Studies at the Nopal and Shinkolowbwe uranium deposits show that the primary uraninite (UO2) altered to a suite of secondary uranyl minerals similar to those observed in corrosion tests with uranium oxide . Although the Nopal I deposit tells us something about the possible fate of uranium, it tells us little about the likely fate of the important long-lived radionuclides; iodine (129I), cesium (135Cs), technetium (99Tc), neptunium (237Np), and plutonium (239Pu). Most performance assessment (PA) models, assume conservatively, that as the UO2 matrix corrodes, the key radionuclides (129I, 99Tc, 237Np, and 239Pu) will be released congruently. In so doing, these PA models force increased reliance on human engineered barriers.
Revised: August 21, 2005 |
Published: October 1, 2004
Citation
Buck E.C., B.D. Hanson, and B.K. McNamara. 2004.The Geochemical Behaviour of Tc, Np, and Pu in Spent Nuclear Fuel in an Oxidizing Environment. In Energy, Waste, and the Environment: A Geochemical Perspective, edited by R. Giere and P. Stille. 65-88. London:Geological Society.PNNL-SA-42972.