ELECTROREFINING OF ZR METAL IN THE LIF-NAF EUTECTIC MELT AT 973K

For the purpose of reprocessing spent metallic nuclear fuels, electrorefining of Zr metal has been studied in the LiF - NaF eutectic melt at 973K. In order to develop the electrorefining cell, cathodic deposition and anodic dissolution mechanisms were examined by the cyclic voltammetry (CV), the potential-step chronoamperometry (PSCA) and the current reversal chronopotentiometry (CRC). These studies revealed that the reversible cathodic reduction; Zr3+ (soluble) + 3e- --> Zr (on Fe cathode) and the reversible anodic dissolution; Zr(on Zr anode) --> Zr3+ (soluble) + 3e- take place in the LiF-NaF eutectic melt at 973K. Electrorefining experiment of Zr metal showed that fine dendritic Zr metal deposits on Fe cathode and the cathodic current efficiency increases with cathodic current density.