(259d) Effect of Rotation on Li2O Entrainment in a Uranium Oxide Reduction Process

To apply pyroprocessing to oxide used fuel, an oxide reduction step must precede electrorefining. The current leading technology for oxide reduction is a high temperature electrolytic process carried out in molten lithium chloride salt. In this process, the used fuel is loaded into cathode baskets. Lithium oxide entrainment in these cathode baskets is problematic, as it can detrimentally affect the electrorefining process if it carries over with the reduced fuel. Gaining an understanding of the operating parameters that effect lithium oxide entrainment in the cathode basket is the goal of the research reported in this paper. In particular, the effect of basket rotation on lithium oxide entrainment has been studied. A special cathode basket has been designed, fabricated, and used in small-scale electrolytic reduction tests of U₃O₈ and UO₂. The basket directly polarizes the uranium oxide particles, while its external walls are electrically isolated. Results of constant current reduction tests at various rates of rotation will be presented. A method for distinguishing between lithium oxide in different environments (inside and outside of the uranium particles) will be presented.