SALT PHASE CHLORINATION OF REACTOR FUELS. III. CATALYZED DISSOLUTION OF URANIUM DIOXIDE IN LEAD CHLORIDE-CHLORIDE SYSTEMS

The rapid dissolution of uranium dioxide is described, wherein copper is added to molten lead chloride at 550 deg C. and chlorine is passed through the melt. The integral dissolution of zirconium-clad uranium dioxide fuels is also described. The dissolution rate of uranium dioxide is directly proportional to the concentration of cuprous chloride if an excess of chlorine is used; the value for the rate constant is approximately 100 mg (UO/sub 2/) cm/sup -2/ min/sup -1/ (CuCl molality). The uranium dioxide is converted to water soluble uranyl chloride. The dissolution rate can be controlled by three factors: the copper concentration, the flow rate of chlorine, and the surface area of uranium dioxide. Scoping work indicates that iron chloride may be as effective catalytically as copper chloride for uranium dioxide dissolution in the lead chloride -chlorine system at 550 deg C; thallium chloride is not as effective. (auth