Monday, June 18, 2007 - 10:15 AM
The Peregrins (Boise Centre on the Grove)

Separation uranium/technetium for the UREX process

Julie Du Mazaubrun1, Frederic Poineau1, Ken Czerwinski1, Gordon Jarvinen2, and Doris Ford2. (1) University of Nevada Las Vegas, Las Vegas, NV, (2) Los Alamos National Laboratory

US fuel cycle program was designed to treat spent fuel solvent extraction process that would separate uranium and technetium in the first step by an ion exchange process. The presented research deals with the separation of uranium from technetium by a combination of two different resins. The goals of the study are: evaluate the technetium separation, develop a process to recover the technetium and synthesize waste forms. This separation was performed using treated Reillex HP and untreated Reillex HP anion exchange resins. Preliminary experiments have shown that the Reillex has a suitable technetium absorption capacity while relatively poor elution properties. To improve elution properties, Reillex was treated. Results indicate that the Reillex soaked for 6 hours in concentrated nitric acid at 85 C (R6) exhibit optimal elution properties. Using the R6 resin, dynamics experiments were performed. An optimal value of 1M NH4OH and a 4 mL/min flow rate were obtained for elution. Experiments were performed on a 150 mL scale using a solution containing [U] ~ 50g/L and [Tc] ~ 60 mg/L. Considering the great absorption capacity of the Reillex and good elution properties of the R6, the final experiment consists of an initial column charged with the R6 and a second containing the Reillex. In this set-up, most of the technetium is sorbed on the R6 resin and the remaining fraction trapped on the untreated Reillex. This process allows producing separate streams. These streams were used to prepare waste forms; solid uranium and metallic technetium.