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Uranium-Series Ages of Secondary Uranium Minerals with Applications to the Long-Term Evolution of Spent Nuclear Fuel

Published online by Cambridge University Press:  15 February 2011

R. J. Finch ,
J. Suksi ,
K. Rasilainen  and
R. C. Ewing
R. J. Finch
Affiliation:
University of Manitoba, Winnipeg, Manitoba. R3T 2N2, Canada
J. Suksi
Affiliation:
University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
K. Rasilainen
Affiliation:
VTT Energy, P.O. Box 1604, FIN-02044 Espoo, Finland
R. C. Ewing
Affiliation:
University of New Mexico, Albuquerque, New Mexico, 87131, USA
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Abstract

Uranium-series activity ratios for U(VI) minerals from the Shinkolobwe mine in southern Zaire indicate that these minerals have not experienced significant preferential loss of uranium since their formation more than 100,000 years ago. The minerals examined include rutherfordine, UO2CO3, schoepite, [(UO2)8O2(OH)12]·12H2O, becquerelite, Ca[(UO2)6O4(OH)6]·8H2O, and uranophane, Ca[(UO2)2(SiO3OH)2]·5H2O. No correlation between mineral species and mineral age was evident. The oxidative dissolution of primary uraninite (UO2+x) has maintained ground waters supersaturated with respect to all of the secondary U(VI) minerals, providing an inexhaustible source of dissolved U6+ for mineral formation and growth. As long as uraninite persists in an oxidizing environment, the assemblage of secondary U(VI) phases is determined by local ground water chemistry (including transitory changes), but not necessarily a unidirectional reaction path towards equilibrium with U(VI) minerals of lower solubility. Thus the Shinkolobwe mine displays a complex assemblage of U(VI) minerals that reflects variations in the availability of dissolved elements besides U. Similarly, for a geologic repository exposed to oxidizing waters, the assemblage of corrosion products that will form during the corrosion of spent UO2 fuel is likely to be as complex as mineral assemblages found in natural uranium deposits under similar conditions.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 412: Symposium V – Scientific Basis for Nuclear Waste Management XIX , 1995 , 823
Copyright
Copyright © Materials Research Society 1996

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References

[1] Finch, R.J. and Ewing, R.C., SKB Technical Report 91-15 (SKB, Stockholm) 1991.Google Scholar
[2] Wronkiewicz, D.J., Bates, J.K., Gerding, T.J., Veleckis, E. and Tani, B.S., J. Nucl. Mater. 190, 107 (1992).Google Scholar
[3] Casas, I., Bruno, J., Cera, E., Finch, R.J., Ewing, R.C., SKB Technical Report 94-16 (SKB, Stockholm) 1994.Google Scholar
[4] Sandino, A. and Grambow, B., Solubility equilibria in the U(VI)-Ca-K-Cl-H2O system: transformation of schoepite into becquerelite and compreignacite. Radiochimica Acta (1995).Google Scholar
[5] Bruno, J., Casas, I., Cera, E., Ewing, R.C., Finch, R.J., in Scientific Basis for Nuclear Waste Management XVIII, edited by Murakami, T. and Ewing, R.C. (Mater. Res. Soc. Proc. 353, Pittsburgh, PA, 1995) pp. 633–639.Google Scholar
[6] Finch, R.J., Suksi, J., Rasilainen, K. and Ewing, R.C. in Scientific Basis for Nuclear Waste Management XVIII., edited by Murakami, T. and Ewing, R.C. (Mater. Res. Soc. Proc. 353, Pittsburgh, PA, 1995) pp. 647–652.Google Scholar
[7] Finch, R.J., Suksi, J., Rasilainen, K. and Ewing, R.C., Joint Annual Meeting, Geol. Assoc. Canada / Min. Assoc. Canada, May 17-19, 1995, Abstracts vol.20, A–31 (1995).Google Scholar
[8] Finch, R.J., Suksi, J., Rasilainen, K. and Ewing, R.C., Chem. Geol. (submitted).Google Scholar
[9] Gauthier, G., Franqois, A., Deliens, M., and Piret, P., The Mineralogical Record 20, 26 (1989).Google Scholar
[10] Finch, R.J. and Ewing, R.C., J. Nucl. Mater. 190, 133 (1992).Google Scholar
[11] Finch, R.J., Ph.D. thesis, University of New Mexico, 1994.Google Scholar
[12] Rasilainen, K. and Suksi, J., On the quantitative interpretation of uranium series disequilibria (in Finnish). VTT Research Notes 1404, 1992.Google Scholar
[13] Finch, R.J., Miller, M.L. and Ewing, R.C., Radiochimica Acta 58/59, 433 (1992).Google Scholar
[14] Kaufman, A. and Ku, T.-L., Geochim. Cosmochim. Acta 53, 2675 (1989).Google Scholar
[15] Kaufman, A., Ku, T.-L. and Luo, S., Chem. Geol. 120, 175 (1995).Google Scholar
[16] Frondel, C., Systematic Mineralogy of Uranium and Thorium. Geol. Soc. Amer. Bulletin 1064 (1958) 399 pp.Google Scholar
[17] Sergeyeva, E.I., Nikitin, A.A., Khodakovkiy, I.L. and Naumov, G.B, Geokhimiya 11, 1340 (1972) [English translation in: Geochem. Internat. 9, 900 (1972)].Google Scholar
[18] Finch, R.J. and Ewing, R.C., Joint Annual Meeting, Geol. Assoc. Canada / Min. Assoc. Canada, May 17–19, 1995, Abstracts vol.20, A–32 (1995).Google Scholar
[19] O'Hare, P.A.G., Lewis, B.M. and Nguyen, S.N., J. Chem. Thermodynamics 20, 1287 (1988).Google Scholar
[20] Nguyen, S.N., Silva, R.J., Weed, H.C. and Andrews, J.E., J. Chem. Thermodynamics 24, 359 (1992).Google Scholar
[21] Vochten, R. and Van Havebeke, L., Mineral. Petrol. 43, 65 (1990).Google Scholar
[22] Finch, R.J. and Ewing, R.C. in Scientific Basis for Nuclear Waste Management XV, edited by Sombret, C. (Mater. Res. Soc. Proc. 257, Pittsburgh, PA, 1992) pp. 465–47 1.Google Scholar
[23] Pearcy, E. et al. Appl. Geochem. 9, 713 (1995).Google Scholar
[24] Murakami, T., Tzuzuki, K., Sato, T., Isobe, H., Ohnuki, T., in Scientific Basis for Nuclear Waste Management XVIII, edited by Murakami, T. and Ewing, R.C. (Mater. Res. Soc. Proc. 353, Pittsburgh, PA, 1995) pp. 1219–1226.Google Scholar
[25] Pearcy, E.C. and Murphy, W.M., Geochemical Natural Analogs Literature Review, Center for Nuclear Waste Regulatory Analyses Report 90-008 (NRC 02-88-005) 1991.Google Scholar