AbstractMelt refining of synthetic EBR-II alloy in oxide crucibles at temperatures between 1200 and 1400°C under an inert atmosphere resulted in a separation of rare earth elements, yttrium, and alkaline earth elements from ingot fractions. The rate of cerium removal is shown to behave as a first-order reaction. Cesium is quantitatively volatilized from highly irradiated uranium fuels refined at 1200°C for 4 hr.