Actinide leaching from waste glass: air-equilibrated versus deaerated conditions
- 1 October 1981
- report
- Published by Office of Scientific and Technical Information (OSTI)
Abstract
Leach tests were conducted in aerated and deaerated solutions using glass containing /sup 239/Pu, /sup 237/Np and /sup 238/U, at temperatures of 25 and 75/sup 0/C and in deionized water, 0.03M NaHCO/sub 3/ and WIPP B salt brine for periods up to 341 days. Neptunium leaching was decreased by factors of 10 to 100 (depending on leach time) in the deaerated solutions at 75/sup 0/C. Plutonium leaching decreased by factors of 3 to 5 due to deaeration, but only in the deionized water leachate at 25/sup 0/C. Uranium leaching in salt brine and deionized water at 25/sup 0/C was decreased by factors of 2 to 5 in deaerated solutions. Time and temperature dependencies were also observed for the leaching of the actinides during the course of this work. After the first leach interval (2 days), the time dependent release curve for Pu was essentially flat or decreasing under all conditions, and maximum Pu solution concentration (at 25/sup 0/C), as implied by release in aerated leachate, agrees with independent solubility data. The low /sup 239/Pu releases observed in leach solutions are consistent with accumulation of /sup 239/Pu on the leached glass surface. The amounts of uranium and neptunium leached increased withmore » time under most conditions. For Pu leaching, temperature has a small effect in deaerated leachates and negative effect in aerated leachates. Neptunium leaching generally increase with temperature under aerated conditions, but not in proportion to increases of matrix element leaching. In deaerated leachates, Np leaching decreases with temperature. Uranium leaching increases with temperature under aerated and deaerated conditions but not in proportion to matrix element increases. 4 figures, 6 tables. « lessKeywords
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