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Potential Incorporation of Transuranics Into Uranium Phases

Published online by Cambridge University Press:  10 February 2011

C. W. Kim
Affiliation:
Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439
D. J. Wronkiewicz
Affiliation:
Dept. of Geology and Geophysics, University of Missouri, Rolla, MO 65409, cheol@umr.edu
E. C. Buck
Affiliation:
Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439
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Abstract

The UO2 in spent nuclear fuel is unstable under moist oxidizing conditions and will be altered to uranyl oxide hydrate phases. The transuranics released during the corrosion of spent fuel may also be incorporated into the structures of secondary U6+ phases. The incorporation of radionuclides into alteration products will affect their mobility. A series of precipitation tests were conducted at either 150 or 90°C for seven days to determine the potential incorporation of Ce4+ and Nd3+ (surrogates for Pu4+ and Am3+, respectively) into uranium phases. lanthinite ([U24+(UO2)4O6(OH)4(H2O)4](H2O)5) was produced by dissolying uranium oxyacetate in a solution containing copper acetate monohydrate as a reductant. The leachant used in these tests were doped with either 2.1 ppm cerium or 399 ppm neodymium. Inductively coupled plasmamass spectrometer (ICP-MS) analysis of the solid phase reaction products which were dissolved in a HNO3 solution indicates that about 306 ppm Ce (Kd = 1020) was incorporated into ianthinite, while neodymium contents were much higher, being approximately 24,800 ppm (Kd 115). Solid phase examinations using an analytical transmission electron microscope/electron energy-loss spectrometer (AEM/EELS) indicate a uniform distribution of Nd, while Ce contents were below detection. Becquerelite (Ca[(UO2)6O4(OH)6]·8H2O) was produced by dissolving uranium oxyacetate in a solution containing calcium acetate. The leachant in these tests was doped with either 2.1 ppm cerium or 277 ppm neodymium. ICP-MS results indicate that about 33 ppm Ce (Kd = 17) was incorporated into becquerelite, while neodymium contents were higher, being approximately 1,300 ppm (Kd = 5). Homogeneous distribution of Nd in the solid phase was noted during AEM/EELS examination, and Ce contents were also below detection.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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References

REFERENCES

1 Wronkiewicz, D. J., Bates, J. K., Wolf, S. F., and Buck, E. C., J. Nucl. Mater. 238, 78 (1996).Google Scholar
2 Wronkiewicz, D. J., Bates, J. K., Gerding, T. J., and Veleckis, E., J. Nucl. Mater. 190, 107 (1992).Google Scholar
3 Finn, P. A., Hoh, J. C., Wolf, S. F., Slater, S. A., and Bates, J. K., Radiochim. Acta 74, 65 (1996).Google Scholar
4 Barner, J. O., Pacific Northwest Laboratory Report PNL-5109 (1985).Google Scholar
5 Buck, E. C., Finch, R. J., Finn, P. A., and Bates, J. K. in Scientific Basis for Nuclear Waste Management XXI, edited by McKinley, I. G. and McCombie, C. (Mater. Res. Soc. Proc. 506, Davos, Switzerland, 1997) pp. 8794.Google Scholar
6 Buck, E. C., Wronkiewicz, D. J., Finn, P. A., and Bates, J. K., J. Nucl. Mater. 249, 70 (1997).Google Scholar
7 Pauling, L., The Nature of the Chemical Bond, 3rd ed. (Cornell University Press, Ithaca, 1960), p. 644.Google Scholar
8 Kim, C. W., Wronkiewicz, D. J., and Buck, E. C., Radiochim. Acta (submitted).Google Scholar
9 Bignand, C., Bull. Soc. Frang. Minér. Crist. 78, 1 (1955).Google Scholar
10 Cordfunke, E. H. P., Prins, G., and Vlaanderen, P. Van, J. Inorg. Nucl. Chem. 30, 1745 (1968).Google Scholar
11 Bums, P. C., Finch, R. J., Hawthorne, F. C., Miller, M. L., and Ewing, R. C., J. Nucl. Mater. 249, 199 (1997).Google Scholar
12 Bums, P. C., Ewing, R. C., and Miller, M. L., J. Nucl. Mater. 245, 1 (1997).Google Scholar
13 Pagoaga, M. K., Appleman, D. E., and Stewart, J. M., Amer. Miner. 72, 1230 (1987).Google Scholar