Uranium (U) was successfully removed from contaminated soils from the Fernald Environmental Management Project (FEMP) site near Fernald, Ohio. The laboratory column leach process, referred to as the simulated heap leach process, using 0.5 M sodium bicarbonate as the dominant reagent, was able to achieve uranium removals of 75-90%, corresponding approximately to the percentage of uranium in the oxidized state. Parametric optimization studies are reported. The dissolution of uranium took place in two stages: a rapid desorption associated with soil surfaces and a slow step associated with diffusion of uranium toward solid surfaces. In addition, use of the oxidizing agent, sodium peroxide, improved uranium removal due to oxidation of U(IV), enhancing the solubility of the uranium. The results suggest that the process will be effective for field scale remediation of uranium-contaminated soils because of the efficiency, mild complexing agent employed, lack of prescreening of the soil and the simple equipment necessary. Two relevant companion studies have recently been completed. The first, a scale-up demonstration [Turney, W.

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Plutonium (Pu) is one of the primary actinides of concern for long-term disposal and storage of nuclear waste. Strong sorption of Pu onto colloids of iron oxide, clay, and silica could result in colloid-facilitated transport of this actinide in groundwater systems. However, fundamental data on Pu sorption to colloids is sparse, resulting in large uncertainties in long-term predictions of colloid-facilitated Pu transport. This sparseness of data and the potential to significantly reduce uncertainties in predictive models served as a motivation for this study. The authors investigated the sorption and desorption behaviors of