Actinide-solubility controls in performance assessment of nuclear-waste repositories

The importance of solubility control of radionuclide concentrations in repository groundwaters is discussed. Such control allows readily defensible estimation of the maximum concentrations of some actinide radionuclides in groundwaters. Estimates from currently available data indicate a number of cases where such maximum concentrations will be near or below the concentrations that are permissible, without the benefit of other processes that will lower the concentrations even more. Available information is briefly summarized and further research needs, which are not overly extensive, are discussed. 6 figures.