Electrochemistry of Uranium on Liquid Sn Electrode in Molten NaCl-2CsCl Eutectic

Abstract The electrorefining of spent nuclear fuel is a key step for extraction of uranium with the application of liquid reactive cathodes. The electrochemical extraction of uranium on W and Sn electrodes in molten NaCl-2CsCl (0.36-0.64) eutectic at the temperature range 823–973 K was investigated. The electroreduction mechanism of U(III) ions on W inert electrode was studied by cyclic voltammetry technique to verify that this process is a one-step reaction. On reactive liquid Sn electrode this reaction took place with the considerable depolarization with the formation of USn3 intermetallic compound. The conditions of the electrochemical production of alloy of a given composition were found. The apparent standard potentials of U(III)/U couple and USn3 alloy were determined by open-circuit potentiometry. The activity, solubility of uranium in liquid tin and the principal thermodynamic properties of uranium compounds in molten salt media were calculated.