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

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 USn 3 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 USn 3 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.