The migration of radionuclides is studied as a function of mineralogy utilizing batch sorption and column experiments. The transport behavior of alkaline, alkaline-earth, and transition metals and actinide species is studied in pure mineral separates. The solid phases utilized for these investigations are silicates, alumino-silicates, carbonates, and metal oxides and oxyhydroxides. The results of this effort are utilized to aid in the elucidation of the dominant chemical mechanisms of radionuclide migration; the prediction of radionuclide transport in conditions similar to those expected at the candidate high-level nuclear waste repository site at Yucca Mountain, Nevada; and the identification of materials that act as natural geological barriers or that can be utilized as strong sorbers in engineered barriers.