Technetium in Reprocessing of spent nuclear fuel

K.E.German

II Letnia Szkoła Energetyki i Chemii Jądrowej

The II Summer school of Energetic and Nuclear Chemistry

Biological and Chemical Research Centre UW16-20 Sept., 2013

Technetium in Reprocessing of spent

nuclear fuel

K. E. G e r m a n

Russian Academy of SciencesA.N. Frumkin Institute of Physical Chemistry and

Electrochemistry

Plan of the presentation

1. Tc and Re discovery, their abundance in the Earth crust 2. The main problems bonded to Tc …3. And its solutions based on the fundamental studies in IPCE RAS4. Development of separation technologies5. Attempts of application (corrosion, metallurgy, catalysts).6. Tc in Spent NF 7. Discussion: Spent Fuel Storage, Separate long-term storage or

Transmutation8. Improvements of separation technologies (SPIN-program (France),

Adv.-ORIENT Cycle (Japan), PO Mayak- IPCRAS- Radium institute Russian program.

9. Scientific International collaboration of IPCE RAS with USA, France Japan and Poland

10. “Renaissance” of Transmutation program

43Tc99 and Re in Earth crust

1937

C. Perrier and E. Segre

Technetium (Z=43)

42MoА (d,n) 43TcА+1

?↔

1908Prof. Ogawa (Japan)

NipponiumConfirmation in 1999: K.Yoshihara,

---------------------------------------------------1925

V. Noddak , I. Taker, O.Berg Mazurium (Z = 43) in one (U,Re) ore

X-ray spectral and ICP MSConfirmation in 1988: P.H.M.Assche

(Molle, Belgium)

Re – the lowest natural abundance of all stable elements, Tc even less...Usually we say – no Tc on the Earth, but :

Tc natural concentration in earth crust 7.10-8 % (Mo, Ru, Nb) cosmic rays → 99Tc (50 ton)

235,238U, 232Th (spontaneous fission) → 99Tc (50 ton)Total Tc 100 ton naturally, plus: accumulation 10 ton per year in NPPs

Question arise : who discovered Tc? .

Our motivation for exploring Tc chemistry for the Closed Fuel Cycle

Tc-99 is a key dose contributor at HLW repositories if TRU elements are greatly reduced by recycling • long half-life of Tc (t1/2 = 2.14 x 105 years), • high mobility, and solubility under oxidizing

conditionsMethods for managing the long-term threat of Tc to the environment• Stable waste form/repository system providing with

strict limits for Tc release over a long period of time (~1 million years?).

• Transmutation of radioactive Tc to stable Ru im nuclear rectors.

Main problems of Tc

Tc is important item in Nuclear IndustryTc redistribution in PUREX produces flows with long-lived high radioactive wastesTc interferes at U/Pu separation stage in PUREX processTc accumulation in High burn-up fuel together with Mo, Ru, Rh Tc in nuclear waste vitrification: Tc-Mo-Ru metal phases, Tc(VII) volatility

Typical nuclear spent fuel reprocessing involving PUREX

High level solid Tc/Mo/NM wastes dissolution and vitrification

Increasing burn-up in the SNF leads to lower oxidativepotential – the metals like Mo, Tc, Ru formingmutual ε-phase (white inclusions) that is insolublein nitric acid – formation of HLSW.

In vitrification of HLLW the same metals (Mo, Tc, Ru)are either volatile (oxic conditions) or formingmetal ε-phase dendrites (reducing conditions)that lead to several furnace problems(Rokkasho-mura vitrification )

Investigation of these phases by means of X-ray,diffraction, NMR, EXAFS and others could helpus in handling them

Another precipitating compound at SNF dissolution stage

No Technetiuminside

Experience and practice

Experience and practice

Experience and practice

Some examples of Russian experience in PUREX

improvement

• The first cycle flowsheet of RT-1plant is essentially similar to theTHORP flowsheet but isdistinguished by more reliable jointstripping of Pu, Np, and Tc due tofairly low acidity.• This is attained owing tointroduction of a special cycle forseparation of Pu and Np using largeamounts of Fe(II);• As a result, there are seriousproblems with evaporation of theraffinate of Pu-Np purification cycesand with localization of Tc in thehigh-level waste.•[Zilberman, Radiochemistry 2008]

Classical Purex processweak-acid

Main problems : increasing burn-up leads toImportant interference by Tc at 2 extractor

Strong-acid mode of PUREX PROCESS

• MAIN PROBLEM : • Interference by Tc at 2 extractor

• Uranium Product is contaminated with Tc

Russian reprocessing plant RT-1 , PUREX part

Separation of U from Pu in extraction reprocessing of WWER-440 and BN-600 SNF on the RT-1 facility (PA «Mayak») using the reductive

agent U(IV)+hydrazine, and the complexing agent (DTPA)

Russian reprocessing plant (RT-1, PO MAYAK, Ozersk)

Main problem :DTPA complexes precipitation (Tc/ΔPu)Tc presents in all streams

Technetium interfering role in the PUREX Pu/U separation stage

Reductive separation of U, Pu, Np (Tc)

Reducing agent+ complexing agent

Extract U,Pu,Np (Tc(STc

1st extcyc =80 -90%))

Back extract Pu, Np (Tc(IV))

Extract U(Tc(VII))

1. Variable red-ox states 2. Variable species

Difficulties in stability of U/Pu separation at UK, Russian and French facilities Catalytic Tc effects in many chem. reactionsVariable Tc redox statesTc - Waste problemsTc-DTPA complex precipitation

DTPA – Tc : EXAFS

Radiochemistry, 2011, Vol. 53, No. 2, pp. 178–185.

DTPA – Tc : EXAFS

MODEL STRUCTURES of Tc-DTPA(K.German, A. Melentiev, et allRadiochemistry, 2010-2011)

7

DTPA – Tc : EXAFS

French mode of PUREX Process (UP-3 RP, La Hague)

Russian new design for RT-2 (GHK,Krasnoyarsk)

Never finished…

Prof. Zilberman and colleagues : SUPERPUREX

(KHI, St-Petersburg/Gatchina)

Reducton of Np(V) by hydrazinein presence of Tc(VII) in 1.5 M

HNO3 (Tc catalytic effect)

0 20 40 60 800,0

0,1

0,2

0,3

0,4

D

time,min

Np (V)

Tc(IV)+Tc(X)

Np (IV)

Starting up

C(Np)=1,6*10-3 моль/л,С(Tc)=1,15*10-3 моль/л,

C(HNO3)=1,67 моль/л,C0(N2H5NO3)=0,3 моль/л,

t=450C,l=1 см

200 4000,00

0,15

0,30

D

time,min

The end of the process

Tc

Np (V)

Np(IV)

Gas evolut.

Np (V)+Tc(VII)

Some important features of liquid waste problems and its actual or

possible solutions

1. Tc redistribution in PUREX produces flows produces long-lived

high radioactive wastes

HLSW HLLW

2. Tc interferes at U/Pupartitionning stage in

PUREX process

Ways of improvement:1. Improved PUREX: Additional step

inserted at E-P for Tc wash-out with 4M HNO3 (Fance, UK, Russia, Japan)

2. Move from PUREX to UREX (considered in USA)

3. Pyrometallurgycal reprocessing of high burn-up fuel (Russia, NIIAR -Dimitrovgrad)

Ways of improvement:1. Preliminary separation of Tc

(Cogema, La-Hague)2. Acidity control and soft

reductors (RT-1, Ozersk)3. Complexation of reduced Tc

with DTPA or other complex forming agent (RT-1, Ozersk)

D UE P P (U/Pu) .

Pu

Ureductorfeed

USA - Advanced Fuel Cycle Initiative

Goals of Advanced Fuel Cycle Initiative (AFCI) separations technology program of GNEP (accord. :• Preclude or significantly delay the need for a

second geologic repository in this century• Reduce volume and cost of high-level waste• Separate TRU elements for fissioning in thermal or

fast neutron-spectrum reactors• Reduce the proliferation risk of the fuel cycle• Facilitate Generation IV nuclear energy systems

Aqueous-based liquid-liquid extraction technology is baseline process because it is most mature - generic name for process variants: UREX+

UREX+1a Process Outline

TALSPEAK

UREX

FPEX

TRUEX

Lanthanide FPs

by G.Jarvinen and K.Czerwinski

U, Tc

Cs, Sr

Non-Ln FPs

Np, Pu, Am, Cm

• Chop/dissolve fuel in HNO3; U and Tc separated in UREX step - TBP

in hydrocarbon solvent• Cs/Sr extracted using

calix-crown and crown etherin FPEX process

• Transuranics and lanthanidefission products extracted inTRUEX step with CMPO, back-extracted with DTPA/lactic acid

• Transuranics and lanthanidefission products separatedusing TALSPEAK, di-2-ethyl-hexylphosphoric acid extractslanthanides from actinides

Elaboration of separation methods and extensive fundamental studies

(by 1957 – 1977)

USA, GermanyBoyd G., Cobble J., Parker G.C. Coleman et all (Oak Ridge, extraction with trilaurylamine)Rapp A.F.Davison S.A, Trop H., Cotton F.A.Schwochau K.

Russia, CzechoslovakiaV. Spitsyn, A. Kuzina, (extraction with acetone, ion exchange)V. Shvedov, Kotegov, later - G. Akopov, A. Krinitsyn (extraction, ion exchange) L. Zaitseva, V. Volk (crystallization and other)Arapova, Yu. Prokopchuk, G. Chepurkov (extraction, ion exchange) Macasek F., Kadrabova(Slovakia)

Industrial scale separation of Tc-99g

Five main approaches were elaborated,each one has its advantages and disadvantages

Precipitation \ co-precipitation(USA, Russia)

Selective gas adsorption (USA, Kentucky)

Anion exchange (USA, Russia)Adsorption at carbon (Japan) Liquid-Liquid Extraction (USA, Russia, France, Japan)

Separation of Tc from HAW of gas-diffusion plant in USA

Back side : releases of Tc from decommissioned plant

Airborne radionuclides discharged at Portsmouth, 1989-1993 (ORNL-DWG 94M-8261)

02468

10

1989 1990 1991 1992 1993Year

CU

RIE

SURANIUMTECHNETIUM

Separation of Tc as TcF6 was made with MgF2 filters at 125oC in 1960 – 1963 from HAW of gas-diffusion plant in Kentucky, USA (Total = 25 kg Tc)Tomlinson, Judson, Zahn, ICPUAE,1964

The reaction of the cascade relevant technetium fluorides

with water

“ … A signifcant number of anecdotal reports of "pouring Tc" from cascade instrument lines exist. Observations of a finning, viscous brownish-red material with high beta activity suggests the presence of this acid, or perhaps a mixture of it, in low(er) temperature copper lines. HTcO, has a relatively low vapor pressure (61 torr at 100OC) at temperatures typical to the cascade, 21 and could also easily migrate as a gas phase compound”

/ D. W. Simmons. An Introduction to Technetium in the Gaseous Diffusion Cascades. Technical report K/TSO–39. Oak Ridge, Tennessee, USA -

September 1996 /

Development of ion-exchange technology for Tc separation

in IPCE RAS (1971-1976)

Prof. A.F. Kuzina (Tc Group leader till 1985 ) presents her Tc samples prepared in the

Institute from the concentrate separated from radioactive

wastes generated at Krasnoyarsk Reprocessing

Plant to Glean SEABORG (1978)

Separation of macro amounts of Tc-99g in USSR

1 kg of Tc was converted to metal in hot cell of IPCE RAS and distributed among different Russian institutesIn 1971-1976 IPC RAS in collaboration with Krasnoyarsk Mining Enterprise has separated from HAW some kilograms of K99TcO4

In 1983 -1986 collaboration of PO “Mayak”, IPCE RAS and Radium Institute resulted in elaboration of anion-exchange technology for Tc separation and 40 kg of K99TcO4. This work was awarded with the special Diploma of the Russian authorities

Anna KUZINA and Victor SPITSYN analyzing the

sample of Tc metal

Some new Tc(VII) compounds synthesised in IPCE RAS and NLVU for reprocessing of SNF

N New compound of Tc or Re Structure C solubility 25°C, M/L ρ Kass

1 Tetrapropylammonium pertechnetate Pna21 a = 13.22(4),b = 12.35(3),

c = 10.13(4) Å

(8.7 ±0.2) x 10-3 1,26 2,6 ± 0,4

2 Tetrapropylammonium perrhenate Pna21 a = 13.169(2), b = 12.311(2), c =

10.107(1) Å

(8.9 ±0.2) x 10-3 1.57 2,5 ± 0,3

3 Anilinium pertechnetate P21/c 9.8388(2) 5.89920(10) 14.6540(2) Å

(7.9 ± 0.2) x 10-2 2.07 -

4 Anilinium perrhenate P21/c 9.8714(4) 5.9729(2) 14.6354(5)

(8.3 ± 0.2) x 10-2 2.7 -

5 Tetrahexylammonium perthechnetate - (7.1 ± 0.5) x 10-5 1,07 40 ± 5

6 Tetrapentylammonium pertechnetate - (8.0 ± 0.2) x 10-4 1.33 -

7 Threephenylguanidinium pertechnetate P-1 9.87(1) 14.09(1) 15.44(1)

99.6 101.8 95.4

(3.9 ± 0.3) x 10-3 1,3 -

8 LiTcO4*3H2O P63mc, a=7.8604(1)b=5.4164(1) A

5. 1

9 [(NpO2)2(TcO4)4*3H2O]n P-1 5.322(5) 13.034(7)

15.46(9) 107.08 98.05 93.86(6)

0.95 4.99

New compounds (continued)

N New compound of Tc or Re Structure C solubility 25°C, M/L ρ Kass

11 Tetraphenylphosphoniumpertechnetate

a=17.25(5) b =17.26(5) c =14.239(5)

(4.0 ±0.2) x 10-4 ~1,1 40 ± 5

12 Cetylpyridinium pertechnetate - (3.9 ± 0.3) x 10-3 ~1,12 -

13 Cetylthreemethylammoniumpertechnetate

- (6,8 ± 0.5) x 10-3 ~1,15 -

14 Guanidinium pertechnetate a=7,338(2) A b=7,338(2) Ac=9,022(4) A γ=120 o

(9.7 ± 0.3) x 10-2 2,30 -

15 Guanidinium perrhenate 4.9657(4) 7.7187(7) 8.4423(7) α=75.314(4) o

(7 ± 0.5) x 10-2 3,30

16 Dodecylthreemethylammoniumpertechnetate

liquide (4.0 ±0.2) x 10-5 ~1,05 -

Some other new interesting compounds have beenmade by K.Czerwinski and co-workers in 2007- 2013

A few examples of new Tc compound structures made in IPCE RAS

(K.German, M.Grigoriev, A.Maruk etc.)

[Anil-H]TcO4[GuH]ReO4

LiTcO4*3H2O

[Bu4N]TcO4

[(AnO2)2(MO4)4*3H2O]n , (An = U, Np; M = Tc, Re)

[Pr4N]TcO4

[Tc2Ac4](TcO4)2

Pyrochemical reprocessing of BN-1200 SNF

(PRORYV project, Russia, 2020)

Tc behavior not well studied

Na2TcCl6 + Li2TcCl6 eutecticReducing cond.: ε-phasesOxidizing cond.:TcO3Cl, …

Top of the fundamental studies on Tc in IPCE RAS10 (!) oxidation states were found for

Tc in HX (X = Cl, Br, I) : 7+, 6+, 5+, 4+, 3+, 2.5+, 2+, 1.83+, 1.66+, 1.5+

1. 3-gonal-prismatic Tc chlorides and iodides ( 2 clusters of Tc(1.83+) and Tc(1.66+) : (Me4N)x[Tc6(m-Cl)6Cl6]Cly ) (K.German and others)

2. 4-gonal-prismatic Tc cluster bromide (addition of Tc2X2 to (1) S.Kryutchkov)

3. octahedral Tc cluster bromides and iodides (angular conversion of (1))

а

в

1 2 3

Each synthesis involve up to 10 g of Tc !Structures: unique in inorganic chemistry

A Trigonal-Prismatic Hexanuclear Technetium(II) Bromide Cluster

Na(Tc6Br12)2Br

Solid-State SynthesisE.V. Johnstone, D.J. Grant, F. Poineau, L. Fox, P. M. Forster, L. Ma, L. Gagliardi, K. R. Czerwinski, A. P. Sattelberger

GAS-PHASE TRANSPORT ? … !

My vision :it’s the world scale

research of the year .Three Profs. Czerwinski

all – radiochemists!

Some important gaps in our knowledge of Tc chemistry and thermodynamics

1. Tc metal: No heat capacities for Tc(cr) above 15, thermodyn. stability of the cubic Tc metal at nano-scale.

2. No heat capacities and entropies for TcO2(cr) and Tc2O7(cr).

3. Poor characterization of TcO3, Tc2O3, Tc4O5 and TcO2*nH2O

4. Poor characterization of Tc sulfides (possible solubility limiting phases under reducing conditions) and carbides (alternative nuclear fuel)

5. Inconsistence of different experimen-tal data on TcO2*nH2O solubility as function of pH (colloid speciation)

6. Poor definition of the protonation constant for HTcO4

7. Almost no equilibrium complexformation constants between Tc(III),Tc(IV) and Tc(V) and even most of the common inorganic anions present in groundwater

8. Inconsistence of stability estimations for Tc(IV) and Tc(V) from environmental and radiopharmaceutical studies

After J. Rard with some modifications

International collaboration of IPCE RAS with DOE and Nevada University (USA)

Tc reduction, co-precipitation studies and U-corrosion studies on decontamination of HAW tanks at Hanford Site (V. Peretrukhin, K. German in 1995-2007) Tc co-precipitation with cancrinite, sodalite, cryolite, oxalate and brown sludges with respect to decontamination of HAW tanks at Savannah River Sites. Fe(II) and Mn(III) oxides wereeffective Tc carriers and underwent chemical transformations on ageing that increased leaching resistance to most agents(K. German, 1999 – 2000, under contract with US DOE)EXAFS and NMR study of Tcin concentrated acid solutions(Nevada Univ.& IPCE, 2010 )

X-ray pattern of simulated Component of brown sludge

of SRS HAW Tanks

99Tc-NMR shift vs. TcO4- of KTcO4

in 3 M to 18 M H2SO4.

99Tc concentrations found in various tank sludges at SRS

Tank Number

[Tc-99], mCi/g dried

solidsReference

17 0.462 d'Entremont et al. 1997

20, white solids

0.34 d'Entremont and Hester 1996

20, brown solids

0.94 d'Entremont and Hester 1996

42 0.22 Hay 199951 0.21 Hay 19998 0.22 Hay 199911 0.34 Hay 1999

The discovery of relatively high 99Tc concentrations in

inorganic mineral sludge heels taken from some tanks at the US-DOE Savannah River Site

(SRS) has prompted investigations of Tc uptake from alkaline highly active

waste (HAW) by solid adsorbents

The SRS waste volumes (Table 2.4 of "Integrated Database Report - 1993: S.Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics,”]

Tc-99 quantities (Table 2.11), and

Volume, Tc-99, Ci [Tc-99], [Tc], 106 Kdliters Ci/liter g/liter total

Liquid 61.4 1.68E+04 2.74E-03 0.162 -Sludge 13.9 1.14E+04 8.20E-03 0.483 3Salt Cake 53.8 2.78E+03 5.17E-04 0.0305 0.2Overall waste 129.1 3.098E+04 2.40E-03 0.141 -

Question was: Which components absorb Tc with Kdhigher than 3 and are resistant to leaching?

Tc-99 concentrations calculated from these data

Sludge components as carriers for Tc(VII) and Tc(IV)

. SODIUM OXALATE .Na2C2O4

. CRYOLITE .Na3AlF6

ALUMINOSILICATESCANCRINITESODALITE

WHITE SOLIDS

. PLATINUM GROUP .METALS

Rh, Ru, Pd

METAL HYDROXIDES(Fe, Cr, Mn)(O)(OH)

BROWN SOLIDS

SOLID SLUDGE COMPONENTS

TiO2 was also tested

Experimental conditions for precipitation and leaching tests:

Precipitation tests: Wastes are alkalineTc is redox sensitiveSharp differences in the redox potential within the tanks are observed,

So, both:oxidizing [Tc(VII)]and reducing [Tc(IV)] conditions were tested in 0.1- 5 N NaOH + 0-5 N NaOH.

Leaching modes: Surface leaching. Complete dissolution.

Leaching agentsall precipitates : 0.1N NaOH aluminosilicates - NaHF2

Na oxalate - 0.1N NaOH, NaNO2

FeOOH - 0.1N NaOH, H2O2

MnOOH - 0.1N NaOH, H2O2

TiO2 - 0.1- 3N NaOH

Methods: Liquid scintillation counting (LSC) of solutions, XRD, NMR, IR

Study of Tc uptake with Aluminosilicates under oxidizing

conditions at 70-130oC

Solution Formed solid Kd

10-3-10-5M Tc0.2-5M NaOH

0.5-5 M NaNO3Cancrinite less 1

10-3-10-5M Tc0.2-5M NaOHNaNO3 free

Sodalite less 1

TcO4- is too large

and therefore it is excluded from the

aluminosilicatestructure in both cancrinite and

sodalite

Literature data have demonstrated the possibility of ClO4

- and MnO4- co-crystallisaton

with aluminosilicates : purple Na8[AlSiO4]6(MnO4)2 (Weller,1999 etc.)OUR EXPERIMENTS on TcO4

- (reaction: NaAlO2+Na2SiO3+NaOH)

Case of Aluminosilicates formed in concentrated Tc(VII) solution

[Tc] = 0.2 Min NaNO3 solutions -cancrinite in NaNO3-free solutions -sodaliteAlthough NMR spectrum presented shift typical for coordinated Tc(VII) its concentration is very low

Dissolution in NaHF2 and LSC has shown : [Tc] in solid cancrinite was 57 mg/kg ~ 100 times less than in initial solution

Fig. 1. NMR-99Tc spectrum of the aluminosilicate containing

57 mg-Tc/kg. Tc spectrum presents evidence for -30 ppm shift

characteristic of coordinated pertechnetate

Study of Tc uptake with Aluminosilicates under reducing conditions(0.2M N2H5Cl, 1M NaNO3, T = 800С, t = 3 d)

Precipitation ofcancrinite↓

Leaching conditions:

NaOHM

Tc yield, %

Leachingagent:

T, oC

Leaching yield , Tc, %

3 hour

1 day 10 days

2.0 18.9 1M NaOH 20 0.8 1 3.7

4.0 32 2M NaOH 20 0.8 1.2 2.0

2.0 25.2 0.1M NaOH + 0.25 M H2O2

60 25 26.9 27

2.0 18.9 0.1M NaOH + 0.5 H2O2

18 4 6.9 7

4.0 32 0.1M NaOH + 0.5 H2O2

18 6.5 6.9 11

Under reducing conditions Tc uptake is important

Tc(IV) in aluminosilicates is resistant to leaching

Study of Tc(VII) sorption by crystalline TiO2

under oxidizing conditions

Tc(VII) was sorbed by TiO2from neutral solution with Kd= 30 ml/g. However, the Kd at pH=10 was only 3.3 ml/gNo affinity to Tc(VII) was noted for TiO2 at pH=12 and higher .

Among the minerals

tested for Tc(VII)

uptake, high-density TiO2

was the most efficient

MST and Silicotitanates yet not tested ..?

Study of Tc uptake withNa oxalate under

oxidizing and reducing conditions

Tc(VII) is excluded from the Na oxalate structure under oxidizing conditions (Kd = 1-2)Under reducing conditions Tc(IV) forms a separate TcO2*1.6H2O phase - no interaction between Tc hydroxide and Na oxalate were detectedTc precipitate is not resistant to leaching with 0.1 N NaNO2

NaOH + H2C2O4 = Na2C2O4X-ray diffraction tests :

the precipitate is sodium oxalate Na2C2O4

(PDF#20-1149)

Study of Tc uptake withCryolite Na3AlF6 under

oxidizing and reducing conditions

Reduced Tc :

17-35% of Tc(IV) as TcCl62- is co-precipitated with cryolite N2H5NO3 inhibits co-precipitation

Oxidizing conditions:

Kd is less 1

Tc(VII) is excluded from cryolite structure

6F-+NaAlO2+Na2CO3X-ray diffraction tests :

the precipitate is cryolite Na3AlF6

Tc(IV) uptake with Cryolite Na3AlF6under reducing conditions

No

[NH4F] initial,

M

[Na2CO3] in final

solution, M

[N2H5NO3], in final

solution, M

Tc(IV) uptake,

%

1234589

10

2,02.53.04,06,02,02,02,0

0,60.60,60.60,60,40,80,6

-------

0,1

202326283525170

• Tc(IV) is added as Na2TcCl6 to (NH4F+NaAlO2) solution• No additional reducing agent in exp. No 1-9• Leaching test were impossible to quantify relative to real cryolitein tanks as complete peptization occurred.

Study of Tc(IV) uptake with FeOOH under reducing conditions

Precipitation test: Leaching test (t=18 oC, d = days):

NaOH M

Tc in solid phase, %

Leaching agent:

Leaching yield ,Tc, % 1 d 10 d 29 d 105d

0.6 97 0.1M NaOH 1.0 9.8 14.9 24

2.0 88.0 1M NaOH 2.9 16.5 40.2 58

4.0 90 2M NaOH 0.8 2 3 8.2

Reducing agent: 0.02M FeSO4, T = 600С, time = 3 h Precipitate : FeOOH/Fe2O3

Though Tc adsorbed better on iron hydroxides from 0.5–2.0 M NaOHthan from 3.0-4.0 M NaOH, the precipitates formed at lower NaOH

concentration were more easily leached by the NaOH leachantTc leaching with H2O2 was 20 % and with Na2S2O8 was70-100% in 100

days

Study of Tc(IV) uptake with MnOOH under reducing conditions

Reaction NaOH + Na2MnO4+ N2H5OH= MnOOHX-ray diffraction tests : the freshly precipitated

solid was Mn2O3 , the aged precipitate was manganite MnOOH (PDF#18-805)

Manganese(III) oxides were effective Tc carriers and underwent chemical transformations on ageingthat increased leaching resistance to most agents.

MnOOH precipitation MnOOH leaching to 0.1 NaOH (1,3,4) and Na2S2O8(2)

Tc & HLW Vitrification

Tc is volatilized at 750 – 850 oCunder oxidizing conditions as MTcO4 (M = Na, Cs)

Russian Tc - Transmutation program (1992-2003)------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

99Tc(n,γ)100Tc(β)100Ru

0,00%

25,00%

50,00%

75,00%

1 2 3 4 5

Irradiation time, days

Tech

netiu

m-9

9 Bu

rnup

, %

Hanford (USA) 1989

Wootan WJordheim DP

Matsumoto WY

Petten (NL) 1994-1998

Konings RJMFranken WMP

Conrad RP et al.

Dimitrovgrad (Russia)

IPC RAS - NIIAR 1999 - 2000Kozar AA

Peretroukhine VFTarasov VA et al.

6%

18%

34%

65%

10.5 days 193 days 579 days 72 days 260 days

0,67 % = Pessimistic

Tc transmutation experiment (IPCE RAS – NIIAR, 1999-2008)In IPC RAS a set of metal disc targets (10x10x0.3 mm) prepared

and assembled in two batches with total weight up to 5 g.Transmutation experiment was carried out at high flux

SM-3 reactor ( NIIAR, Dimitrovgrad )

2nd batch: Ft > 2× 1015 cm-2s-1

1st batch: Ft=1.3× 1015 cm-2s-1

99Tc burnups have made: 34 ± 6 % and 65 ± 11 %

for the 1st and 2nd targets batches----

The high 99Tc burn-ups werereached and about 2.5 g of newmatter - transmutationruthenium were accumulated asa result of experiments on SM-3reactor

These values are significantlyhigher of burnups 6 and 16 %achieved on HFR in Pettenearlier

1 − центральный блок трансурановых мишеней; 2 − бериллиевые вкладыши;3 − бериллиевые блоки отражателя; 4 − центральный компенсирующий орган

− автоматический регулятор

− стержень аварийной защиты

− ячейка активной зоны с ТВС

− компенсирующий орган

− канал и его номер7 Д-2 81

91КО-

АР

4 3

2

1

Д-3 Д-1

9 12

465666768696

6575 45558595

425262728292

4151617181

44548494

43538393

КО4КО3

КО191КО2

Д-2

2

6

1415

3

7

816

Д-4

Д-5

АР17

Д-6

Д-10

Д-9

13

Д-8

АР1

19

4

10Д-7

5

20

11 2118

Рис.5. Картограмма реактора СМ

Preparation of artificial stable Ruthenium by transmutation of

Technetium

Rotmanov K. et all. Radiochemistry, 50(2008)408New Ruthenium is almost monoisotopic Ru-100It has different spectral propertiesIt is available only to several countries that develop nuclear industry

Tc target material:Tc metal powder / Kozar (2008)Tc – C composite Tc carbide / German (2005)

The IPCE publications used in the presentation

The principle achievements of recent Russian researches in technetium chemistry, metallurgy, environmental science, nuclear reprocessing and applications are overviewed. The allied aspects of rhenium chemistry and applications are compared. The progress in technetium handling during the spent nuclear fuel reprocessing was based on the fundamental studies of numerous new technetium mono- and polynuclear compounds and species [1-10]. The previous achievements were reviewed in [11].In concentrated water solutions Tc(VII) often forms crystals isomorphous with perchlorates while in concentrated unhydrous solutions Tc(VII) behaviour is more similar to Re(VII) compared to Cl(VII) [4-6]. Interesting results were obtained with the Tc-DTPA complex formed under advanced PUREX conditions [6-7]. Great progress have been achieved in the understanding of Tc(VII) behaviour in acids [8-10] that is important for explanation and prediction of Tc and Re handling in acids, including the concentrated acid solutions up to highest. The investigation in crystal structures of Tccompounds [2] enabled us with direct recommendations for the template synthesis for Tc and Re sensors [6]. The progress in Tc carbonyl compounds gave chance for advanced Tc metal and Tc carbide films deposition [7]. Technetium sulphide and rhenium were studied both with respect to medicine and to environmental behaviour of these elements [11]. The work on technetium nanomaterials was carried in Russia in 2009-2010 within RFBR-09-03-00017, while the work on DTPA complexes with RFBR-09-08000153. References.Peretrukhin V.F., German К.E., Маslennikov А.G. etc. Development of chemistry and technology of technetium. In.: «Modern problems of physical chemistry» р. 681 – 695. М.: «Granitsy Publ.» (2005) 681-695.Grigoriev M.S., German K.E., Maruk A.Y. // Acta Crystallogr. Sect E. (2007) V. 63. Pt.9. : P. m2061, and p. m2355.Maruk A.Y. Grigoriev M.S., German K.E. Russ. Coord.Chem (2010) v.36, No 5, pp. 1–8.Maruk A.Y. Grigoriev M.S., German K.E. Abstracts of the ”Conference on diffraction methods for substance investigations: from molecules to crystals and nanomaterials”, Chernkgolovka. 30 june-3 july 2008. p.Maruk A.Y. Grigoriev M.S., German K.E. Abstracts of the ”Conference on diffraction methods for substance investigations: from molecules to crystals and nanomaterials”, Chernkgolovka. 25 june- 28 june 2010. p.D.N. Tumanova, K.E. German, V.F. Peretrukhin, Ya.A. Obruchnikova, A.Yu. Tsivadze. Stabilization and spectral characteristics of technetium and rhenium peroxides. In: 6-th International Symposium on Technetium and Rhenium. NMMU-Port Elizabeth, 7-10 October 2008, p.47.D.N. Tumanova, K.E. German, V.F. Peretrukhin, A.Yu. Tsivadze. Formation of technetium peroxydes in anhydrous sulfuric acid. Doklady Phys. Chem. 420 (2008) 114-117.German K.E., Melentiev A.B., Kalmykov S.N., etc. Tc-DTPA sediments formed in technetium – hydrazine – DTPA – nitric acid solutions. Journ. Nucl. Medcine and Biol.(2010). Sept. pp. B.Ya. Zilberman. Radiochemistry , 42 (2000) 1-14. Katayev E.A., Kolesnikov G.V., Khrustalev V.N. etc. // J. Radioanal. Nucl. Chem. (2009) 282: p. 385–389.Maruk A.Y., German K.E., Kirakosyan G.A. etc. HtcO4. Abstracts of the 6-th Russian conference on radiochemistry, 12-16 Oct. 2009. Moscow. p.F. Poineau, Ph. Weck, K. German, A. Maruk, G. Kirakosyan, W. Lukens, D. B. Rego, A. P. Sattelberger, K. R. Czerwinski . Speciation of Heptavalent Technetium in Sulfuric Acid: Structural and Spectroscopic Studies. RSC-Dalton Transactions (2010) Dec. pp. (in press).

The IPCE publications used in the presentation (continued)

Peretrukhin V.F., Moisy Ph., German K.E. etc. J. de la Soc. de Chim. D.I. Mendeleiev (2007) v.51, № 6, p.11-23.Plekhanov Yu.V., German K.E., Sekine R. Electronic structure of binuclear technetium chloroacetate cluster: quantum Chemical calculations and assignement of optical and XPE spectra. Radiochemistry, 45 (2003) 243-249.German K.E., Kryutchkov S.V. Polynuclear technetium halide clusters. Russ. Journ. Inorg. Chem. 47 (2002) 578-583. N. N. Popova, I. G. Tananaev, S. D. Rovnyi, B. F. Myasoedov, Russ. Chem. Rev., 72 (2003) 101.German K.E., Peretrukhin V.F., Gedgovd K.N., etc.// Journ. Nucl. Radiochem. Sci. 6 (2006) No.3, pp. 211-214. Alekseev I.E., Antropov A.E. Accelerated transport of impurity Tc-99m atoms at polymorph transition in irradiated metal molybdenum. Radiochemistry, 44 (2002) 334-336 (Rus).Sidorenko G.V., Miroslavov A.E., Suglobov D.N. Vapor deposition of technetium coatings by thermolysis of volatile carbonyl complexes : II. Chemical and phase composition, microstructure, and corrosion resistance of coatings. Radiochemistry, 51 (2009) 583-593.K.E. German, Yu.V. Plekhanov. // Quantum chemical model of Technetium Carbide. Journal of Nuclear and Radiochemical Sciences (2006) V. 6, No.3, pp. 215-216. A.B. Melent’ev, V.A. Misharin, A.N. Mashkin, I.G.Tananaev, K.E.German. Abstracts of the 6-th Russian conference on radiochemistry, 12-16 Oct. 2009. Moscow. p. 209.D.N.Tumanova, K. E. German, Ph. Moisy, M. Lecomte, V. F. Peretrukhin. Catalytic effects of Tс ions on the Np -hydrazinium - nitric acid system. In: Abstracts of the 6-th International Symposium on Technetium and Rhenium. NMMU-Port Elizabeth, 7-10 October 2008, p.46.German K. E., Dorokhov A. V., Kopytin A. V., etc. // Journ. Nucl. Radiochem. Sci. (2006) V. 6, No.3, pp. 217-220. German K.E., Kosareva I.M., Peretroukhin V.F., etc. In: Proceedings of the 5-th Int.Conf. on radioactive wase management and environmental remediation. ICEM'95. V.1. Cross-cutting Issues and management of high-level waste and spent fuel. (Eds.: S.Slate,Feizollahi, C.Creer), NY(1995) p. 713 - 722. Slobodkin A.I., Tourova T.P., German K.E., etc. Int. Journ. System. Evolut. Microbiol. (2006). V. 56. P. 369-372. Tarasov V.P., Muravlev Yu. B., German K.E., Popova N.N. Tc-99 NMR of Technetium and Technetium-Ruthenium nanoparticles. In: Magnetic Resonance in Colloid and Interface Science. Edited by Jacques P. Fraissard and Olga Lapina. Book Series: NATO Science Series: II: Mathematics, Physics and Chemistry: Volume 76. Kluwer Academic Publishers. Netherlands (2002) Pp. 455-468.Pirogova G.N., Panich N.M. Physicochemical properties of Technetium. Russ. Journ. Inorg. Chem. 47 (2002) 681-687. Maruk A.Ya., Khaustova T.A., German K.E. etc. Labeling conditions study for technetium-99m thiosemicarbazid derivatives. School-conference on radiochemistry 2010 Ozersk. German K.E., Obruchnikova Ya.A., Popova N.N. etc. Abstracts of All-russian conference ” Physico-chemical aspects of nanotechnology – properties and applications”. Moscow, L.Ya. Karpov Institute of Physical Chemistry. 2009. P. German K.E., Popova N. N., Tarasov V.P., etc. Journ. Russ. Chem. Soc. Mendeleev, (2010) Sept.No. pp. (in press).Peretrukhin V. F., Rovnyi S. I.,. Ershov V. V, German K. E., Kozar A. A., Russ. J. Inorg. Chem., 47 (2002) 637.

For conclusion:

OUR MODERN VISION oF Tc-99 FATE :Born to Burn

And this fire will give not ash

but the noble metal