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