Process Engineering Challenges for the Development of Electrolytic Reduction of Uranium Oxide in Molten LiCl-Li2O

Electrolytic uranium oxide reduction has the potential to be used for recycling spent fuel to a range of nuclear reactors from commercial light water reactors to advanced nuclear reactors—including molten salt reactors and sodium cooled reactors. However, several process engineering-related problems have been identified that need to be addressed to support efficient, cost-effective commercial implementation. Two keys are cathode product purity and cell current efficiency. High product purity relies upon the effective removal of LiCl-Li 2 O from the cathode basket and reduced uranium. Removal of the salt from the basket can be achieved via high speed spinning at 650 o C. But entrained Li 2 O will remain and should be minimized during the reduction process. Methods for removing hydroxide impurities from the salt are reported that improve cell-current efficiency. The extent of this reduction can be determined via three distinct techniques (thermogravimetric analysis, elemental oxygen analysis, and bromine dissolution) and is key in helping determine the efficiency of the electrochemical cell.