Reprocessing spent nuclear fuel using molten carbonates and subsequent precipitation of rare earth fission products using phosphate / Griffiths T.R., Volkovich V.A., Yakimov S.M., May I., Sharrad C.A., Charnock J.M. // Journal of Alloys and Compounds. - 2006. - V. 418, l. 1-2. - P. 116-121.

ISSN:

09258388

Type:

Article

Abstract:

Uranium (and plutonium) can be separated from spent fuel by treatment in molten carbonates and air sparging. UO2 is converted into insoluble uranate species that can be filtered off. The rare earth and other fission product elements remaining in solution can be later precipitated using phosphates as precipitants. A sequence is described that can (in principle) be used to recover and recycle the carbonate melt used. Molten chloride eutectics are more convenient solvents than carbonates for obtaining the detailed chemistry of fission products in molten salts and their selective precipitation as phosphates. We have investigated the behavior of: Cs, Mg, Sr, Ba, lanthanides (La to Dy), Zr, Cr, Mo, Mn, Re (to simulate Tc), Fe, Ru, Ni, Cd, Bi and Te, but here report results for the rare earths. The distribution coefficients of these elements between chloride melts and precipitates were determined. Lithium-free melts favored formation of double phosphates. Rare earth elements and zirconium can be removed from chloride melts but Sr, Ba and Mg are melt cation specific. EXAFS and XANES measurements have established the speciation of both transition and non-transition elements in molten chlorides. EXAFS is largely model dependent, and to ensure the correct coordination number requires absorption spectroscopy data. EXAFS provides the element-Cl distance in the melt, not previously available. At high concentrations, the presence of bridging chlorine atoms can be established by EXAFS. The effect of diluting such melts and preliminary data on the solubilities of rare earth fission product elements in carbonate melts are reported. © 2005 Elsevier B.V. All rights reserved.

Author keywords:

EXAFS; Molten carbonates; Phosphate precipitation; Rare earth fission products; Reprocessing

Index keywords:

Carbonates; Fission products; Phosphates; Precipitation (chemical); Rare earth elements; Uranium; EXAFS; Molten carbonates; Phosphate precipitation; Rare earth fission products; Reprocessing; Nuclear

DOI:

10.1016/j.jallcom.2005.10.060

Смотреть в Scopus:

https://www.scopus.com/inward/record.uri?eid=2-s2.0-33744808317&doi=10.1016%2fj.jallcom.2005.10.060&partnerID=40&md5=47f24cf9267fe1731f8e75494efc4c39

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Link	https://www.scopus.com/inward/record.uri?eid=2-s2.0-33744808317&doi=10.1016%2fj.jallcom.2005.10.060&partnerID=40&md5=47f24cf9267fe1731f8e75494efc4c39
Affiliations	Redston Trevor Consulting Limited, 58 High Ash Avenue, Leeds, LS17 8RF, United Kingdom; Ural State Technical University, UPI, Ekaterinburg, 620002, Russian Federation; Centre for Radiochemistry Research, The University of Manchester, Manchester, M13 9PL, United Kingdom; CLRC Daresbury Laboratory, Warrington, WA4 4AD, United Kingdom
Author Keywords	EXAFS; Molten carbonates; Phosphate precipitation; Rare earth fission products; Reprocessing
References	Volkovich, V.A., Griffiths, T.R., Fray, D.J., Fields, M., Wilson, P.D., (1996) J. Chem. Soc., Faraday Trans., 92, p. 5059; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Fields, M., (1997) J. Chem. Soc., Faraday Trans., 93, p. 3819; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Fields, M., Thied, R.C., (1998) J. Chem. Soc., Faraday Trans., 94, p. 2623; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Fields, M., (1998) J. Nucl. Mater., 256, p. 131; Griffiths, T.R., Volkovich, V.A., (1999) J. Nucl. Mater., 274, p. 229; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Fields, M., Thied, R.C., (1998) Proceedings of the 11th International Symposium on Molten Salts, vol. 98-11, pp. 612-626. , Trulove P.C., De Long H.C., Stafford G.R., and Deki S. (Eds). San Diego, California, USA, 3-8 May, The Electrochemical Society Proceedings Series, Pennington, NJ, USA; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Thied, R.C., (1999) Phys. Chem. Chem. Phys., 1, p. 3297; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Thied, R.C., (2000) Phys. Chem. Chem. Phys., 2, p. 3029; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Fields, M., Thied, R.C., (2000) Proceedings of the 12th International Symposium on Molten Salts, vol. 99-41, pp. 441-450. , Trulove P.C., De Long H.C., Stafford G.R., and Deki S. (Eds). Honolulu, Hawaii, USA, 17-22 October, The Electrochemical Society Proceedings Series, Pennington, NJ, USA; Volkovich, V.A., Griffiths, T.R., Fray, D.J., Thied, R.C., (2000) J. Nucl. Mater., 282, p. 152; Volkovich, V.A., Griffiths, T.R., Anghel, E.M., (2002) Proceedings of the 13th International Symposium on Molten Salts, vol. PV 2002-19, p. 306. , Delong H.C., Bradshaw R.W., Matsunaga M., Stafford G.R., and Trulove P.C. (Eds). Philadelphia, PA, USA, 12-17 May, The Electrochemical Society, Pennington, NJ; Matsuzawa, K., Tatezawa, G., Matsuda, Y., Ryoke, H., Mitsushima, S., Kamiya, N., Ota, K.-I., (2004) Proceedings of the 14th International Symposium on Molten Salts, , Honolulu, Hawaii, USA, 3-8 October; Kryukova, A.I., Masterova, L.Y., Skiba, O.V., (1990) Sov. Radiochem., 32, p. 368; Shannon, R.D., (1976) Acta Crystallogr. A, 32, p. 751
Correspondence Address	Griffiths, T.R.; Redston Trevor Consulting Limited, 58 High Ash Avenue, Leeds, LS17 8RF, United Kingdom; email: T.R.Griffiths@chem.leeds.ac.uk
CODEN	JALCE
Language of Original Document	English
Abbreviated Source Title	J Alloys Compd
Source	Scopus