Recovery, Concentration, and Solidification of Europium by Ion Exchange from a Dilute Process Stream

摘要

A promising process to recover americium from a very dilute waste solution and convert it to a stable solid suitable for waste disposal is to load the americium onto organic ion-exchange resins and burn the resins to yield a granular solid that can be disposed of directly or formed into a monolith using known solidification processes. Experiments were carried out in which europium, a stand-in for americium, was loaded onto small ion exchange resin columns from dilute aqueous solutions containing nitric acid and, in some cases, iron. The effluent solution was decontaminated sufficiently to be a non-TRU waste in the plant application. The volumetric distribution coefficient under anticipated conditions was in the range of 18,000, indicating that a relatively very small volume of solid, americium-loaded, ion-exchange resin would be produced. Burning the loaded resin in air yields a stable, solid oxysulfate with a further volume reduction of about a factor of six. Iron, and possibly other impurities, can interfere with the americium recovery. 8 refs., 7 figs., 2 tabs. (ERA citation 13:011009)