

Contents 2: Assay quality seed crops grown in vitro Lisianthus in the field

- Greenhouse trials: Testing the quality of seed plants cultured in vitroLisianthus commercial field with seed trees.

Contents 3: Assessing the economic efficiency between plants in vitro withseed trees


Contents 1: Construction and finishing processes in vitro seed cultureLisianthus

- Sterilized sample

Table 1: Sterilized sample results (based on sample rate live %) after 15 days ofculture

Disinfectants Sterilization time

2 minutes 5 minutes 7 minutes 10 minutes 15 minutes

Ca(OCl)2 7% 12.5 35.6 40.2 56.9 41.8

HgCl2 0.1% 26.8 31.5 68.3 64.5 36.7

HgCl2 0.2% 26.7 39.4 11.5 0 0

Using 0.1% HgCl2 during 7 – 10 minutes for the highest proportion in life: 68.3% -64.5%

- Shoot proliferation

Table 2: Effect of NAA and BA on shoot grown from buds Lisianthus invitro after 45days.

Treatment Theaveragenumbershoots /clusters

Averageheight ofshoots

The variation inquantitative

MS no additional 4.200 C 2.90 A Long shoots, small

MS + 0.3 mg/l NAA + 0.5 mg/l BA 24.725 A 2.35 B Shoot sharks, reachingboth leaf green

VINATOM-AR 11--21


MS + 0.3 mg/l NAA + 1.0 mg/l BA 25.500 A 1.75 C Fat buds, not reachingall

MS + 0.3 mg/l NAA + 1.5 mg/l BA 10.475 B 1.75 C Garden Buds small, notreaching the shoots ofbrown, deadMS + 0.3 mg/l NAA + 2.0 mg/l BA 1.250 D 1.13 D

Optimal medium of shoot proliferation: MS supplemented with 0.3 mg/l NAA and 0.5mg/l BA.

- Plantlets

Table 3: Effects of NAA on the rooting process Lisianthus after 4 weeks.

Treatment % Shoot toroot

Numberaverage root

/ shootDescription

MS no additional 0 0.000 C No rooting

MS + 0.3 mg/l NAA 92 7.300 AB The roots beautiful, healthyplant

MS + 0.5 mg/l NAA 90 7.975 A Elastic short roots, the plantprimarily

MS + 1.0 mg/l NAA 85 5.925 B Rooting out irregular, shortshirt, soft tissue scarring

Complete plantlets obtained on medium MS supplemented 0.3 mg/l NAA.

Contents 2: Assay quality seed crops grown in vitro Lisianthus in the field

- Greenhouse trials: Testing the quality of seed plants cultured in vitroLisianthus commercial field with seed trees.

Table 4: The quality decision flowers

Treatments Date offlowering

Height

(cm)

The numberof flower/

tree

Diameter offlower (cm)

Flower color

Tree seed 110 76.76 ± 0.34 30.54 ± 0.77 6.72 ± 0.31 Beautiful flower

Plants in vitro 125 76.22 ± 0.58 30.60 ± 0.61 6.68 ± 0.28 Beautiful flower

Greenhouse trials also show results on par with trees planted by seed (seedimported).

VINATOM-AR 11--21


Contents 3: Assessing the economic efficiency between plants in vitro withseed trees

Through calculating the cost of in vitro plants are: 544.5 đ/ Tree

The cost of seed trees at the present time: 1.200 – 1.500 đ / Tree

Compare the cost of tree found in vitro offer is acceptable.

IV. CONCLUSIONS

Thread has been effective in the time of implementation was built, completeprocess in vitro seed culture Lisianthus commercial, the training opportunities of youngstaff, as well as building the scientific credibility study of the units. In the future, theunit will continue to invest to produce localized products the same source, contributingto economic development for the local society.

Picture 2: Propagation in vitro process Lisianthus

VINATOM-AR 11--21


REFERENCES

[1]. Duong Tan Nhut – Plant Biotechnology: Basic research and applications, File 1 –Publishing Agriculture, 2011.

[2]. Duong Tan Nhut – Induction arising from cloned embryos implanted sample leavesof Lisianthus (Eustoma grandiflorum (raf.) Shinn). A number of methods, the new system inplant technology research, pages 158 – 159, 2010.

[3]. Duong Tan Nhut – The shoots and root regenerated directly from leaf tissue ofplants flowering Lisianthus (Eustoma grandiflorum) in vitro culture. Joumal of Biotechnology,4(2): pages 249 – 256, 2006.

[4]. Griesbach R. J. and Semeniuk P, Use of soma clonal variation in the improvementof Eustoma grandiflorum. The Journal of Heredity 78 (2):114-116, 1987.

[5]. Harbaugh, B. K. and J. W. Scott, Florida Pink and Florida Light Blue – Semi-dwarfheat-tolerant cultivars of Lisianthus. Hort Science 34:364-365, 1999.

[6]. Harbaugh, B. K. and J. W. Scott. Maurine Dawn–A heat-tolerant Lisianthus withpink/white bicolored flowers. HortScience 40:858-860, 2005a.

[7]. Murashine M, Skoog F. A revised medium for rapid growth and bioassays withtobacco tissue cultures. Physiol. Plant 15: 473 – 497, 1962.

[8]. Ahloowalia B. S. In vitro mutation and multiplication of Chrysanthemum cultivars.Farm Food 2: 28 – 29, 1992.

VINATOM-AR 11--22


STUDY ON THE GROWTH PROMOTION EFFECT OFGRAPEFRUIT OLIGOPECTIN PREPARED BY RADIATION

PROCESSING ON MUSTARD GREENS

Nguyen Huynh Phuong Uyen1, Le Quang Luan1,Le Thi Thuy Trang1 and Vo Thi Thu Ha2

1Center For Nuclear Techniques,VINATOMNo.217, Nguyen Trai, Ho Chi Minh, Vietnam

2Saigon Thuy Canh Corporation

Abstract: Nowadays, oligosaccharides such as oligochitosan, oligoalginate, andoligopectin, etc. were asserted as natural active compounds. These products not onlyshowed the plant growth promoter effect, but also stimulated the phytoalexin inductionthat helped plant against the diseases cause by microorganisms. The process forextraction of pectin from discard-waste grapefruit peels with a high pectin content and ashorter extraction time has been set up. The degradation of pectin solutions with theconcentrations of 1-4% by Co-60 gamma irradiation was studied. The obtained resultson the characterization of irradiated products including molecular weight (Mw), IR-spectra and UV-spectra indicated that gamma-rays induced the degradation of pectinand slightly reduced the methyl ester degree in the molecular structure of radiation-degraded oligopectin. The results also showed that oligopectin with molecular weightabout 3.53 kDa prepared by irradiation of 2% pectin solution at 75 kGy displayed agood effect on the growth and development of mustard greens (Brassica junco Varyrugs) cultivated in hydroponics system. The optimal concentration of radiation-degraded oligopectin for treatment of mustard greens was found at 75ppm. Thetreatment with 75ppm radiation-degraded oligopectin increased the plant height, rootlength and fresh biomass of mustard green in 6.5, 4.8 and 17.7%, respectively. Theabove results indicated that produced natural product, i.e. oligopectin, may potentiallyto apply in high-tech agriculture for increase of safe-agro-products and for environmentprotection.







L.Q. Luan, N.H.P. Uyen, L.T.T. Trang, L.V. Truong, L.D. Quynh, V.T.T. Ha, Studyon preparation of oligopectin from waste grapefruit peel by irradiation degradationmethod and its application for vegetables production using hydroponics, Journal ofBiotechnology, 9, 549-556, 2011 (in Vietnamese).


VINATOM-AR 11--22


I. INTRODUCTION

Homogalacturonan, the pectic polysaccharide composed of 1,4-linked α-D-galactosyluronic acid residue and its partially methyl-esterified derivative, is animportant structural component of the primary cell walls of higher plants [1,2].

Pectic polysaccharides of non-graminaceous plants are a vital structuralcomponent of the plant cell wall and pectin extracts are commercially important to thefood and pharmaceutical industries; in a normal western diet around 4-5g of pectin isconsumed each day. Pectin is used in a range of processed food products as a gellingagent or as a stabilizer in acidic milk drinks. The degree and distribution ofesterification vary according to the plant species, age and location in the plant cell walland is implicated in controlling the extent to which gelation, a commercially importantproperty of extracted pectins, can be induced by divalent cations such as calcium [3]. Sofar, the extraction of pectin was mainly conducted in an aqueous acid medium. Forgetting a high yield extraction of pectin, pH, temperature and time are three importantparameters [4]. Acid hydrolysis has been used for the selective degradation of pecticsubstances, using the fact that the different glycosidic linkages are hydrolysed atdifferent rates. Specific depolymerization of the polygalacturonic acid chain can also beachieved by using purified pectolytic enzymes [5]. Although radiation has been reportedas an effective tool for degradation of polysaccharides, very few of study has reportedfor preparation of oligopectin by radiation. Ayyad, et al. used γ-rays for degradation ofpectin but not for oligopectin preparation [6].

Oligopectin (OP) has been reported to have morphogenesis ability of tobacco inthin cell layer explants culture at a concentration of 10-8-10-9 M. The effects are:induction of tobacco explants to form vegetative buds instead of flower or callus,induction of tobacco explants to form flower instead of vegetative buds and induction oftobacco explants to form root instead of vegetative buds [7]. OP can also induce defensereactions in plants, and in this case, the degradation of the cell surface of the host plantby invading pathogens can be interpreted to generate the warning signal. It has beenshown that some plants produce a polygalacturonase-inhibiting protein which may serveto prevent further degradation of OP by pathogenic polygalacturonase to maintain asuitable size of OP as the warning signal. On the other hand, OP acids are digestedproducts of the plant cell wall, the result of microbial pectic enzymes secreted bypathogens. OP with DP~10-12 induces phytoalexin in soybean tissues and stimulateslignin and protease inhibitor in several other plants. Plants are capable of responding notonly to fragments of the pathogen but also to their own cell wall produced by theenzyme of the pathogen. OP is effective on the concentration from µM to mM and thereis a synergistic effect when hepta β-glucoside and oligogalacturonides are both appliedto soybean tissues. It has been shown that some plants produce a polygalacturonase-inhibiting protein which may serve to prevent further degradation of OP by pathogenicpolygalacturonase to maintain the suitable size of OP as the warning signal [7-13].

The project of “Study on the growth promotion effect of grapefruit-oligopectinprepared by radiation processing on mustard greens” had been carried out in 12 months(from January, 2011 to April, 2011). The aims of this study were to set up a completeprocess for pectin extraction from discard-waste grapefruit peels, to prepare ofoligopectin by gamma Co-60 radiation degradation method and to test the growthpromotion effect of degraded products on mustard greens.

VINATOM-AR 11--22


II. EXPERIMENTS

II.1. Materials

The grapefruit peels were collected in Ho Chi Minh city. Seeds of mustardgreens (Brassica juncea Var rugosa) were supplied by Trang Nong Co. (Ho Chi Minhcity). Plant nutrient products and coconut coins for hydroponic culture were supplied bySaigon Thuy Canh Corp. (Ho Chi Minh city).

II.2. Methods

Extraction of pectin: For extract pectin, 100g of grapefruit peel powder wereused. The ratios of grapefruit peel powder to HCl solution were conducted at 1:30, 1:20and 1:10 (g/g). The pH in a range of 1-5 was tested for extraction mixtures. The effectof temperature was investigated at 30, 50 and 100oC. The extraction time with 1, 2 and3 hours were also applied for observating the extraction yield. The yields of extractedpectin in grapefruit peel powder were calculated as follow: Pectin yield (%) = (Weightof pectin/Weight of grapefruit peel powder) × 100

Degradation of pectin by γ-rays: The pectin solutions with contents of 1, 2 and3% were prepared by dissolving 10g, 20g and 30g pectin in 100ml distilled water. Thesolutions were then irradiated by γ-rays from a Co-60 resource with doses in range of24-100kGy for degradation.

Characterization of degraded pectin: To determine the molecular weight (Mw),pectin was dissolved in an aqueous solution of 0.1 M NaCl. The intrinsic viscosities [η]of pectin solutions at different concentrations were measured with an Ubbelohdeviscometer at 25oC. The Mw was calculated according to the following Mark-Houwink-Sakurada equation:[η] = K×Mα; where K = 0.0216 and α = 0.79 [14]. FTIR spectra ofsamples were run in a Spectrum one FT-IR spectrometer in KBr disc form by mixing3mg sample with 100mg KBr. All spectra were recorded at ambient temperature in4000-500cm-1 using resolution of 4cm-1 over 128 scans. UV spectra of irradiated pectinwere performed at 25oC using a Shimadzu spectrophotometer UVmini-1240 in therange of 200 - 600 nm to determine the absorbance. Aqueous solutions consisting of0.025% (w/v) of pectin were used for analysis

Growth promotion test: The effect of irradiation dose for degradation of pectinwas tested on mustard greens using hydroponics cultivation. While the growthpromotion effect of oligopectin concentration on mustard greens was investigated byadding 10-150ppm oligopectin. The growth promotion effect was determined via theshoot height, root length, fresh biomass and dried matter content of mustard greenscultivated in 28 days.


III.1. Pectin extraction

There are several parameters affected to the extraction yield of pectin. The firstexperiment was performed for investigated the suitable volume of acidic solution forextraction. The results in Table 1 showed that the yields of extracted pectin wereobtained about 14.4, 24.6 and 31.8% by the extracted ratios (grapefruit peelpowder/acidic solution) of 1/10, 1/20 and 1/30, respectively. In addition, an equivalent

VINATOM-AR 11--22


volume of alcohol (1 volume of alcohol/1 volume of extracted solution) was used forprecipitation of pectin in the extracted solution. It can be seen from Table 1 that theextracted yield of pectin by the ratio of 1/30 was about 7.2% higher than that of by theratio of 1/20, while the alcohol volume used for pectin precipitation of 1/30 was 50%higher than that of 1/20, therefore, the ratio of 1g grapefruit peel powder/20g of acidicsolution was selected for pectin extraction.

Table 1: The effect of acidic solution volume, extraction time,pH and temperature on the extraction yield of pectin from grapefruit peel

Parameters for extraction Yield of pectin, %

The ratio of grapefruit peelpowder/ acidic solution

1/10 14.4 ± 0.37

1/20 24.6 ± 0.24

1/30 31.8 ± 0.33

Extraction time

1 16.7 ± 0.25

2 20.9 ± 0.20

3 22.5 ± 0.13

pH

1 14.0 ± 0.17

2 9.0 ± 0.17

3 6.8 ± 0.05

5 3.3 ± 0.19

Temperature, oC

30 5.8 ± 0.08

50 11.6 ± 0.13

100 28.4 ± 0.24

The effect of time (1, 2 and 3hrs), on the extraction yield of pectin was alsoinvestigated and the results showed that the efficient time for extraction were found at 2hours. On the other hand, the parameters such as pH~1-2 and temperature about 100oCwere also found as suitable conditions for high yield of pectin extraction. Our results arein good agreement with that of Arslan, N. (1995) [4].

III.2. Degradation of pectin by irradiation

The extracted pectin with Mw about 363kDa was irradiated in solution of 1, 2and 4%. The results from Fig. 1 showed that the irradiation doses displayed as afunction for the decrease of Mw of pectin in irradiated solusions. The Mw of pectin wasrapid decreased by the irradiation dose in range of 4-24kGy, and it was then slowly

VINATOM-AR 11--22


decreased by the increase of irradiation dose up to 100kGy. The Mw about 1.0, 1.7 and22 kDa were determined by 100kGy-irradiation of pectin in solutions of 1, 2 and 4%,respectively.

1

10

100

1000

0 20 40 60 80 100 120

Mw,kDa

Dose, kGy

1%

2%

4%

Figure 1: The change in Mw of pectinby irradiation

Figure 2: FTIR spectra of pectin;a: Control, b: Sample irradiated at 24kGy and

c: Sample irradiated at 100kGy

0.55

0.56

0.57

0.58

0.59

0.60

0 20 40 60 80 100 120

A1740/(A1740+A1650)

Dose, kGy

0.00

0.20

0.40

0.60

0.80

1.00

200 250 300 350 400 450 500

Absorband

Wave length, nm

50kGy

24kGy

Control

Figure 3: The MEDs of pectinsirradiated in 2% solution

Figure 4: The UV spectra of pectinsirradiated in 2% solution

Ayyad, et al. (1990) [6] reported that the methyl esterification degree (MED)was slightly decreased by irradiation The FTIR pectra of irradiated pectin werepresented in Fig. 2 showed that compared to the control, there is no new peak appearedin the spectra of pectin irradiated at 24 and 100kGy. According to Guillermo et al. [15],the MED of pectin was determined by the following equation: MED (%) =A1740/(A1740+A1630); where A1740 is the intensity of the absorption bands with peak1740cm-1 corresponds to carbonyl group from COOCH3 group and A1630 is the intensityof the absorption bands with peak 1630cm-1 corresponds to symmetrical stretchingvibration of COO- group. In this study, the MEDs of irradiated pectin were calculated

VINATOM-AR 11--22


based on Fig. 2 and presented in Fig. 3. It can be seen from Fig. 3 that the MED ofirradiated pectin was almost unchanged after irradiation with the doses up to 100 kGy.

In addition, the UV spectra of pectin presented in Fig. 4 showed that in controlsample, a peak with low intensity was appeared at 270 nm corresponds to theesterification group. While the peaks in irradiated samples were shipped to 280nm andthe peak intensity was increase by the increase of the irradiation dose. The reason maydue to the generation of oligopectin in irradiated samples.

III.3. Growth promotion test

Oligosaccharides such as oligoalginate, oligochitosan prepared by radiationtechnique have been reported to have plant growth promotion effect for plant [16-18].The Mw of oligosaccharide was recognized as a trigger for promotion effect on plant. Inthis study, the effect of irradiated pectin was investigated on mustard greens. It can beseen from Fig. 5 that the growth and development of mustard greens were different bysupplementation of pectin products irradiated at different doses. The shoot height, rootlength and fresh biomass of mustard greens were not significantly increased by theaddition of pectin products irradiated dose in range of 4-24 kGy. Whereas, theoligopectins prepared by 50-100kGy irradiation increased the shoot height (11-19%),root length (13-14%) and fresh biomass (16-30%) of the tested vegetable compared tothose of the untreated control. The highest plant growth promotion on shoot height, rootlength and fresh biomass were found at the supplementation of oligopectin irradiated at75 kGy with Mw was determined about 3.5 kDa. In addition, the dried matter contentsof tested vegetable treated with oligopectin were also increased in 17-33% compared tothat of the untreated control.

90

100

110

120

130

140

Control 0 4 16 24 50 75 100Dose, kGy

Gro

wth

pro

mot

ion

degr

ee, %

Shoot height

Root length

Fresh biomass

Dried matter content

Figure 5: Effect of irradiation dose for pectinon the growth of mustard greens

VINATOM-AR 11--22


50

60

70

80

90

100

110

120

130

140

0 25 50 75 100 150 200 500Concentration, ppm

Gro

wth

pro

mot

ion

degr

ee, %

Shoot heightRoot lengthFresh biomassDried matter content

Figure 6: The effect of oligopectin concentrationon the growth of mustard greens

To investigate the suitable concentration for the mentioned vegetable, theoligopectin with Mw~3.5 kDa prepared by irradiation of 2% pectin solution at 75 kGywas used in arrange of 25-500 ppm. The presented data in Fig. 6 showed that the shootheight, root length and fresh biomass of mustard greens were not significant increasedby the supplementation of 25-50 ppm, while these data were insignificant decreased bythe additions of high concentrations (200-500 ppm). The concentration of 75ppm wasfound as the best suitable supplementation for increasing the shoot height (6.5%), rootlength (4.8%), fresh biomass (17.6%) and dried matter content (23.2%) of thementioned vegetable (Fig. 6 and 7).

Figure 7: Photographs ofmustard greens treatedwith 75ppm oligopectinwith M~3.5kDa (a) andthe untreated control (b)after 28 days cultivation ina hydroponics system.

VINATOM-AR 11--22


IV. CONCLUSIONS

The process for extraction of pectin from discard-waste grapefruit peels withsuitable parameters such as ratio of grapefruit peel powder/acidic solution (1/20, g/g),pH (~1), extraction time (2hrs) and temperature (~100oC) has been successfully set up.Radiation degradation was found as a suitable method for induction of oligopectin. Thetreatment with optimal concentration (75ppm) of oligopectin increased the shoot height,root length, fresh biomass and dried matter content of mustard greens (Brassica junceaVar rugosa) in 6.50, 4.81, 17.65% and 23.2, respectively. The radiation-degradedoligopectin derived from a natural product may potentially to apply in high-techagriculture for increase of safe-agro-products and for environment protection.

REFERENCES

[1]. Baldwin, E.A., Biggs, R.H. Cell-wall lysing enzymes and products of cell-walldigestion elicit ethylene in citrus, Plant Physiology, 73, 58-64, 1988.

[2]. O’Neil, M., Albersheim, P., Darvill, A. The pectic polysaccharides of primary cellwall. In: Dey P.M. (eds), Method in Plant Biochemistry, 2, 415-441, Academic Press, London,1990.

[3]. Andrew, N. R., Neil, M. R., Alistair J. M., Victor J. M. A new view of pectinstructure revealed by acid hydrolysis and atomic force microscopy, Carbohydrate Research,345, 487–497, 2010.

[4]. Yapo, B. M., Robert, C., Etienne, I., Wathelet, B., Paquot, M. Effect of extractionconditions on the yield, purity and surface properties of sugar beet pulp pectin extracts, FoodChemistry, 100, 1356–1364, 2007.

[5]. Kravtchenko, T. P., Penci, M., Voragen, A. G. J., Pilnik, W. Enzymic andchemical degradation of some industrial pectins. Carbohydrate Polymers, 20, 195-205,1993.

[6]. Ayyad, K., Hassanien, F., Ragab, M. The effect of γ irradiation on the structure ofpectin. An electrophoretic study, Food/Nahrung (Currently known as: Molecular Nutrition &Food Research), 34, 465-468, 1990.

[7]. Thanh Van, T. K., Toubart, P., Cousson, A., Darvill, A. G., Gollin, D. J., Chelf, P.,Albersheim, P. Manipulation of morphogenetic pathways of tobacco explants byoligosaccharides, Nature, 314, 615-617, 1985.

[8]. Cote, F., Hahn, M. G. Oligosaccharins: Structure and signal transduction, PlantMolecular Biology, 26, 1379-1411, 1994.

[9]. Hahn, M. G., Darvill, A. G., Albersheim, P. Host-pathogen interactions. XIX. Theendogenous elicitor, a fragment of a plant cell wall polysaccharide that elicits phytoalexinaccumulation in soybeans, Plant Physiology, 68, 1161-1169, 1981.

[10]. Davis, D., Darvill A. G., Albersheim, P., Dell, A. Host pathogen interactions.XXX. Characterization of elicitors of phytoalexin accumulation in soybean released fromsoybean cell walls by endo-polygalacturonic acid lyase, Z. Naturforsch, 41, 39-48, 1986.

[11]. Jin, D. F., West, C. A. Characteristics of Galacturonic acid oligomer as elicitorsof casbene synthetase activity in castor bean seedlings, Plant Physiology, 74, 989-992, 1984.

[12]. Broekaert, W. F., Peumans, W. J. Pectic polysaccharides elicit chitinaseaccumulation in tobacco, Physiol. Plant, 74, 740-744, 1988.

[13]. Famer, E. E., Moloshok, T. D., Saxton, M. J., Ryan, C. A. Oligosaccharidesignaling in plants: Specific of oligouronic-enhanced plasma membrane proteinphosphorylation, Journal of Biological Chemistry, 266, 3140-3145, 1991.

VINATOM-AR 11--22


[14]. Arslan, N. Extraction of pectin from sugar-beet pulp and intrinsic viscosity-molecular weight relationships of pectin solution, J of Food Sci. Tech. 32: 381-385, 1995.

[15]. Guillermo, D. M., Franco, M. L. FT-IR spectroscopy as a tool for measuringdegree of methyl esterification in pectins isolated from ripening papaya fruit, PostharvestBiology and Technology, 25, 99-107, 2002.

[16]. Ravin, G. and Proctor A. Determination of pectin degree of esterification bydiffuse reflectance Fourier transform infrared spectroscopy, Food Chemistry, 68, 327-332,2000.

[17]. Hien, N. Q., Nagasawa, N., Tham, L. X., Yoshii, F., Dang, V. H., Mitomo, H.,Makuuchi, K., Kume, T. Growth-promotion of plants with depolymerized alginates byirradiation, Radiat. Phys. Chem., 59, 97-101, 2000.

[18]. Luan, L. Q., Nagasawa, N., Hien, N. Q., Kume, T., Yoshii, F., Nakanishi, T. M.Biological effect of radiation-degraded alginate on flower plants in tissue culture, Biotechnol.App. Biochem., 38, 283-288, 2003.

[19]. Luan, L. Q., Nagasawa, N., Ha, V. T. T., Kume, T., Yoshii, F., Nakanishi, T. M.Biological effect of irradiated chitosan plant on plant in vitro, Biotechnol. App. Biochem., 41,49-57, 2005.

VINATOM-AR 11--23


A STUDY FOR IMPROVING APPLICATION OF TWO TLDDOSIMETER TYPES (CaSO4: Dy AND LiF-TLD-100) IN

ENVIRONMENTAL RADIATION DOSE RATE MONITORING

Hoang Van Nguyen, Pham Van Dung, Phan Van Toan,Dinh Xuan Hoang and Nguyen Thi Ha

Nuclear Research Institute,VINATOMNo.1 Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: The theme studied to improve the application of the CaSO4: Dy (made in theNRI) and LiF-TLD-100 for environmental dose Monitoring. Some important dosimetriccharacteristics of the above-mentioned TLD materials were determined (for example,Energy Dependence, TLD Response – Dose Curve, Fading and Minimum DetectableDose). A new Solution for environmental dose monitoring by TLDs was proposed. Thatis a Pb shielding block of dimensions 31 cm x 31 cm x 14 cm was added to preventterrestrial Radiation. The theme also established a Procedure for environmental doseMonitoring by TLDs. Furthermore, the new solution was tested in two positions at theNRI.

I. INTRODUCTION

Monitoring environmental radiation dose is necessary. Normally, the TLDmethod is used for this purpose. But its disadvantages are that it shows only totalenvironmental radiation dose and can’t distinguish the terrestrial radiation dose fromcosmic radiation dose.

The aim of the theme is to improve the application of two TLD dosimeter types(CaSO4: Dy and LiF-TLD-100) in environmental radiation dose rate monitoring.

The research contents are: Determining dosimetric characteristics of CaSO4: Dy(made in the NRI) and LiF-TLD-100; improving the TLD method for environmentalradiation dose rate monitoring; and testing the improved method for monitoringenvironmental radiation dose rate around the Dalat nuclear research reactor.

II. EXPERIMENTS AND RESULTS

II.1. Energy Dependence of CaSO4: Dy and LiF-TLD-100

Both TLDs were exposed by gamma sources (Cs-137 and Co-60) and a X-raymachine. Calculation results and experiment results are shown in Figure 1.








VINATOM-AR 11--23


0

1

10

100

10 100 1000 10000

E (keV)

K

CaSO4-calculation

LiF-calculation

CaSO4-experiment

LiF-experiment

Figure 1: Energy Dependence of CaSO4: Dy and LiF-TLD-100

II.2. Dose – Response Curve of CaSO4: Dy and LiF-TLD-100

Both TLDs were exposed by a Co-60 source and results are shown in Figure 2and Figure 3.

0

200,000

400,000

600,000

0 200 400 600

Dose (mGy)

TL

Res

pons

e (C

ount

)

Figure 2: Dose – Response Curve of CaSO4: Dy

0

5,000

10,000

15,000

20,000

0 200 400 600

Dose (mGy)

TL

Res

pons

e (C

ount

)

Figure 3: Dose – Response Curve of LiF-TLD-100

VINATOM-AR 11--23


III.3. Fading of CaSO4: Dy and LiF-TLD-100

These TLDs were irradiated and stored in different temperature conditions(laboratory room condition, 400C and 800C). Fading curves are given in Figure 4 andFigure 5.

0.80

0.85

0.90

0.95

1.00

0 500 1000 1500 2000 2500

Time storage (h)

TS

Room temperature

40 C

80 C

Figure 4: Fading curves of CaSO4: Dy

0.80

0.85

0.90

0.95

1.00

0 500 1000 1500 2000 2500

Time storage(h)

TS

Room temperature

40 C

80 C

Figure 5: Fading curves of LiF-TLD-100

III. DISCUSSION

The energy dependence of CaSO4: Dy is too high in the range from 20 keV to150 keV. In the range of more than 200 keV, its response does not fluctuate more than15 %. The energy dependence of LiF-TLD-100 is low. It does not change more than 30%.

The dose – response curves of both TLDs are nearly linear with R2 coefficientsnear 1.

When environmental temperature does not exceed 400C, fading of both TLDsare too low, only about 4 – 8 % per 3 months. Therefore they are suitable for long timemonitoring periods.

VINATOM-AR 11--23


IV. IMPROVING MONITOR METHOD

The usual TLD method for environmental dose monitoring only gives total doseinvolved both cosmic and terrestrial doses. Now, an improvement was proposed,namely two boxes containing TLDs are used simultaneously in every monitoring place.One of them contains lead block for shielding terrestrial radiation. The improvementpermits us to monitor terrestrial and cosmic doses separately.

V. TESTING IMPROVED METHOD

Experiments were done in two places of the Dalat Nuclear Research Reactor totest the improved method and determinate necessary coefficients.

VI. CONCLUSION

- Experimental Results show that: Both CaSO4: Dy and LiF-TLD-100 havedosimetric properties suitable for environmental dose monitoring. But the CaSO4: Dy isbetter due to its high sensitivity.

- The theme also proposed an improvement of the monitoring method. It permitsof monitoring terrestrial and cosmic doses separately.

REFERENCES

[1]. Alam M.N., Environmental radiation measurements by TLD, β-γ survey meterand γ-spectrometry, Proceedings of the international Workshop, Bangladesh, 1996.

[2]. Bilski P., Thermoluminescence Efficiency of LiF:Mg,Cu,P (MCNP-N) Detectorsto Photons, Beta Electrons, Alpha Particles and Thermal Neutrons, Radiat. Prot. Dos. 55, 1,1994.

[3]. Commission of the European Communities, Intercomparison of environmentalgamma dose rate Meters, Report EUR 11665 EN, CEC Luxembourg, 1989.

[4]. De Planque G., Environmental Measurements with ThermoluminescentDosimeters – Trends and Issues, Radiat. Prot. Dos. 17, pp 193 – 200, 1986.

[5]. Losana M.C., Comparison of different Methods for the assessment of theenvironmental gamma dose, Radiat. Prot. Dos. 97(4), pp. 333 – 336, 2001.

[6]. Lowder W. M., Cosmic-Ray Ionization in the Lower Atmosphere, J. Geophys.Res. 71, pp. 4661 – 4668 , 1966.

[7]. McKeever S. W. S., Thermoluminescence Dosimetry Materials: Properties andUses, Nuclear Technology Publishing, 1995.

[8]. Mclaughlin W.L., et al, Trends in Radiation Dosimetry, Pergamon Press, 1982.

[9]. Metivier H., Natural radiation sources, C.R. Physique 3(7), pp. 1035 – 1048,2002.

[10]. Nguyễn Thị Minh Tâm, Xác định một số đặc trưng đo liều quan trọng của chấtCaSO4:Dy, Luận văn tốt nghiệp đại học, Trường Đại học Đà lạt, 1990.

[11]. Olko P., Microdosimetric Analysis of the Response of LiF ThermoluminescentDetectors to radiation of different Qualities, Radiat. Prot. Dos. 52, pp 405 – 408, 1994.

[12]. Piesch E., Application of TLD systems for Environmental Monitoring, Appliedthermoluminescence Dosimetry, Eds M. Oberhofer and A. Scharmann, pp. 11-38, AdamHilger Ltd, Bristol, 1981.

VINATOM-AR 11--23


[13]. Teledyne Isotopes, Dosimeter Manual, Laboratory Products Division, NewJersey, 1988.

[14]. UNSCEAR, Report of the United Nations Scientific Committee on the Effectsof atomic radiation to the General Assembly, New York, 2010.

[15]. Tsui K.C., Field estimation of cosmic contribution to total external gammaradiation in Hong Kong, Royal Observatory Report No.4, 1991.

[16]. Ngô Quang Huy và cộng sự, Nghiên cứu bước đầu về hoạt độ phóng xạ tựnhiên ở Việt Nam, Tuyển tập báo cáo hội nghị khoa học và công nghệ hạt nhân toàn quốc lầnthứ VI, Trang 355 – 361, Nhà xuất bản Khoa học và Kỹ thuật, Hà nội, 2006.

[17]. Hoàng Văn Nguyện và cộng sự, Nhiệm vụ đảm bảo an toàn bức xạ năm 2002,Báo cáo kết quả thực hiện nhiệm vụ cấp bộ về an toàn bức xạ tại Viện nghiên cứu hạt nhân, ĐàLạt, 2003.









VINATOM-AR 11--24


RESEARCH ON IMMOBILIZATION OF RADIOACTIVEWASTE SLUDGE FROM URANIUM MILLING

ACTIVITIES BY CEMENTATION

Nguyen An Thai, Nguyen Ba Tien, Pham Thi Quynh Lương, Vương Huu Anh,Nguyen Hoang Lan and Nguyen Thi Thu Trang

Centre for Radioactive Waste Management and Environment Treatment,Institute for Technology of Radioactive and Rare Elements,VINATOM

No.1 Lang Ha, Dong Da, Hanoi, Vietnam

Abstract: In this paper, we immobilized radioactive sludge by several types of cementto find out which type is the most suitable for treating radioactive sludge come out fromresearch laboratory. Our study will be carried out on some aspects, such as capability ofimmobilizing radioactive nuclei, price and availability of cement in the market. Thestudy will also be carried out on some additives added to cementation mixture toimprove its physical and chemical behavior. Each specimen is measured in leachingcapability by ANSI/ANS-16.1-1986 standard and compress durability by TCVN3118:1993 standard. The experimental results showed that Portland cement is the mostsuitable for solidifying radioactive sludge; additives such as bentonite and epoxy resinadded will enhance both physical and chemical durability of cementation mixture.

I. EXPERIMENTAL RESULTS AND DISCUSSION

I.1. Liquid waste composition and properties of radioactive sludge

Liquid radioactive waste collected from uranium milling process has high acidic(pH = 1.89); it contains many radioactive nuclei such as U, Th, Ra and other poisonousheavy metal ions. It also contains high concentration of Al and Fe (4-5 g/l) as well asheavy metal ions (such as Pb, Hg, Cu…) or poisonous non-metal ion (As) which are farsurpass safe level according to Vietnam industrial wastewater standard QCVN 24:2009.Besides, radioactivity of liquid waste sample is also very high (145 Bq/l) (acceptancelevel according to QCVN 24:2009 is 2 Bq/l).

After neutralization process by NaOH to pH = 9, liquid waste becomes sludgewhich contains 70% approximately water, all radioactive nuclei and heavy metal ionsfrom liquid waste. Because of high water content in sludge, no water addition is neededin cementation process.








VINATOM-AR 11--24


I.2. Effect of cement ratio on cementation mixture

I.2.1. Effect of cement ratio on mechanical properties

After hardening for 72 hours, only 5 samples that contain from 40 – 60%Portland cement are able to form harden object. Sample containing 35% cement and65% waste sludge can’t archive solid form.

In order to minimize secondary waste, cement with ratio of 40% is chosen for allour experiments.

I.2.2. Leaching ability of cementation mixture

Portland cement and waste sludge are mixed with various ratios: 40:60; 50:50and 60:40. These mixtures will be hardened for 72 hours in 2 cm diameter and 10 cmlong cylindrical moulds. After hardening process, cementation sample is immersed in 5litres of de-ionized water (samples are hung by thin string in order to maximize surfacecontact with water). After 9 days, water is sampled and measured some heavy metalcontents by ICP/MS method.

The results showed that heavy metal contents like Pb or Hg in the sample aremet Vietnam industrial wastewater TCVN 5945:2005. Except uranium concentration,the sample containing 40% cement has as leaching resistant property as other sampleswhich has higher ratio of cement.

The results also showed that leaching ratio of all ions is less than 0.1% andleaching speed is less than 10-9 g/cm2/day. So, Portland cement is suitable material forimmobile radioactive waste.

I.3. Effect of cement type on cementation mixture

I.3.1. Effect of cement type on compression strength

Cement is mixed with radioactive sludge with ratio 40:60, then the mortar iscubed to 50 x 50 x 50 mm cubic (according to TCVN 3118:1993 standard). Afterhardening for 72 hours, samples are taken for testing compress. The results are shown inthe following table.

Sample ML1 ML2 ML3 ML4

Name of cement PCB-30 PCB-40 PCW-30 PCSr30

Compressionstrength (MPa)

6.2 6.8 5.7 5.9

Compression strength of the sample is significant lower than compressionstrength of pure cement mortar or concrete (12 – 18 MPa) because of high pH value ofthe sludge and low cement content in it. However, after hardening for 72 hours, thesolid sample met requirement of Russia standard for radioactive waste cementation (>5MPa), so all of above cement types are suitable for solidifying radioactive sludge.

VINATOM-AR 11--24


Look at the above table, we can see that PCB-40 cement has the highestcompression strength for solidified mix (6.8 MPa), and come after is PCB-30 cementwhile other cement types like PCW- 30 and PCSR30 do not show any advantages.

I.3.2. Leaching ability comparison

Cementation sample is made in cylindrical shape and tested leaching ability inthe way similar to the part 2.2. The final results are as charts follow:

Figure 1: α activity

Figure 2: β activity

Leakage water has α and β activity met the requirement of TCVN-5945-2005standard (α < 0.1 Bq/l and β < 1 Bq/l). Activity value is the highest right after 2 firsthours because radioactive nuclei are rapidly washed out of surface of the sample. Thisvalue becomes more stable when sampling after that.

VINATOM-AR 11--24


There isn’t significant difference between radioactive leakage resistance abilityof PCB-30, PCB-40 and PCW-30, only PCSr-30 cement has the best radioactiveleakage resistance ability.

All four types of cement have good ability to prevent heavy metal ions fromleaching into water with ratio of all ions is less than 0.1% and leaching speed is lessthan 10-9 g/cm2/day.

Although PCSr-30 cement has better ability of radioactive leakage resistance, itdoesn’t achieve the advantages of compress strength. Moreover, it is extremely rare andexpensive. So, PCB-30 cement is chosen for further experiments.

I.4. Role of additive in radioactive sludge cementation

I.4.1. Effects of additive on compressive strength

Bentonite and epoxy resin are added to cement - sludge mixture with bentonitecontents from 5% to 10% and epoxy resin contents from 2% to 6%. Density of themixture is higher than density of bentonite but lower than density of epoxy resin. So,adding bentonite makes density of the mixture lower as well as adding epoxy resinmakes density of the mixture higher.

The compressive strength test was carried out in the way similar to experimentsin the part 3.1. The results showed that if 7.5 – 10% cement content in the mixture wasreplaced by bentonite, compressive strength of the sample can increase up to 13%. Itcan be explained that high expand property of bentonite solution causes it to fill up anybubbles in hardened cement. The number of bubbles is finite, keep adding bentonite willmake no positive effect; so, 7.5% is optimum ratio for bentonite.

Like bentonite, epoxy resin also increases compressive strength of the sample upto 23 – 38% because epoxy resin has very high compressive strength (120 MPa)

I.4.2. Leaching ability comparison

Carry out experiment in the way similar to experiments in the part 2.2 and 3.2.The result showed that bentonite and epoxy resin added to the mixture make leakageresistance ability of cementation sample higher. Especially, radioactive nuclei in thesample covered by epoxy resin are not washed out like normal sample in the first 2 – 7hours.

II. CONCLUSIONS

PCB-30 cement is suitable for treating radioactive sludge come out fromuranium milling process. With ratio 40%, mixture of cement and sludge can becomehard form waste with high compressive strength (6.2 MPa). It has ability resist leakageprocess in water, prevents radioactive nuclei such as U, Th or heavy metal ions fromspreading to the environment. The research also figures out bentonite and epoxy resinare very good additives for cementation process because they not only increase strengthof cement but also decreases leak resistance property of solidified waste.

In Vietnam, uranium will be extracted from uranium ore in near future.Therefore, uranium milling process soon generates abundance of radioactive sludgewaste. We hope that this research will help to build effective radioactive sludge wastetreatment facility.

VINATOM-AR 11--24


REFERENCE

[1]. American National Standard, ANSI/ANS-16.1-1986: Measurement of theLeachability of Solidified Low-Level Radioactive Wastes by a Short-Term Test Procedure, 1986.

[2]. S.Goni, M.S.Hernandez, A.Guerrero, Cemented matrices used in the storage of lowand medium radioactive waste, Spanish experience, Madrid, Spain, 2009.

[3]. International atomic energy agency, Classification of radioactive waste, IAEASafety Standards for protecting people and the environment No. GSG-1, IAEA, Vienna, pp. 4-16, 2009.

[4]. Safety series No. 111-G-1.1; Classification of Radioactive Waste, A Safety Guide;A Publication within the RADWASS Programme, IAEA, Vienna, 1994.

[5]. International Atomic Energy Agency, Predisposal Management of low andintermediate level Radioactive Waste, IAEA Safety Standards Series No. WS-G-2.5, IAEA,Vienna, 2009.

[6]. Wayne S. Adaska, Stewart W. Tresouthick, Presbury B. West, Solidification andstabilization of wastes using Portland cement, 1998.

[7]. K.Sakr, M.S.Sayed, M.B.Hafez; Immobilization of radioactive waste in mixture ofcement, clay and polymer, 2002.

[8]. W.E.Lee, An Introduction to Nuclear waste immobilisation, 2005.

VINATOM-AR 11--25


DETERMINATION OF PERCENTAGE DEPTH DOSES IN WATERFOR A MEDICAL LINEAR ACCELERATOR OF 6 MV PHOTON

ENERGY BY EGS5 CODE

Le Ngoc Thiem, Nguyen Huu Quyet, Chu Vu Long, Vu Van Cam,Le Dinh Cuong and Pham Ngoc Diep

Institute for Nuclear Science and Technology,VINATOMNo.179 Hoang Quoc Viet, Nghia Do, Cau Giay, Hanoi, Vietnam

Abstract: The objective of this study was the simulation of percentage depth doses inwater for a medical linear accelerator. In this study, the determination of percentagedepth doses in water was performed by using EGS5 simulation code, the obtainedsimulated data were compared with the experimental data that were obtained by theresearch team in some practical works. The comparison between the simulated data andexperimental data shown the good agreement that the maximum uncertainty were in theacceptable range of 3.6%. The simulated results revealed an evidence that the EGS5simulation code is an useful tool to know an experimental trend.

I. METHOD AND RESULT

I.1. Writing EGS5 simulation geometries

In this part, the simulation geometries for the problem of percentage depth dosedetermination in a water cubic phantom for a medical linear accelerator (linac) of 6 MVphoton energy and different field sizes at phantom surface were written by CgViewsoftware[1]. The geometries of this problem were that the linac spectrum came to thewater cubic phantom surface from the distance of 100 cm. There were 20 ionizationchambers located in the water phantom from 1 cm to 20 cm with the step of 1 cm. Forthat explanation, the geometries of this simulation were described as followings:

- The geometry of the water cubic phantom with 30 cm each size locatedsymmetrically through z axis on the axial positive side with a surface on xOy plane

- The geometries of 20 ionization chambers, each one was a cylinder with thebase radius of 0.3 cm and the high of 2.4 cm located symmetrically through centralbeam axis in the phantom








VINATOM-AR 11--25


- The geometry of the air region between the water phantom and the radiationsource this region was a right parallelepiped

- The geometry of outer void region, the region covered overall othergeometries that was a right parallelepiped. When radiation enters this region itsinteraction will be avoided

The simulation geometries were visually shown in the Figure 1.

I.2. Determination of percentage depth doses in water for the depths from 1cm to 20 cm with the step of 1 cm for a medical linear accelerator of 6 MV photonenergy with different radiation field sizes of 5 cm x 5 cm, 10 cm x 10 cm and 15 cmx 15 cm

In this section, percentage depth doses (PDD) in water for a medical linearaccelerator with the photon energy of 6 MV for the depths from 1 cm to 20 cm with thestep of 1 cm were simulated by using EGS5 with the geometries that the distance fromthe source to the phantom surface (SSD) was 100 cm, the radiation field size at thephantom surface (FS) was 5cm x 5cm, 10cm x 10cm and 15cm x 15cm respectively.The simulated results were shown in the Table 1, Table 2 and Table 3 by the mean thatthe simulated data were normalized as 100% at the value of 2cm depth.

a. zOy view b. xOy view

Figure 1: Combinational geometries of EGS5 simulation

1: phantom3. air region

2. ionization chamber4. outer void region

Table 1: Simulated results of percentage depth dose (PDD) in water for a medical linearaccelerator of 6 MV photon energy with the combinational geometries of the distancefrom the source to the phantom surface was 100 cm, the radiation field size was 5 cm x5 cm at the phantom surface

Depth (cm) PDD (%) Depth (cm) PDD (%)

1 96.7 11 61.9

2 100.0 12 58.4

3 95.7 13 55.2

1

2

3

44

3

1

2

VINATOM-AR 11--25


4 91.2 14 52.0

5 86.5 15 49.1

6 82.0 16 46.2

7 77.8 17 43.8

8 73.6 18 41.3

9 69.3 19 38.9

10 65.6 20 36.8

Table 2: Simulated results of percentage depth dose in water for a medical linearaccelerator of 6 MV photon energy with the combinational geometries of the distancefrom the source to the phantom surface was 100 cm, the radiation field size was 10 cm x10 cm at the phantom surface


1 97.0 11 65.7

2 100.0 12 62.1

3 95.9 13 59.0

4 91.9 14 55.9

5 87.9 15 53.0

6 83.9 16 50.5

7 79.9 17 47.9

8 76.3 18 45.1

9 72.7 19 42.8

10 68.9 20 40.7

Table 3: Simulated results of percentage depth dose in water for a medical linearaccelerator of 6 MV photon energy with the combinational geometries of the distancefrom the source to the phantom surface was 100 cm, the radiation field size was 15 cm x15 cm at the phantom surface


1 96.4 11 67.2

2 100.0 12 64.2

VINATOM-AR 11--25


3 96.5 13 61.2

4 92.8 14 58.1

5 88.7 15 55.1

6 84.8 16 53.0

7 81.4 17 50.1

8 77.5 18 47.5

9 73.8 19 45.3

10 70.5 20 43.0

I.3. Comparison between the simulated data and the experimental data

The objective of this section was to compare the depth dose distribution in waterof a medical linear accelerator gained by the EGS5 simulated data with those from theexperimental data. The comparison results shown the good agreement between themwith the maximum error of 3.6%. The evidence is that the EGS5 simulation code can beused to simulate an experimental trend. The comparison results were shown in Table 4,Table 5 and Table 6 corresponding to the different field sizes of 5cm x 5cm, 10cm x10cm and 15cm x 15cm.

Table 4: Error of percentage depth dose for a medical linear accelerator of 6 MVphoton energy between the simulated data and the experimental data with thecombinational geometries of the distance from the source to the water phantom surfaceof 100 cm, the radiation fields sizes of 5cm x 5cm

Depth(cm)

PDD (%)Error (%)

Depth(cm)

PDD (%)Error(%)Simulated Experimental Simulated Experimental

1 96.7 96.4 0.36 11 61.9 60.5 2.28

2 100.0 100.0 0.00 12 58.4 57.1 2.25

3 95.7 95.3 0.47 13 55.2 53.7 2.91

4 91.2 90.5 0.70 14 52.0 50.7 2.71

5 86.5 85.8 0.78 15 49.1 47.6 3.02

6 82.0 81.2 1.00 16 46.2 44.9 2.96

7 77.8 76.7 1.43 17 43.8 42.3 3.60

8 73.6 72.4 1.60 18 41.3 39.9 3.50

VINATOM-AR 11--25


9 69.3 68.2 1.70 19 38.9 37.7 3.37

10 65.6 64.2 2.18 20 36.8 35.5 3.39


Depth(cm)

PDD (%)Error (%)

Depth(cm)


1 97.0 98.1 -1.10 11 65.7 64.3 2.13

2 100.0 100.0 0.00 12 62.1 61.0 1.83

3 95.9 96.1 -0.14 13 59.0 57.7 2.31

4 91.9 91.7 0.21 14 55.9 54.7 2.18

5 87.9 87.6 0.34 15 53.0 51.8 2.28

6 83.9 83.5 0.54 16 50.5 49.2 2.60

7 79.9 79.1 1.01 17 47.9 46.3 3.50

8 76.3 75.3 1.32 18 45.1 44.0 2.59

9 72.7 71.6 1.54 19 42.8 41.6 2.91

10 68.9 67.8 1.49 20 40.7 39.4 3.23


Depth(cm)

PDD (%) Error(%)

Depth(cm)


1 96.4 98.0 -1.61 11 67.2 66.5 1.08

2 100.0 100.0 0.00 12 64.2 63.3 1.51

3 96.5 96.2 0.33 13 61.2 60.1 1.74

4 92.8 92.2 0.59 14 58.1 57.2 1.54

VINATOM-AR 11--25


5 88.7 88.3 0.50 15 55.1 54.4 1.26

6 84.8 84.5 0.38 16 53.0 51.8 2.46

7 81.4 80.7 0.82 17 50.1 48.9 2.37

8 77.5 77.1 0.59 18 47.5 46.5 2.15

9 73.8 73.3 0.74 19 45.3 44.3 2.37

10 70.5 69.9 0.87 20 43.0 42.1 2.24

II. CONCLUSION

In this study, such following items were performed:

- The EGS5 simulated combinational geometries were successfully written.

- The percentage depth doses in water for a medical linear accelerator weresimulated by using EGS5 with some specific geometries which are usual geometriesapplied in real practices.

- Comparison between the simulated data and the experimental data shownthe good argreement in the range of 3.6%

REFERENCES

[1]. Y.Namito, H. Hirayama. CgView Particle Trajactory and Geometry DisplayProgram, Ver2.3

[2]. Hideo Hirayama and Yoshihito Namito. The EGS5 Code System.2005

[3]. The British Institute of Radiology, the Institution of Physics and Engineering inMedicine and Biology. Central Axis Depth Dose Data for Use in Radiotherapy: 1996. 1996

[4]. IAEA, WHO, PAHO, ESTRO. Absorbed Dose Determination in External BeamRadiotherapy. 2000

[5]. Daryoush Sheikh-Bagheri and D.W.O. Rogers. Monte Carlo Calculation of NineMegavoltage Photon Beam Spectra Using the BEAM Code. American Association for MedicalPhysics, Vol.29, No.3 . 2002

[6]. J. H. Hubbell, S. M. Seltzer. Table of X-ray Mass Attenuation, Coefficients andMass Energy-Absorbtion, Coefficients 1keV to 20 MeV for Elements Z=1 to 92 and 48Additional Substances of Dosimetric Interest.1995

[7]. E.B. Podgorsak. Radiation Oncology Physics: A Handbook for Teachers andStudents. 1957

[8]. Walter R. Nelson and Theodore M. Jenkins. The Geometry Methods and Packages.1988

[9]. Hideo Hirayama and Yoshihito Namito. Practices of How to Write Source Routine.2006

VINATOM-AR 11--26


STUDY ON DEGRADATION OF SILK FIBROINBY IRRADIATION TREATMENT FOR COSMETIC

AND PHARMACEUTICAL APPLICATIONS

Tran Bang Diep, Tran Minh Quynh, Nguyen Van Binh, Hoang Phuong Thao,Pham Duy Duong, Hoang Dang Sang, Pham Quan Hieu and Nguyen Thuy Huong Trang

Hanoi Irradiation Centre,VINATOMMinh Khai, Tu Liem, Hanoi, Vietnam

Abstract: As a kind of protein, silk fibroin is created with silkworm Bombyx mori inproducts of silk. The fibroin was irradiated using Co-60 gamma source and itsdegradability and solubility were investigated with various radiation doses to apply inpharmacy and cosmetic. Addition to the morphological changes of irradiated fibroinfibers shows that its mechanical properties were much influenced by the irradiation.Tensile strength and elongation at break of the silk fibroin significantly decreased withincreasing of radiation dose up to 1000 kGy. The tensile strength and elongation atbreak of the irradiated fibroin at 1000 kGy reduced to 71% and 94% respectively incompared with non-irradiated one. The solubility of silk fibroin in both calciumchloride (CaCl2/C2H5OH/H2O=1:2:8) in mole ratio and distilled water were improvedby the irradiation. UV spectrometry revealed the structure of silk fibroin was alsochanged by irradiation.

Key word: Silk, Fibroin, Radiation Degradation, Dissolution.

I. INTRODUCTION

Silk is generally defined as a continuous protein fiber produced by somelepidoptera larvae such as silkworms, spiders, scorpions, and mites to form theircocoons. The most extensively characterized silk is from Bombyx mori silkworms. Infact, silkworm silk is strongest natural protein fiber; it is stronger than an equal-diameterfilament of steel. Normally, a silk fiber consists of two types of protein, fibroin andsericin. The fibroin is a major component of silk fiber (75%), serving as the core. Itcontains 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 proteincoated on the two fibroin cores to conceal a unique luster of fibroin. Both fibroin andsericin contain the same 18 amino acids, although in different amounts. Another








VINATOM-AR 11--26


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-sheetmicrocrystallines. This reinforcement contributes the strength and stiffness to the silkfiber.

Silk fibroin has been used as textile material for thousands years because it hasexcellent natures such as lightness and warmth on wearing, beautiful gloss, etc...Recently silk fibroin is also considered to be natural protein with interesting charactersand applications in new diversified fields, especially medical, cosmetic andpharmaceutical materials. On practical application, it is necessary to change form of silkfiber in many cases. For example, skin film and block are studied for artificial skin andfor contact lens respectively. Powder has been already used as additions for food,cosmetic or pharmaceutical materials.

In fact, silk fibroin fiber has mechanical strength due to its crystal structure, so itis difficult to degrade or dissolve the silk fibroin in water. Silk can be categorized asnon-degradable materials, as defined by the United States Pharmacopeia (USP).Nonetheless, silk can be gradually digested by proteolytic enzymes and absorbed invivo over a long time period. There are many reports on the biodegradation of silkfibroin treated with proteolytic enzymes. However, there are only few reports of silkfibroin degradation by other techniques, particularly by the gamma irradiation.

The radiation technique has been increasingly used for synthesis andimprovement of polymers due to its low energy consumption and strong strength ofpenetration. Gamma radiation can cause the macromolecule chains to cross-link, graftand degrade. Recently, some authors reported that the conversion efficiency from fiberto powder of silk fibroin improved by EB treatment, that the solubility in water of silkfibroin improved while the mechanical properties weakened after treatment with gammaradiation. The latest studies showed the antioxidant, tyrosinase inhibitory ability... ofsilk fibroin were enhanced by gamma irradiation.

Studying on radiation degradation of silk fibroin was successfully performed atsome overseas laboratories but they’re still completely new in Vietnam. Our study wascarried out in order to evaluate the effect of gamma radiation treatment on degradationand solubilization of silk fibroin. The results of this study should be a reason to expandthe applications of radiation technology for using abundant silk fibroin of country ascosmetic and pharmaceutical materials.

II. EXPERIMENTAL

II.1. Materials

Silk fibroin fiber was purchased from My Duc Commune, Ha Noi. Thechemicals such us Na2CO3, CaCl2, LiBr at analytical grade was supplied by Merckchemical company, Germany, while C2H5OH was bought from domestic company.

II.2. Silk fibroin preparation

Raw silk fibers were subjected to removal of the sericin by the method describedby Kim et al.

VINATOM-AR 11--26


II.3. Irradiation

The raw silk fibers and silk fibroin were irradiated with Co-60 sources at dosesrange from 0 to 1000 kGy in Hanoi Irradiation Center and Dalat Nuclear ResearchInstitute.

II.4. Characterization silk fibroin

Microphotographs of irradiated silk fibroin were obtained by scanning electronmicroscopy (FEI Quanta 200).

Mechanical properties of silk fibroin were measured using the Lloyd Instrument(England) according to ASTM-D 1294-2005.

II.5. Solubilization behavior of the irradiated silk fibroin

The solubilization behavior of the irradiated silk fibroin was evaluated for thecases of the calcium chloride solution (CaCl2/C2H5OH/H2O=1:2:8 in mole ratio) anddistilled water.

For dissolution in calcium chloride, 50 mg of silk fibroin sample was added into2ml of the calcium chloride solution in a glass test tube, heated in water bath at 100oCand then time was measured for up to time the sample completely dissolved.

For dissolution in water, 0.1 g of non irradiated and irradiated silk fibroin wereadded into 10 ml of distilled water. The solution of the samples was put in water bath at100oC with the room temperature (25oC). Centrifugal was done for 15 min at 1300 rpm.The supernatant was left and wet silk fibroin was dried at 105oC. Re-weigh ofcompletely dried silk fibroin was done. Silk fibroin solubility was calculated from lostweight.

II.6. Degradation of silk fibroin

Silk fibroin was dissolved in 9.3 M LiBr solution at 60oC for 4 h. This solutionwas 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 determined by weighingthe remaining solid after dry.

In order to determine structural modification of the silk fibroin by gammairradiation, the silk fibroin solution (2mg/ml) was analyzed through UV-VIS spectrumat 190nm to 400nm using a UV spectrophotometer AV-2450 Shimadzu, Japan. An un-irradiated silk fibroin was used for control.


III.1. Effects of gamma radiation on silk fibroin

The gamma irradiation on silk fibroin showed that the physical of silk fibroinhad been altered; i e., the color and glossy appearance was gradually darkened and thescent was stronger (Fig. 1.).

VINATOM-AR 11--26


Figure 1: Irradiated raw silk fibers and silk fibroin at dose range 0-1000 kGy

Tensile strength and elongation at break of silk fibroin decreased with increasinggamma radiation intensity (Fig. 2., Fig. 3.). Up to 500 kGy, the tensile strength andelongation at break were reduced by 69.5 % and 83.17%, respectively. Tensile strengthof silk fibroin irradiated at 1000 kGy was reduced by 71% and elongation at breakalmost disappeared (94% decreasing compare with unirradiated silk fibroin).

0

50

100

150

200

250

0 100 200 300 400 500 600 700 800 900 1000 1100

Doses (kGy)

Ten

sile

str

engt

h (M

Pa)

Figure 2: Effects of gamma radiation on tensile strength of silk fibroin

0

5

10

15

20

25

30

0 100 200 300 400 500 600 700 800 900 1000 1100

Doses (kGy)

Elo

ngat

ion

(%)

Figure 3: Effects of gamma radiation on elongation of silk fibroin

VINATOM-AR 11--01


The SEM images in Fig. 4. show an increase of erosion and cleft formation ofthe exposed fibroin fibers with increasing dosages of radiation. This indicates astructural change of silk fibroin after irradiation.

Figure 4: SEM images of silk fibroin after gamma irradiation: 0 kGy (a),100 kGy (b), 200 kGy (c), 500 kGy (d), 750 kGy (e), and 1000 kGy (f)

III.2. Effects of gamma radiation on solubility of silk fibroin

The dissolution behavior of irradiated silk fibroin in the calcium chloridesolution was illustrated in Fig.5. The time for silk fibroin to completely dissolve in thesolution decreased significantly by irradiation. The time for complete dissolving of silkfibroin irradiated at 1000 kGy is 3.2 minutes, while at the same condition it takes 14minutes for unirradiated fibroin completely dissolving. This trend is consistent withexpected one from result of the radiation effect on tensile strength that shown in Fig.2.and Fig.3.

0

5

10

15

20

25

0 100 200 300 400 500 600 700 800 900 1000

Dose (kGy)

Sol

uble

fra

ctio

n (%

)

Figure 5: Radiation effect on dissolution of silk fibroin in the calcium chloridesolution (CaCl2/C2H5OH/H2O=1:2:8 in mole ratio)

b ca

d e f

VINATOM-AR 11--01


0

2

4

6

8

10

12

0 100 200 300 400 500 600 700 800 900 1000

Dose (kGy)

Tim

e fo

r com

plet

e so

lubi

lizat

ion

(min

)

Dose (kGy)

Figure 6: Radiation effect on solubility of silk fibroin in distilled water(♦ room temprature/1hours; 100oC/hours)

One of the typical features of silk fibroin is quite insoluble in water. However, itwas found that the irradiated silk fibroin dissolved in water depending on doses. Thedissolved fractions of silk fibroin irradiated at 500 kGy were approximately 13.21% at100oC and about 12.78% at room temprature. After 1 hours, the dissolved fractions ofsilk fibroin were 22% at 100oC and about 19.78% at room temprature when theirradiation dose increasing to 1000 kGy (Fig.6.)

III.3. Effects of gamma radiation on degradation of silk fibroin

Table 1: Concentration of silk fibroin after dialyzing against deionized waterwith a molecular weight cutoff 12-14 kDa

SampleRadiation dose (kGy)

0 100 200 500 750 1000

Concentration(g/ml)x100

7.80±

0.21

7.68±

0.07

6.40±

0.19

6.09±

0.14

4.98±

0.12

2.63±

0.07

Table 1 shows the yields of silk fibroin that were dissolved and dialyzed by themembrane with a molecular weight cutoff 12-14 kDa. The concentration of silk fibroinsolution after dialysis decreased remarkably with the increasing of radiation dose. Theconcentration of unirradiated silk fibroin solution was 7.8%, while this value of silkfibroin solution irradiated at 100 kGy was 2.3%.

UV absorption spectrum exhibited structural modification via absorbency ofbranched chains in an aromatic amino acid presented on a surface of the fibroin. Each of

VINATOM-AR 11--01


three amino acids such as phenylalanine, tyrosine and tryptophan has aromatic branchedchains and the aromatic amino acid absorbs light at UV spectral regions (260-280 nm).

Figure 7. shows an absorbency of the silk fibroin treated by gamma irradiationincreases at 260 nm and 280 nm according to an increase in radiation absorbed dose. Avariation in UV absorbency demonstrates that there is a structural modification of silkfibroin by irradiation. A reason of such structural modification is that aromatic aminoacids in a fibroin are exposed by structural breakup of the irradiated fibroin.

Figure 7: UV absorption spectrum of irradiated silk fibroin

IV. CONCLUSIONS

The irradiation caused a significant degradation of silk fibroin. The morphologyand mechanical property of silk fibroin were much influenced by irradiation. Tensilestrength and elongation at break of silk fibroin significantly decreased with increasingof radiation dose to 1000 kGy. The tensile strength and elongation at break of irradiatedfibroin at 1000 kGy reduced to 71% and 94% respectively in compared with non-irradiated one. The solubility of silk fibroin in both calcium chloride(CaCl2/C2H5OH/H2O=1:2:8) in mole ratio and distilled water were improved byirradiation. UV spectrometry revealed the structure changes of the silk fibroin byirradiation.

REFERENCES

[1]. Altman, G. H., Diaz, F., Jakuba, C., Calabro, T., Horan, R. L ., Chen, J., Lu, H.,Richmond., Kaplan, D.L. Silk-based biomaterials. Biomaterials. 24, 401- 416, 2003.

[2]. ASTM D: Test method for tensile strength and breaking tenacity of wool fiberbundles 1 in, 1294-2005.

VINATOM-AR 11--01


[3]. Ishida, K.; Takeshita, H.; Kamiishi, Y.; yoshi, F.; Kume, T. Radiation degradationof silk. Jaeri-conf. 005, 130-138, 2001.

[4]. Kim U., Park J., Li Ch., Jin H., Valluzzi R. and Kaplan D. L. Structure andProperties of Silk Hydrogels. Biomacromolecules. 5, 786-792, 2004.

[5]. Pewlong, W., Sudatis, B., Takeshita, H., Yoshii, F., Kume, T. Radiationdegradation of silk protein. In: Proceedings of JAERI Conference 2000-2003, Takasaki, Japan,pp. 146-152.

[6]. Sudatis, B. and Pongpat, S. Solubilization of Silk Protein by Radiation. NipponGenshiryoku Kenkyujo JAERI, Conf. 101-104, 2002.

[7]. Xiong, S.; Xu, Y.; Jiao, Y.; Wang, L.; Li, M. Effects of Gamma irradiation on thestructure and mechanical properties of wild silkworms and Bombyx Mori silk fibroin films.Trans tech publications. 27, 197-198, 2011.

[8]. Yao, W.; Liu, Z.; Yi, H.; Wang, J. Structure and mechanical property of silk fiberunder gamma radiation.Trans tech publications. 85, 175-176, 2011.

[9]. Zhao, Y.; Yan, X.; Ding, F.; Yang, Y.; Gu, X. The effects of different sterilizationmethods on silk fibroin. J.Biomedical Science and Engineering. 4, 397-402, 2011.

VINATOM-AR 11--27


RADIATION POLYMERIZATION AND CROSSLINKINGOF POLY(N-ISOPROPYLACRYLAMIDE) HYDROGELS

AND THEIR PROPERTIES

Pham Duy Duong, Hoang Dang Sang, Hoang Phuong Thao and Tran Minh Quynh

Hanoi Irradiation Center, VINATOMMinh Khai, Tu Liem, Hanoi, Vietnam

Abstract: Poly (N-isopropylacrylamide) (PNIPAM) and its hydrogels were synthesizedfrom the aqueous solutions of N-isopropylacrylamide (NIPA) by radiation-inducedpolymerization, combined with crosslinking of the growing polymer chains with 60Cogamma source in Hanoi Irradiation Center. Degrees of polymerization and gelationdepends on initial concentration of irradiated solution and radiation dose. Conversionyeild to polymer increased with the NIPA amount and reached a maximum when NIPAexceeds 10%. Crosslinking density, i.e, gelation ratio also increased with monomerconcentration and radiation dose. 10% NIPA solution was irradiated at different dosesin low dose range and the gel dose (Dg, dose for incipient gel formation) wasextrapolated to be 178 Gy. The influence of temperature of swelling media on theswelling properties of the hydrogel was investigated from room temperature to 45°C.The results suggested that the obtained hydrogels are thermoresponsive with an aparenttransition from hydrophilic to hydrophobic state in around 31.5 to 33°C. Phasetransition temperatures of hydrogel, which ussualy knows as its lower critical solutiontemperature (LCST) slightly reduced with increasing of radiation dose.

I. INTRODUCTION

Several techniques have been reported for the synthesis of hydrogels. Firstapproach involves crosslinking by radical polymerization or copolymerization ofcomonomers using multifunctional comonomers, which act as crosslinking agents. Thepolymerization reaction is initiated by a chemical initiator. The polymerization reactioncan be carried out in bulk, in solution, or in suspension. Some of the commoncrosslinking agents include N, N'-methylenebisacrylamide, divinyl benzene, ethyleneglycol dimethacrylate [1]. Using similar procedures, a great variety of other hydrogelsystems have been prepared and studied. The stimuli sensitive materials can be obtainedby the addition of suitable components.








VINATOM-AR 11--27


While the chemical polymerization usually requires the presence of additives,which may contaminate the products, those initiators and catalysts do not requires incase of radiation-induced polymerization. High energy radiation, in particular gammaand electron beam can be used to polymerize unsaturated compounds. Moreover, highenergy irradiation is able to crosslink water-soluble polymer without additional vinylgroups. During irradiation, in aqueous solutions of polymers, radicals can be formed onthe polymer chains by the homolytic scission, such as C-H bonds [2-4]. On the otherhand, radiolysis of water molecules generates hydroxyl radicals which can attackpolymer chains also resulting in the formation of macroradicals and then covalent bondswithin crosslinked structure.

Poly(N-isopropylacrylamide) PNIPAM can be synthesized from thecorresponding monomer (N-isopropylacrylamide-NIPA) by radiation polymerization inthe solid state and in solution. In aqueous solution, PNIPAM can absorb water tobecome hydrogels. PNIPAM hydrogels can be also prepared by irradiation, whereby theformation of polymer molecules and crosslinking of the growing polymer chainssimultaneously occur. And the properties of obtained PNIPAM hydrogels can bemodified with the monomer concentration and irradiation conditions [4-6]. Withreference to chemical structure, PNIPAM contains both hydrophilic and hydrophobicgroups. In aqueous media, hydrophilic and hydrophobic domains can rearrange intodifferent shapes depending on the solution temperature. At temperature higher than itslower critical solution temperature (LCST), hydrophobic groups shrunken whilehydrophilic groups become more hydrophobic, resulted in the phase transition fromcoils to globule and precipitation at high temperatures. Besides this thermo-responsibility, other stimuli-responsive PNIPAM hydrogels can also be prepared.

Recently, PNIPAM hydrogels were prepared and studied as the drug deliverysystems at Hanoi University of Science. The characteristics of chemical preparedPNIPAM were also obtained at Institute of Chemistry, Vietnam academy of science andtechnology. PNIPAM hydrogels were prepared in aqueous medium with amonipesunfat(APS) as initiator, N,N'-metylenbisacrylamit (MBA), and N,N,N',N'tetrametyletylendiamin (TEMED) as crosslinker and catalyst. For drug deliverysystems, the authors applied the restrict procedure for purification of the obtainedPNIPAM.

In this study, therefore, gamma ray irradiation was applied to prepare thethermo-sensitive hydrogels from the aqueous solutions of NIPA monomer with thepurpose of expanding the applications of the obtained hydrogels. Influences of initialconcentration of monomer, radiation conditions on polymerization and characteristics ofPNIPAM hydrogels were investigated. Gelation dose and the thermo-sensitivity of thehydrogels were also determined.

II. EXPERIMENTS

N-isoprpylacrylamide 98% (NIPA) monomer was bought from Wako PureChemical Inc., Japan, and its different aquoeus solutions were prepred in distilled water.30 mL of NIPA solution was put in the plastic vials, bubbled with nitrogen gas for 15min to remove the dissolving oxygen, sealed and irradiated by gamma source at HanoiIrradiation Center.

VINATOM-AR 11--27


The NIPA solutions were irradiated at the same dose rate of about 4,1 kGy perhour with the dose ranging from 0.05 to 50 kGy. The conversion yield ofpolymerization was calculated by the obtained product after filteration of all residualmonomers as follow:

100(%)0

×=W

WConversion d (1)

where Wd and W0 are the weights of initial monomer in solution and dried product.

The irradiated PNIPAM was immerged in hot water at 60°C for a week toremove non-crosslinked PNIPAM polymer molecules and ratio of gelation wascalculated by the following equation:

100(%) ×=−d

g

W

WGGelation (2)

where Wd, Wg are the weights of dried product and remained hydrogel after extractingwith hot water.

About 0.5 g dried hydrogels were swollen in 200 mL distilled water to reach theequilibrium and degree of swelling was investigated with initial concentration ofmonomer and radiation doses from room temperature to 45°C. The swelling degree wascalculated by the weight of swollen water per initial gel as follow:

Swelling ratio 100)/( ×−

=g

gs

W

WWgg (3)

where Ws and Wg are the weights of swollen and initial hydrogel.


a. Conversion yield of PNIPAM and gelation degree of PNIPAM hydrogels onconcentration of NIPA monomer.

Table 1: The effects of NIPA concentration on polymerizationand gelation of PNIPAM

NIPA concentration(%)

Polymerizationdegree (%)

Gel Fraction(%)

5 74.57 92.29

10 87.43 95.26

15 87.58 96.24

20 86.10 96.97

VINATOM-AR 11--27


Table 1 showed conversion yield of radiation polymerization and crosslinkingfor gelation of PNIPAM with initial concentration of NIPA solutions, which irradiatedat the same radiation conditions. The results revealed the degree of polymerization andgelation increased with monomer concentration. The highest conversion reached to 87%for all NIPA solutions with concentration higher than 10%, whereas the gel fractionslightly increased with monomer concentration up to 20%. Some researchers reportedthat PNIPAM hydrogels can also form in higher concentrated solutions, even the solidstate of NIPA by irradiation with higher radiation dose. However, the higher dose wasnot expected for application, then we choose the monomer concentration of 10% assuitable solution for radiation polymerization.

b. Influence of radiation conditions on degree of radiation polymerizationand crosslinking of PNIPAM

Table 2: The effects of radiation doses on polymerizationand gelation of PNIPAM

Dose (kGy) Conversion yield (%) Gel fraction (%)

5 63.74 74.26

10 87.43 95.26

20 91.91 95.80

30 92.85 95.75

40 89.22 96.91

50 88.47 97.46

10% NIPA solutions were irradiated with different radiation dose forpolymerization and crosslinking. Table 2 showed the conversion yield of PNIPAMpolymerization and their gel fraction of crosslinked PNIPAM. It was found thatpolymerization and crosslinking increased with radiation dose. Relative high conversionof PNIPAM can be obtained with radiation dose of 5 kGy, then it slightly increased to20 kGy and seemed to be stable with higher radiation doses. It may be explained by thepolymerization rate increased with radiation time during irradiation. However, somepolymer chains may not crosslink in the network, but only entrap or tangle in thenetwork. As a result, these non-crosslinking chains were degraded into the shortpolymer segments, namely the polymerization degree of PNIPAM decreased with theincreasing of radiation dose.

VINATOM-AR 11--27


c. Gelation dose for 10% NIPA solution

As one can see from Figure 1, hydrogels were formed in the irradiated NIPA solutions,and a certain transparent gel can be observed with the solution irradiated at 200 Gy,namely, the radiation dose of 200 Gy is enough for gelation. Figure 2 shows thedependence of gel fraction on absorbed dose for 10% NIPA solution. Gelation dose (Dg)is about 178 Gy was determined by extrapolating the plot to the gel = 0 as mentioned byCharlesby [7]. Comparing this Dg with the doses for other polymers, it is rather low. Itmay be due to the free radicals formed by radiolysis of water. Oterga et al also reportedthat the presence of water, especially in the binary mixture of NIPA and crosslinker wasmuch decreased the Dg from 9.4 to 0.18 kGy for 10% NIPA solutions.

Figure 1: Aqueous solutions of NIPA irradiated with different radiation doses

Figure 2: Gelation of irradiated NIPA solution with radiation dose

0

20

40

60

80

100

0 .01 0 .1 1 10

Ge

l fr

act i

on

(%

)

Radiation dose (kGy)

VINATOM-AR 11--27


When the aqueous solution of monomer was irradiated, monomer radicals weregenerated by both direct and indirect effects of radiation. The total yield of reactiveintermediate species formed in radiolysis of water including of e-

aq, H*, OH* is about 6.

Some of those intermediates will form radicals on the monomer, while others willundergo recombination or other reactions. According to the literature, monomericradical is most probably responsible for the initiation of the polymerization andcrosslinking is the α-carboxyl alkyl radicals. And this radical could be formed both bydirect and indirect reactions with OH* radicals.

It also found that the radiation polymerization in solid state may be ionic, freeradical or both, but in aqueous solutions, the principal effect that distinguishes withsolid state is the diffusion phenomena. Such diffusion of reactants is several orders ofmagnitude slower in the solid phase than in aqueous phase.

d. Water swelling and thermal-sensitivity of crosslinked hydrogels

Swelling process of the crosslinked hydrogels was investigated withtemperature. The water swelling of the obtained hydrogels was indicated as functions ofthe medium temperature. Figure 3. showed the swelling degree of different hydrogelsprepared from 10% NIPA solutions irradiated with different radiation doses. At the lowtemperature, water swelling of all hydrogels ranging from 25 to 35 times of the driedhydrogels, but the swelling rapidly decreased and weights of the swollen hydrogelsgradually decreased to 40°C and did not decreased further with temperature to 45°C.

From these temperature-dependent swelling of PNIPAM hydrogels, we canestimate the phase transition temperature of the hydrogels around 31-32.5°C by the 50% reduction of swelling. It may be explained that, the hydrogen bonds formed betweenhydrophilic groups in polymer such as NH and C=O with surrounding water, strongerthan the free energy for exposure of hydrophobic isopropyl groups of the side chain towater at low temperature. As results, the hydrogels are in a highly swollen state at thetemperature under its lower critical solution temperature (LCST). Those hydrogen

Figure 3: Water swelling of PNIPAM hydrogels prepared from the 10% NIPAsolutions irradiated at different radiation dose with temperature

0

5

1 0

1 5

2 0

2 5

3 0

3 5

4 0

2 0 .0 2 5 .0 3 0 .0 3 5 .0 4 0 .0 4 5 .0 5 0 .0

T e m p e ra tu re (oC )

Sw

ellin

g ra

tio (t

imes

)

10 kG y

20 kG y30 kG y

40 kG y50 kG y

VINATOM-AR 11--27


bonds weakens, which leads to a reduction in the structuring of water around thehydrophobic groups when the temperature rises. At the same temperature, the swellingof hydrogels reduced with radiation doses because the crosslinking points somewhatoverlap.

IV. CONCLUSION

Different PNIPAM hydrogels without any chemical residues were successfullyprepared from aqueous solutions of NIPA monomer by radiation-inducedpolymerization and crosslinking of the growing polymers, simultaneously. Theconversion yield of polymerization and crosslinking degree for gelation depend oninitial NIPA concentration and radiation dose. The monomer solution of 10 % andradiation dose of 20 kGy were enough for preparing of the stable hydrogels.

Gelation dose is 178 Gy when irradiating of 10% NIPA solutions by the gammairradiator at Hanoi Irradiation Center. The obtained PNIPAM hydrogels are thermo-responsive with the shape phase transition at around 31-.32.5°C.

REFERENCES

[1]. Bhattacharyaa A, Misra BN. Progress Polymer Science, 29;767–814, 2004.

[2]. Kabanov VY. Radiation High Energy Chemistry, 34(4);203-211, 2000.

[3]. Melendez-Ortiz HI, Bucio E, Burillo G. Radiation Physics and Chemistry, 78;1-7,2009.

[4]. Ortega A, Bucio E, Burillo G. Polymer Bulletin, 58;565-573, 2007.

[5]. Quynh TM, Yoneyama M, Maki Y, Nagasawa N, Dobashi T. Key EngineeringMaterials, 459;51-56, 2011.

[6]. Nagaoka N, Safranj A, Yoshida M, Omichi H, Kubota H, Katakai R.Macromolecules, 26;7386-7388, 1993.

[7]. Charlesby A. Atomic Radiation and Polymers. Pergamon, Oxford, 1960.

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STUDY ON EFFECT OF IMMUNE STIMULATIONOF γ-RAY IRRADIATED CHITOSAN ON TILAPIA

Nguyen Ngoc Duy, Nguyen Quoc Hien and Dang Van Phu

Research and Development Center for Radiation Technology, VINATOMNo.48 Lang Ha, Dong Da, Hanoi, Vietnam

Abstract: Low molecular weight chitosan (LMWC) powder and oligochitosan solutionwere prepared by γ-irradiation method. The efficiency of the degradation process wasdemonstrated by gel permeation chromatography (GPC) analysis of the averagemolecular weight of degraded chitosan. Results showed that the molecular weightsdecreased with increasing doses. For LMWC molecular weight reduces from120,000Da to 40,000 Da when dose raises from 0 kGy to 50 kGy and oligochitosanreduces to 6100 Da at 20 kGy. Tilapia fish, which was fed with LMWC andoligochitosan 100 ppm for 45 days, was challenged with Streptococcus agalactiaebacteria to investigate immune response. The results also exhibited that oligochitosanhas effect of immune response higher than LMWC. The effect of variousconcentrations (50 ppm, 100 ppm, 150 ppm) was investigated. Results showed thatoligochitosan 100 ppm shows survival rate the highgest.

Keywords: Low molecular weight chitosan, oligochitosan, immune stimulation, gammairradiation.

I. INTRODUCTION

Overcrowding tends to adversely affect the health of cultured fish. Warm wateraquaculture in Asia has proplems with bacterial diseases such as molite aeromonadssepticaemia, furunculosis, columnaris, and edwardsiellosis. Among these, disease causeby Aeromonas hydrophila, Streptococcus agalactiae is most widespread in freswaterfish [1]. A. Hydrophila, Streptococcus agalactiae... with disease incarp, eels, milkfish,channel cat fish, tilapia and ayu and produces stress related diseases in salmonids withthe common symptoms of ulcerations, exophthalmia abdominal distension etc [2]. Theuse of antimicrobials for disease control and growth promotion in animals increases theselective pressure exrted on the microbial word and encourges the natural emergence ofbacterial resistance. Vaccination may be the most effective method of controlling fishdisease, even though disease caused by bacterial like A. Hydrophila has not beencontrolled by vaccination due to thier hetorogeneity. However , when applied to hatchcondition some immunization techniques are not as effective as they should be.








VINATOM-AR 11--28


Immunostimulants may represent an alternativeand a supplemental treatment tovaccination in the prevention of diseasesin aquatic animal.

Immunostimulant and immunomodulators comprise a group of biological andsynthetic compounds that enhance the nonspecific cellular and humoral defensemechanisms in mammals. These susstance, such as levamiso, β-glucan, peptidoglycan,chitin, chitosan yeast and vitamin combinations as well as various products derivedfrom plants and animals are effective in preventing disease[3,4]. Most of the research onimmunostimulants has been focused on the treatment of tumor in human and aniamal[5]. The basic for this approach in tumor therapy is the fact that natural or syntheticimmunostimulants active macrophages, neutrophils, natural ability to destroy tumorincrease resistance to viral, bacterial and fungal infection [ 6,7]

Chitin is a natural polymer found abundantly in the shells od crustaceans insects,and fungi. Chitin and its deacetylated product chitosan are commercially manufacturedfrom shells of shirmp and crab. Chitosan has many aplications inmedicine, agricultureand aquaculture. In aquaculture, it is used as an immunostimulant to protect salmonidagainst bacterial disease [8,9]. However, reported depressed growth in tilapia afterfeeding chitin and chitosan. The present study was undertaken to evaluate thecomparrative efficacy of chitin, chitosan and levamisol on enhancing nonspecificimmunity as well as thier effect on the immune response agianst Streptococcusagalactiae of talipia under field conditions

II. EXPERIMENTAL

II.1. Chemicals: Low molecular weight chitosan (LMWC) powder andoligochitosan solution were prepared by γ-irradiation method, pure water from Merck,Germany, Tilapia fishs were brought from a fish farm in Binh Duong province.Streptococcus agalactiae bacterial was isolated from diseased fish collected from localfish farm in Dong Thap province. Nutrient broth and nutrient agar from India.

II.2. Method

Preparation LMWC powder and oligosolution: Chitosan powder and chitosansolution 3% was irradiated on the gamma Co-60 irradiator STSVCo-60/B (Hungary),dose rate ~1.25 kGy/h at VINAGAMMA Center (HCM City) with dose from 0kGy to50kGy for chitosan powder and from 0 kGy to 20 kGy for chitosan solution.

Molecular weight and degree deacetylation: The Mw of degraded chitosan wasmeasured by an Agilent 1100 gel permeation chromatography (GPC) with detector RIG1362A and the columns ultrahydrogel model 250 and 500 from Waters (USA). Thestandards for calibration of the columns were pullulan. The eluent was aqueous solution0.25 M CH3COOH/0.25 M CH3COONa with the flow rate of 1.0 ml min-1 andtemperature at 30oC (Knaul et al., 1998). The chitosan sample concentration was ca.0.1% (w/v).

Effect of immune stimulation of LMWC and oligochitosan on tilapia: Tilapiafish, which was fed with LMWC and oligochitosan 100 ppm for 45 days, waschallenged with Streptococcus agalactiae bacteria to investigate immune response.Morality was recorded daily up to 21 days and relative percentage survival wascaculated.

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Effect of immune stimulation of oligochitosan with different concentrations ontilapia: Tilapia fish, which was fed with oligochitosan 50 ppm, 100 ppm, 150 ppm for45 days, was challenged with Streptococcus agalactiae bacteria to investigate immuneresponse. Morality was recorded daily up to 21 days and relative percentage survivalwas caculated.


III.1. Reductions of LMWC molecular with irradiation dose

Figure 1: Reductions of LMWC molecular with increase dose

The result of molecular weight (Mw) in Fig. 1 indicated that LMWC wasprepare very easily by γ-ray irradiated chitosan powder or flake. The molecular weightsdecreased with increasing doses. Molecular weight of LMWC reduces from 120,000 Dato 40,000Da when dose raises from 0 kGy to 50 kGy

Table 1: Mw, Mn and polydispersity index (PI, PI = Mw/Mn) of LMWC

Dose (kGy) 0 10 20 30 50

Mw 120,669 112,050 85,853 63,548 40,747

Mn 46,377 54,598 44,027 36,732 25,153

PI 2.60 2.22 1.95 1.73 1.62

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Results in Table 1 indicated that as the dose increased the PI decreased from 2.20to smaller values (~1.620). These results showed that the smaller the Mw ofoligochitosan the narrower the molecular weight distribution was attained for particulardose used. Similar results were already reported by Czechowska-Biskup et al. (2005) intheir study of γ ray degradation of chitosan [19].

III.2. Reductions of oligochitosan molecular with irradiation doses

Figure 2: The molecular weight (Mw) of chitosan versus treatmenttime with H2O2 and γ ray (dose rate: 1.14 kGy/h)

The synergic degradation effect of chitosan by H2O2 and γ ray was typicallystudied for 3% chitosan solution containing 0.5% H2O2 to prepare oligochitosan. Basedon the data in Fig. 2 and calculation formula of the synergic degradation effect throughthe percentage of Mw decrease as described in the previous paper (Hien et al., 2011),the results of the synergic degradation effect obtained were of 42.2% at 4 kGy (~3.5 h)and gradually decreasing to 22.6% at 8 kGy (~7 h), 9.4% at 12 kGy (~10.5 h).Accordingly, the synergic degradation effect was reduced with the increasing of dose.Oligochitosans with Mw from 5,000 to 10,000 and narrow molecular weightdistribution can be effectively prepared by γ-irradiation of 3% chitosan solution in thepresence of 0.25 – 1.0% H2O2 at low dose less than 10 kGy. Thus, γ-irradiation ofchitosan solution containing a small amount of H2O2 is feasible and potentiallyapplicable technique for production of oligochitosan on large scale.

103

104

105

106

0 4 8 12 16 20

Tia γ + 0,5% H2O2

Tia γ + 0,25% H2O2

0,5% H2O2Tia γ

Tia γ + 1,0% H2O2

Time (hour)

Mw

,Da

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Table 2: Mw and polydispersity index (PI, PI = Mw/Mn) of oligochitosan

Dose, kGy 4 8 12 20

γ-ray/0.25% H2O2

Mw 12,700 9,300 8,400 7,200

PI 1.67 1.51 1.47 1.39

γ-ray/0.5% H2O2

Mw 9,700 8,300 6,700 5,400

PI 1.95 1.70 1.63 1.42

γ-ray/1.0% H2O2

Mw 6,100 5,100 4,600 3,400

PI 2.05 1.82 1.77 1.54

*Mw0 = 110,000; Mw0/Mn0 = 2.26

Changes of Mw and polydispersity index of oligochitosans obtained fromdegrading chitosan by synergic effect (γ ray/H2O2) were also shown in Table 2. It isobvious from the results in Table 1 that as the dose increased the PI decreased from 2.26to smaller values (~1.50) for all three H2O2 concentrations. These results indicated thatthe smaller the Mw of oligochitosan the narrower the molecular weight distribution wasattained for particular H2O2 concentration used. Similar results were already reported byFeng et al. (2008) in their study of γ ray degradation of chitosan in solution (2%). ThePI of their original chitosan used was 7.32 (Mw 210 × 103) and decreased to 1.53 (Mw2.1 × 103) after irradiation at dose of 20 kGy

III.3. Result effect of immune stimulation of LMWC and oligochitosan

Table 3: The survival rate of tilapia after 21 days challenged withStreptococcus agalactiae bacterial of LMWC and oligochitosan compare with controlsample.

Iterms Control -1* Control-2** LMWC Oligochitosan

Survival rate

(%)***

90.00 ± 5.00a 46.67 ± 10.41cd 63.33 ± 10.41bc 73.33 ± 2.89ab

*Control-1: Without infected with Strep. Agalactide; **Control-2: infected withStreptococcus agalactiae; ***Means values followed by the same letter within a columnare not statistically different according to a Duncan’s multiple range test at P < 0.05.

After challenge with Strep.agalactide bacterial, the relative percentage survivalof fish fed with LMWC 100 ppm and oligochitosan 100 ppm supplemented feed washigher than the control-2 fish. The results of the present study clearly that LMWC andoligochitosan supplementation enhanced the nonspecific immune system of talipia fish.Results in table The 3 indicated that survival rate of fish fed with oligochitosan washigher than fish fed with LMWC. This may be due to the oligochitosan has molecularweight smaller than LMWC.

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III.4. Result effect of immune stimulation of oligochitosan with differentconcentrations.

Table 4: Survival rate of tilapia after 21 days challenge with Streptococcusagalactiae bacterial of oligochitosan at concentrations of 50, 100 and 150 ppm comparewith control sample

Iterms Control -1 Control-2 Oligo-50 Oligo-100 Oligo-150

Survivalrate (%)

88.33 ±2.89a

43.33 ±10.41d

61.67 ±2.89bc

76,67 ±2.89ab

75.00 ±10.00ab

Means values followed by the same letter within a column are not statisticallydifferent according to a Duncan’s multiple range test at P < 0.05.

The effect of oligochitosan concentration has also been studied for the immunestimulation of talipia fish. Results table 4 also exhibited that the fishes fed witholigochitosan at concentration 50 ppm has effect the immune stimulation lowest in allsamples. The immune stimulation raise with increasing oligochitosan concentration.However, the fish fed with oligochitosan at concentration 100 ppm has survival ratehigher than the fish fed with oligochitosan at concentration 150 ppm. This result showedthat oligochitosan at 100 ppm was the best concentration to used as immunostimulant.

III.5. Result effect immune stimulation of oligochitosan at 100 ppmconcentration on farm

Table 5: Survival rate of tilapia after 21 days challenge with Streptococcusagalactiae bacterial of oligochitosan at concentrations of 100 ppm on farm

Iterms Control-1 Control-2 Oligochtisan

Sulvival rate (%) 6.67 ± 5.77a 60.00 ± 10.00c 23.33 ± 5.77 ab

Means values followed by the same letter within a column are not statisticallydifferent according to a Duncan’s multiple range test at P < 0.05.

Results in table 5 showed that the immune stimulation of oligochitosan at 100ppm concentration on farm was the same immune stimulation of oligochitosan at 100ppm concentration with small fish. Base on this result it is evident that oligochitosancan use as immunostimulant in aquaculture and has potential use in fish farming.

IV. CONCLUSIONS

LMWC powder has molcular weight about 40,000-60,000 was prepared by γ-irradiated at dose from 30 kGy to 50 kGy. Oligochitoan solution has molercular weight5,000-7,000 was prepared by γ-irradiated chitosan solution at 12 kGy dose. The effectimmune response of LWMC and oligochitosan was investigated. The results alsoexhibited that oligochitosan has effect of immune stimulation higher than LMWC. Theeffect of various concentrations (50 ppm, 100 ppm, 150 ppm) was studies. Resultsshowed that oligochitosan 100 ppm shows survival rate the highest.

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REFERENCES

[1]. Karunasagar et al., Immunological response of the Indian major carps toAoremonas hydrophila vaccine, Journal of fish Diseases, 14, pp. 93-97, 1985.

[2]. Amin, N.E et al., Motile Aoremonas septicaemia among Tilipia nilotica(Sarotherodon niloticus) in upper Egypt. Fish Pathology, 20, pp.93-97, 1985.

[3]. Baulny, M.O.D et al., Effect of long term oral administration of β-glucan as inimmunostimulant or an an adjiuvant on some non-specific parameters of the immune responseof turbot Scophthlmus maximus. Diseases of Aquatic Organisms, 26, pp.139-147, 1996.

[4]. Mulero, V et al., Dietary intake of levamisol enhances the immune response anddisease resistance of the marine teleost gilthead seabream (Sparus aurata L). Fish and ShellfishImmunology, 8, pp.49-62, 1998.

[5]. Verlhac, V et al., Immunomodulation by dietary vitamin C and glucan in rianbowtrout Oncorhynchus mykiss. Fish and Shellfish Immunology, 8, pp.409-424, 1998.

[6]. Nishmura, K et al., Immunological activity of chitin and its derivaties. Vaccine 2,pp.93-98, 1984.

[7]. Azuma, I et al., Development of immunostimulants in Japan. In: ImmunostimulantsNow and Tomorrow, jpn. Soc. Press. Tokyo, Springer verlag, Berlin, pp.41-46, 1987.

[8]. Suzuki, K et al., Protecting effect of chitin and chitosan experimentally inducedmurine candidiasis. Microbiology and Immunology, 28, pp.903-912, 1984.

[9]. Anderson, D.P et al., Duration of protection against Aromonas salmonicida inbrook trout immunostimulated with glucan or chitosan by injection or immersion. ProgessiveFish Culturist, 56, pp. 258-261, 1994.

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STUDYING ON PREPARATION OF SUPER WATER ABSORBINGMATERIALS BY RADIATION MODIFICATION TECHNIQUES

USING BENTONITE AND WATER SOLUBLE MONOMER

Le Hai, Nguyen Tan Man, Tran Thi Thuy, Nguyen Trong Hoanh Phong,Nguyen Tuong Ly Lan, Le Van Toan, Le Thi Tho and Tran Thi Dao

Radiation Technology Department, Nuclear Research Institute,VINATOMNo.1 Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: Research on preparing water super absorbent materials using Di Linh’sbentonite and water soluble acrylic monomer has been carried out by gamma radiationgrafting /and crosslinking techniques. The research results showed that gel formeddepends on the absorbed dose and the concentration of bentonite used, and not affectedby the cleanliness of them. In the dose range studied, water swelling content reached579 g.g-1 with swelling rate of 20 g.g-1.min-1, in salting solution water absorptioncapacity decreased very much in particular at high concentrations. In salting media, thewater absorption capacity of studied product depends on the type of salt in order asfollows NaCl<FeSO4<Cu(NO3)2< SC(NH2)2. Absorption capacity of the polymer alsodepends on pH, particle size and drying temperature. The effect of water retention insandy soil, the spectral characteristics XRD, FT-IR were also studied.

I. INTRODUCTION

Research and application of water super absorbent materials which have beenprepared from the natural ingredients is a path has been more attention to developingcountries, the focus of many research laboratories in many countries, particularly thatthe countries in the Asia – Pacific Region. Water super absorbent polymer materialshave been studied and widely applied since 1960, and recently they have beenpowerfully developed. Water super absorbent materials have been efficiently applied insome industries, particularly in the high-tech agriculture field and environmentalremediation.

Super absorbent polymer material was prepared from the synthetic monomer,polymer which was studied very much, but water super absorbent composite polymerfrom bentonite mineral very limited while the mineral resource is very popular variableand abundant in Vietnam. In order to enhance the utilizing value and expand theapplication scope of bentonite mineral in the country, the subject on “Research onpreparing the water super absorbent material by gamma radiation modificationtechniques using bentonite and water soluble monomer” has been implemented





- Contact Email: : [email protected]/ or [email protected]




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II. EXPERIMENTAL

II.1. Equipment and apparatus

- Gamma irradiator: GC 5000 (India), 5kCi

- Mechanical stirrer KIKA (Germany), magnetic stirrer (Japan)

II.2. Materials and Chemical

- Raw bentonite material supplied by Hiep Phu Company (Di Linh – Lam Dong)

- Acrylic acid (Japan), Carboxymethyl cellulose (China)

Other chemicals are PA grade, and used directly without further purification.

II.3. Preparation of super water absorbing materials

- Preparation of solution for irradiation: concentration range of bentoniteused for study from 4 to 12 %, they were mixed in double distilled water to create liquidbentonite suspensions. (Distilled water volume changes in the amount of bentonite to bemixed solution of 28 % suspension). Stir the mixture solution of 20 % acrylic acid,distilled water (10 mL) and CMC (2 %) for 15 minutes to get a homogeneous solution,pour 30 ml 25 % NaOH solution. After 15 minutes, the solution to the bentonite slurrymixture, stirring for 45 minutes to obtain a homogeneous mixture.

- Irradiation of samples: Mixture solution was packaged in PE bags andirradiated on gamma radiation Co-60 source at dose rate 4.6 kGy/h with various doses:7, 10, 20, 30, 40 and 60 kGy

- After irradiation, samples were soaked in 70 % ethanol for 24 h, then rinsedtwo times in 98 % ethanol, each for 30 minutes. Finally, gel samples were cut into smallpieces, dried at 600C to constant weight. Weigh the dry gel volume to determine theamount of gel by the following method: sample leaching with water for 72 hours atroom temperature to remove homopolymer, reaction additives, the monomer did notreact [11], drying the insoluble to constant weight to determine the amount of gel.Calculate the volume variation method [8] and based on the formula [5, 6, 12] as follows

0

% 100tg

mW

m= ×

Where: Ms – gel weight after swelling at t time, Mo - initial dry gel weight.

II.4. Characteristics and properties of product

II.4.1. Swelling ratio of gel

Swelling ratio of gel was determined by the gravimetric method [7-9]. The driedgel samples were immersed in double distilled water, at room temperature for 72 hrs,remove excess water on the sample surface by tissue paper. The swelling ratio wascalculated base on formula of research works [1-4, 7, 9, 10].

II.4.2. Determine the capacity and speed of the gel absorbs water

Water absorption capacity (Water Absorption Capacity - WAC) of the gel isdetermined by soaking dried gel in distilled water at room temperature. Then, the gelsamples were weighed periodically at different time intervals (using a paper towel toremove excess water on the surface of gel) [4,7,8].

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II.4.3. Infrared absorption spectrum (IR)

The samples were measured on Jasco FT-IR spectrum IR 4100, in the regionfrom 400 ÷ 4000 cm-1, the Department of Chemistry of Natural Products – Tay NguyenInstitute of Biology.

II.4.4. X-ray diffraction (XRD)

The samples were measured on X 'X-ray Diffract meter PertPro its Analytical,the Netherlands; Target 45 kV - 40 mA, 250C, CuKα-ray tube, scan angle 2θ between0.5 ÷ 400 changes, the speed of 0.010 /s, VINAGAMMA.

II.4.5. Determination of water retention of polymer in sandy soil

Mixture of sand and polymer materials with accurate mass contained in plasticbottles 2L, empty bed covered by nickel mesh size small enough to keep sand andpolymer samples. These bottles were soaked in water for 24 hrs, and weigh in certaintime.

II.4.6. The effect of pH and metal ion salts

pH range studied 4, 5, 6, 7, 8 and 9 adjusted by NaOH and HCl. The saltsexamined include: SC(NH2)2, Cu(NO3)2.3H2O, (NH4)2Fe (SO4)2.6H2O and NaCl.

II.4.7. The effect of particle size and drying temperature

The temperature range examined 30, 50, 70 and 100°C and particle size 0.5, 1.0and 2.0 mm.

III. RESULTS & DISCUSSION

III.1. Effect of bentonite/Acrylic acid on gel forming

Research results on the influence of bentonite/ acrylic acid ratio onto forminggel of processed and refined bentonite is presented on Figure 1 (a & b). The resultsshowed that gel formation increases with the increase of absorbed dose, and at higherconcentration of bentonite gel formed as much in the concentration range studied. Inboth cases gel content are not different.

Figure 1: (a&b). Dependence of gel content vs. absorbed dose.a(Left)- processed bentonite ,b(Right)- refined bentonite

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III.2. Characteristics and water absorption behavior of composite polymer

III.2.1. Water absorption capacity and speed of polymer composite

The water absorption behavior of composite polymer of bentonite is indicated inFigure 2 (a & b). For processed bentonite, water absorption capacity achieved 504times after immersion for 72 hours, it is lower than ~ 15% compared with refinedbentonite it reached 579 times at the same period of time soaking conditions andguidelines. In the studied bentonite concentration range showed polymer compositeproducts with bentonite concentration of 6% for the results of water absorption capacityof the highest.

Figure 2: (a&b). Water absorption capacity with soaking time.a(Left)- Processed Bentonite, b(Right)- Refined Bentonite

III.2.2. Water swelling at saturation state

Survey results of water absorption capacity at the saturation state of the studiedpolymer products are shown in Fig. 3a for processing bentonite and refined bentonite inFig. 3b. For the case using processed bentonite, the absorption capacity of watersignificantly reduced from 20 to 40% when irradiation dose increases. Whereas in caseof refined bentonite, WAC of the polymer decreased less, spend ~ 25% maximum.

Figure 3:(a&b). Water swelling at saturation state wit irradiation dose.a(Left)- Processed bentonite, b(Right)- Refined bentonite

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III.2.3. Effect of pH and salt

Effect of pH and salt solution such as SC(NH2)2; Cu(NO3)2; FeSO4 and NaClon water absorption capacity of the polymer composite is presented in Figure 4 (a & b).Water absorption capacity increased as pH increased, and increased rapidly in the pHrange from 4 -7. So Polymer absorb water so well in alkaline medium. Water absorptioncapacity of the studied polymer significantly reduced with studied salts in special forsalt solutions at high concentration.

Effects of salt reduces the WAC of polymer products can be arranged insequence as follows SC(NH2)2 > Cu(NO3)2 > FeSO4 > NaCl

Figure 4: (a&b). Water absorption capacity with soaking timea(Left)- Effect of pH, b(Right)- Effect of salts.

III.2.4. Effect of particle size and drying temperature

Figure 5: (a&b). WAC with drying temperature (Left)and particle size (Right)

Affect the drying temperature and particle size on water swelling properties ofthe polymer is shown in Figure 5 (a & b). The results recorded on the graph shows theabsorption capacity of the polymer decrease as drying temperature increases at a

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temperature of 50° C (280.9 times) and 100° C (266 times). In the studied range of theparticle size 0.5, 1.0 and 2.0 mm of the swelling ratio of polymer with particle sizes infollowing order 0.5> 1.0> 2.0 for the polymer of particle size 0, 5 mm reachedsaturation swelling value after 60 minutes while it reached 1.0 mm polymer particlessaturated it takes 120 minutes and 480 minutes for the polymer size 2.0 mm. Thus,polymer particles size stretcher its account higher speed and reach saturation point soon,but saturation swelling degree does not change.

III.2.5. Water retention of polymer in sandy soil

Results presented in Fig. 6. that the experimental results showed that watercontent in soil decreases with storage time. When sandy soil contains without polymer,water content is almost completely loss after 20 days. Meanwhile for sandy soilcontained 0.1% polymer after 60 days to dry completely and water remaining below30% for 0.7% polymer used. Thus, in the case of using the super absorbent polymer inorder to improve the moisture stability of sandy soil 0.7% polymer should be used.

Figure 6: The water retention of polymer in sandy soil

III.2.6. The structural characteristics of bentonite and their modified products

Figure 7: (a&b). a(Left) IR spectra of processed and refined bentonite, b(Right) IRSpectra of their modified products

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Figure 8: (a&b). XRD spectra processed bentonitea (Left) Before radiation modification b (Right) After radiation modification

Figure 9: (a&b). XRD spectra refined bentonitea (Left) Before radiation modification b (Right) After radiation modification

IV. CONCLUSIONS

1. The conditions to prepare water super polymer composite materials base onDi Linh’s bentonite with acrylic monomer have been surveyed. Concentration ofbentonite should be not exceed 12%, and the optimal concentration is 6%.

2. Water swelling at saturation state (qw) and water absorption capacity ofpolymer composite products essentially depend on the concentration of bentonite andirradiation dose.

3. The conditions to prepare water super polymer composite base on Di Linh’sbentonite and acrylic acid have been surveyed.

4. The process for manufacturing water super polymer composite by gammaradiation modification techniques has been established on base of Di Linh’s bentoniteand acrylic monomer. Water swelling degree products achieved 579 g.g-1, atconcentration of bentonite of 6% and 10 kGy.

5. The parameters affected to the water absorption behavior of polymercomposite products such as pH; salts of metal ions; drying temperature, particle size andwater release of polymer composite in sandy soil have been completely evaluated.

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REFERENCES

[1]. Ali Pourjavadi, Rouhollah Soleyman, Hossein Ghasemzadeh, and Hamid Salimi,CMC/Celite Superabsorbent Composites: Effect of Reaction Variables on Saline-absorbencyunder Load, 2010.

[2]. Baojun Bai, Liangxiong Li, Yuzhang Liu, He Liu, Zhongguo Wang andChunmeiYou, Preformed Particle Gel for Conformance Control: Factors Affecting Its Properties andApplications, 2007.

[3]. Montes-H G., Swelling–shrinkage Measurements of Bentonite Using CoupledEnvironmental Scanning Electron Microscopy and Digital Image Analysis, Journal of Colloidand Interface Science 284 (2005) 271–277.

[4]. Javad Alaei, Saeid Hasan Boroojerdi & Zahra Rabiei, Application Of Hydrogels InDrying Operation, Petroleum & Coal 47 (3), 32-37 2005.

[5]. Lim Jian Wei, Development of Layered Silicates Montmorillonite Filled Rubber-toughened Polypropylene Nanocomposites (RTPPNC), 2006.

[6]. Gueddouda M.K., Md.Lamara, Nabil Aboubaker, Said Taibi, HydraulicConductivity and Shear Strength of Dune Sand–Bentonite Mixtures, Vol. 13, Bund. H.

[7]. Mohammad Reza Saboktakin, Abel Maharramov, Mohammad Ali Ramazanov,Modification of Carboxymethyl Starch as Nano Carriers for Oral Drug Delivery, Nature andScience, 5(3), 2007.

[8]. Dafader N. C, M. N. Adnan, M. E. Haque, D. Huq and F. Akhtar, Study on TheProperties of Copolymer Hydrogel Obtained from Acrylamide/2-hydroxyethyl methacrylate byThe Application of Gamma Radiation, 2011.

[9]. Oguz Okay and Wilhelm Oppermann, Polyacrylamide-Clay NanocompositeHydrogels: Rheological and Light Scattering Characterization, 2007.

[10]. Lanthong p., R. Nuisin, S. Kiatkamjornwong, Graft Copolymerization,Characterization, and Degradation of Cassava Starch-g-acrylamide/itaconic AcidSuperabsorbents, 2006.

[11]. Shaghayegh Jafari and Hamid Modarress, A Study on Swelling and ComplexFormation of Acrylic Acid and Methacrylic Acid Hydrogels with Polyethylene glycol, 2005.

[12]. Wael Sabry Mohamed, Applications of Nanotechnology in The Polymer andTextile Fields, Universität Stuttgart Institut für Polymerchemie, 2009.

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RADIATION SYNTHESIS AND APPLICATION OF ABSORBENTHYDROGELS TO ENHANCE THE QUALITY OF BASADIESEL

Nguyen Duy Hang, Pham Thi Le Ha, Tran Thi Thuy, Le Hai, Nguyen Tan Man,Le Huu Tu, Nguyen Trong Hoanh Phong, Tran Thi Tam and Tran Thu Hong,

Pham Thi Sam and Nguyen Tuong Li Lan

Radiation Technology Department, Nuclear Research Institute,VINATOMNo.1 Nguyen Tu Luc, Da Lat, Lam Dong, Vietnam

Abstract: Studying on the using ability of radiation synthesis hydrogels to enhance thequality of the biodiesel produced from Basa fish oil was implemented. Radiationsynthesis of absorbent hydrogels and their application to removal of contaminants frombiodiesel produced from fish oil were the major problems. The preparation of the superabsorbent hydrogel obtained by radiation induced cross linking of polyacrylamide andpolyacrylic was investigated and its application in removal of water, catalyst from thebasadiesel emulsion is reported. The hydrogels were characterized in terms of gelcontent, swelling, character of water and mineral catalyst removal were studied. Theeffect of temperature, NaOH and KOH content of solution on the swelling degree ofhydrogels was also determined. The results showed that the gel fraction ofPAAm/PAAc hydrogel with PAAm/AAc (1/4) ratio and dose of 20kGy was used tosynthesized the Gel of A-311. Studies also made on the application of Gel A-311during the refining process in Basadiesel industry.

INTRODUCTION

Biodiesel is produced by chemically reacting vegetable based oil, animal fat, orwaste cooking oils with an alcohol (usually methanol), using either sodium or potassiumhydroxide as a catalyst (Hamet M.El-Mashad et al 2008). Removal of contaminantsfrom biodiesel products during the refining process in biofuel industries is one of themajor problems. In the conventional refining process of biodiesel, water is used toremove the contaminants from biodiesel (Cherng et al 2009). The contaminants of thecrude biodiesel mainly are free fatty acids, glycerin, water and catalysts. The use ofhydrogel products is finding widened applications in various fields. Water superabsorbent hydrogels for agriculture (A.I. Raafat 2010), hydrogels as agrochemicals(H.L.Abd El-Mohdy 2007), hydrogels for metal adsorption (Hiroki et al 2009) fromindustrial effluents and great potential as flocculent ( Nanakon et al 2010), controlleddrug delivery devices (Zou et al 2005) are the highlighted uses. The absorbent material








VINATOM-AR 11--30


synthesized by radiation is used to remove the contaminants from the basadiesel toreplace the use of water in the refining process. In this paper, the preparation of thesuper absorbent hydrogel obtained by radiation induced cross linking of polyacrylamideand poly acrylic was investigated and its application in removal of water, catalyst fromthe crude basadiesel emulsion is implemented.

I. EXPERIMENTAL

I.1. Materials

Polyacrylamide (PAAm) was purchased from BASF Co. Ltd., Germany wasused as received. Acid Acrylic (AAc), NaOH, KOH were used in this experimentalswere of grade from China. The basafish oils were purchased from Minh Tu Co.Ltd.,Viet Nam.

I.2. Radiation preparation of PAAm/PAAc hydrogels

PAAm solution (5%; 5g in 100ml distilled water) were dissolved and mixedwith various amounts of AAc and then exposed to gamma ray from 60Co source. Thegels formed were cut into small pieces, dried at 50oC temperature and stored in sealedcontainer.

I.3. Gel fraction

The prepared hydrogels were soaked in water for 48h at 98±2oC. Then, theywere taken out and washed with hot water to remove the soluble parts, dried andweighed. Gel percent was determined from equation:

Gel(%) = (W1/Wo)100

Where W1 and Wo are dry hydrogel weights after and before extraction,respectively.

I.4. Swelling measurement

Hydrogels, dried in oven at 50oC, of known weights were immersed in distilledwater at 23±2oC until each swelling time was reached. The gel was removed, blottedquickly with the absorbent paper, and then weighed. The following equation was usedto determined water uptake.

Swelling = (We-Wd)/Wd

Where We and Wd represent the weights of wet and dry gel films, respectively.

I.5. Application of hydrogel in removal of the contaminants from basadieselemulsion

To study the removal of water, catalysts from basadiesel emulsion, the gels wereblended into biodiesel as a powder. The mixture is then agitated at the requiredtemperature for a period of time necessary to allow the contaminants such as water andcatalysts to be adsorbed by the hydrogel. The mixture is filtered to remove the spenthydrogel. The basadiesel mixture was collected and evaluated the characterizations ofbasadiesel. Some technical parameters such as density, total glycerin, kali element,water in basadiesel were determined.

VINATOM-AR 11--30


0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

3 12 24 48 72 96 120

Time (h)

Swel

ling

(g.H

2O/g

.gel

)

1/1 1/2 1/4

1/6 3/1

0

20

40

60

80

100

120

140

160

3 12 24 48 72

Time (h)

Sw

ellin

g (g

.H2O

/g.g

el)

10 kGy

15 kGy

20 kGy

30 kGy


II.1. Influence of PAAm/AAc compound ratio on the swelling of hydrogelsas gamma irradiated

Figure 1. shown that the swelling behavior of the PAAm/PAAc hydrogels wasstudied by varying PAM/AAc composition in the mixture. The swelling degreedecreases with increasing both AAc content in mixture. The results can be explained bythe fact that increasing content of the AAc monomer in the mixture will result in agreater of cross-linked PAM and PAAc chains in the hydrogel network which reducethe degree of swelling.

II.2. Influence of various PAAm/AAc ratio on the gel formation ofhydrogels as gamma irradiated

The effect of various PAAm/AAc compositions on the gel(%) of PAAm/PAAchydrogels with irradiation dose of 20 kGy was investigated and shown in Tab.1. It isshown that the gel content and cross linking of PAAm/PAAc hydrogel increase withincreasing of AAc content in the blend solution as gamma irradiated. The gel content ofprepared hydrogels increase to reach at value ranged from 84.94% to 98.21% of 1/1;1/2; 1/4 and 1/6 PAAm/AAc ratio.

Figure 1: Swelling of PAM/PAAc hydrogels prepared at irradiationdose of 20kGy with various PAM/AAc component ratio

Figure 2: Swelling of PAM/PAAc hydrogels preparedat various irradiation dose with PAM/AAc (1/4) component ratio

VINATOM-AR 11--30


II.3. Influence of various radiation dose on the gel formation and theswelling behavior of PAAm/AAc (1/4) hydrogels as gamma irradiated

Table 1: Influence of various PAAm/AAc (P/A) ratioon the gel formation gamma-irradiated with dose of 20kGy

Figure 3: Gel (%) of PAM/PAAc hydrogels prepared at differentirradiation doses with PAM/AAc (1/4) composition

The swelling behavior and the gel formation of the PAAm/PAAc hydrogels withPAAM/AAc (1/4) composition in the mixture and various irradiation doses of 10, 15, 20and 30 kGy were studied. The results are presented in Fig.2 which shown that theswelling behavior of the PAAm/PAAc hydrogels with 1/4 ratio as irradiated withvarious radiation doses decreases with increasing irradiation doses.

The swelling dgree of hydrogel, at dose of 10kGy; 15kGy; 20kGy; and 30kGy,is 98.30, 71.62, 67.92 and 52.8 (g.water/g.gel), respectively after immerging in distilledwater during 24 hours. The effect on gel (%) of PAAm/PAAc hydrogel with 1/4component ratio was investigated and shown in Fig.3. The gel content of PAAm/PAAchydrogel increases with increasing the irradiation doses.

The compound ratio (P/A) (%) Gel

3/1 82.89 ± 0.89

1/6 98.21 ± 0.21

1/4 98.17 ± 0.37

1/2 90.29 ± 0.42

1/1 84.94 ± 0.68

1/0 82.87 ± 0.75

% g

el

84

86

88

90

92

94

96

98

100

10 15 20 30 kGy

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II.4. Evaluating the performance of water removal of PAAm/PAAchydrogel from basadiesel emulsion

Removal of water from biodiesel products during the refining process inbiodiesel industry is one of the major problems of this study.

The results are presented in Tab.2. which shown that PAAm/PAAc hydrogelsabsorb effectively water from basadiesel emulsion.

Table 2: The performance of water removal from basadieselemulsion by PAAm/PAAc hydrogel

Temperature of treatment (oC)

H2O (% in v/v, ml H2O /100ml Basadiesel)

Before treatment After treatment

20 10.00 0.00

35 10.00 0.00

60 10.00 0.00

Water in basadiesel-water emulsion at temperature of 20; 30 and 60oC isabsorbed by this hydrogel. The results shown that at temperature of 30 and 60oC wateris absorbed from basadiesel faster than at 20oC temperature.

II.5. Application of PAAm/PAAc hydrogel in removal of the contaminantsfrom basadiesel emulsion

Table 3: Characterization of biodiesel from Basafish oilrefined by PAAm/PAAc hydrogel

ParametersAnalytic results

Basadiesel untreated gel Basadiesel treated gel

Density at 15oC (g/cm3 ) 0.88 0.83

Water (%) 1.68 Undetected

Kali (mg/100ml) 38.00 Undetected

Total glycerin (%) 0.339 0.017

Acid value(mgKOH/g.basadiesel)

0.36 0.38

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In this study the water and catalysts were absorbed from basadiesel emulsion,the gels were blended into biodiesel as a powder. The mixture is then agitated at therequired temperature for a period of time necessary to allow the contaminants such aswater and catalysts to be adsorbed by the hydrogel. The mixture is filtered to removethe spent hydrogel. The basadiesel mixture was collected and evaluated the quality.Some technical parameters such as density, total glycerin, kali element, water inbasadiesel were determined. Results are shown in Tab.3.

III. CONCLUSIONS

The preparation of the super absorbent hydrogel obtained by radiation inducedcross linking of polyacrylamide and polyacrylic was investigated and its application inremoval of water, catalyst from the crude basadiesel emulsion is proved. This studyshows that it is feasible to apply this super absorbent hydrogel during the refiningprocess in the basadiesel industry.

REFERENCES

[1]. Abd El-Mohdy, H.L.Water sorption behavior of CMC/PAM hydrogels preparedby γ-irradiation and release of potassium nitrate as agrochemical. Reactive and FunctionalPolymer 67, 1094-1102, 2007.

[2]. Cherng-Yuang Lin, Rong-Li Li. Fuel properties of biodiesel produced from thecrude fish oil from soap stock of marine fish. Fuel Processing Technology 90, 130-136, 2009.

[3]. Hiroki, A., Tran, H.T., Nagasawa, N., Yahi, T., Tamada, M. Metal adsorption ofcarboxymethylcellulose/Carboxymethylchitosan blend hydrogels prepared by gammairradiation. Rad. Phys. and Che. 78, 1076-1080, 2009.

[4]. Hamed M. El-Mashad, Ruihong Zhang, Roberto J. Avena. A two-step process forbiodiesel production from salmon oil. Biosystems Engineering 99,220-227, 2008.

[5]. Nappakundilograt, S., Nanakon, P. Synthesis of acrylamide/acrylic acid-basedaluminum flocculent for dye reduction and textile waste under treatment. Polymer Engineeringof Science 50, 2010.

[6]. Raafat, A.I., Eid, M., El-Arnaouty, M.B. Radiation synthesis of super absorbentCMC based hydrogels for agriculture applications. Int. Nucl. Inf. System (INIS) 01-01, 2010.

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STUDY ON THE IMMOBILIZATION OF SILVERNANOPARTICLES ONTO THE ACRYLIC-GRAFTEDPOLYETHYLENE NONWOVEN FABRIC BY GAMMA

RADIATION FOR WATER TREATMENT

Dang Van Phu, Vo Thi Kim Lang, Nguyen Thi Kim Lan,Nguyen Tue Anh and Nguyen Quoc Hien

Research and Development Center for Radiation Technology, VINATOMLinh Xuan, Thu Duc, Ho Chi Minh, Vietnam

Abstract: The AgNPs ~10 nm immobilized PE nonwoven fabric was prepared bysoaking acrylic-grafted PE synthesized by pre-irradiation process into the colloidalAgNPs/PVA solutions. The effect of dose and acrylic acid concentration on the graftingdegree (%PAAc) was investigated. The dose of about 20 – 30 kGy, acrylicconcentration of 20 - 30%, and the reaction time of about 2 hrs at ~900C were suitablefor modifying PE. The content of AgNPs immobilizing on PAAc-g-PE was dependenton %PAAc. The results of water swelling degrees, IR spectra, XRD patterns, ICP-AESanalyses and SEM images indicated that PAAc has been grafted on PE and AgNPsimmobilized onto PE fabric. The release level of silver into water filtrate determined byICP-MS was less than 0.1 ppm. The PAAc-g-PE contained 7,000 – 8,000 ppm ofAgNPs exhibited high antimicrobial activity against E.coli in water, namely thebactericide effect was more than 99% for shaking with suspension of about 106 CFU/mland reduced to 1 – 2 log of E.coli in filtrate from water containing about 105 CFU/ml.The PAAc-g-PE/AgNPs provided vigorously antimicrobial activity that can bepotentially applied for water and/or air treatment.

I. INTRODUCTION

The presence of toxic metals and pathogenetic microbes in drinking water is apotential health risk. According to WHO, at least one billion people in the worldwide donot have access to clean, potable water sources [1]. Therefore, the development ofinnovative drinking water quality control strategies is of the utmost importance.Recently, considerable interest has arisen in the use of silver nanoparticles (AgNPs)based on high antimicrobial and biofouling improvement for water disinfection [2]. Inparticularly, the formation of by-products into water by conventional treatmenttechniques and the increasing of resistance of some pathogens to conventionaldisinfectants have encouraged researchers to explore the antimicrobial activity of








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AgNPs [3]. The reliability and ease of operation of membrane-based water filtrationsystems such as PU foam [4], PSf [5], paper [1], porous ceramic [6], PP/PE nonwovenfabrics have led to its enlarging use in water treatment. However, the most of theireffect on antimicrobial activity and/or biofouling resistance were being ineffectiveduring water filtration. Consequently, the numerous investigations have been carried outon the functional polymer membrane with AgNPs as an effectively antimicrobial agentfor water treatment [4]. Unfortunately, the AgNPs were commonly inert with polymersurfaces [7], so that it’s releasing into water filtrate with overdoses to permitted limit,according to the EPA and WHO standard at maximum 0.1 mg/L [5]. Several approacheswere studied to improve on loading and holding abilities of AgNPs onto polymer filters,mainly the using a binder or coupler and surface modification by appropriate monomerscontaining functional groups which have affinity with AgNPs [6, 7]. In this study, wepresented a new method to immobilizing AgNPs onto the acrylic-grafted PE nonwovenfabric by gamma Co-60 irradiation for drinking water treatment. The advantage of thistechnique is not only to improve the stability of AgNPs on PE fabric but also toameliorate the effect of microbes elimination from water sources. Additionally, thisfilter origin PAAc-g-PE/AgNPs can be further utilized for air treatment.

II. EXPERIMENTAL

II.1. Materials and chemicals: The PE nonwoven fabrics with the density 6.4mg/cm2 and the thickness 0.35 mm were obtained from Japan. The colloids of AgNPs~10 nm stabilized in PVA solution were prepared by gamma radiation-inducedreduction of Ag+ solution as presented in previously reports by our group. The pureacrylic, acetone and Mohr’s salt were purchased from Shanghai Chemical Co., Chinaand all used as received. The Luria-Bertani medium and agar plates used for bacteriaincubation were purchased from Himedia, India. The Escherichia coli ATCC 6538 wasprovided by Univer. Medic. Pharmacy, Ho Chi Minh City and propagated and preservedat biology laboratory, VINAGAMMA, Ho Chi Minh City.

II.2. Method

II.2.1. Preparation of acrylic grafted pre-irradiated PE nonwoven fabric (PE)and impregnated with AgNPs: The PE pieces cutted into (5×5 cm) were treated by amixture of acetone/H2O solution and dried before irradiation. The PE was irradiated tothe required doses (10-50 kGy) by γ-ray under atmosphere at a dose rate ~1.2 kGy/h,VINAGAMMA center. Thereafter, the graft reactions were carried out at ~900C in aflash containing 100 ml of 1 g pre-irradiated PE and 0.05% Mohr’s, and acrylic withconcentrations of 10 – 50%, H2O as a solvent. After a pre-determined period, the PAAc-g-PE were taken out from grafting solution, washed three times with hot water toremove the homopolymer and residual monomer [8]. The PAAc-g-PE with differentamounts of grafted polyacrylic (PAAc) was soaked for overnight at room temperature inthe AgNPs colloidal dispersions contained 100 to 1.000 ppm of AgNPs. The PAAc-g-PE/AgNPs were the squeezed to remove the excess AgNPs, rinsed with pure water,dried in an oven at ~700C for 2hrs, and then annealed at ~1200C for 1h [9].

II.2.2. Measurement and Characterization: The percentage of grafting (PAAc%) onto PE was expressed as the increasing in weight divided by the initial weight. The

VINATOM-AR 11--31


X-ray (XRD) diffraction patterns and the infrared spectra (IR) were also measured forestimate to structure of the PE and/or the modified PE [7]. The AgNPs content onto PEwas accessed by an ICP-AES analyzer [1]. The concentration of silver ions or AgNPsreleased into water filtrate from PE filters was analyzed by ICP-MS technique [5].

II.2.3. Bactericidal activity evaluation: The bactericidal activity of PE/AgNPsfabric against E.coli ATCC 6538 which as an indicator of fecal contamination of water[6] was determined by two different methods: i) quantitative evaluation was realized ina flask involving PE/AgNPs fabric pieces and suspension of water contaminated E.coli~106CFU/ml by using shaking method [10] and then plated on nutrient agar plates forenumerated surviving bacterial cells and ii) the exclusive and sterile effect of PE/AgNPsfabric for water contaminated E.coli ~105CFU/ml were carried out by pass through on awater filtration model with flux rate of ~2L/h and then analysis of amount of E.coli cellsin effluent water [1]. The bactericidal effect was calculated using the equation:η(%)=(N0−N)×100/N0, where N0 and N are survival number of bacteria in the controland studied samples, respectively [10].


III.1. The influence of pre-irradiation dose and AAc concentration to graftdegree PAAc/PE

The radiation induced graft polymerization is a convenient and powerful tool.Various shapes and sizes of polymer such as bead, fiber, nonwoven polymer fabrics canbe used in this technique. The polymers, typically as nonwoven PE fabric, underirradiating by EB or γ-ray in presence of air and H2O was formed to radical peroxidesand/or hydroperoxides on PE chains which it can be arisen subsequently strong graftreactions with AAc during heating [8]. The grafting degree (%) was mainly dependedon doses and monomer concentrations [11].

Figure 1: The relationship between PAAc (%) and time (h) of differentpre-irradiated PE doses, 30% AAc (left) and different AAc concentration,

pre-irradiated PE of 25 kGy (right)

The obtained results from Fig. 1 showed that the grafting degree (PAAc%) ontoPE fabrics were increased with the dose, the AAc concentration, and the time reaction,it tends to be a curvature relationship. The reasons can be explained based on the

0

20

40

60

0 2 4 6 8Time (h)

PA

Ac

(%)

10% 20% 30% 40% 50%

0

30

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90

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0 2 4 6 8Time (h)

PA

Ac

(%)

9.8 17.4 20.827.9 34.9 41.4

VINATOM-AR 11--31


interaction degree of AAc to radical species, the higher the doses or the concentration ofAAc was the higher grafting degree [11]. In additionally, the PE fabric grafted PAAchigher than 40% can be reduced of physicomechanical properties due to the PE samplesmust be to irradiated with high dose and/or being the longer chains of PAAc than thatafterward formed on PE fabric surfaces [12]. Accordingly, we chosen the PE graftedAAc with PAAc content less than 40% which prepared by treatment pre-irradiated PEwith 20-30 kGy and grafting reaction with 20-30% AAc during 2-4 hrs for followingexperiments.

III.2. Preparation of PAAc-g-PE immobilized AgNPs

A good idea about the selection acrylic for grafted modification with PE fabricusing to immobilized AgNPs based on the fact that the PAAc chains having highhydrophilic and bring forward –COO- groups which were ability strong affinity to Ag+.The AgNPs can be ionized surface became to cation clusters under wetted and presentedoxygen conditions [13] which could form attractive electrostatic forces with the anioniccharged PAAc onto PE fabric. Furthermore, the AgNPs stabilized by a surface cappingagent as PVA that having –OH groups were also contributed to hold strictly AgNPsonto PAAc-g-PE membranes owing to ester binds formed under annealed temperaturecondition [9, 10].

Figure 2: The relationship between AgNPs content (ppm)on PAAc-g-PE and PAAc (%), immerged in colloid of 500 ppm AgNPs (left)

and AgNPs 100-1.000 ppm in colloid solutions, PAAc ~20% (right)

The results from Fig. 2 represented that the adsorbed AgNPs content on PEfabrics was increased with the PAAc% content and the concentration of AgNPs incolloid solution. These reasons also proved similarly by previous investigation [13] thatthe content of AgNPs on modified polymer membrane was depended on theconcentration of AgNPs in immerging bath and the amount of adsorption affinity groupsto AgNPs. However, the content of AgNPs on PAAc-g-PE was low down from ~18,000ppm for 20%PAAc to ~5,000 ppm for 70%PAAc. This problem can be explained by thetoo long chains of PAAc/AgNPs disrupted and removed during further washingprocesses. The base on obtained results in this study was realized that the 20%PAAc-g-PE and immerged in 500 ppm AgNPs colloid solution are optimal factors forpreparation of PAAc-g-PE/AgNPs filter. Other results about of grafted AAc andimmobilized AgNPs onto PE fabric also evaluated through IR spectra and XRD patterns

0

4

8

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16

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0 20 40 60 80PAAc (%)

AgN

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m)

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0 300 600 900 1200AgNPs conc. (ppm)

AgN

Ps

(×10

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m)

VINATOM-AR 11--31


on Fig. 3, respectively. From IR spectra showed that the peaks at 1724, 1647 specificfor carboxylic or ester groups [7, 8] only occurred on PE-g-PAAc and PAAc-g-PE/AgNPs and on the XRD patterns the peaks at 2θ of 38, 44, 64 and 780 specific forAgNPs [6] destituted of PE in which it was confidence that the AAc and AgNPscrosslinked onto PE fabric.

Figure 3: IR spectra (left) and XRD patterns (right) of various PE fabrics

III.3. Bactericidal activity of PAAc-g-PE/AgNPs

Up to now, the antimicrobial mechanism of AgNPs is still remained unclear.However, recent reported results showed that the antimicrobial, antivirus activity relatedtoxicity mechanism of Ag+ that dissolved from AgNPs [1, 2, 13]. Moreover, the AgNPswith larger interactive surface and stable released of Ag+ so that having the highbactericidal ability at low concentration in comparison with other constituents of silver[13].

Figure 4: The dependant of percentage reduction (η%) and the reduction login E.coli cells with the PAAc-g-PE/AgNPs (cm2) contents, the 100ml of suspensionof ~107 CFU/ml, shaking ~30 min., 150 rpm at RT; C0 & C30 are control samples

(without PE) at initiation & after 30 min. contacted, respectively

Results showed that the η% was increased lead to near 100% and the log(CFU/ml) of E.coli in suspension was decreased to 3 orders log when the PAAc-g-PE/AgNPs content was increasing. In additionally, the inhibition zone was also sawonly for PAAc-g-PE/AgNPs when placed in the agar plates spreaded with E.coli. Thehighly bacterial effect of AgNPs was also observed similarly by other research teams [1,2, 5].

4

5

6

7

C0 C30 5 10 15 20PE/AgNPs (cm2)

Log

(C

FU

/ml)

40

60

80

100

η(%

)η (%)Log(CFU/ml)

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The elimination effect of E.coli contaminated in water with ~105CFU/ml wasalso estimated through filtrate model with flux rate of 2 L/h, the amount of E.coli ineffluent filtrate was counted. The obtained results showed decrease to ~2 orders log andthe η ~98% for PAAc-g-PE/AgNPs with diameter of 7 cm2, particularly the amount ofE.coli in the effluent filtrate was also decreased with η ~54% (data not shown).However, the filters after that incubated on agar plates during ~16 hrs as in Fig. 5 weredemonstrated that the PE fabric could not killed E.coli in comparison with PE/AgNPsfabric. The better bactericidal effect, antivirus activity, and biofouling resistance of filtercontained AgNPs were also evaluated by previous researches and showed a potentialusing for water treatment [1, 2, 4].

Figure 5: The antimicrobial test against E.coli through filtration model

As above mentioned, the difficulty was to control silver of release into drinkingwater filtrate under permitted limit (100 µg/L), while to ensure bactericidal effectconcentration of silver (more than 1 µg/L) [14]. The obtained results in this study (Table1) for tap water treatment showed the PAAc-g-PE/AgNPs satisfied with two criteria asmentioned above. In addition, the coliform cells were not detected in water filtrate whilethe coliform cells in tap water were of 6 CFU/100ml that meet with the WHOrequirements for drinking water [4].

Table 1: The content silver in water filtrate, flux rate of 2 L/h,through PE/AgNPs filter of 7 cm2

Samples Tap water 1 L 4 L 9 L

Silver (µg/L) 0.02 9.27 2.07 0.76

Conductivity (µS/cm) 102.3 122.4 114.9 104.2

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IV. CONCLUSIONS

The PAAc-g-PE/AgNPs fabrics were prepared by immobilization AgNPs ontothe AAc-grafted PE nonwoven fabric by γ-ray pre-irradiation technique. The modifiedPE fabrics contained of about 7,000 – 18,000 ppm AgNPs with the size of ~10 nmshowed strongly bactericidal effect against E.coli in water. The preparation process ofPAAc-g-PE/AgNPs fabric was easy and can be developed for other polymer fabrics.Based on the high bactericidal effect and a suitable released silver into water of PE-g-PAAc/AgNPs fabrics can be adaptable to use for treatment of drinking water inhousehold and putting on line air cleaners.

REFERENCES

[1]. Dankovich, T.A., Gay, D.G. (2011). Bactericidal paper impregnated with silvernanoparticles for point-of-use water treatment. Environ. Sci. Technol. 45, pp. 1992-1998.

[2]. Zodrow, K. et al. Polysulfone ultrafiltration membranes impregnated with silvernanoparticles show improved biofouling resistance and virus removal. Water Res. 43, pp. 715-723, 2009.

[3]. Gusseme, B.D. et al. Biogenic silver for disinfection of water contaminated withviruses. Appl. Environ. Microbiol. 76, pp. 1082-1087, 2010.

[4]. Jain, P., Pradeep, T. Potential of silver nanoparticle-coated polyurethane foam asan antibacterial water filter. Biotechnol. Bioengin. 90 (1), pp. 59-63, 2005.

[5]. Taurozzi, J.S. et al. Effect of filler incorporation route on the properties ofpolysulfone-silver nanocomposite membranes of different porosities. J. Membr. Sci. 325, pp.58-56, 2008.

[6]. Yaohui, L.V. et al. Silver nanoparticle-decorated porous ceramic composite forwater treatment. J. Membr. Sci. 331, pp. 50-56, 2009.

[7]. Tseng, C.H., Wang, C.C., Chen, C.Y. Polypropylene fibers modified by plasmatreatment for preparation of Ag nanoparticles. J. Phys. Chem. B, 110, pp. 4020-4029, 2006.

[8]. Said, H.M., Sokker, H.H., Ali, A.E.H. Acrylation of pre-irradiated polypropyleneand its application for removal of organic pollutants. Rad. Phys. Chem. 79, pp. 534-539, 2010.

[9]. Moreno, M., Hernandez, R., Lopez, D. Crosslinking of poly(vinyl alcohol) usingfunctionalised gold nanoparticles. Europ. Polym. J. 46, pp. 2099-2104, 2010.

[10]. Zhang, F. et al. Application of silver nanopaticles to cotton fabric as anantibacterial textile finish. Fibers and Polymers 10 (4), pp. 496-501, 2009.

[11]. Hai, L., Hien, N.Q., Man, N.T. Grafting of acrylic acid onto polyethylene filmsby gamma radiation-peroxidized method. Tap chi Hoa hoc 37 (3), pp. 89-93, 1999.

[12]. Kavakl1, P.A. et al. Radiation-induced grafting of dimethyl aminoethylmethacrylate onto PE/PP nonwoven fabric. Nucl. Instr. Meth. Phys. Res. B 265, pp. 204-207,2007.

[13]. Klemencic, D. et al. Biodegradation of silver functionalised cellulose fibers.Carbohydr. Polym. 80, pp. 427-436, 2010.

[14]. Zhu, X. et al. Membrane surfaces immobilized with ionic or reduced silver andtheir anti-biofouling performances. J. Membr. Sci. 363, pp. 278-286, 2010.

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ESTABLISHMENT OF THE STERILIZATION PROCESS BYIRRADIATION IN ELECTRON BEAM UELR-10-15S2 FOR SOME

MEDICAL DEVICES WITH CURRENT HIGH DEMAND

Doan Thi The, Nguyen Thuy Khanh, Vo Thi Kim Lang, Pham Thi Thu Hong,Cao Văn Chung and Le Quang Thanh

Research and Development Center for Radiation Technology, VINATOMLinh Xuan, Thu Duc, Ho Chi Minh, Vietnam

Abstract: Bioburden of four medical devices included Petri dish, cotton gauze,container of eye drop and plastic box which have been sterilized by gamma rays inResearch and Development Center for Radiation Technology was determined. This is animportant step to set the sterilization dose for each product. Cotton gauze and plasticbox for culturing plant tissues have high and unstable bioburden to compare with theothers. Based on bioburden data, the dose verification was set to each product andvalidated by sterility test. The mechanical properties of materials before and afterirradiation were measured. The obtained results showed that there is not significantchange of material properties between non-irradiated and irradiated samples, exceptplastic boxes. The suitable size and weight of each carton for sterilizing products by EBwas calculated and recommended to manufacturers. A sterilization irradiation generalprocess for some medical devices was established to aim quality assurance of theproduct.

I. INTRODUCTION

A sterile product is one that is free of viable microorganisms. Items producedunder controlled manufacturing conditions can, prior to sterilization, havemicroorganisms on them, although ordinary in low numbers. Such products are non-sterile. The purpose of sterilization processing is to destroy the microbiologicalcontaminants on these non-sterile products. The radiation process is a physical one,involving the exposure of a product to ionizing radiation. The product is exposed inspecially designed equipment to gamma rays from cobalt 60 (60Co) radionuclides or







The, D.T., Khanh, N.T., Lang, V.T.K., Hong, P.T.T, and Chung, C.V, Establishingthe sterilization process by electron beam irradiation in electron beam acceleratorUELR-10-15S2 for some medical devices, the 10th National Conference on NuclearScience and Technology, Vung Tau City, Ba Ria – Vung Tau, August 15-16, 2013(in Vietnamese).


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cesium 137 (137Cs) radionuclides, or to electron or x-ray beam from an electron beamgenerator. When properly applied, radiation sterilization is a safe, high sterilityassurance level (SAL) and reliable industrial process [1-3]. At the present, this processis quite popular in Vietnam proved by increasing the numbers of irradiators in recentyears and the quantity of medical products. To meet requirement of manufacturers,Research and Development Center for Radiation Technology (VINAGAMMA) isinvested to establish an electron beam accelerator named UELR – 10-15S2 with energyof 10 MeV and maximum power of 15 kW. E-beam irradiation method is attractingmore attention recently for the sterilization of medical devices and have manyadvantages like being safe, having no emission and high speed processing. Medicalproducts with low density (normally it density around 0.1 to 0.2 g/cm3) will be suitablefor radiation sterilization. However, according to ISO 11137 in the item ‘Transfer ofsterilization dose’, transfer between gamma facility to electron beam (gamma ↔ EB),data shall be available to show that microbial inactivation is not affected by differencesbetween the two facilities in source characteristics, particularly radiation energy and therate at which dose is delivered or by differences in dose distribution through the product[1].

The main objectives of the study are that 1) Determine bioburden on some mainmedical products being irradiated in gamma facility; 2) Set up the sterilization dose inelectron beam facility for each product; 3) Evaluate sterilization process; and 4)Establish a general sterilization process of medical products on EB to assure quality ofirradiation products at VINAGAMMA.

II. EXPERIMENT

II.1. Selection of sample

Samples of product were taken at random from a batch of routine production andwere representative of processing procedures. Samples of four medical products whichhave been sterilized by gamma facility were chosen that are Petri dish, cotton gauze,container of eye drop and plastic box.

II.2. Study methods

- Sample item potion - SIP: The SIP should be as large a portion of the productunit as it is possible to manipulate readily in the laboratory. SIP can be calculated on thebasic of length, mass, volume or surface area of the product. If all unit of the product isused to be test, SIP=1.

- Dose setting method: Based on method 1 in ISO 11137 - Dose setting usingbioburden information. If dose setting Method 1 is used, following stages shall be doneincluded select SAL and obtain samples of the product units; determine averagebioburden (ISO 11737-1 [5]); establish verification dose; perform verification doseexperiment; and establish sterilization dose.

- Irradiation method: all samples were packaged by two layers of polyethylene(PE) and irradiated in EB facility with power of 2.5 kW, scanning width of 50 cm,speed of conveyor depended on determined dose. Absorbed dose was measured bycalorimeter and Radiochromic B3 (Gex Corporation, USA).

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- Evaluation of plastic material after irradiation: Evaluating tensile strength andbreak elongation of irradiated samples followed by ASTM D638, tear strength byASTM D-1004-66, test for discoloration by optical spectrometry in UV-VIS.


III.1. Results of bioburden

Avergage bioburden on samples of four products was determined in Table 1.

Table 1: Result of bioburden on experimental samples

No. Sample

Bioburden (SIP=1)

Average ofbatch 1

Average ofbatch 2

Average ofbatch 3

Average of3 batches

1 Bottle NNV2 5.0 18.5 6.2 9.9

Bottle YL2F 35.5 30.0 75.0 46.8

Cap NNV2 310 125.0 151.0 195.3

Cap YL2F 25.9 30.0 24.8 26.9

2 Cotton gauze 70.5 143.0 63.5 92.3

3 Petri dish PD 10025 0.1 0.1 0.2 0.13

4 Plastic box 72.0 28.5 31.3 43.93

Obtained result showed that average bioburden on Petri dish is lowest (0.13). Itis proved that this product is manufactured in good conditions (GMP). Highest averagebioburden is on Cap NNV2 and cotton gauze with value of 195.3 and 92.3, respectively.

III.2. Result in establishing verification dose

Using Table B 1 in ISO 11137, determine the verification dose based on theaverage bioburden (overall average or highest batch average). If the average bioburdenis not given in the table, use the closest average bioburden number greater than theactual average bioberden (Table 2).

Table 2: Establishment of verification dose (Table B.1 ISO 11137-1)

No. SampleBioburden Bioburden in

Table B.1Verification dose at

SAL=10-2 (kGy)

1 Bottle NNV2 18.5 19.87 6.0

Bottle YL2F 75.0 75.51 7.6

Cap NNV2 310 333.4 9.5

VINATOM-AR 11--32


Cap YL2F 26.9 28.0 6.4

2 Cotton gauze 143 154.3 8.5

3 Petri dish PD10025

0.13 0.14 1.5

4 Plastic box 72.0 75.51 7.6

III.3. Result of performing verification dose

To perform the experiment, select 100 product unit samples from a single batchof product. Individually test the irradiated product units for sterility. Sterility test thesamples in Soybean Casein Digest Broth, incubated at (30±2)ºC for 14 days (inaccordance with ISO 11737-2 [4]). The number of possitive sterility test was recordedin Table 3. Statistic verification is accepted if there are no more than two possitivesterility test from 100 tests carried out. In this experiment, all of the test were acceptedbecause the result showed in Table 3.

Table 3: Results of performing sterility test

No. Sample Verificationdose (kGy)

Actual dose(kGy)

Positive test

1 Bottle NNV2 6.0 6.5 <2

Bottle YL2F 7.6 8.0 <2

Cap NNV2 9.5 9.5 <2

Cap YL2F 6.4 6.5 <2

2 Cotton gauze 8.5 8.5 =2

3 Petri dish PD 10025 1.5 1.5 0

4 Plastic box 7.6 8.0 =2

III.4. Establish sterilization dose

If the verification procedure is passed, table B1 (ISO 11137) is used to obtainthe sterilization dose for the product unit by finding the closest bioburden number on thetable that is equal to or greater than the average bioburden for the product unit, and thenreading off the dose necessary to achieved the desired SAL (Table 4). Based on purposeof use, the sterilization dose of bottles and gauze were chosen at SAL=10-6, while twoother samples (Petri dish and plastic box) chosen at SAL=10-4 or SAL=10-5.

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Table 4: Establishment of sterilization dose (Table B1, ISO 11137-1)

No. SampleSterilization dose (kGy)

SAL=10-4 SAL=10-5 SAL=10-6

1 Bottle NNV2 - - 18.7

Bottle YL2F - - 20.8

Cap NNV2 - - 23.1

Cap YL2F - - 19.3

2 Cotton gauze 18.3 21.9

3 Petri dish PD 10025 5.7 8.4 -

4 Plastic box - 17.3 20.8

III.5. Product dose mapping

Dose mapping was carried out for a representative irradiation box of product toknow the dose distribution whole the box after irradation (Table 5 and Figure 1). In EBirradiation, dose uniform ratio (DUR) depends on much density and dimension ofproduct.

Figure 1: Diagram of dosimeters in a product box

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Table 5: Measured dose at above position in determining dose mappingof product boxes - Cap YL2F, Bottle YL2F and Bottle NNV2

No. of dosimeter Cap YL2F Bottle YL2F Bottle NNV2

1 17.1 19.8 21.3

2 18.2 18.3 21.2

3 18.2 21.0 23.5

4 22.3 23.2 20.9

5 20.8 19.6 20.2

6 22.7 22.0 19.7

7 23.7 27.9 20.5

8 25.4 27.5 18.9

9 22.4 26.5 19.7

10 22.1 21.2 18.1

11 21.7 21.4 18.5

12 24.5 25.4 19.0

13 16.3 19.4 18.4

14 17.2 18.2 20.6

15 16.5 21.0 18.9

Dmin 16.5 18.2 18.5

DUR 1.54 1.53 1.3

DUR (In calculation) 1.5 1.2 1.2

III.6. Properties of product material after sterilization irradiation

Each polymer reacts differently to ionizing radiation. Thus, it is important toverify that the maximum administered dose will not have a detrimental effect on theproduct’s function or the patient’s safety over the product’s intended shelf life. Forsome materials and products that are sensitive to oxidative effects, such as lowmolecular weight polypropylene and polytetrafluorethylene, radiation tolerance levelsfor electron beam exposure may be slightly higher than for gamma exposure. This is

VINATOM-AR 11--32


due to the higher dose rates and shorter exposure times of EB irradiation which havebeen shown to reduce the degradative effects of oxygen [2]. Mechanical properties ofmaterial of some products after irradiation were measured in Table 6.

Table 6: Mechanical properties of material of products after irradiation

Sample Parameter Non-irradiated Irradiated Remark

1. Gauze ASTM D638

- Package (PE) - Tensile strength,MPa

45.0 ± 1.3 40.7 ± 2.6 Crosshead:50mm/min,Load: 20kgf

- Elongation atbreak, %

37.5 ± 2.5 35.9 ± 4.3

- Cotton - Tensile strength,MPa



19.5 ± 1.2 16.0 ± 0.8

2. Plastic box ASTM D638and D 1004-66

- Box - Tensile strength,MPa



3.64 ± 0.08 2.75 ± 0.11

- Tear strength,N/cm

858.3 ± 20.4 633.4 ±36.6

- Cover of box - Tensile strength,MPa

26.5 ±1.3 22.1 ± 0.7


4.00 ± 0.23 3.40 ± 0.35

3. Petri dish - Izod, kJ/m2 0.78 ± 0.06 1.36 ± 0.05 ASTM D256

III.7. Result of test for discoloration

In Table 7, no significant changes were observed in absorption and transmittancebetween non-irradiated and irradiated samples. It is seem to be that EB irradiation wasnot effected much these materials.

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Table 7: Test for discoloration of non-irradiated and sterile irradiated samples

Sample Non-irradiated Irradiated Remark

Bottle NNV2(Dmin:19.0 kGy)

5.0 5.0 Absorbance UV-VIS,

λmax: 672 nm

Bottle YL2F

(Dmin: 21.0 kGy)

100 100 Transmittance by UV-VIS,

λmax: 736 nm

Cap YL2F

(Dmin: 25.0 kGy)

1.01 1.04 Absorbance by UV-VIS,

λmax: 420-423 nm

Plastic box

(Dmin: 22.0 kGy)

99.82 99.84 % Transmittance by UV-VIS,

λmax: 800 nm

Petri dish

(Dmin: 6.0 kGy)

99.69 99.72 % Transmittance by UV-VIS,

λmax: 750 nm

The comparation of the sterilization dose between gamma and EB irradiationwas described in Table 8. In which, three samples including cotton gauze, Petri dish andplastic box could be keep in the same dose and bottles for containing drop eye could bedecreased sterilization dose.

Table 8: Comparation of the sterilization dose between gamma and EB irradiation

No. Sample Sterilization dose by γ(kGy)

Sterilization dose by EB(kGy)

1 Bottle NNV2 25.0(*) 18.7

Bottle YL2F 25.0(*) 20.8

Cap NNV2 - 23.1

Cap YL2F 17.5(*) 19.3

2 Cotton gauze 18.0-20.0 21.9

3 Petri dish PD10025 6.0-7.0(*) 5.7

4 Plastic box 18.0-20.0 20.8

(*) Sterilization doses were decided by manufacturers

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A general process for EB sterilization for medical products was established asfollowing:

Information of products (bioburden, dimension of product box, weight and mainmaterial- QA/QC & EB Operator) Establish sterilization dose (Dmin, DUR- QA/QC& EB Operator) Attach dosimeter (QA/QC) Operation and IrradiationMeasuredosimeter (QA/QC).

IV. CONCLUSIONS

1. Bioburden on some medical products which have been irradiated by gammafor sterilization at VINAGAMMA was determined. Petri dish has lowest bioburden(0.13) to compare with the others. Bioburden on bottle NNV2 and cotton gauze ishighest at 195.3 and 92.3, respectively.

2. Verification dose for all of samples set up from information of determinedbioburden is evaluated by sterility test with ≤ 2 possitive samples in 100 experimentalsamples.

3. Material properties of samples after sterilization irradiation were not changesignificantly, except plastic box (tear strength decreased to compare with non-irradiated).

4. Dose uniform dose (Dmax/Dmin) in EB irardiation depended on muchsurface density (g/cm2) of product box.

5. Tranfering products from gamma sterilization irradiation to EB can be keepthe same dose for Petri dish or light greater dose for cotton gauze and plastic box. Forbottle and cap of eye drop container, strilization dose could be decreased whenirradiated by EB.

6. A general irradiation procedure was established for some medical productswith aiming good assurance of their quality.

REFERENCES

[1]. ISO 11137: 2006, Sterilization of health care products-Requirements for validationand routine control – Radiation sterilization.

[2]. http://www.sterigenics.com/services/medical-sterilization

[3]. M. Silindir, A.Y. Ozer, Sterilization methods and the comparison of E-beamsterilization with gamma radiation sterilization, FABAD, Journal of Pharmaceutical Science, 34,pp. 43-53, 2009.

[4]. ISO 11737-2: 1998(E), Sterilization of medical devices – Microbiological methods– Part 2: Tests of sterility performed in the validation of a sterilization process, 1998.

[5]. ISO 11737-1: 1998(E), Sterilization of medical devices – Microbiological methods– Part 1: Estimation of population of microorganisms on products, 1998.

http://www.sterigenics.com/services/medical-sterilization

VINATOM-AR 11--33


THE STUDY ON PREPARATION OF UO2 POWDER VIA AUCPRECIPITATION ROUTE FROM UO2F2 SOLUTION

Nguyen Trong Hung, Do Van Khoai, Dang Ngoc Thang, Nguyen Van Tung,Nguyen Thanh Thuy, Dao Truong Giang, Ngo Quang Hien, Ha Dinh Khai, Doan Thi Mo,

Tran Thi Thanh Hien, Ta Phuong Mai, Cao Thi Phuong Anh and Tran Thi Hong Thai

Center for Technology of Nuclear Fuel,Institute for Technology of Radioactive and Rare Elements,VINATOM


Abstract: The studies on preparation of UO2 powder via ammonium uranyl carbonate(AUC) precipitation route from the UO2F2 – HF solution system have beenimplemented in the report. The precipitation agents used are (NH4)2CO3 and mixture ofNH3+CO2 gases. The AUC precipitation reached the highest yield of 99% with(NH4)2CO3 precipitation agent and of 99.9% with NH3+CO2 gas precipitation agent. Fcontent in AUC powder is low, reached value of from 700 to 1200 ppm. The AUCpowder was defluorinated by pyrohydrolysis method, using F elimination agent to bemixture of H2O (gas)+N2 (or CO2, or H2), and then converted into U3O8 powder. Someproperties of U3O8 powder were estimated.

The study on reduction process of U3O8 into UO2 indicated that at conditions ofreduction temperature and timing – 6500C and 4 hrs; ratio of H2 to N2 – 3 to 1 (v/v),UO2 powder ex-AUC has properties as follows: particle size ∼ 30µm; specific surfacearea ∼ 3.9-4.5 m2/g; F content < 100 ppm; bulk and tap density 2.05 g/cm3 and 2.3g/cm3, respectively; O/U ratio 2.05-2.1.

I. INTRODUCTION

In the nuclear fuel cycle, UO2 (uranium dioxide) ceramic pellets – nuclear fuelfor LWR – are fabricated from enriched UF6 (uranium hexafluoride). Some processesare being applied:

UF6 → UO2 dry methodsUF6 → UF4 → UO2

UF6 → ADU → UO2

wet methodsUF6 → AUC → UO2

UF6 → UO4 → UO2

Project Information:- Code: ĐT.04/10/NLNT- Managerial Level: Ministry

- Allocated Fund: 1,040,000,000 VND

- Implementation Time: 24 months (Feb 2010 - Feb 2012)




VINATOM-AR 11--33


In the wet methods, UF6 is hydrolyzed to form UO2F2 (uranyl fluoride) – HF(hydrofluoric acid) solution system. From the latter, there are two main ways forfabricating the UO2 powder, namely ADU (ammonium diuranate) and AUC precipitateroute. Alternatively, the intermediate product UO4 – uranium peoxide – is precipitatedto prepare UO2 powder [1, 2, 3].

Reactions for AUC formation from uranyl solution are as below:

UO2F2 + 3(NH4)2CO3 = (NH4)4UO2(CO3)3 + 2NH4F

UO2F2 + 6NH3 + 3CO3 = (NH4)4UO2(CO3)3 + 2NH4F

The process for UO2 powder preparation has two continuous steps: conversionof AUC into U3O8 powder and then reduction of U3O8 into UO2 ceramic powder. Thefirst step is F elimination process [4].

AUC process for UO2 powder manufacture was applied on an industry scale insome countries, such as Korea, Germany, Sweden and Argentina. UO2 ex-AUC powderis found to be giving the following advantages:

- High recovery, up to 95% in comparison with ADU process in palletizingoperations

- Free flowability, the powder is free flowing and enables elimination of pre-compaction and granulation steps

- Easy mechanization, since the UO2 ex-AUC powder is free flowing it ispossible to completely mechanize its transfer through an enclosed system which wouldeffectively avoid airborne activity in the environment during its production.

Besides, the AUC process is automatically refining [5, 6]. From above goodpoints, the study on preparation of UO2 ceramic via AUC route needs to be interesting.

II. EXPERIMENTAL

The simulative solution of UF6 hydrolyzing process is the mixture of UO2F2 andHF (UF) with U/F molar ratio of 1/6. The ammonium solution, (NH4)2CO3 precipitationagent, gases (NH3, CO2, N2 and H2) are chemicals of analytical grade.

The uranium concentration in solutions was determined by the vanadate titrationmethod. XRD and SEM methods were applied for examining the composition andmorphology of the AUC and U3O8, UO2 powder. The particle size distribution of theAUC and U3O8, UO2 powder was measured by the measure IT and the laser scatteringmethod (Horiba – LA950 particle size analyzer). The specific surface area (SSA) of theAUC and U3O8, UO2 powder was measured by BET method (Coulter SA 3100).Thermal analysis of the AUC was performed on Setaram thermal-analyzer.

Conversion of the AUC into U3O8 and reducing process of U3O8 into UO2 areconducted in the apparatus system, consisting of LORA furnace 10000C and hydrogen-nitrogen-stream supply system. The conversion occurred at the temperature of 650-7000C in mixture of steam and nitrogen gases, nitrogen flow rate is 21 ml per minute.The reducing process is also performed at the temperature of 6500C in a reducingmedium that is mixture of hydrogen and nitrogen gases in ratio of 3:1, hydrogen flowrate is 62 ml per minute. The temperature program for both processes is as follows: therate of heat increase is 2000C per hour, the time for remaining heat is 4 hours, and therate of heat decrease is natural.

VINATOM-AR 11--33


III. RESULTS AND DISCUSSIONS

III.1. Investigation on AUC precipitation from solution system UF/HF,using precipitation agent of (NH4)2CO3 (AC) and NH3+CO2 gases

Results of the study on AUC precipitation, using precipitation agent of(NH4)2CO3 and NH3+CO2 gases indicated that the parameters of AUC precipitation are:U concentration in stock solution of 100-120 gU/L, ratio C/U of 7-8 (mol/mol). At theseconditions, the highest yield of AUC precipitation reached 99.9% - using precipitationagent of NH3+CO2 gases, and 99% - using precipitation agent of (NH4)2CO3. Featuresof AUC precipitate are rapidly sedimentation and clear crystal (Figure 1). F content inthe AUC precipitate is from 700 to 1200 ppm. With ADU process, F content in ADUprecipitate is 8600 ppm. Change of particle size and SSA of the AUC depending onexperiment parameters is not strong. Particle size and SSA are ∼ 30 µm and from 4-7m2/g, respectively.

Figure 1: SEM picture of AUC precipitate

Figure 2: XRD of AUC precipitate

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III.2. Investigation on F elimination in the AUC and conversion of the AUCinto U3O8

On the base of thermal analysis diagram (Fig. 3), there are some commentsabout thermal decomposition of the AUC:

- Temperature range from 1700C to 4200C is conversion of AUC into UO3,according to reaction equation: (NH4)3UO2(CO3)3 = 4NH3↑ + 3CO2↑ + UO3 + 2H2O.Mass change in the temperature range is 44.1%, in accordance with formula of AUC.

- Temperature range from 4500C to 7300C is conversion of UO3 into U3O8.

Thus, U3O8 is final product of AUC thermal decomposition in the airenvironment. From the about comment, investigation on AUC decomposition and Felimination are implemented in temperature range from 5500C to 7500C.

Figure 3: Thermal analysis diagram of AUC precipitate

Three F elimination agents, namely H2O(gas)+N2 (CO2 and H2) mixture, wereused to remove F from U3O8 powder. The study results indicated that F eliminationability of H2O(gas)+N2 mixture is more than that of H2O(gas)+CO2 mixture.H2O(gas)+H2 mixture has the highest ability in F elimination. That was explained indocument [4].

Features of U3O8 powder obtained from conversion of AUC into U3O8 (ex-AUCU3O8) depended on thermal program of the conversion. At high temperature (> 7000C)and rapidly temperature raise, particle size of ex-AUC U3O8 powder will decrease andSSA – increase, F content – decrease. When timing of roasting increase, particle size ofex-AUC U3O8 powder and F content – decrease. Table 1 indicated the results ofdefluorination and AUC into U3O8 conversion.

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Table 1: Parameters of defluorination and AUC into U3O8 conversion

Parameters Defluorination agent and AUC into U3O8 conversion

H2O(gas)+N2 mix. H2O(gas)+CO2 mix. H2O(gas)+H2 mix.

Roasting temperature 650-7000C 7500C 6500C

Roasting timing 4 hrs 5 hrs 4 hrs

Temperature raise 200 0C/h 200 0C/h 200 0C/h

Ratio of mix. 1:1 1:1 1:1

Features of ex-AUC U3O8 powder:

Particle size (µm) ∼30 -- --

SSA (m2/g) 3.9-4.5 -- --

F content (ppm) < 100 ∼ 100 ∼ 50

III.3. Investigation on reduction of ex-AUC U3O8 into UO2 ceramic powder

The results of the study on reduction of ex-AUC U3O8 into UO2 ceramic powderindicated that particle size of UO2 powder decreases with increase of reductiontemperature and timing. This is due to break of AUC crystal in high temperature andlong reduction timing. Consequently, SSA of ex-AUC UO2 powder increase. Theparticle size and SSA of the UO2 reached values of 3.5-5.5 m2/g and 20-30µm,respectively.

Ratio of O/U decrease with increase of reduction temperature and timing andmove to formula value of UO2. The ratio has value of 2.05 – 2.3.

Bulk (dB) and tap (dT) density of ex-AUC UO2 powder are already relationshipto ratio of O/U, density of the UO2 decrease with increase of the O/U ratio. The dB anddT of the UO2 have values of 1.9 – 2.1 g/cm3 and 2.2 – 2.4 g/cm3, respectively. Fcontent in the UO2 samples has value of < 100 ppm.

On the base of experimental data that describe dependence of the UO2 SSA onfour factors, namely reduction (TK) and conversion (TN) temperature, reduction (tN) andconversion (tK) timing, the multiple regression model that describes the effect of thefactors on the SSA of UO2 powder is established.

The model is: y = 1.000988 × (0.0044 TK + 1.4276) × (0.0002 TN + 0.888) ×(0.0377 tN + 0.8558) × (0.0417 tK + 0.808).

The parameters of the reduction are as follow:

- Reduction temperature: 6500C;

- Reduction time: 4 hours;

- Temperature raise: 2000C/h;

- Ratio of H2/N2: 3/1.

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Features of ex-AUC UO2 ceramic powder are: particle size ∼30 µm; SSA ∼ 3.9-4.5 m2/g; F content < 100 ppm; dB – 2.05 g/cm3; dT ∼ 2.3; O/U – 2.1

Figure 4: SEM picture of ex-AUC UO2 ceramic powder

III.4. Comparing the ex-AUC UO2 with ex-ADU UO2 powder

There are some differences between the ex-AUC UO2 and ex-ADU UO2 powderwhich were indicated in the table 2.

Table 2: Comparing the ex-AUC UO2 with ex-ADU UO2 powder

Feature AUC method ADU method

AUC and ADU precipitate

SSA < 10 m2/g > 20 m2/g

Particle size distribution d0.9 30 µm 15µm

U precipitation yield 98% and 99.9% 94-95%

Sedimentation Very fast slowly

Mophology Clear crystal Not clear

F content 700-1200 ppm 8300ppm

UO2 powder

Particle size distribution d0.9 30 µm 15-16 µm

SSA 3.9-4.5 m2/g 3.8 – 4.1 m2/g

F content ∼ 6 ppm 1,51ppm

Bulk density dB 2.05 g/cm3 1.33 – 1.35 g/cm3

Tap density dT ∼2.3 g/cm3 2.27 – 2.31 g/cm3

O/U ratio 2.05-2.1 2.09 – 2.11

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IV. CONCLUSION

The AUC precipitation from UF/HF solution system has the highest yield of99.9%. The ex-AUC UO2 ceramic powder reached some features of sintering UO2

ceramic powder. On the base of the report, the differences between the ex-AUC UO2

and ex-ADU UO2 powder were indicated.

REFERENCES

[1]. Kan-Sen Chou and Ding-Yi Lin, “Precipitation studies of ammonium uranylcarbonate from UO2F2 solutions”, J. Nucl. Mat. 165, 171-178, 1989.

[2]. Maw-Chwain Lee, et. al., “Conversion of UF6 to UO2: A quasi-optimization of theammonium uranyl carbonate process”, J. Nucl. Mat. 185, 190-201, 1991.

[3]. C.S. Choi , et. al., “The influence of AUC powder characteristics on UO2 pellets”,J. Nucl. Mat. 153, 148-l55, 1988.

[4]. N. Lindman, “THE KINETICS OF THE ELIMINATION OF FLUORINE FROMURANYLFLUORIDE/URANIUMDIOXIDE PELLETS”, Journal of Nuclear Materials, 66,23-36, 1977.

[5]. A. Marajofsky, Lidia Perez and Julia Celora, “On the dependence of characteristicsof powders on the AUC process parameters”, J. Nucl. Mat. 178, 143-151, 1991.

[6]. H. Tel, M. Eral, “Investigation of production conditions and powder properties ofAUC”, J. Nucl. Mat. 231, 165-169, 1996.

VINATOM-AR 11--34


STUDY ON THE INFLUENCE OF PORE-FORMING SUBSTANCEAMMONIUM OXALATE ON PORE SIZE AND PORE

DISTRIBUTION OF UO2 CERAMIC PELLET

Dao Truong Giang, Nguyen Trong Hung, Dang Ngoc Thang,Ha Dinh Khai and Ngo Quang Hien

Center for Technology of Nuclear Fuel,Institute for Technology of Radioactive and Rare Elements,VINATOM

No.48 Lang Ha, Dong Da,Hanoi, Vietnam

Abstract: In this study, the effect of ammonium oxalate additive on the size anddistribution of pores in UO2 ceramic pellets has been studied. UO2 powder used for theexperiments was prepared by precipitation of AUC from uranyl salt. UO2 ceramicpellets were prepared with different contents of ammonium oxalate. Pores in sinteredpellets had sizes in range of 0.5 - 5 μm, and pore distribution was homogeneous. In thecontent range of 0.2 - 0.4% of ammonium oxalate, the sintered pellet density was atacceptable value.

Key words: Fuel ceramic pellet, UO2, ammonium acetate, additive, pore.

I. INTRODUCTION

Ceramic fuel is widely used in the most types of existing modern nuclearreactors where uranium dioxide (UO2) is the main material. Nuclear fuel for heavywater reactors are manufactured from natural uranium. But uranium must be enriched(3-5%) for manufactoring fuel of light water reactors.

The properties of UO2 ceramic pellets are closely related to their structure.The parameters of structure reflect essential properties of the ceramic pellets such asmechanical strength, thermal conductivity, the possibility of fission gas retention, etc.The distribution and size of pore are two of the important parameters that determineworking ability of the ceramic pellets in nuclear reactions [1-4]. For fuel used in lightwater reactors (LWR), in addition to U3O8 and some toxic burnable poison, a smallamount of pore-forming substance (ammonium oxalate, azocacbonamit, etc.) isalso added so that more pores occurs and the pore distribution range is larger. Duringthe working time in reactions, the pores have a function of containing fission gases, theyalso affects the thermal conductivity of the pellets. Pore ratio should be controlled to beat certain values because over large amount of pore will reduce the thermal




- Implementation Time: 12 months (Mar 2011 – Jun 2012)




VINATOM-AR 11--34


conductivity of the pellet. While with too little amount of pore, the space for temporarystorage of fission products will not be enough, so the fuel pellets can becomeswollen and broken down. To prevent from those, some amount of additive/pore-forming substance is always used in the production of uranium dioxide ceramic pellets.The pore-forming substance has an important role by the presence of it at asmall content (about 0.2 - 0.5%) allows controlling the sintered pellet porosity as wellas the distribution and the size of pores.

II. EXPERIMENT

Composition and morphology of UO2 powder were determined by the methodof XRD and SEM imaging. Specific surface area of UO2 powder was determinedby BET method.

The convert process of AUC into UO2 was done in the system including Lora-1000 furnace and gas supply system. Gas mixture was H2/N2 having volume ratio of3/1, the gas flow was 62 ml/min. Heat rate was 2000C/ h. Heat retaining time was 4hours. And then the cooling process was natural (non-controlled) to room temperature.

The distribution and pore size was determined by ASTM E 407-07 methods andSEM imaging

III. RESULT AND DISCUSSION

Properties of UO2 powder

Figure 1: SEM image of UO2 powder

VINATOM-AR 11--34


Figure 2: XRD graphic of UO2 powder

SEM and XDR results (Figures 1 and 2) showed that UO2 powder obtainedfrom the AUC convert process is pure. Powder crystals were obvious. The powder hadparticle size of 10-70 μm, specific surface area of 5-7m2/g, bulk density of 1.8 -2.0 g/cm3.

Characteristics of ceramic pellet

The density of the sintered pellets was 92 - 94% TD. When increasingconcentrations of ammonium oxalate, the number of pores increased that led to decreasedensity of the sintered pellets. The ammonium oxalate content of 0.2 - 0.4% was used toensure that obtained sintered pellets have appropriate density. The sintered pellets hadrelatively high shrinkage (about 18.0 ÷ 18.6%) and good ability of agglomeration,which denoted that the powder had good sintering ability. The very littledifference between horizontal and vertical shrinkage (about 0.05 ÷ 0.15%) showed thedistribution of density in the sintered pellets was nearly equal

Figure 3: Density suppression of UO2 with different contents of AO

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Effect of ammonium oxalate on the distribution and size of pores in sintered pellets

(a) (b)Figure 4: SEM image of the ceramic pellets

(a) without ammonium oxalate and (b) with 0.4% ammonium oxalate

The metallographic image showed that in the case of adding ammonium oxalatethe distribution of pores in the sintered pellets was rather homogeneous. Almost poreswhich were strong had the sphere shape, their sizes were in the range of 0.5-5 µm.

In the case of not using ammonium oxalate, pores had sizes distributed in two sharplydifferent ranges. One was less than 0.5 micrometers and the other was 2 μm or more.In the presence of ammonium oxalate, the size of pores was various and pore sizedistribution extended to the range of 0.5 - 5 μm (figure 5). This was because ammoniumoxalate with different sizes dispersing in the powder was decomposed when sintering toproduce the pores with different sizes.

Figure 5: Porosity distribution of pores in UO2

with different contents of AO

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IV. CONCLUSION

Ammonium oxalate in ceramic pellets has made them more porous, it alsoincreases pore size and the range of pore size distribution extends from 0.5 to 5 μm aswell as the density of the ceramic pellets decreased. Ammonium oxalate content of 0.2 -0.4% was found appropriate to ensure the density of ceramic pellets are not lower thanthe permitted norm for fuel ceramic.

REFERENCE

[1]. Kun Woo Song, et al, Reduction of the open porosity of UO2 pellets through porestructure control, Journal of Nuclear Materials 279, 253-258, 2000.

[2]. Kun Woo Song, et al, Pore growth in sintered UO2, Journal of Nuclear Materials209, 263-269, 1994.

[3]. K.C. Radford and J.M. Pope, Controlled porosity reactor fuel, Journal of NuclearMaterials 64, 289–299, 1977.

[4]. Yang Xiao-dong, Gao Jia-cheng, Wang Yong, Chang Xin, Low-temperaturesintering process for UO2 pellets in partially-oxidative atmosphere. Trans Nonferrous Met. Soc.China 18, 171-177, 2008.

VINATOM-AR 11--35


STUDY THE POSSIBILITY OF PREPARING TITANIUM (Ti)METAL FROM TiCl4 BY HEATING MAGNESIUM

RECONSTITUTION METHOD

Ngo Xuan Hung1, Nguyen Van Sinh1, Tran Duy Hai1,Nguyen Trong Hai1 and Vu Thi Loan2

1Center for Technology of MaterialsInstitute for Technology of Radioactive and Rare Elements,VINATOM

No.48 Lang Ha, Dong Da, Hanoi, Vietnam2Bach Khoa University of Technology

Abstract: Titanium metal and alloys are widely applied in many fields such asaerospace, shipbuilding, metallurgical industry, chemical industry, domesticutensils,…Thermic – reduction of titanium tetrachloride (TiCl4) with magnesium (Mg)has been utilized by many countries on the world. The contents that have been done inthe work as follows: (1) the systems of equipment for metal – thermic method reductionof titanium tetrachloride in the experimental scale; (2) the procedure for preparation oftitanium tetrachloride by metal – thermic reduction of titanium tetrachloride. Titaniummetal that was obtained by this method had purity [Ti] = 97.48%.

Key words: Processing flow sheet, name element: titanium tetrachloride (TiCl4);magnesium (Mg).

I. INTRODUCTION

We use magnesium metal reduction of TiCl4 in a vacuum electric furnace at hightemperature, together with a mixture fluxes MgCl2 and NaCl salt. The results were theproduct of titanium metal powder if handled with wet sponge and titanium metalsproducts if handled by vacuum distillation method.

II. EXPERIMENTAL RESULTS AND DISCUSSION

II.1. Raw materials

- Chemical materials

The main chemical used is: TiCl4 99.8%, Mg 99.5%, HCl 36.0%, HNO3 65.0%,acetone 98.0%, 99.99% Ar gas, the chemical analysis.

- Picture material




- Implementation Time: 12 months (Mar 2011 – Jun 2012)




VINATOM-AR 11--35


Magnesium metal:

1 2 3

Figure 1: Mg ingots. Figure 2: Mg turnings Figure 3: Mg granules,powder

II.2. Equipment and technology research and quality assessment

1. Heat generation equipment metal vacuum self-study design and manufacture.

2. Content analysis method of impurities by ICP - MS plasma.

3. Analysis of molecular structure on the device X-ray diffraction Bruker-D5005.

- Imaging equipment

Based on the principles of system equipment from Russia, America, Japan. Themain part of the second generation device is a different room, different temperatures:reaction chamber containing Mg, Ti product temperature set at 8500C – 10000C; TiCl4separate chamber above the required temperature to 1500C ≈ steam, to steam TiCl4

reacts with Mg. TiCl4 liquid container at the top level down gradually.Experimentalresults and discussion:

Figure 4: The drawing of thermal equipment of metal Ti treatment

Safety Valve

Evaporation chamber

Cup

vacuum tube

ecu 16

Gas ducts

reaction chamber

temperature probe

Magnesium melting

VINATOM-AR 11--35


Figure 5: Evaporating chamber and supply system TiCl4

Figure 6: The high temperature vacuum thermal furnace

II.3. Study influence of magnesium volum ratio compared with the actualtheory to product quality.

Base on reaction to form product: TiCl4 + 2Mg = Ti + 2MgCl2

So, if has 189.9 g TiCl4 + 48.6 g Mg then gained 47.9 g Ti + 190.6 g MgCl2

MTiCl4 = 189.9g; the reaction temperature t: 850oC; Time for reaction: τ = 4h.

Experiment results as:

Table 1: Influence of Mgfact/theory mass ratio to product quality

TNRatio

Mgfact/theory, %

Result, %

MTi/Mintermediate products ηTi

1 80 15.66 78.0

2 90 16.06 80.0

3 100 17.05 84.0

VINATOM-AR 11--35


4 120 18.07 91.0

5 140 17.60 88.0

Table above: MTi: metal Ti mass.Mintermediate products: Sum of intermidiate product mass after thermal.

ηTi, %: ProductivitySo, select best mass ratio is: Mgfact/theory = 120%.

II.4. Research the effects of batch refining temperature to the recallproductivity

Result

Research the effects of batch refining temperature from 7500C to 950oC.

MTiCl4 = 189.9g; MMg = 58.32g; smelting time: τ = 4 hours.

Experiment results are presented in the following table.

Table 2: Research the effects of temperature to the recall productivity

TN TemperatureExperiment results, %

MTi/ Mintermediate products ηTi

1 750 15.26 76.0

2 800 16.46 82.0

3 850 18.07 91.0

4 900 18.00 90.0

5 950 16.80 84.0

You can monitor clearly the graphic as following:

Figure 7: Smelting temperature influences to recall product mass

Pro

duct

ivit

y

Temperature

VINATOM-AR 11--35


At 850oC productivity maximum η% = 90%.So choose temperature t = 850oC

II.5. Research the effects of batch refining time to the recall productivity

Research changing reaction time from 1 hours to 6 hours.

Experiment results are presented in the following table.

Table 3: Research the effects refining time to the recall productivity

TN ,hExperiment results, %

MTi/ Mintermediate products Ti

1 1 14.68 78.0

2 2 16.06 80.0

3 3 17.60 88.0

4 4 18.07 91.0

5 5 18.02 90.3

6 6 18.00 90.0

So choose best time 4 hours.

II.6. Research handling intermidate product (SPTG)

Handl Mintermediate products usually by 2 methods.

* Axit method (or wet methhod).

* Vacuum distillation method at P = 0.07 mmHg; 9000C.

II.7. Quantity product evaluation

II.7.1. Powder metal form

After treatment Mintermediate products gained powder metal Ti as photo under:

0020021.0 mm1.0 mm1.0 mm1.0 mm1.0 mm

VINATOM-AR 11--35


Table 4: Contents of powder Titanium is: [Ti]= 86.56%

ZAF Method Standardless Quantitative Analysis

Fitting Coefficient : 0.3547

Element (keV) Mass% Error% Atom% Compound Mass% Cation K

N K 0.392 7.10 0.67 20.68 17.1141

Al K 1.486 1.99 0.43 3.01 1.0942

Si K* 1.739 0.33 0.40 0.48 0.2238

Ti K 4.508 86.54 0.60 73.67 78.5348

Cr K* 5.411 0.19 1.05 0.15 0.1414

Mn K* 5.894 0.18 1.23 0.13 0.1361

Fe K* 6.398 0.85 1.23 0.62 0.6806

Zr L 2.042 2.82 1.01 1.26 2.0750

Total 100.00 100.00

II.7.2. Form of metal spongySPTG distilled in vacuum, get spongy metal titanium, analysis results as

following:

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

keV

002

0

100

200

300

400

500

600

700

800

900

1000

Co

un

ts

NK

a

NK

sum

AlK

aS

iKa

TiL

l

TiK

esc

TiK

a

TiK

b

TiK

sumC

rLl

CrK

a

CrK

b

Mn

Ll M

nL

a

Mn

Lsu

m

Mn

Kes

c

Mn

Ka

Mn

Kb

FeL

l FeL

a

FeK

esc

FeK

a

FeK

b

ZrM

ZrL

l ZrL

aZ

rLb

ZrL

sum

VINATOM-AR 11--35


0 .0 0 1 .0 0 2 .0 0 3 .0 0 4 .0 0 5 .0 0 6 .0 0 7 .0 0 8 .0 0 9 .0 0 1 0 .0 0

k eV

0 0 1

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 0 0 0

Co

un

ts

NK

a

NK

sum

Mg

Ka

TiL

lT

iLa

TiL

sum

TiK

esc

TiK

a

TiK

b

a) Form of Ti – XH.1



Fitting Coefficient: 0.2006


N K 0.392 2.28 0.14 7.36 5.5770

Mg K* 1.253 0.24 0.12 0.45 0.1406

Ti K 4.508 97.48 0.28 92.19 94.2824

Total 100.00 100.00

001001

0.1 mm0.1 mm0.1 mm0.1 mm0.1 mm

Title : IMG1---------------------------Instrument : 6490(LA)Volt : 15.00 kVMag : x 400Date : 2011/12/19Pixel : 512 x 384

001001

0.1 mm0.1 mm0.1 mm0.1 mm0.1 mm


VINATOM-AR 11--35


b) Form of Ti- XH. 2

Table 6: Contents of powder Titanium is: [Ti]= 96.26 %


Fitting Coefficient: 0.2089


N K 0.392 3.48 0.14 10.96 8.4033

Mg K 1.253 0.26 0.12 0.47 0.1481

Ti K 4.508 96.26 0.29 88.58 91.4486

Total 100.00 100.00

0 .0 0 1 .0 0 2 .0 0 3 .0 0 4 .0 0 5 .0 0 6 .0 0 7 .0 0 8 .0 0 9 .0 0 1 0 .0 0

k eV

0 0 1

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 0 0 0

Co

un

ts

NK

a

NK

sum

Mg

Ka

TiL

lT

iLa

TiL

sum

TiK

esc

TiK

a

TiK

b

0 0 20 0 20.1 mm0.1 mm0.1 mm0.1 mm0.1 mm

Title : IMG1---------------------------Instrument : 6490(LA)Volt : 15.00 kVMag. : x 400Date : 2011/12/19Pixel : 512 x 384

VINATOM-AR 11--35


c) Form of Ti –XH.3



Fitting Coefficient : 0.1919


N K 0.392 2.71 0.14 8.69 6.6137

Mg K 1.253 0.18 0.12 0.33 0.1022

Ti K 4.508 97.11 0.29 90.98 93.2842

Total 100.00 100.00

0 0 30 0 30.1 mm0.1 mm0.1 mm0.1 mm0.1 mm


0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

keV

003

0

100

200

300

400

500

600

700

800

900

1000

Co

un

ts

NK

a

NK

sum

Mg

Ka

TiL

lT

iLa

TiL

sum

TiK

esc

TiK

a

TiK

b

VINATOM-AR 11--35


Titanium formed powder has quality lower than Ti formed spongy, due to theTitannium powder handled by axit method, quantity of gas impurities as N, O, H inH2O, in axit penetration to product. And Titanium that distilled in a vacuum, lessimpurities gas penetrated thus has a higher Ti content.

II.8. Result of impurities components evaluation

Apply ICP – MS method, analysis impurities in vacuum distillation of Titaniumwith result as under:

Tabel 8: The impurities composition in spongy metal Ti

TT Norm Unit Content TT Norm Unit Content

1 Mg mg/kg 838.68 11 Zn mg/kg 3106.62

2 Al mg/kg 50.64 12 Ga mg/kg 4.87

3 K mg/kg 7.41 13 As mg/kg 0.33

4 V mg/kg 5.07 14 Se mg/kg 1.48

5 Cr mg/kg 540.39 15 Sr mg/kg 2.83

6 Mn mg/kg 232.93 16 Cd mg/kg 0.12

7 Fe mg/kg 212.42 17 Ba mg/kg 189.59

8 Co mg/kg 0.37 18 Pb mg/kg 17.24

9 Ni mg/kg 12.29 19 U mg/kg 0.57

10 Cu mg/kg 322.96

Base on the result table, small amounts of impurities included: Zn = 0.3106%,Mg = 0.0838%; Cr = 0.054%; Cu = 0.032%; Therefor, the product is clean relatively.

VINATOM-AR 11--35


II.9. Technological process of Titanium Preparation

II.9.1. Outline of preparing process

II.9.2. Technology process of preparing metal Titanium

Weight material as calculation, take it to the furnace, close the door, raisingtemperature of under to 850oC and continuously desiccate vacuum to 10-2 at.

- When the calcination temperature reached 850oC, Mg melted completely,close vacuum valve, charge TiCl4 with speed υ = 5 ml/ph. Metal thermal reactionoccurs, and metal bomb pressure decreases.

- After 4 hours, bomb metal pressure increased, indicating gradual reaction iscomplete, close vacuum valve, switch off furnace interruptor, charge Ar gas to metalbomb reached pressure at P = 0.5 at, finish metal reconstitution process.

When furnace cooled to temperature of the room, bring product to handle bymethod of axit or vacuum distillation.

TiCl4 Mg metal

BOM FORTHERMALREACTION

Product after Thermal(Intermidiate product)

Clean Ti

Vacuum desiccate,load Ar

t1:150oC;t3:900oC

Wet powderTi

Porous Ti dry powder

Vacuum distillationevaporation

Mg, MgCl2900oC, 10-2at

Porous dry piece Ti

Separate H2O

Separatexit

Pastry

Vacuum drying

H2O

70oC, 10-1at

HCl 20%

VINATOM-AR 11--35


III. CONCLUSION

The project has targeted initial results as:

1. Design and manufacturer prepare equipment system of metal Titanium.

2. Research and develop technical process for titanium metal preparation fromTiCl4 with Mg reagents.

3. Has been prepared metal Ti reached high metal content, Ti = 97.48%.

The preparation of metal Titanium is very difficult in technology and equipment,but we had obtained this product, which is the success of projects as well as it is reachedto a larger scale research.

REFERENCES

[1]. Symposium Report "Development Consultant titanium industry in Vietnam", TheScientific casting metallurgy Vietnam, Hanoi March/2011.

[2]. А.Н. Зеликман, О.Е. Креин. Металлургия Редких Металлов. Москва«Металлургия»1978.3. Bui Van Muu, Nguyen Van Hien, Nguyen Ke Binh, Truong Ngoc Than. Theory ofmetallurgical processes. Fire training. Hanoi-1997.

[3]. Iu. V. kariakin. Pure chemicals. Publishing House of Science and Technology inHanoi in 1990.

[4]. J.W. Mellor, D.Sc., F.R.S. Inorganic and Theoretical Chemistry. Volume VII.Longmans, Green and co. London. New York. Toronto.

[5]. Nguyen Van Sinh. A scientific report. Research on manufacturing equipment andbuilding process zirconium metal sponge prepared by the method of TiCl4 with Mg saltsreconstituted. Hanoi 2011.

[6]. Phung Viet Ngu, Pham Kim Dinh, Nguyen Kim Thiet. Theory of metallurgicalprocesses. Fire practiced 2. Hanoi-1997.

[7]. United State Patent 4,285,724. Continuous production of zirconium powder finelyDivided - 2006.

[8]. Z.L.K. Yasuda et al J alloys and Comp. Vol 193, 26-28, 1993.

[9]. X-Kh Nguyen Khac Xuong. "Material metal."

VINATOM-AR 11--36


REREARCH ON DETERMINATION OF U(IV) AND U(VI)IN URANIUM ORE

Le Hong Minh, Nguyen Xuan Chien, Do Thi anh Tuyet and Bui Thi Ngan

Center for Analytical Chemistry,Institute for Technology of Radioactive and Rare Elements,VINATOM


Abstract: In this project, we have researched on the method for determination of U(IV)and U(VI) in uranium ore. Uranium ore is decomposed with concentrate hydrofluoricacid (HF). U(VI) is dissolved and remained in the solution. U(IV) is also dissolved andcombined with F- ion in the solution to form precipitate UF4 that is settled. Two valenceforms of uranium are separated from each other and determined by suitable methods.The method was well applied to determine contents of U(IV) and U(VI) in uranium oreswith different weathering levels.

I. RESULTS AND DISCUSSION

I.1. Research on conditions for quantitative precipitation of U(IV) with HF

Put a certain volume of U(IV) solution into the Teflon beaker, add 5 ml ofconcentrate HF acid, the blue-green precipitates UF4 are occurred in the beaker.

So, U(IV) could combine with F- ion in the solution to form the precipitates UF4

that have typical blue-green color.

To research on conditions for quantitative precipitation of U(IV) with HF, weput each volume of U(IV) solution that contains 1,0 mg of U(IV) and 5 ml ofconcentrate HF into each Teflon beaker. Keep one Teflon beaker at room temperaturefor 1 hour. Heat other beakers slightly in electric plate for different time (if most HFacid in the beaker fumes, it is necessary to supply more HF and continue to heat thebeaker). The Teflon beakers with precipitates UF4 are then kept cool down to roomtemperature. The precipitates formed in those beakers are filtered in the plastic funnelswith grade 390 Sartorius filtering papers. Then, precipitates are washed with dilute HFacid (5%). After being filtered, the solutions are collected into other Teflon beakers andthen are evaporated to almost dryness to eliminate HF. After that, add 2 ml of HNO3

into the mixtures and then boil them down to almost dryness. Add 10 ml of 0.3M HNO3




- Implementation Time: 12 months (Apr 2011 - Mar 2011)




VINATOM-AR 11--36


and boil them slightly, take them out of the electric plate and cool down to roomtemperature. Fill up the solutions to 25 ml to determine uranium by ICP-MS. Theexperiment results are shown in the table 1.

Table 1: The precipitation of UF4 in different time and temperatures

Duration of timefor heating

No heating 15 minutes 30 minutes 1 hour 2 hours

U amount in thesolution

No No No No No

The results in the table 1 show that, U(IV) combined with F- ion to formquantitatively UF4 precipitates at room temperature as well as at high temperature. Inthe most cases, ore samples are decomposed in high temperature condition. The aboveexperiment result proves that when uranium ore is decomposed with HF acid at hightemperature, U(IV) in ore combines with F- ion to form UF4 precipitates quantitatively.

Replace Teflon beakers with Teflon bombs and carry out another experiment.Put a volume of U(IV) solution containing 1,0 mg of U(IV) and 5 ml of concentrate HFacid into each Teflon bomb, place those bombs in drying oven at 1800C. After gettingrequired temperature, the bombs are kept in drying oven for 30 minutes. Then, takethem out of the oven and kept cool down to room temperature. The other steps of theexperiment are implemented as described in the previous experiment. The results showthat U(IV) is completely transformed into UF4 precipitate and it is not found in filteringsolution.

The making of UF4 precipitates up in the Teflon bomb has the advantage that theprecipitates are formed in close system without adding more HF. In practice, thedecomposition of samples in the Teflon bombs is more effective than in Teflon beakers.

I.2. Research on decomposition of UF4 precipitate

The UF4 precipitates in filtering paper are transferred into another Teflon beakerand then rinsed with HNO3 or HCl or dilute HNO3 + HCl mixture (corresponding toadding concentrate HNO3; HCl or HNO3 + HCl mixture for UF4 decomposition then).The collected solution and precipitates are evaporated to dryness. Add 10 ml ofconcentrate HNO3 or HCl or (1+3) HNO3 + HCl mixture to the residues, boil slightlythe mixtures in electric plate that has a temperature control. If the solution in the beakeris exhausted, it is necessary to supply it more and continue to boil. After being dissolvedcompletely, the solutions of UF4 are evaporated to dryness to eliminate HF. Add 5 ml ofconcentrate HNO3 into the mixture, boil it down to dryness again. Finally, the residuesare dissolved in 10 ml of 0.3M HNO3 and the solutions are slightly boiled. Keep cooldown the solutions and fill them up to 25 ml to determine uranium by ICP-MS.

The experiment results showed that the blue-green precipitates UF4 wereremained in the beaker if only HNO3 or HCl acid is used to decompose them evenduring a long time. That means only HNO3 or HCl acid could not completelydecompose UF4 in the described experiment conditions. The precipitates UF4 werecompletely decomposed with (1+3) HNO3 + HCl acid mixture. The obtained solutionwas transparent.

VINATOM-AR 11--36


To investigate a required duration of time for decomposition of precipitates UF4, weboil the mixtures in electric plate for different duration of time. The results are shown in thetable 2.

Table 2: The obtained U amount depends on the duration of time for decompositionof precipitates UF4 (the amount of U(IV) is 1.0 mg from beginning)

Duration of time (hour) 0.5 1.0 1.5 2.0 2.5 3.0

Obtained amount of U(mg)

0.79 0.88 0.92 0.97 0.96 0.98

The results in the table 2 proved that the precipitates are decomposed with (1+3)HNO3 + HCl mixture and the required duration of time is 2 hours.

I.3. Investigating kind of filtering paper and duration of time for settlingprecipitates UF4

I.3.1. Filtration of UF4 with different kind of filtering paper

The precipitates UF4 obtained from the amount of 1.0 mg of U(IV) are settledfor 5 hours, then filtered with yellow-mark, green- mark filtering paper of China andgrade 390 Sartorius filtering paper of Germany, rinsed with (5%) dilute HF acid. Theprecipitates are decomposed and U is determined as described above. The results areshown in the table 3.

Table 3: The obtained U amount depends on the kind of filtering paper usedforfiltration of precipitates UF4 (the amount of U(IV) is 1.0 mg from beginning)

Kind offiltering paper

Yellow-mark(China)

Green- mark(China)

Grade 390 Sartorius(Germany)

Obtained amountof U (mg)

0.67 0.82 0.98

The results showed that yellow-mark, green- mark filtering paper of China arenot good for the filtration of precipitates UF4. The grade 390 Sartorius filtering paper ofGermany is good enough and suitable in this case.

I.3.2. Investigating suitable time for settling the precipitates

Add HF into U(IV) solution, the precipitates UF4 obtained are settled fordifferent duration of time before filtration. The precipitates are filtered, decomposed andU is determined as described in the previous experiments. The result shows that thesuitable duration of time for settling the precipitates is 3 hours, as demonstrated in thetable 4.

Table 4: The obtained U amount depends on duration of time for settlingthe precipitates UF4 (the amount of U(IV) is 1.0 mg from beginning)

Duration of time (hour) 1 2 3 4 5

Obtained amount of U (mg) 0.90 0.95 0.98 0.97 0.98

VINATOM-AR 11--36


Look at the table 4, we can see that the duration of time for settling theprecipitates affects the experiment results. The cause is may due to the smooth, smallprecipitates UF4 stay close to filtering paper, that make difficulty in washing them outof the filtering paper. So, 3 hours is the most suitable duration of time for precipitates toform and not stay close to filtering paper.

I.4. Study on the possibility for separation of U(IV) and U(VI) from eachother

U(IV) and U(VI) mixture solutions are prepared with different ratios in Teflonbeakers as shown in the table 5.

Table 5: The constituent of U(IV) and U(VI) mixture solutions

Beaker U(IV) and U(VI) mixture solutions Ratio U(IV) : U(VI)

1 0.75 mg of U(IV) + 0.25 mg of U(VI) 3:1

2 0.75 mg of U(IV) + 0.5 mg of U(VI) 3:2

3 0.5 mg of U(IV) + 0.5 mg of U(VI) 1:1

4 0.5 mg of U(IV) + 0.75 mg of U(VI) 2:3

5 0.25 mg of U(IV) + 0.75 mg of U(VI) 1:3

Add 5 ml of HF to each of Teflon beaker, the precipitates obtained are settledfor 3 hours at room temperature. They are then filtered in plastic funnel with grade 390Sartorius filtering paper and washed with 5% HF acid. The solutions after being filteredare collected into other Teflon beakers and evaporated to dryness to eliminate HF. Add5 ml of concentrate HNO3 then boil the solutions down to near dryness again. Finally,the residues are dissolved in 10 ml of 0.3M HNO3. The solutions are slightly boiled onelectric plate and then taken out for keeping cool. Fill up the solutions to 25 ml todetermine U by ICP-MS. These are U(VI) form.

The precipitates on filtering paper is transferred to other Teflon beakers andwashed with dilute HNO3 + HCl solution. The obtained solutions and precipitates UF4

are evaporated to eliminate HF. Add 10 ml of concentrate (1+3) HNO3 + HCl mixtureacid, boil the solutions slightly for 2 hours for dissolution of precipitates. Afterprecipitates UF4 dissolve completely, add 5 ml of concentrate HNO3 and boil thesolutions down to near dryness again. Finally, the residues are dissolved in 10 ml of0.3M HNO3. Those solutions are slightly boiled on electric plate and then taken out forkeeping cool. Fill up the solutions to 25 ml to determine U by ICP-MS. These are U(IV)form.

The results are shown in the table 6.

VINATOM-AR 11--36


Table 6: Obtained amount of U(IV) và U(VI) in mixture solution

Beaker

Amount of U from the beginning(mg)

Obtained amount of U(mg)

U(IV) U(VI) U(IV) U(VI)

1 0.750 0.250 0.732 0.245

2 0.750 0.500 0.725 0.442

3 0.500 0.500 0.508 0.495

4 0.500 0.750 0.483 0.760

5 0.250 0.750 0.232 0.740

The result showed that, the obtained amounts of U(IV) and U(VI) are inagreement with that of U from the beginning. That means two valence states of uraniumare completely separated from each other in HF medium in experimental conditions asdescribed above.

II. CONCLUSION

The aim of scientific research subject is achieved, that includes:

- The procedures for analysis of U(IV) and U(VI) in uranium ore are build-up ontwo aspects: determination of U(IV) and U(VI) separately or determination of U(VI)and total U in advance, the content of U(IV) is the difference of total U and U(VI). Bothof them have their own advantages and disadvantages and they can be used for controlthe precision of an analysis.

+ First procedure: uranium ore is decomposed with concentrate HF acid, theprecipitates UF4 are filtered, U(VI) is determined in solution part, the precipitates UF4

are decomposed with HNO3 + HCl acid mixture to determine U(IV).

+ Second procedure: uranium ore is decomposed with concentrate HF acid, theprecipitates UF4 are filtered and discharged, U(VI) is determined in solution part. Thesame amount of uranium ore is decomposed with concentrate HF + HNO3 + HCl acidmixture to determine total U, the content of U(IV) is the difference of total U andU(VI).

- The procedures were applied to determine the contents of U(IV) and U(VI) inuranium ore in Pa Lua, Quang Nam province, that have a different weathering level.

REFERENCES

[1]. Thủy luyện Urani, Thân Văn Liên, Nxb. Đại học Quốc gia Hà Nội;[2]. Chemical Analysis of Geological Materials: Theory and Practice, AMD, Chemistry

Group, Hydrebad, India, 2003;

VINATOM-AR 11--36


[3]. Depleted Uranium in Serbia/Montenegro, Post-Conflict EnvironmentalAssessment, UNEP document, 2002;

[4]. About Uranium Determination, I.Topaloglu, N.Baycin;

[5]. Recent Development in uranium resources and production with emphasis on in-situleaching mining, IAEA-TECDOC-1396 (2004);

[6]. Uranium production and raw materials for the nuclear fuel cycle. IAEA-CN 128(2005);

[7]. Manual of acid in-situ leaching uranium mining technology, IAEA-TECDOC-1329(2001);

[8]. Determination of UO3 and U3O8 in brown oxide, L. G. Stonhill, Canal. J. Chem.Vol. 36 (1958);

[9]. Oxidation state analyses of uranium with emphasis on chemical speciation ingeological media, Heini Ervanne, University of Helsinki, Finland (2004).

VINATOM-AR 11--37


STUDY OF THE INFLUENTIAL FACTORS IN ESTERPREPARATION OF 2, 4, 6-TRIFLUOROBENZOIC ACID

SURVICING TO FBA ANALYSIS PROCESS

Huynh Thai Kim Ngan, Vo Thi Ngoc Cam, Dang Nguyen The Duy, Tran Tri Hai,Ho Tran The Huu, Nguyen Huu Quang and Le Thi Thanh Tam


Abstract: DOE pack 2000 has been used to evaluate factors that are influential on thederivative of 246TFBA reaction, such as time, temperature, moles ratioPFBBr/246TFBA and Na2CO3. The structure of ester of 246TFBA was established byspectroscopic methods. The influences of produced water components (alkylphenol,sanility, benzoic acid, aliphatic acid) on FBA’s analysis process are hereafter discussed.

Keywords: 246TFBA, PFBBr, spectroscopic method, produced water.

I. INTRODUCTION

Tracers used in Interwell Tracer Test in principle can be either chemical orradioactive which are suitable for the purposes of tracing reservoir fluids under reservoirconditions. Both radiotracer and non-radioactive tracers in general can be used forIWTT [1]. On the other hand, non-radioactive tracers such as Fluorinated Benzoic Acids(FBA) and FBA’s derivation are now commonly used for the interwell tests yet FBA isless volatile for GC analysis, so FBA must be transformed into different types orvolatile substances such as ester [8]. Derivatization can also be used to enhance thedelectability of the analytes [6]. The derivatization of the 246TFBA is as followed:

DOE pack 2000 is an easy-to-use design of experiments software guiding usersthrough a logical process of planning, designing, implementing and interpreting




- Implementation Time: 14 months (Mar 2011-May 2012)




VINATOM-AR 11--37


industrial experiments. The software is used to evaluate factors that are influential onsuch those reactions like time, temperature, PFBBr/246TFBA, Na2CO3…

Moreover, ester of 246TFBA is not on sale in store thus there must be synthesesof ester of 246TFBA compounds for GC’s calibration standard. The structure of thisproduct was established by using spectroscopic methods. In addition, the analyte has tobe separated from the naturally high content of inorganic and organic material existingin aqueous reservoir sample. Therefore, the influence of components of produced water(alkylphenol, salinity, benzoic acid, aliphatic acid) on FBA’s process is discussed.


II.1. 246TFBA Derivation

2ml of a 4% solution of pentafluorobenzyl bromide in acetone is placed in 4 mLscrew-cap vial. Then add a few grains of anhydrous potassium carbonate, the vial iscapped, and then placed in a 95oC heater in 60 minutes. After the 60-minute period, thevial is removed from the heater and cooled in ambient temperature. The reactionproduct, which is now a pentafluorobenzyl ester of the corresponding 246TFBA, mustbe separated from “un-reacted reagents and impurities” (1) which may be co-elutedaccordingly during analysis process. (1) can be executed by performing a liquid/liquidextraction followed by solid phase extraction. The liquid/liquid extraction is executedby adding 6ml n-hexane to the above solution which is then vigorously shaken in 1minute and centrifuged in 3 to 4 minutes afterwards. The hexane phase will be the clearupper layer and then be treated in a SiO2 SPE cartridge. A 6ml, 1g SO2 SPE cartridge isconditioned by treating with 5 ml hexane at gravity flow rate. The exit is capped to stopthe flow accordingly once the hexane level in the reservoir reaches about 2mm. Add2ml of hexane to the SPE and then the 1ml aliquot of sample. The eluted aliquot (4ml of6:1 toluene in n-hexane) is applied once the entire sample has passed onto the resin. Thegreat majority of the ester is removed in this aliquot, and then the liquid must beevaporated at ambient temperature and weighing until a constant weight.

The structure of this ester was established by spectroscopic methods.[9]

II.2. Optimizations of ester yield by DOE pack 2000

The regression equation was calculated by composite central model as follows:

Y = -221+0,161X1+0,375X2+8,24,3X3-0,0000597X12-0,00229X2

2-0,0256X32

R2=0,924

In which: Y = yield of ester, %

X1= moles ratio PFBBr/246TFBA

X2= time, minute.

X3= temperature,oC

A coefficient of determination equal to 0,924 indicates that there would be agood fit to the data.

On the basis of finding optimal solution for regression equation, determine thevalue Y = Y max by Solve in DOE pack 2000 and predicted results as follows: Y = 84%at X1 = 1350, X2 = 84, X3 = 80.

VINATOM-AR 11--37


From the results of the optimal prediction model, the reaction of 246TFBA andPFBBr at 84oC in 80 minutes with mols ratio PFBBr/246TFBA 1350 have a good yield(80%).

II.3. Study of influence factors in produced water on yield of ester

Alkylphenol

Recovery efficiency (R) of ester as table 1:

Table1: Studying influence of alkylphenol on yield of ester 246TFBA.

Sample 1P 2P 3P 4P 5P Average SD Confidence level

R, % 81 78 75 69 78 76 4 5

There is not phenol’s peak in the chromatograph. The cause maybe:

- Phenols were lost by evaporated with acetonitrile solution at 40oC.

- Capacity of sorption of solid phase extraction.

Capacity of sorption of solid phase extraction: carried out as scheme below

There are phenol, o-cresol and 2,6-dimethylphenol in the chromatograph.

In fact, retention of alkylphenol by SPE is done. Therefore, the presence ofalkyphenol does not influence yield of ester.

Aliphatic acid

There is no existence of aliphatic acid’s peak in the chromatograph. So the246TFBA’s procedure does not find aliphatic acid in sample. That means there is noinfluence on the yield of ester with the presence of aliphatic acid.

Adjusted pH by HCl to pH 1,5

100ml of produced water and spike solution(phenol, 2MP, 26DMP)

Filter aliquot through filter paper paper

Loading sample on SPE Strata X (500mg, 6ml) conditioned

Rinsing SPE by 5ml of HCl pH 1.5

Allowing the vacuum to thoroughly dry the resin in 30minutes

Eluted by 4ml of Acetonitrile solution GC/MS analysis

VINATOM-AR 11--37


Benzoic acid (BZA)

In the chromatograph, there are peak of 246TFBA (tR=10,645) and peak of esterof benzoic acid (pentafluorobenzyl benzoate, tR=10,266). Yield of ester 246TFBA is(74±5) %.

Figure 1: Chromatograph of BZA and ester 246TFBA

There is obviously no influence of benzoic acid in produced water on the yieldof ester since the mol of PFBBr is so many times higher than benzoic acid.

Salinity

The results in table 2 indicate that there is the decrease of ester 246TFBArecovery efficiency once the salinity increases.

Table 2: Studying influence of salinity on yield of ester 246TFBA

Salinity, %R, %

18 9 6 4 3

1M 11 32 55 76 75

2M 15 28 61 75 81

3M 13 31 66 69 80

4M 12 34 63 73 71

5M 8 26 52 71 77

Average 12 30 59 73 77

SD 3 3 6 3 4

Confidence level 3 4 7 4 5

VINATOM-AR 11--37


III. CONCLUSION

In summary, the Project “Study of influenced factors on ester of 2,4,6-Trifluorobenzoic acid preparation for FBA’s procedure” was performanced from 4/2011to 5/2012, have achieved the target set, the completion of research content as follows:

- Derivatization of 246TFBA by PFBBr providing ester of 246TFBA forGC/MS’s calibration standard. The structure of this product was established byspectroscopic methods.

- Reaction of the 246TFBA with PFBBr in Na2CO3 at 84oC in 80 minuteswith the ratio mol of PFBBr/246TFBA 1350 providing ester of 246TFBA in good yield.

- The presence of alkyphenol, aliphatic acid, benzoic acid do not significantlyinfluence on yield of ester. Thus, the recovery efficence of FBA’s procedure as wellderivatization of 246TFBA is increase when the salinity of produced water > 4%.

REFERENCES

[1]. B. Zemel, Tracer in the Oil Field, Developments in Petroleum Science, 43, ElsevierScience, NewYork, 1995.

[2]. Ralph L. Shriner, Christine K. F. Hermann, Terence C. Morrill, David Y. Curtin,Reynold C. Fuson, The Systematic Identification of Organic Compounds, John Wiley & Sons,Seventh Edition, 1998.

[3]. Jerry M. Neff, Bioaccumulation in Marine Organisms: Effect of Contaminantsfrom Oil Well Produced Water, Elsevier Science, 2002.

[4]. Joseph F. Gibbens, An Evaluation of Several Fluorinated Benzoic Acids for use assoil and groundwater Tracers,New Mexico Institute of Mining and Technology Socorro, NewMexico, 1989.

[5]. Journal of Chromatography A, 793 (1998).

[6]. K.Blau and J.M.Halket , Handbook of Derivatives for Chromatography, JohnWiley and Sons, 1993.

[7]. Rene K. Juhler, Annette P.Mortenen, Analysing fluorobenzoate tracers ingroundwater samples using liquid chromatography-tandem mass spectrometry. A tool forleading studies and hydrology, Denmark.

[8]. Clas Ulrich Galdiga, Tyge Greibrokk, Ultra trace determination of Fluorinatedaromatic carboxylic acids in aqueos reservoir fluids by solid phase extraction in combinationwith negative ion chemical ionization mass spectrometry after derivatisation withpentafluorobenzyl bromide, Springer 1998.

[9]. Typical analytical and spectroscopic data:[10]. Pentafluorobenzyl 2,4,6-trifluorobenzoate: IR

(CHCl3) ν 1728 (COO); 1H NMR (300 MHz, CDCl3) δ 5,452(2H, S, -CH2), 6,696-6,704 (6H, t, arom H); 13C NMR (75 MHz,CDCl3) δ 193.9 (C-4), 161.02 (C-2, C-7), 160.95 (C-11,C-13),160.9 (C12), 160.07 (C-10, C-14), 101.26 (C-3, C-5), 101.5 (C-1,C-9), 54.4 (CH2) ; MS m/z (rel intensity) 396 (71, M+), 181 (81),

159 (81), 131 (58), 81 (45).

71

6

54

32

O

O

F

F F

89

10

11

12

1314

F

F

F

F

F

VINATOM-AR 11--38


DETERMINATION OF U, FE, V IN URANIUM OREAND GROSS ALPHA BETA THROUGH THE EXPLOITATION,

PROCESSING AND HANDLING OF RADIOACTIVE OREON THE PORTABLE XRF SI-PIN DETECTOR AND DEVICE

OF ALPHA BETA MPC-2000

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

Institute for Technology of Radioactive and Rare Elements,VINATOMNo.48 Lang Ha, Dong Da, Hanoi, Vietnam

Abstract: The concentration of some elements such as U, Fe, and V in uranium ore wasdetermined by using Si-PIN detector fluorescence spectrometry. The technicalparameters of Si-PIN spectrometry were investigated. The fundamental parameters inQXAS software were used for calculating analytical results. The gross alpha beta fromthe liquid radioactive liquid was also determined by MPC-2000 instrument based on thedependence of the signal received ability of detector on thickness of analysis samples.The precision and accuracy of quantitative analysis were tested by references materialstandard and comparative analysis with different analytical methods.

INTRODUCTION

The quantitatively analysis of U, and other chemical elements such as Fe, V inuranium mineral is very important in the evaluating uranium mineral resources andchoosing an appropriate technology for the separating uranium mineral. Thedetermination of gross alpha and beta is very important in the field of treatment andmanagement of radioactive wastes.

I. EXPERIMENTAL

The X-ray fluorescence method

- Investigate the current, voltage of X ray generator to obtain thecharacteristic X-ray with the highest intensity.

- Study the quantitative methods for determination of U, Fe, V in uraniumore.




- Implementation Time: 12 months (Jan 2011 – Dec 2011)




VINATOM-AR 11--38


Determine the gross alpha and beta

- Study on the effect of the thickness of the analysis samples on signalreceived ability of detector of alpha, beta.

- Analyze certified reference material and compare with other analyticalmethods.


II.1. X-ray fluorescence analysis

II.1.1. Investigate the current, voltage of X ray generator to obtain thecharacteristic X-ray with the highest intensity

The relationship between characteristic X ray intensity and high voltage of X-ray generator are shown in the table 1.

Table 1: Study the depend of characteristic X line of U, V with x-ray tube intensity

Fe(counts)

U(counts)

V(counts)

Si(counts)

Measurementtime (s)

Current(µA)

Dead time(%)

120932 6562 5267 11305 572.64 5 4.56

219653 12198 9489 20601 534 10 11

302589 16598 12944 27096 498.36 15 16.94

372083 20982 16091 32958 466.26 20 22.29

427832 24264 18623 37152 435.24 25 27.46

475266 26663 20529 39869 407.34 30 32.11

516695 29059 22508 42243 380.76 35 36.54

539934 30442 22834 43025 362.76 40 39.54

566216 32560 24661 44068 336.84 45 43.86

613886 35842 26104 42376 276.9 60 53.85

II.1.2. Fundamental parameter method

Fundamental parameter is the most versatile method for quantification in theQXAC package and suited even for completely unknown samples. Practically all modesof excitation with electromagnetic radiation in the range of X-rays can be covered andmany more parameters can be selected to match the assumptions needed for thecalculations with the experiment.

VINATOM-AR 11--38


The specially characteristic when calculating using fundamental parametersmethod are some factors such as absorption and enhancement correction are taken intoconsideration.

II.2. Determination of gross alpha beta

Calculate the dependence of the signal received ability of detector on thicknessof analysis samples.

Effb= (ncgb-nbb)/Ab

with Ab= AK-40 x mKCl

Table 2: The dependence of the signal received ability of detector on thicknessof analysis samples.

Number Samplemass(mg)

Mass ofKCl in

disk(mg)

Activitiesof K-40in disk(cpm)

ncgb

(cpm)nbb

(cpm)

(ncgb-nbb)/

(cpm)

Efficiency(%)

1 28.9 10 8.87 42.9 39.2 3.7 41.7

2 47.4 25 22.175 48.3 39.2 9.1 41.0

3 127.5 50 44.35 57.2 39.2 8.9 40.1

4 191.8 100 88.7 74.3 39.2 35.1 39.6

5 398.4 100 88.7 72.7 39.2 33.5 37.8

6 608.5 100 88.7 71.6 39.2 32.4 36.5

7 802.8 100 88.7 71 39.2 31.8 35.8

8 997.9 100 88.7 69.9 39.2 30.7 34.6

9 1514.2 100 88.7 69.3 39.2 30.08 33.9

VINATOM-AR 11--38


y = 5E-06x2 - 0.0123x + 41.71

R2 = 0.9911

05

1015202530354045

0 500 1000 1500

Mass of analysis sample(mg)

Efficiency(%)

Figure 1: The dependence of the beta signals received abilityof detector on thickness of analysis sample.

II.3. Comparison of analytical results by different methods and using IAEACRMs

II.3.1. Analyze U, Th in uranium ore by X-ray fluorescence Si-PIN detectorusing fundamental parameter method, compare with the one when analyzing U, Th byGamma Spectrometry.


Table 3: Analytical Results obtained by XRF and Gamma spectrometry

Sample code

U(ppm) Th(ppm)

FoundValue

byXRF

FoundValue bygamma

Relative

Error(%)

FoundValue by

XRF

FoundValue bygamma

Relative

Error (%)

Uranium ore 566 545 3.85 25.3 28.4 10.92

Uranium ore BPH 773 757 2.11 50.2 53.4 5.99

Uranium ore CPH 625 625 0.00 69.4 64.0 8.44

Uranium ore PH 147 137 7.30 27.5 28.4 3.17

II.3.2. Compare the reference material standards on 5 IAEA sample 5 withIAEA Sample 3 ( IAEA-CU-2008-03 World-wide open proficiency test on thedetermination of gamma emitting radionuclides. Laboratory No 388).


VINATOM-AR 11--38


Table 4: Analysis of two IAEA-CRMs

Samplecode

Radio.activity

Mass ofdisk

withoutsample (g)

Massof diskwith

sample(g)

Masssample(mg)

Volume(mg)

Count Background

Efficiency ( %)

Result(Bq/l)

CertifiedValue(Bq/l)

IAEA-Sample 5

Alpha 9.4734 9.4921 18.7 0.016 1.8 0.2 21.15 7.88 7.68

Beta 9.4734 9.4921 18.7 0.016 51.11 39.1 41.48 30.16 30.7

IAEA-Sample 3

Alpha 9.4104 9.5025 92.1 0.1 0.08 0.06 9.84 0.03 < 0.2

Beta 9.4104 9.5025 92.1 0.1 39.9 39.1 41.71 0.160 < 0.3

Look at the table 4, we can see that analysis results are reliable, compare withthe reference material standard.

III. CONCLUSION

Project has solved the following issues:

1. The technical parameters of Si-PIN spectrometry were investigated. Somequantitatively analysis methods used in X-ray fluorescence such as calibration curveand fundamental parameters were studied. The detection limit of U= 30 ppm, Fe= 50ppm and V= 30 ppm in uranium ore was received.

The gross alpha, beta from the liquid radioactive waste was also determined byMPC-2000 instrument based on the study of the dependence of the signal receivedability of detector on thickness of analysis samples.

2. The precision and accuracy of quantitative analysis were tested byreferences material standard and comparative analysis with different analytical methods.

Base on the results received, the procedure for analysis of U, Fe, and V inuranium ore by using portable X-ray fluorescence Si-PIN and the procedure fordetermination of gross alpha, beta in liquid radioactive wastes were established.

REFERENCES

[1]. Ron Jenkins , X-ray Fluorescence Spectrometry. John Wiley &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. Ver1.2(1995-1996)

[4]. Rafal Sitko. Quantification in X-ray Fluorescence analysis theoretical background

[5]. TCVN 6219:1995. Water quality - Measurement of gross beta activity in non -saline water - Thick source method. Ha noi -1995

[6]. TCVN 6053:1995. Water quality - Measurement of gross alpha activity in non -saline water - Thick source method. Ha noi -1995

[7]. UNLV Department of Health Physics Laboratory Operating Procedure

Determination of Gross Alpha and beta Radioactivity in Water.

VINATOM-AR 11--39


RESEARCH ON THE ESTABLISHMENT OF DESIGNREQUIREMENTS (TOR) FOR CENTER FOR NUCLEAR SCIENCE

AND TECHNOLOGY

Le Van Hong, Nguyen Nhi Dien, Nguyen Kien Cuong, Nguyen Thanh Binh, PhamVan Lam, Nguyen Minh Tuan, Nguyen Canh Hai, Trinh Van Giap, Than Van Lien

Vietnam Atomic Energy Institute (VINATOM)

No.59 Ly Thuong Kiet, Hoan Kiem, Hanoi, Vietnam

Abstract: The report presents four chapters related to the following topics: Generalexplanation and description of the Center of Nuclear Science and Technology; The roleof new research reactor; Economic efficiency evaluation directly of applications onresearch reactor and Requirements for selection of new research reactor. The functionsand missions of the Center with the main laboratories and main equipments have beenidentified. The main equipment of the Center is research reactor with power from 10 to20 MW. In order to satisfy long term application requirements, the designcharacteristics and the safety features of the new research reactor have been consideredin detail. The basic content of the Terms of Reference (TOR) of the Center wasprepared and submitted to counterpart for consideration.

I. INTRODUCTION

Based on actual national development strategy of atomic energy and nuclearprogram as well as on the different governmental legal basic, Vietnam Atomic EnergyInstitute is preparing necessary documents for establishment of Center for NuclearScience and Technology (CNST), including the Terms of Reference (TOR) of theCenter. Basically, the goal of the Center is in order to proceed to master technology,better support for nuclear power projects, oriented basic research and applications inmany areas of life, improve national potential in nuclear technology and humanresources training. The main mission of the Center related to national nuclear programincluding research on nuclear reactor, the basics research oriented applications,production and services implementation, personnel training. The organizational modelof the CNST with Centers and Departments has been determined in detail with specificfunctions and missions to each organization.








VINATOM-AR 11--39


In the first stage, main equipments for the CNST have been establishedincluding research reactor, hotcells and isotope production lines, neutron activationanalysis equipment, research instruments of horizontal beam tubes, thermal hydraulicsexperimental equipment, material testing systems, equipment for operator training,server system. Roadmap for implementation and investment for construction project ofCNST started in 2012 and the Center will be operated in 2019.


The role of the new research reactor is very important in the CNST constructionproject. The lessons learned from advanced countries show that, for preparing qualifiedhuman resource, it takes time from 10 to 15 years to accumulate operational experiencesand technology. The project of CNST will help to sole the problem of self-training ofhuman resources in the fields of reactor technology, reactor design, safety analysis,spent fuel management, radiation protection, support and transfer technology to nationalindustrial companies. organizations. The project effects directly when using, exploitingthe facilities of CNST, experiences about nuclear technology will be increased clearlynot only in science but also in management. So during the stage of projectimplementation, knowledge, experiences will be obtained, accumulated in the projectpreparation stage, design of new research reactor as well as running test. Theapplication on new research reactor will have a better service for research in technologyand safety of nuclear power plant. For the matter related to socio-economicdevelopment of the country, the direction of the main application was identifiedtogether with demanding about equipment as well as initial investment cost as follows:radioisotope production using in medicine and industry, neutron activation analysis andother applications, silicon doping, gemstone colorization, research related to neutronbeam (neutron scattering, neutron radiography), prompt neutron, gamma activationanalysis, patient treatment by boron neutron capture therapy.

Thus, the new research reactor of CNST of Vietnam must be satisfied thefollowing applications:

- Fuel and material of nuclear power plant irradiation testing;

- Radioisotope production and sealed sources application in medicine andindustry;

- Neutron activation analysis, including NAA and PGNAA;

- Silicon doping and gemstone colorization;

- Materials research on horizontal neutron beam tubes of reactor;

- Neutron radiography;

- Development of treatment by BNCT technique;

- Basic research and training & human resources development.

The research reactor has power 10 MW will be satisfied the requirements atpresent and near future. If looking in view of long term of reactor life time with 60years, the investment for research reactor with power 20 MW will be more optimal, inthe first 15 to 20 years the reactor will be operated at power 10 MW when demandinghigher power 20 MW the reactor shall not be upgraded.

VINATOM-AR 11--39


Based on the applications that will be carried out on research reactor, theselection of the research reactor suitable both in technology and safety features shouldbe based on many criteria including possibility of funding, the research and applicationin the future. In addition, upgrading ability, flexible in changing (design and layout ofexperimental instruments) to have the application, good utilization to meet futurerequirements is also needed to carefully considering. Based on the survey fromadvanced research reactors in the world, consideration of demands in using, exploitingresearch reactor of the country in the future, new research reactor of CNST should havefeatures basically related to safety and utilization as follows:

- Maximum thermal neutron flux at irradiation positions in reactor core andreflector around 3x1014 and 2x1014 n.cm-2.s-1 respectively. Because:

+ The experimental irradiation fuel and material testing require neutron flux ≥2x1014 n.cm-2.s-1;

+ Radioisotope production: for having 5000 Ci radio isotopes per year, theestimated demand in 2020, require neutron flux > 1x1014 n.cm-2.s-1;

+ Silicon doping single crystal for semiconductor manufacturing requiresneutron flux at irradiation positions about 5x1013÷2x1014 n.cm-2.s-1;

+ Experimental neutron scattering on neutron beam tubes requires neutron fluxin the reactor core > 1x1014 n.cm-2.s-1.

- Neutron flux needs to be stable for the experiments. The changing ofneutron flux in an irradiation position is smaller than 5% when loading and unloadingsamples.

- Neutron flux gradient in height must be < 20% of length 50 cm.

- The average of fuel assembly removed from the reactor core >50% offissionable material U-235 initially.

- The cycle of reactor operation is about 25 days continuously.

- There should be arranged logically in size, type and direction of laboratoryequipments.

- The reactor should have intrinsic safety features.

More specifically, the new research reactor should have characteristics: a multi-purposes, open pool, design power 20 MW, during the first 15-20 years only operated atpower about 10 MW.

- Moderation and coolant by light water with force convection (from bottomto the top), reflector by Beryllium or heavy water.

- Thermal neutron flux in the reactor core and reflector must be reachedminimum 1.0 x 1014 n.cm-2.s-1 and optimization is 3-5 x 10

14n.cm

-2.s

-1.

- The height of reactor core is about 700 mm, using MTR fuel with density4.8 g/cm3.

- There should be 22-25 vertical irradiation tubes and 6-8 horizontal neutronbeam tubes. The number of experimental instruments will be flexible to change as

VINATOM-AR 11--39


required by users. The ability using vertical irradiation tubes and horizontal neutronbeam tubes including:

+ 3 channels in the reactor core for material capsules irradiation and fuel testloop for nuclear power plant; target irradiation for radio isotope production;

+ 4 channels in the reflector for material capsules and fuel of nuclear powerplan irradiation; target irradiation for radio isotope production;

+ 4 channels in the reflector connected with pneumatics system for sampleirradiation of neutron activation analysis;

+ 2 channels in the reflector connected with the transfer samples systems byhydraulics for radioisotope production;

+ 4 channels in the reflector having big diameter, good in uniform neutron fluxfor Silicon doping transmutation doped 8 inches and capable expanding to 10 inches inthe future;

+ 1 channel to create cold neutron source;

+ 4-7 channels for radioisotope production, gemstone colorization, …

- There is at least 6 and optimal is 8 horizontal neutron beam tubes to performbasic research and applications, including:

+ 2 channels to obtain thermal neutron to install instruments for neutronscattering research;

+ 1 channel to obtain cold neutron to install instruments for neutron scatteringresearch;

+ 1 channel for neutron radiography;

+ 1 channel for BNCT and PGNAA;

+ 2-3 channels for basic research in nuclear physics and nuclear structure.

- Having at least 1 hotcell with 2-3 chambers mounted on service pool in thereactor building for handling to irradiated samples with high radioactivity.

- Having the flexibility of the reactor core structure and reflector to meet newrequirements may occur in the future.

The main experimental equipment for research reactor is determined at positionsinside reactor core, reflector and outside reflector. The equipment inside reactor core isusually irradiation positions that require very high neutron flux for material irradiation,fuel testing or production of special isotopes. The device in reflector may includevertical irradiation channel for radioisotope production, activation analysis, Silicondoping and cold, ultra cold neutron source. Outside reflector is radial and tangentialhorizontal channels. Horizontal neutron beam tubes may be extended to hundreds ofmeters through experimental buildings assemble with reactor hall. In principle whenputting reactor into operation, irradiation equipment needed immediate operation shouldbe designed from the beginning. Particularly for complex of instruments is still notused, it is necessary to reserve a place for using later. The arrangement of verticalchannels inside the reactor core to serve for irradiation testing of materials and fuelshould be designed first, to avoid effect to the neutron field distribution in reactor core.

VINATOM-AR 11--39


Vertical channels and irradiation holes at reflector needed to take into account aboutperturbation, effect of neutron flux to each other and optimize irradiation positions toavoid changing of neutron flux during operation cycle of reactor. There are currentlyabout ten applications on horizontal neutron channels need attaint ion include: study ofnuclear reactions based on filters, study (n, 2 γ) reaction on the filtered neutron beam,prompt neutron gamma activation analysis, neutron radiography, boron neutron capturetherapy, 3-axis neutron scattering spectrometer, polarized neutron study, small angleneutron scattering, neutron spin-echo spectrometer and polycarpellary neutron lenses.Thus there are at least 8 to 10 horizontal channels can meet the demands of theseapplications. Besides, the creation of cold and hot neutron source is also needed for thefuture. For silicon doping, the number of irradiation holes at least from 4 to 6 withdifferent size, such as diversified irradiated products with different radii meet thedemands of all customers.

Research reactor should be meet the safety criteria of IAEA, so the exchangeexperience and learning from other countries will be easily carried out. Procedures,operation regulations need to be established in accordance with the condition ofVietnam. The documents must be updated and used in any status of reactor. Safetysystems must be operated properly functioning in normal operation condition, abnormalcondition and accident. The principle of diversity, independence and redundancy indesign must be applied thoroughly. The auxiliary system related to safety need toimplement the functions in accident conditions such as fuel failure detection system,stack system, power supply system, ventilation system, dosimeter radiation system, fireprevention system, anti-flood system,… Emergency control room needs to beconstructed to intervene promptly when reactor shutdown system is malfunction or cannot access the main control room in accident condition. Also other building structuressuch as reactor hall, laboratories around in case necessary can be isolated and meetproperly safety functioning in accident condition.

Control system is an important part of the reactor as this system controls andmonitors during operation time of reactor. Thus the basic safety principals must besatisfied to shut reactor down in any situation. Components of control system needed tobe simple, easily replaced, special components can be bought easily on the market avoiddepending on other countries. Because the changing of world economy is complicated,problem related to merge or disband of companies often happens thereforeunderstanding and became owner of control system of reactor is very necessary. Abilityto understanding and localization in control system must be considered and put in thetop priority. The control software of control system must be transferred; in addition thesoftware must be stored for using when the system is malfunctioning. The safety,stability of control system must be satisfied. Function of control system must be strictlyenforced to avoid extraordinary effects caused reactor shutdown that affects safeoperation and utilization of the reactor.

The detailed information related to design and technology includes detail data ofinstrument, materials, documentations, and procedures should be transferred to end-userin order to operating reactor in safety condition and gradually understanding allreactors, actively in research and experiment on the reactor. More information and fulldetails will help Vietnam can operate reactor with high efficiency to improve the qualityof research and creating human resources enough knowledge and experiences. In the

VINATOM-AR 11--39


design stage, Vietnam needs to be involved from the beginning to have knowledgeablestaff about reactor in the future. So that the appropriate solution will be presented whenreactor is in trouble condition and the staff also can convey the experience andknowledge to younger generation. During the design calculation, information onrequirements needs to be updated and clearly communicated between Vietnam andRussia to create high quality, efficiency in the design and meet requirements demandswhen using reactor in the future. The process in human resource training should bepushed up through the design, construction of new research reactor. Beside currentnational human resource, young staff having research capabilities should be sent to betrained in Russia or other countries to participate in the operation, research when puttingreactor into operation.

The training of research and operation staff for research reactor must be carriedout early thus when reactor will be in operation enough employees for operation,research and understanding about the research reactor. Between operational andresearch staff is necessary having relative independence in order to professionalize ofwork. The mission of operational staff is to ensure safe operation, conduct experiments,as well as installation and dismantling experimental equipment when necessary.Research team should be focused in research, calculation of reactor parameters, fuelcycle, normal and abnormal states of the reactor. With long term operation, number ofoperators should be enough. In normal operating a shift includes supervisor, operator,health physics, and electronic, electric, mechanic. So the number of employees in a shiftis about 8 persons. With 5 shifts, the total operating staff is about 40 to 50 persons.Research staff can be divided with different ways such as basic reactor research groupand applications deployment group. Such employees will have to untaken both missionsin research and applications deployment.

III. CONCLUSION

Experience from other countries involved to nuclear program showed that forsuccessful development of nuclear power program in a country, R&D organizationshould be developed as early as possible compared to the start of construction of thefirst nuclear power plant. R&D organization is an important component in theinfrastructure of nuclear safety of a country, its function and main mission are researchabout safety and scientific development of nuclear technology, human resource trainingfor nuclear power development program.

Recognizing the role and importance of R&D research institute to developnuclear power program in Vietnam, modern CNST has research reactor with power of10 to 20 MW and specialized laboratories will be constructed. The construction processand installation of new research reactor is an important period to contribute forpersonnel training about project manager, accumulated necessary knowledge andexperiences to start building the first nuclear power plant. When CNST is in operation,laboratories will be play very important role in helping safe operation of nuclear powerplant, quickly learning and understanding about nuclear technology, and after 15 to 20years nuclear power plant will be designed and fabricated by ourselves as the strategy ofnuclear energy application for peaceful purposes to 2020 and orientations developmentof planning for nuclear power plant to 2030 were approval by Prime Minister.

VINATOM-AR 11--39


Acknowledgements

The authors would like to express their thanks to the Ministry of Science andTechnology and Vietnam Atomic Energy Institute for their great encouragement andfinancial support for this work. We also want to express our gratitude to NuclearResearch Institute, Dalat for their active participation and contribution on this work.

REFERENCES

[1]. Website address: http://www.iaea.org/worldatom/rrdb/

[2]. IAEA TEC-DOC-1234, The Applications of Research Reactors, Report of anAdvisory Group Meeting held in Vienna, 4-7 October 1999. IAEA, Vienna, August 2001.

[3]. B. J. Jun et al., Overview of Research Reactor Experiences in Korea, Proceedingsof IAEA/RCA Meeting on Design Aspects for a New Research Reactor, Hanoi, Vietnam, 2005.

[4]. B. J. Jun et al., Research Reactor Design and Utilization: The Korean experience,7th National Conference on Nuclear Science & Technology, Danang, VN, Aug., 2007.

[5]. Alexander et al., Research Reactors as a Stepping Stone Towards a Nuclear PowerProgram”, 2nd Nuclear Power, ASIA 2011, Hanoi, January 18-19, 2011.

[6]. ROSATOM, Modern Nuclear Research Centre, Presentation of Russian Delegationat the Seminar in Hanoi, May 26, 2010.

[7]. Arkhangelsky N., Nuclear Research Centre by Module Structure, Presentation ofRussian Delegation at the Seminar in Moscow, October 18, 2010.

http://www.iaea.org/worldatom/rrdb/

VINATOM-AR 11--40


COMPLETE THE PLANS OF TRAINING HUMAN RESOURCESIN THE NUCLEAR ENERGY FIELD FOR THE MINISTRY

SCIENCE AND TECHNOLOGY TO YEAR 2020 AND BUILDSPECIALIZED TRAINING PROGRAMS AT THE NUCLEAR

TRAINING CENTRE

Nguyen Manh Hung and Cao Đinh ThanhVietnam Atomic Energy Institute (VINATOM)

No.59 Ly Thuong Kiet, Hoan Kiem, Hanoi, Vietnam

Abstract: The report is presentation the two parts related to the following topics: Theplans of training human resources in the nuclear energy field for the Ministry scienceand technology to year 2020 and build specialized training programs at the NuclearTraining Centre .The functions and missions is to prepare human resources need topush for the progress of putting up nuclear power in operation. The human resourcesfor management, safety analysis and technical support of the MOST is necessary. Onthe based analysis of the current situation and actual needs of the task ,the authors havebeen studying and working out measures to solve, in addition the authors has been tobuilding specialized Training Programs for Nuclear Training Center ( NTC) belongVINATOM.

I. INTRODUCTION

On August 20th, 2010 the Prime Minister Nguyen Tan ZDung has signed adecree related to the developing of the education and training programme in the frameof the NPP project in Vietnam. Several universities in Vietnam are encouraged toparticipate to such a programme. To 2020, the expected number of experts working indifferent nuclear field would be around 3000.

The development of a highly skilled human resource is an essential element inthe infrastructure required by a country planning to introduce nuclear power. As IAEApoints out /68/, the principle involved is to identify the human resource knowledge,skills and abilities needed to implement the nuclear project and to develop theeducational and training institutions to prepare the human resources necessary for thedischarge of their function. This paper describes some of the skills needed, gives somequantitative estimates of the numbers of experts needed, identifies some possible

Project Information:- Code: 276/QĐ-VNLNT







VINATOM-AR 11--40


education and training resources and concludes with some suggestions for gettingstarted on this important infrastructure element in Vietnam with regard to the decree justsigned by the Prime Minister Nguyen Tan Dung mentioned above. The problempreparation Human resource for MOST (VINATOM, VARANS and VAEA) isimportance also, because MOST is organization have function: radiation safety, nuclearsafety, State management of nuclear Energy, Program R/D in nuclear Energy andConsulting for NPP plan.


Developing the Human Resourse (HRS) of project Nuclear power in Vietnam isimportance now , the preparation HRS Ministry of Science and Technology ( MOTS) isnecessary, because the MOST is organization, which funtion managerment anddevelopment R/D for project application Nuclear energy and NPP (Nulear Power Plan).The report is include:

A. Complete the plans for training human resources in the nuclear energyfield of the Ministry of Science and Technology to 2020

B. Construction of the specialized training programs in Nuclear TrainingCentre :

On the part A, the author have research the problems as:

1. Determine needs of professional staff by professional groups required by2020 of each agency on the number and qualifications.

2. Determine the need to recruit staff every year until 2020: number, major,level.

3. Determine the number of staff required training input for staff induction,

4. Determine the number of people and training of additional knowledgefor specialized agencies to organize in-country training.

5. Plans to invite foreign experts to Vietnam to teach courses and professionaltraining enhanced.

6. Develop training plan by e-kip: outbound for training by the professionalteam of management agencies, research and development of some guidingprinciple.Select the address to send them for training.

7. Develop a plan to appoint professional staff training overseas long-term,high level. Identify the address sent for training to.

8. Develop a master plan report on training and development S & T humanresources in the nuclear field Ministry of Science and Technology for 2020.

The authors have to Completed Plan to Training Professional personnel for thefield of management and technical support for nuclear energy of the MOST. Someproblems as planning issues such as staff recruitment, professional subgroups, trainingplans and financial have been presented details in the plan. This is the legal basis forDevelopment HSR for program nuclear energy of MOST in the period 2012 – 2020.

VINATOM-AR 11--40


On the part B, the authors have presentation there specialized training programsin Nuclear Training Centre (NTC), which are three models:

1. Training courses additional knowledge input to staff induction, this programincludes lectures and theory nature of file-based modern equipment in the lab of theInstitute of Atomic Energy Research Institute to complement the knowledge recruitingnew staff.

2. Programs are professional training courses for staff of the Institute(Institute for Nuclear Research, Institute of Nuclear Science and Technology, Instituteof Radiation rare and Institutes Centers VAEI). Due to the specific characteristics of theoriented expertise of the Institute should VAEI staff need to learn and practice in thespecialty group of the Institute.

3. Training programs according to the certificates from the Ministry of Scienceand Technology, to serve the practicing certificate for individuals and organizationsworking for nuclear power engineering and industry related to applications of nucleartechniques in atomic service sector industries of national economy.

The entire program consists of 11 based on 45 thematic lectures and courses, thecurriculum subjects are elaborated in chapter. There programs should be training atNuclear Training Center, it is contributing developing HRS for VINATOM, VARANSand VAEA.

III. CONCLUSION

Finally, the authors proposed commendations and measures to promote theHuman Resource Development as:

- Coordinate with relevant agencies to secure funding for implementationplan to train human resources for nuclear bodies in the Ministry of Science andTechnology.

- Implementation Plan for training personnel for nuclear MOST made from2012 - 2015.

- Continue to allocate funds for curriculum and training in nuclear TTDT.

- Develop financial mechanisms specific to the teaching faculty.

- Pursuant to the recruitment needs of the units in the building planrecruitment and training. Coordinate with relevant agencies to build policy regime forstaff abroad for training in the nuclear field.

- Organize trips to countries such as Russia, Japan, China, Korea, Hungaryto exchange experience in teaching learning.

Acknowledgements

The authors would like to express their thanks to the Ministry of Science andTechnology and Vietnam Atomic Energy Institute for their great encouragement andfinancial support for this work. We also want to express our gratitude to colleagues,which are participation and contribution on this work.

VINATOM-AR 11--40


REFERENCE

[1]. Xây dựng năng lực nghiên cứu triển khai và hỗ trợ kỹ thuật cho chương trình điệnhạt nhân của Việt Nam.

PGS.TS Vương Hữu Tấn Viện NLNTVN – Tạp chí Thông tin KH&CN Hạt nhân.

[2]. Đề án đào tạo và phát triển nguồn nhân lực ngành NLNT.

TS. Cao Đình Thanh Viện N LNTVN - Tạp chí Thông tin KH&CN Hạt nhân.

[3]. Vấn đề đào tạo nhân lực cho điện hạt nhân ở Việt Nam.

PGS.TS Vương Hữu Tấn Viện NLNTVN – Tạp chí Thông tin KH&CN Hạt nhân.[4]. Strategy and Challenges of Nuclear HRD for Introduction of the 1st Nuclear Power

Plant in VIETNAM .

Nguyen Manh HUNG NTC- VINATOM – Hội nghị Bangkok 2011.

[5]. Challenges in developing HR for Nuclear Education Programmes in Vietnam.

Nguyen Manh HUNG NTC- VINATOM – Meeting Coordinator FNCA 2012.

[6]. Tài liệu hôị thảo quốc gia Công tác an toàn bức xạ, đảm bảo chất lượng và kiểm trachất lượng trong xạ trị. Bộ KHCN & MT và Bộ y tế – 2009.

[7]. IAEA Technical Document: Minimum Infrastructure for a Nuclear Power Project,Final draft, 12 January 2006.

VINATOM-AR 11--41


THE ENVISAGEMENT OF EDUCATION PROGRAM FORDEVELOPMENT OF NUCLEAR SCIENCE AND TECHNOLOGY

IN VIETNAM

Pham Dinh Khang1, Nguyen Xuan Hai1, Nguyen Kien Cuong1, Than Van Lien1

Nguyen Ngoc Anh1, Luu Thu Hoa1, Nguyen Thuy Linh1 and Nguyen An Son2

1Vietnam Atomic Energy Institute (VINATOM)No.59 Ly Thuong Kiet, Hoan Kiem, Hanoi, Vietnam

2Dalat University

Abstract: Nuclear Training Centre envisaged BSc program for development of nuclearscience and technology to advice and recommendations for the Ministry of Educationand Training in Vietnam. This report had been wrote on basics of programes ofeducation of MIFI (Russia), TIT (Japanese), SNU (Korea), 4 schedule curriculums and4 current curriculums of Hanoi University of Natural Science, Hanoi University ofTechnology, Dalat University, HoChiMinh University of Natural Science, thereference’s universities, and the post of Dr. Luu Lam - the Ministry of Education andTraining. As a result, the team came up with the view of BSc program consistent withthe design, organization train BSc in Vietnam and provide nuclear staff.

Acronyms:

MIFI: National Research Nuclear University (Russia)

SNU: Seoul National University (South Korea)

TIT: Tokyo Institute of Technology (Japan)

ĐHKHTN: Hanoi University of Natural Science

ĐHGHN: Hanoi National University

TTĐTHN: Nuclear Training Center

KAERI: Korea Atomic Energy Research Institute

ĐHBK: Hanoi University of Technology

NCHN: Nuclear Research Institute

CNXH: Institute for Technology of Radioactive and Rare Elements

NCS: PhD student




- Implementation Time: 6 months (Jul 2011-Dec 2011)




VINATOM-AR 11--41


I. THE CURRENT SITUATION OF NUCLEAR TRAININGUNIVERSITIES IN VIETNAM

I.1. Human train nuclear major in Vietnam

Human train nuclear major: Now, we have five universities train nuclear sub-major and nuclear major, that are Hanoi University of Natural Science, HochiminhUniversity of Natural Science, Hanoi University of Technology, Dalat university,Electric Power University. In all five universities, there are only 4 professors/assistanceprofessors, 9 doctors, 25 masters and 19 engineers/ bachelors. Because the limit ofquantity and quality of human so the developments of human sources in universities arevery limited and cannot ability.

I.2. Training programs

Now, in universities make nuclear training that are mainly two specialized:Nuclear Physics and Technical Physics. The different specialized: Technical nuclear,nuclear safety, radioactive safety, electricity nuclear is the similar training program ofNuclear Physics and Technical Physics, only a small number of subjects are differentbut those subjects are not nuclear technology subjects.

Training programs of universities are not lack training system to train peoplewho work nuclear field. Those programs do not separated deep specialized. Inparticular, there is no nuclear reactor program (technology, operations, safety analysis,etc.).

I.3. Facilities for specialized nuclear training

Facilities and equipments in universities that make nuclear training are poor,outdated and inconsistent with nuclear training program. At the Hanoi University ofNatural Science there is a 1.6 MeV accelerator that make material analysis, is difficultto study nuclear reactions and nuclear data. Hanoi University of Natural Science has aneutron generator and neutron spectroscopy that imported 2006 but has still not beenuse.

I.4. The number of people train nuclear field for every year

Every year, all the nuclear majors training (Hanoi University of Natural,Hochiminh University of Natural, Hanoi University of Technology, Dalat University,Electric Power University) trained about 70 engineers and nuclear physics BSc.Nevertheless, this resource is mainly theory training, nuclear physics and chemistry, isnot the chance of really, so the ability should be limit to accept the transfer oftechnology, operation, operators of nuclear power plants. More people, who graduatedto work in the non-nuclear fields, consequently, to need re-train this resource if we wantto use this resource in the nuclear fields.

I.5. Comment the training curriculum of the universities

The review training programs that prepare universities have led to the followingconclusions:

a. The training programs were submitted to the Ministry of Education andTraining to prepare nuclear staffs of universities to have differences with assignment indispatch No. 1063/TB-BGDDT days 31/10/2011.

VINATOM-AR 11--41


b. Compared with the actual requirements, graduates severe deep specialized.The universities train nuclear physics are different curriculums and differentrequirements works.

c. The curriculums of universities are not separate basic specialized and deepspecialized, cannot train people who enough knowledge to meet the new job.

II. MIFI, SNU AND TIT

II.1. MIFT education system

MIFI education systems and the MIFI education program is complex: There are82 departments in different departments and in different brands of MIFI. The number ofinstitutes, sub-institutes and learning facilities of MIFI are 19. There are 13 codes of theeducation program, for example, the code 020100 of chemistry is 4 education programsor code 140 700 of nuclear technology is 6 education programs in deep specialized anddifferent training levels. If we only interested in undergraduate programs, the samecode, but the institutes of MIFI just the same in the basic and different characteristics.Each education program can rearrange to train variety of different specialized.

I.2. SNU education system

SNU education system about nuclear technology of Seoul National University isrally simple. This program is in nuclear science technology department of SNU, andeducation system has three main problems:

a. Innovation and assessment of nuclear reactor safety

b. Design nuclear power plant

c. Nuclear changes

The education of SNU is to manufacture and export nuclear reactor. The studyand generator of nuclear power plant for students of SNU and engineers of otheruniversities will held at the Nuclear Training Center of KAERI and at the nuclear powerplants (both re-training and skills).

II.3. TIT education system

TIT education system is divided two levels: School and Graduate School.School teaches physics including general nuclear physics. Nuclear technology (nucleartechnology major) and intensive nuclear physics (physics major) are trained in GraduateSchool. The nuclear technology major has 33 laboratories where train here (such asnuclear reactor design, hydrothermal ...). Each lab has one professor, associateprofessors and lecturers of the laboratory who respond both teaching and research.

The knowledge system, research of TIT toward nuclear science and technologyare more deeper than training mission and operation nuclear power plants, even researchnuclear technology in Vietnam.

The preparation of operator staffs of Japan's nuclear power plants are made byrecruiting engineers in technique majors, physics major, retrain in the Nuclear TrainingCentre.

VINATOM-AR 11--41


II.4. Conclusions

The using the design of MIFI program is best suited Vietnam (of course notcomplete as MIFI’s codes but make some of the main content):

Nuclear education undergraduate at Vietnam from now until (2020 – 2025) is toprepare nuclear staffs to operation, nuclear power safety;

The organizational structure of the universities in Vietnam and program designof Vietnam have many similarities with MIFI’s program;

For preparing teachers, technology staffs, operation of nuclear power plantsstaffs.

III. PROPOSED CURRICULUM

III.1. The principle of construction of the education program

- The construction of education programs must come from the requirementsof work system for input staffs and accordance with the task of the Ministry ofEducation and Training.

- The development of education programs in nuclear science and technologyis made in the only last two years of the course. The basic subjects, the support subjectsin the early years of the course are not included in this system, but universities designdepend on staffs (training time, the task .. .).

- The curriculum is designed to ensure graduates complete specialized field.This ensures that students are provided the knowledge base enough to work after aperiod (3 months to 1 year).

- In nuclear physics majors have many specialized fields such as: nuclearexperimental; accelerator; radiation applications. In nuclear engineering, major hasnuclear reactor technological system; analysis reactor safety.

- The curriculum in order the work - will take in Vietnam in 10 - 15 years,then updated and supplemented to suit the status. Thus, further work such as preparationbooks and textbooks; teachers; equipment to practice..., consistent with the trainingprogram.

- The curriculum to provide continuity between the universities is assignedthe task of decided 1558/QĐ-TTg. For example, to experimental nuclear physics, basicknowledge of nuclear physics of the universities must be the same 80%. Thisorganization increases training capacity, reduce management costs, and increaseexchanges to students at the professional level (allowing students to change universitywithout lost intelligence, time). Some difference of training program of less than 20% isallowed and respected peculiarities, characteristic of the universities.

- The curriculum must clear structure. This structure represents thedevelopment of science and technology. After completing basic specialized, the studentswill follow the different deep specialized.

VINATOM-AR 11--41


III.2. Counseling Curriculum for the Ministry of Education and Training

a. The Major of Nuclear Physics

Basis nuclear physics:

Table 1: The course, credits

No Course name Credits

1 General Nuclear Physics 4

2 Neutron Physics 3

3 Theory of nuclear reactions 3

4 Nuclear structure models 3

5 Nuclear electronic 3

6 Radiation Dose and Radiation Safety 1

7 Nuclear Data processing and Nuclear Data processing programming 3

8 Practice in Radiation Measurement and Nuclear electronic 4

9 Application of Numerical Methods 3

10 Measurement Technique for Radiation 3

11 Accelerators 3

The major subjects:

Group 1: Experimental Nuclear Physics



1 Modern nuclear analytical techniques 2

2 Nuclear equipments and applications 2

3 Lab view 2

4 X-ray fluorescence analysis 2

5 Practice in NAA at Dalat nuclear reactor 4

6 Practice in nuclear reactions at Dalat nuclear reactor 5

Group 2: Acceleration and Application Acceleration

VINATOM-AR 11--41




1 Plasma physics 2

2 Vacuum physics and technique 2

3 Radiation dose and radiotherapy technique 3

4 Analyze the Particle Beam of Accelerators 2

5 The circuit in Accelerator 2

6 Applications accelerator (research, production and health) 3

7 the beam characteristics of accelerator 3

Group 3: Radiation Technology



1 Application of Radiation technology in Industry 2

2 Non-Destructive Testing Methods (NDT) 5

3 Radioactive Tracer Technique (RTT) and Isotope Hydrology 2

4 Nuclear Medicine 2

5 Radiation Dose and radiotherapy technique 3

6 Application of Radiation technology in Agriculture and Biology 2

7 Radiation control system 1

b. Nuclear Engineering

Basis nuclear Engineering



1 General Technology Nuclear Electronics 3

2 Numerical Methods and Application 5

VINATOM-AR 11--41


3 Nuclear reactor Physics 3

4 Nuclear fuel cycle 3

5 Nuclear reactor thermal hydraulics 3

6 Nuclear reactor kinetics 3

7 Safety Analysis of Nuclear Reactor 3

8 Reactor systems technology 3

9 Nuclear Reactor materials 2

10 Calculating and design of nuclear reactor 3

11 Neutron Physics 2

The major subjects:

Group 1: The System of nuclear reactor technology



1 The programming of Nuclear reactor thermal hydraulics 2

2 The Monte-Carlo Simulation Programming of Neutron Distribution 2

3 Nuclear power thermal hydraulics characteristics 2

4 Instrumentation and Control Technologies of the Nuclear PowerPlant

2

5 Nuclear electronic and processing electronic signal 2

6 Calculating nuclear reactor design 3

7 Calculation methods for nuclear reactor 2

8 Nuclear reactor Material 2

Group 2: nuclear safety analysics



1 Nuclear reactor safety principles and IAEA safety assessment 2

VINATOM-AR 11--41


2 SRAC code and MVP code system 3

3 Programming safety code 3

4 Analytical methods for nuclear reactor safety 3

5 Analysis reactivity of the reactor 3

6 Nuclear reactor safety with computer codes 3

c. Radioactive chemical

Specialized facilities



1 General radiochemistry 4

2 Application radiochemistry 2

3 Measurement radiochemistry 2

4 Nuclear fuel 3

5 Chemical in nuclear reactor 3

6 Radiochemistry waste treatment and management 3

7 Radiochemistry Lab 6

Specialized training



1 Chemical of actinits 4

2 Analysis of nuclear and nuclear fuel 2

3 Location, chemical, uranium and radioactive elements 2

4 Technology radioactive element ore selection 3

5 Uranium ore and thorium ore selection 3

6 Treatment waste of uranium ore and thorium ore 3

7 Production of radioactive pharmaceutical in nuclear reactor andaccelerator

6

VINATOM-AR 11--41


Combine overall programs with the project of National Steering Committeethrough Notice 1063/TB-BGDĐT, the universities can determine their own trainingprograms and prepare quality and amount of teachers, equipment training (depend tooperation or research, etc.).

Conclusion: The construction of training programs need to understand the needsof user, and assigning tasks of the Ministry of Education and Training, planning groupsbase on basic specialized and depth specialized. All of the preparation: teachers, booksand curricula, equipment training equipment are sub-training program, not consideredcritical.

REFERENCES

[1]. The training program of MIFI (Russian language) MIFI published.

[2]. The training program of TIT (English language) provided by TIT.

[3]. The training programs of the SNU (website: http://www.useoul.edu/)

[4]. The summary of nuclear training at the Universities: Hanoi University of NaturalSciences university, Ha Noi University of Technology, Dalat University, Hochiminh Universityof Natural Sciences.

http://www.useoul.edu/

VINATOM-AR 11--42


STUDY AND PROPOSAL FOR SOLUTIONS ON ATTRACTINGHUMAN RESOURCES, TECHNICAL SUPPORT ACTIVITIES FORATOMIC ENERGY APPLICATIONS AND SPECIALIZED & SAFE

TRAINING FOR RADIATION WORKER

Cao Hong Lan 1, Nguyen Trong Trang1, Vu Thanh Huyen1, Nguyen The Khanh1,Bui Dang Hanh1, Vu Manh Khoi1, Hoang Hoa Mai1, Nguyen Trong Hiep1,

Nguyen Nhi Dien1, Nguyen Bich Thu2, La Thi Huong3 and Luu Lam4

1Vietnam Atomic Energy Institute (VINATOM)No.59 Ly Thuong Kiet, Hoan Kiem, Hanoi, Vietnam

2Ministry of the Interior3Vietnam Atomic Energy Institute Agency

4Ministry of Educatiom and Training

Abstract: The Law on Atomic Energy of Vietnam is a comprehensive law, whichregulates all of matters relating to development promotions, guaranty safety and securityfor the activities in the field of atomic energy. It also provided responsibilities ofcompetent authorities in guidance many issues mentioned in the Law to facilitate theenforcement. To implement one of these responsibilities on behalf of the Ministry ofScience and Technology, this task studied the scientific and practical basis for draftinglegal documents on attracting human resources, technical support activities for atomicenergy applications and specialized and safe training for radiation worker. It resulted insix sets of draft documents and reports to competent authorities for consideration andpromulgation by the objectives set out in the task.

CONTENT

Objectives

The goal of the task is to study the scientific and practical basis for drafting legaldocuments in attracting human resources in the field of atomic energy, technical supportactivities for atomic energy applications and specialized and safe training for radiationworker.

Base on the study, the Task proposed six sets of draft of documents and reportsto competent authorities for consideration and promulgation the following documents:




- Implementation Time: 8 months (May 2011-Dec 2011)




VINATOM-AR 11--42


- Decision of the Prime Minister on approving the career preferentialallowances for people working in the field of atomic energy;

- Decision of the Prime Minister on preference for highly qualified expertworking in the field of atomic energy;

- Circular of the Ministry of Home Affairs provides in detail and guides theimplementation of the preferential recruitment for employees in the state managementagencies; governmental training, research and applications of atomic energy institutions;

- Circular of the Ministry of Education and Training provides in detail andguides the implementation of the training preference in the field of atomic energy;

- Circular of the Ministry of Science and Technology regulates serviceactivities support the application of atomic energy;

- Circular of the Ministry of Science and Technology regulates specializedand safe training for radiation workers.

Methodology

For the formulation the drafts of documents and reports mentioned above, theauthor and her colleagues included research practice in the country, study the similardocuments in Vietnam and from foreign countries as well as international organizations.

The drafts were commented at the seminars with the participation of relevantexperts.

Depending on the requirement on each document, the drafts would be sent forcomment of related ministries, branches and the concerned organizations.

The opinions were synthesized and studied to complete the draft.

Results

The task proposed 6 set of drafts of documents and reports to the competentauthorities for approval. The reports were made clear the legal basis and practices aswell as explain the contents of the draft of the documents.

The draft of documents base on the objectives of the task basically listed below:

1. Decision of the Prime Minister on approving the career preferentialallowances for people working in the field of atomic energy

The content of the Decision Draft including: Scope and objects; classification ofcareer preference allowance (based on the attraction of qualified people to work tostrengthen management research - development and technical support capacity foractivities in the field of atomic energy, as well as give priority to attraction youngpeople and directly working people); and funding sources.

2. Decision of the Prime Minister on preference for highly qualified expertworking in the field of atomic energy

Draft of Decision of the Prime Minister on preference for highly qualified expertworking in the field of atomic energy including 8 articles which cover: the definition ofhighly qualified expert and standards of highly qualified expert; regime of preference

VINATOM-AR 11--42


for foreign highly qualified expert and Vietnamese highly qualified expert; rights andobligations of highly qualified expert; commitments to work...

3. Circular of the Ministry of Home Affairs provides in detail and guides theimplementation of the preferential recruitment for employees in the state managementagencies; governmental training, research and applications of atomic energy institutions

Draft of this Circular including 5 chapters with 12 articles cover the followingspecific contents: Scope, objectives, conditions to be employed in the state managementagencies; governmental training, research and applications of atomic energy institutions,preferential policies for those who are trained domestic or foreign countries; rights andresponsibilities of those who enjoy preferential policies; application and procedure forpreferential policies.

4. Circular of the Ministry of Education and Training provides in detail andguides the implementation of the training preference in the field of atomic energy

The Draft of this Circular including 11 articles cover the contents as follows:Scope, objective; specialized training in the field of atomic energy; preference intraining fee, scholarships; internships and equipped learning mode for specializedstudents in the field of atomic energy; conditions for staff who is nominated forpostgraduate training abroad and domestic training; incentives and subsidies for staffwho is nominated for training or self-funding, and training fee.

5. Circular of the Ministry of Science and Technology regulates serviceactivities support the application of atomic energy

Draft of this Circular basically details the requirements in paragraphs 2 and 3 ofArticle 69 and paragraph 3 of Article 70 of the Atomic Energy Law. The Draft consistsof 13 articles including: Scope; objective; types of service activities (exclusive ofengineering and technology advisory in the field of atomic energy; assessment,valuation and assessment of radiation technology, nuclear technology, radiation workertraining, reloading fuel in nuclear reactors which will be provided in other documents);procedures and application for grant, amend, supplement, revoke services registration;procedures and application for grant, amend, supplement, revoke service practicecertificate; recognition certificate issued by foreign organizations.

6. Circular of the Ministry of Science and Technology regulates specialized andsafe training for radiation workers

Certification for radiation workers in Vietnam has stipulated in Circular No.08/2010/TT-BKHCN on authority body, application, procedure to get certificate. So thedraft of this Circular was made in consistency and complementation to existingCircular.

The contents of the Draft of Circular including: Scope and objectives,registration of training facilities; the general and specific requirements for each type ofradiation workers; training programs, specialized certification and safety certification.The draft also provides the application form, registration and certificates templates.

VINATOM-AR 11--42


Recommendations

The tasks completed research and proposed 6 set of drafts and reports to thecompetent authorities as its objectives.

In general, the procedures for promulgation normative documents can becomplex and time consuming. In order to turn the drafts become official documents, it isrequired the cooperation from the leaders of related ministries and appropriateorganizations as well as professional executor. /.

REFERENCES

[1]. Law on Atomic Energy, 2008.

[2]. Atomic Energy Act of the Public of Korea.

[3]. Enforcement Regulation of the Atomic Energy Act of the Public of Korea.

[4]. Qualification and Training of Personnel for Nuclear Power Plants.Regulatory Guide 1.8. NRC.

[5]. Personnel Selection, Training, Qualification, and Certification Requirementsfor DOE Nuclear Facilities, O 426.2 DOE.

[6]. 10 CFR Part 55, Operators Licenses.

[7]. Recruitment, Qualification and Training of Personnel for Nuclear PowerPlants, INTERNATIONAL ATOMIC ENERGY AGENCY Safety Standards Series No.NS-G-2.8, IAEA, Vienna (2002).

ProjectNumber

Title Insitution Counterpart Year ofApproval

TotalBudget

VIE2009 Nuclear Analytical Techniques forEnvironmental Pollution Control

Institute or Technologyfor Radioactives and RareElements

Nguyen Thi KimDung

2009 232,140

VIE4015 Developing Nuclear PowerInfrastructure

Vietnam Atomic EnergyInstitute

Hoang Anh Tuan 2009 635,260

VIE6024 Establishing National CyclotronFacilities and Centres for MedicalApplications and Research

Tran Hung Dao GeneralHospital, ChoRayHospital, DaNangHospital, KienGiangHospital

Pham Thi Minh Bao,Nguyen Truong Son

2009 252,455

VIE8020 Developing Advanced Non-DestructiveTesting Techniques for Inspection ofHeat Exchangers of Thermal PowerPlants

Center for Non-destructiveEvaluation

Vu Tien Ha 2009 287,500

VIE9010 Strengthening the Technical Capacityof the Regulatory Body for Radiationand Nuclear Safety

Vietnam Authority forRadiation Protection andNuclear Safety

Ngo Dang Nhan 2007 275,403

2.1. LIST OF VIE PROJECTS 2011

VIE9011 Improving the Capability for SiteCharacterization and Evaluation ofNew Nuclear Installations

Nuclear Research Institute Pham Van Lam 2009 293,975

VIE9013 Strengthening the Technical Capacityof the Radiation and Nuclear SafetyRegulatory Body


Ngo Dang Nhan 2009 394,302

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2.2. LIST OF RESEACH CONTRACT 2011

CRPCode

CRP Title Start Date End Date Fundfor

2011

ChiefInvestigator

Institution

F22051 CRP on Radiation Curingof Composites forEnhancing their Featuresand Utility in HealthCare and Industry

2011-03-14

2015-03-14

4000 Dang VanPhu

ResearchandDevelopmentCentre forRadiationTechnology

E13037 The Use of SentinelLymph Node in Breast,Melanoma, Head & Neckand Pelvic Cancers

2010-10-12

2013-10-12

6000 Le HongQuang

NationalCancerHospital

E43023 Stable IsotopeTechniques in theDevelopment andMonitoring of NutritionalInterventions for Infantsand Children withMalaria, TB and otherInfectious Diseases

2009-09-08

2013-09-09

15000 Vo HanhPhuc

Institute ofNuclearSciences andTechnology

D62008 Development of GenericIrradiation Doses forQuarantine Treatments

2009-06-11

2013-06-11

7000 Doan ThiThe

Research andDevelopmentCentre forRadiationTechnology

F33017 Use of EnvironmentalIsotope TracerTechniques to ImproveBasin-scale RechargeEstimation

2009-03-26

2013-03-26

5000 Vo ThiTuong Hanh


D24012 Enhancing the Efficiencyof Induced Mutagenesisthrough an IntegratedBiotechnology Pipeline

2009-02-04

2014-02-04

8000 Ho QuangCua

Soc TrangAgriculturalDepartment

VINATOM-AR 11


D12011 Integrated IsotopicApproaches for an Area-wide PrecisionConservation to Controlthe Impacts ofAgricultural Practices onLand Degradation andSoil Erosion

2008-12-08

2013-12-07

7000 NguyenThanh Lam

AgriculturalUniversity

T24008 Planning, Managementand OrganizationalAspects inDecommissioning ofNuclear Facilities

2008-05-15

2012-05-14

2700 Pham VanLam

NuclearResearchInstitute(NRI)

F22047 Development ofRadiopharmaceuticalsBased on 188Re and 90Yfor Radionuclide Therapy

2008-04-01

2012-03-31

5000 Nguyen ThiThu

NuclearResearchInstitute(NRI)

F22046 Development ofRadiation-ProcessedProducts of NaturalPolymers for Applicationin Agriculture,Healthcare, Industry andEnvironment

2007-12-01

2012-12-31

4000 NguyenQuoc Hien

Research andDevelopmentCentre forRadiationTechnology

E13034 Assessment of LeftVentricular Function inCoronary Artery Diseasewith Nuclear Techniques

2007-09-15

2011-12-31

6000 NguyenTruong Son

ChoRayHospital

D12009 Managing IrrigationWater to Enhance CropProductivity underWater-LimitingConditions: A Role forIsotopic Techniques

2007-09-15

2012-09-14

8000 Duong HaiSinh

Institute forWaterResouresResearch ofVietnam

J71011 Modelling and Analysisof RadionuclidesTransport and SourceTerm Evaluation within

2007-04-15

2011-07-31

Luong BaVien

NuclearResearchInstitute

VINATOM-AR 11


Containment /Confinement and Releaseto the Environment, forResearch Reactors

(NRI)

E13032 Performance of RestMyocardial PerfusionImaging in theManagement of AcuteChest Pain in theEmergency Room

2007-03-15

2011-12-31

5000 Vu DienBien

Tran HungDao GeneralHospital

D32025 Coordinate a CRP for theearly and rapid diagnosisof emerging diseases(focus on avianinfluenza) (2006-2010)

2006-12-15

2011-12-31

6000 NguyenTien Dung(Vien ThuY)

VeterinaryInstitute

E13031 Role of NuclearCardiology Techniquesin Ischemia Assessmentwith Exercise Imaging inAsymptomatic Diabetes

2006-03-15

2012-03-14

6000 Le Ngoc Ha Tran HungDao GeneralHospital

D20013 Crop Improvement forHiegh Yield andEnhanced Adability toClimate Changes

2007-12-15 6000 Mai QuangVinh

AgricuturalGeneticsInstitute

K41010 Application ofRadiotracer andRadioassay terchnologyto seafood SafetyAssessment

2007-09-15 5000 Dang DucNhan


VINATOM-AR 11


2.3. LIST OF ACTIVE REGIONAL/INTERREGIONALPROJECTS 2011 (41 projects)

ProjectNumber

Title Field 1st Year ofApproval

TotalBudget

INT4142 Promoting Technology Development andApplication of Future Nuclear Energy Systemsin Developing Countries

4W 4D 4Q 2009 1,083,365

RAS0047 Supporting Web-Based Nuclear Education andTraining through Regional Networking

0I 2007 783,255

RAS0053 Providing Decision Support for Nuclear PowerPlanning and Development

0E 2009 1,016,278

RAS0056 Providing Legislative Assistance 0D 2009 353,575

RAS0057 Reviewing Country and Regional Programmes 0B 0M 2009 1,095,500

RAS0059 Enhancing Human and Nuclear TechnologyCapacities

0A 2009 2,701,634

RAS2013 Good Radiopharmacy Practice and GoodManufacturing Practice

2G 2H 2I6B

2007 510,745

RAS4029 Strengthening Nuclear Power Infrastructureand Planning

4V 4P 2007 595,810

RAS4032 Improving Integrated Management Systems forNuclear Power Plants

4M 2009 367,930

RAS5045 Improvement of Crop Quality and StressTolerance for Sustainable Crop ProductionUsing Mutation Techniques and Biotechnology(RCA)

5C 2007 417,360

RAS5046 Novel Applications of Food IrradiationTechnology for Improving SocioeconomicDevelopment (RCA)

5H 2007 379,290

RAS5049 Sharing Regional Knowledge on the Use of theSterile Insect Technique within IntegratedArea-Wide Fruit Fly Pest ManagementProgrammes

5D 2007 235,244

VINATOM-AR 11


RAS5050 Enhancing Sanitary and PhytosanitaryTreatment of Regional Products for Export byIrradiation (RCA)

5H 2009 364,050

RAS5052 Sharing Regional Knowledge on the Use of theSterile Insect Technique within IntegratedArea-Wide Fruit Fly Pest Managem

5D 2009 251,685

RAS6038 Strengthening Medical Physics throughEducation and Training (RCA)

6F 2003 1,608,491

RAS6049 Strengthening Clinical Applications of PET inRCA Member States (RCA)

6B 2007 644,778

RAS6053 Improving Image Based Radiation Therapy forCommon Cancers in the RCA Region (RCA)

6C 2009 557,489

RAS6055 Controlling and Preventing ChildhoodMalnutrition in Asia

6K 2009 78,223

RAS6057 Strengthening and Standardizing NuclearMedicine Applications in Cardiology in Asiathrough Education and Training

6B 2009 390,000

RAS6059 Quality Assurance Team for RadiationOncology (QUATRO) Training in South-EastAsia

6C 2009 335,300

RAS6060 Supporting Comprehensive National CancerControl

6J 2009 330,000

RAS7015 Characterization and Source Identification ofParticulate Air Pollution in the Asian Region(RCA)

7L 2007 649,620

RAS7016 Establishing a Benchmark for Assessing theRadiological Impact of Nuclear PowerActivities on the Marine Environment in theAsia-Pacific region (RCA)

7M 2007 635,800

RAS7019 Harmonizing Nuclear and Isotopic Techniquesfor Marine Pollution Management at theRegional Level (RCA)

7M 2009 431,850

VINATOM-AR 11


RAS7021 Marine benchmark study on the possibleimpact of the Fukushima radioactive releases inthe Asia-Pacific Region

7A 7F 7L7M 7N

2011

RAS8108 Assessing Trends in Freshwater Quality UsingEnvironmental Isotopes and ChemicalTechniques for Improved ResourceManagement (RCA)

8M 2009 329,600

RAS8109 Supporting Radiation Processing of PolymericMaterials for Agricultural Applications andEnvironmental Remediation (RCA)

8H 2009 595,524

RAS8110 Applying Advanced Digital IndustrialRadiology and Computed Tomography inIndustry and Civil Engineering (RCA)

8P 2009 610,435

RAS8111 Diagnosing Industrial Multiphase Systems byProcess Visualization using Radiotracers andSealed Sources (RCA)

8J 2009 680,675

RAS9042 Sustainability of Regional Radiation ProtectionInfrastructure (RCA)

9C 2007 781,392

RAS9046 Strengthening Technical Capacities forOccupational Exposure Control

9I 2007 1,364,761

RAS9050 Education and Training in Support of RadiationProtection Infrastructure

9X 2007 868,600

RAS9053 Strengthening Occupational RadiationProtection

9I 2009 360,893

RAS9054 Strengthening National RegulatoryInfrastructures

9H 2009 436,148

RAS9055 Strengthening Radiation Protection in Medicine 9J 2009 450,918

RAS9056 Strengthening Capabilities for Protection of thePublic and the Environment from RadiationPractices

9K 9S 9X9Q 9C

2009 853,900

RAS9057 Strengthening National and RegionalCapabilities for Response to Radiological andNuclear Emergencies

9L 2009 418,862

VINATOM-AR 11


RAS9058 Supporting Education and Training inRadiation Protection

9X 2009 1,468,722

RAS9059 Strengthening Nuclear Regulatory Authoritiesin the Asia and the Pacific Region

9H 2009 897,275

RER3006 Supporting the Repatriation, Management andDisposal of Fresh and/or Spent Nuclear Fuelfrom Research Reactors

3G 4B 9S 2009 30,177,780

RER4028 Repatriation, Management and Disposition ofFresh and/or Spent Nuclear Fuel from ResearchReactors

4B 2005 10,019,936

Field(Lĩnh vực)

Project Title(Tên dự án)

Institution(Đơn vị thực hiện)

Counterpart(Chủ dự án)

1.Public Information(Thông tin đại chúng)

Public Information for betteracceptance of Nuclear Application(Thông tin đại chúng về ứng dụng hạtnhân)


Ms. Dang Thi Hong

2. Human ResourcesDevelopment(Phát triển nguồn nhân lực)

Human Resources Development forNuclear Science Application(Phát triển nguồn nhân lực)


Mr. Vu Dang Ninh

From Jul 2011 Ms.Cao Hong Lan

3. Nuclear Safety ManagementSystem (Hệ thống quản lưan toàn hạt nhân) (New)

Nuclear Safety Management System(Hệ thống quản lư an toàn hạt nhân)

Nuclear Research InstituteMr. Nguyen Nhi Dien

4. Radioactive WasteManagement(Quản lư chất thải phóng xạ)

Radioactive Waste Management(Quản lư chất thải phóng xạ)

Institute or Technologyfor Radioactives and RareElements

Mr. Le Ba Thuan

5.

Utilization of ResearchReactors (Ứng dụng L phảnứng nghiên cứu)

5.1 Neutron Activation Analysis(Phân tích kích hoạt nơtron NAA)

Nuclear Research Institute

Mr. Nguyen NgocTuan

5.2 Research Reactor Network Nuclear Research Institute Mr. Duong Van Dong

2.4. LIST OF FNCA PROJECTS OPERATING IN 2011

6.Applications in Industry(Ứng dụng công nghiệp)

Radiation Processing of NaturalPolymer (Ứng dụng công nghệ bứcxạ xử lư các polymer tự nhiên )

Research andDevelopment Center forRadiation Technology

Mr. Nguyen QuocHien

7.Applications of Radiationand Isotopes in Agriculture(Ứng dụng bức xạ và đồng vịphóng xạ trong nông nghiệp)

7.1 Mutation Breeeding(Tạo giống đột biến)

Agricultural GeneticsInstitute

Mr. Le Huy Ham

7.2 Biofertilizer (Phân bón sinh học)Ministry of Agricultureand Rural Development

Mr. Pham Van Toan

8.

Applications of Radiationand Isotopes in Medicine(Ứng dụng bức xạ và đồng vịphóng xạ trong y học)

8.1 Radiation Oncology (Xạ trị ung th-ư)

Hospital K Mr. Nguyen Ba Duc

8.2 Cyclotron and PET in Medicine(Dự án PET/Cyclotron trong y học)

Central Military Hospital(Hospital 108)From Dec 2009 Bach MaiHospital

Ms. Pham Thi MinhBao/From Dec 2009Mr. Mai Trong Khoa

9.Nuclear Security andSafeguards


Ms. Nguyen Nu HoaiVi

VIETNAM ATOMIC ENERGY INSTITUTE

THE ANNUAL REPORT FOR 2011

Responsible for publishing

Pham Ngoc Khoi

Editor Nguyen Quynh Anh

Conver designer Nguyen Hoang Anh

SCIENCE AND TECHNICS PUBLISHING HOUSE

70 Tran Hung Dao, Hoan Kiem, Hanoi, Vietnam

Publishing registration no 384-2013/CXB/317-20/KHKT

Quanlity 100, size 21 x 295cm

Printing finished and copyright deposited in the 3rd quarter, of 8/2013

VIỆN NĂNG LƯỢNG NGUYÊN TỬ VIỆT NAM

The ANNUAL REPORT for 2011

Ban biên tập:TS. Trần Chí Thành, Tổng biên tậpTS. Cao Đình Thanh, Phó tổng biên tậpKS. Nguyễn Hoàng Anh, Ủy viên, Thư ký Ban biên tậpTS. Nguyễn Thị Kim Dung, Ủy viênThS. Nguyễn Thị Định, Ủy viênCN. Nguyễn Thị Phương Lan, Ủy viên .

NHÀ XUẤT BẢN KHOA HỌC VÀ KỸ THUẬT70 Trần Hưng Đạo, Hà Nội

Số đăng ký kế hoạch xuất bản

384-2013/CXB/317-20/KHKT

Theo quyết định xuất bản số 151/QĐ-NXBKHKT, cấp ngày 15 tháng 8 năm 2013

In xong và nộp lưu chiểu tháng 9 năm 2013

8 935048 931561

213156B00

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