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Kulyako Y.M.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Perevalov S.A.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Trofimov T.I.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Malikov D.A.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | And 6 more authors.
Journal of Radioanalytical and Nuclear Chemistry | Year: 2014

It was established that heating to 90 C of nitrate solutions of U, Np and Pu in the presence of hydrazine hydrate results in the formation of hydrated dioxides of these elements. On ignition under inert or reducing conditions in the temperature range of 280-800 C hydrated uranium dioxide transmogrify into crystalline UO2. On ignition in air atmosphere UO2· nH2O turns into UO3 at 440 C and into U3O 8 at 570-800 C. It was shown that thermolysis of the solution containing a mixture of uranium, neptunium and plutonium nitrates at 90 C in the presence of hydrazine hydrate allows one to prepare hydrated dioxides (U, Np, Pu)O2·nH2O which on heating to ~300 C transmogrify into crystalline product of UO2, NpO2 and PuO2 solid solution. The technique of preparation of solid solutions of U and Pu dioxides is very promising as simple and effective method of production of MOX-fuel for. © 2013 Akadémiai Kiadó, Budapest, Hungary.


Karasev Y.,Bochvar Institute VNIINM | Malchenkov A.,Bochvar Institute VNIINM | Lukyanov P.,Bochvar Institute VNIINM | Polikarpova M.,Bochvar Institute VNIINM | And 8 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2016

More than 100 tons of Nb-Ti superconducting strands were produced by JSC 'ChMP' (RF) for the ITER poloidal field coils (PF16) in the period from 2010 to 2014. The strands were manufactured based on the NT-47 alloy with a titanium content within 46.0-48.5 wt%, using the technology developed at Bochvar Institute. Measurements of the temperature and field dependence of the critical currents were carried out at the Low Temperature Physics Department of Atominstitut, Technische Universität Wien, on strands stemming from the 30%, 60%, and 90% stages of industrial production. The facility for variable temperature critical current measurements was upgraded in order to provide direct measurements of the critical current up to 300 A at relatively high temperatures (T > 5 K) in a gas-cooled mode and up to 900 A in liquid helium. Unique results regarding the field and temperature dependence of the critical current in the range from 2 to 12 T and from 3.5 to 7 K, respectively, are presented and discussed based on single-and two-component pinning models. On the basis of mathematical models, the critical temperature at which the transition to the resistive state occurs (Tcs) was evaluated for the operating conditions (6.4 T and 33 A) of the poloidal field coils. Statistical analysis revealed that both models adequately describe the experimental Ic(T,B) data; however, a comparison of the models based on the Fisher test shows a statistical difference. © 2016 IEEE.


Karasev Y.V.,Bochvar Institute VNIINM | Pantsyrny V.I.,Bochvar Institute VNIINM | Polikarpova M.V.,Bochvar Institute VNIINM | Lukianov P.A.,Bochvar Institute VNIINM | And 6 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2014

Commercial multifilamentary Nb-Ti strands produced by the Russian Federation DA for the ITER poloidal field coils PF1 and PF6 were characterized regarding the critical current versus magnetic field dependence from 2 to 10 T over a wide range of temperatures from 2.5 to 7 K. The data were collected on several Nb-Ti strands at the stage before production and after 30% of the production for the ITER program. J{\rm c}(B, T) fits were determined using parameterization models with single pinning and two-pinning components. The validity and limitation of these estimations will be discussed. The pinning force curves are presented in the temperature range from 2.5 to 4.2 K and indicate a shift of the pinning force peak to lower fields with increasing temperature. The current sharing temperature T\rm cs at the operating current (33 A) and field (6.4 T) was determined from both parameterization models. The results of T\rm cs show good reproducibility for each set of Nb-Ti strands. The good agreement between experimental and fit results over very wide temperature ranges can be used for the analysis of experimental data on the PF conductor performance and for the design of future superconducting magnets. © 2002-2011 IEEE.


Abdyukhanov I.M.,Bochvar Institute VNIINM | Vorobyeva A.E.,Bochvar Institute VNIINM | Beliakov N.A.,Bochvar Institute VNIINM | Dergunova E.A.,Bochvar Institute VNIINM | And 5 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2012

Bronze processed Nb 3Sn strands, differing by specific layouts, and the Sn content of 14.5 and 15.5 wt% in the matrix, were produced and investigated. In order to optimize the production process the investigation of the mechanical properties of doped and undoped bronze samples was done. The microstructure features of strand samples were explored by means of electron microscopy. X-ray analysis was used to determine the characteristics of Nb 3Sn phase after diffusion annealing. The current capacity of strands and n parameter has been investigated in magnetic fields from 8 T up to 12 T at 4.2 K and it was established that the critical current density (J c) is higher than 900 A/mm 2 (non-copper, diameter 0.82 mm, 4.2 K, 12 T) for the investigated strands with doped bronze matrix. © 2002-2011 IEEE.


Polikarpova M.V.,Bochvar Institute VNIINM | Lukyanov P.A.,Bochvar Institute VNIINM | Abdyukhanov I.M.,Bochvar Institute VNIINM | Pantsyrny V.I.,Bochvar Institute VNIINM | And 5 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2014

High strength and high electrical conductivity Cu-Nb tape was tested as the new type of stabilizing layer for YBCO-coated conductor. For electrical interconnection of stabilizing layer to coated conductor the soldering process was used and no degradation in critical current, Ic, of laminated coated conductor after soldering process was observed. The dependence of normalized transport critical current, Ic/Ic0, on the bending radius of coated conductors with and without Cu-Nb stabilizing layer was investigated using the bending test probe providing the uniform bend process at 77 K and under self-field conditions. The reversible and irreversible variations of Ic/I0 with inverse bending radius were found and the irreversible bending radius limit was observed to depend on the neutral axis shift. The generation of the cracks appears to be the primary reason for the Ic/Ic0 degradation that was supported by ScanHall technique investigations. © 2013 IEEE.


Abdyukhanov I.M.,Bochvar Institute VNIINM | Vorobieva A.E.,Bochvar Institute VNIINM | Dergunova E.A.,Bochvar Institute VNIINM | Polikarpova M.V.,Bochvar Institute VNIINM | And 5 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2012

Residual Resistance Ratio (RRR) is one of the relevant parameters for Nb 3Sn strands and cables to be used in windings of high field magnet systems. The increase of the cable stability is provided by attaining of the high RRR-values. However, the RRR values of strands comprising the cable could deviate significantly from the average ones. Oxygen free high purity copper with RRR <250 is used for Cr-plated Nb Sn strand fabrication for ITER, but after the final reaction heat treatment at 650° C during 100-200 hours RRR values are reduced. The influence of the Cr-plated ITER strands annealing on the RRR values have been investigated for the wide range of temperatures from 200 ° C to 700 ° C, and the influence of duration of last stage of reaction heat treatment at 650° C from 100 to 200 hours have been studied. X-ray spectral microanalysis of strand outer surface and peripheral copper layer has been carried out for determining the chromium and oxygen contents. Also the content of Cr and other impurities in copper shell of Nb 3 Sn strand has been done by ICP (Inductively coupled plasma) mass spectrometric method. It has been shown that RRR is affected by oxygen and chromium diffusion from coating during annealing at 650° C. The Cr-diffusion distance has been estimated on the base of mass spectrometry data. Optimal annealing conditions of Cr-plated Nb 3 Sn strands have been determined. © 2011 IEEE.


Shadrin A.,Bochvar Institute VNIINM | Dvoeglazov K.,Bochvar Institute VNIINM | Ivanov V.,Bochvar Institute VNIINM
International Nuclear Fuel Cycle Conference, GLOBAL 2013: Nuclear Energy at a Crossroads | Year: 2013

The closed nuclear fuel cycle (CNFC) with fast reactors (FR) is the most promising way of nuclear energetics development because it allows to prevent spent nuclear fuel (SNF) accumulation and to minimize radwaste volume due to minor actinides (MA) transmutation. CNFC with FR requires the elaboration of safety, environmentally acceptable and economically effective methods of treatment with SNF with high burn-up and low cooling time. The up-to-date industrially implemented SNF reprocessing technologies based on hydrometallurgical methods are not suitable for reprocessing of SNF with high burn-up and low cooling time. The alternative "dry " methods applicable for such SNF reprocessing have not found implementation at industrial scale. So the cost of SNF reprocessing by means of "dry" technologies can hardly be estimated. Another problem of "dry" technologies is recovery of fissionable materials pure enough for dense fuel fabrication. Combination of technical solutions realized in hydrometallurgical and "dry" technologies is promising way for elaboration of economically, ecologically and socially accepted technology of FR SNF management. This paper deals with discussion of main principle of "dry" and "aqueous" operations combination that probably would provide safety and economic efficiency of the FR SNF reprocessing.


Salunin N.,Bochvar Institute VNIINM | Kozlenkova N.,Bochvar Institute VNIINM | Polikarpova M.,Bochvar Institute VNIINM | Potanina L.,Bochvar Institute VNIINM | And 4 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2012

The commercial multifilamentary NbTi strands produced for ITER poloidal field coils PF1 and PF6 have been characterized on J c(B,T) at various manufacturing stages: bare strand, Ni-plated strand and the strand after impregnation heat treatment. We present the results of critical current measurements at magnetic fields in the range of 4.5-10 T, and temperature within 4.2-7 K. Current sharing temperature T cs of these strands has been determined with a precision of few tens of mK, using fit formula that provides the critical current density as a function of temperature and field. The results show that T cs of commercial strands exceeds the required value of 5.9 K at 6.4 T and the operating current of 33 A. These measurements allowed us to get a database, essential for the future analysis of the experimental data, and to find the strand characteristic parameters for the J c(B,T) fit. © 2002-2011 IEEE.

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