Kinetics of electrode processes in the NaCl-KCl-UCl3-UO2 oxide-salt melt

kinetics of the cathodic processes in the molten NaCl-KCl-UCl 3 -UO 3 oxide-salt composition are studied by linear voltammetry at temperatures ranging from 973 to 1073 K in an inert gas atmosphere. It is shown that UO + and UO 2+ are formed in the reaction between the uranium ions in the +3 oxidation state and uranium dioxide. The mechanism of their electroreduction and the limiting step of each of the processes are discussed. The diffusion coefficients for UO 2+ and the apparent equilibrium constants for the reactions UO 2(s) + U 3+ (1) ⇇ UO + (1) + UO 2+ (1) and UO (s) +UO 2+ (1) ⇇2UO + (1) are calculated. These are equal to (4±2)x10 -4 and (4±2)x10 -2 , respectively, at 1023 K