Radiation Induced Dissolution of UO2

Abstract

AbstractA model for the radiation induced dissolution of U02has been developed and tested using experiments described in the literature. The model makes use of computer calculations based on a reaction mechanism in which the dissolution is initiated by reactions of H202, OH and H02 radicals with the U02surface. The model gave a fair agreement between calculated and experimental results: For a dose rate of 400 rad/s the calculated yields of oxidation were 2.6 and 2.1 % - h−1· m−2after 1 and 2 h, respectively. The corresponding experimental yields were 1.9 and 1.5 % ·h−1· m−2, when corrected for dissolution without irradiation. The effect of various initial concentrations of H202has been tested, and a reasonable rate constant for the reaction of U02and H202has been found. The requirement for the rate constant is that H202begins to be effective above concentrations of 10−3 mol · dm−3in accordance with experiments by L. Johnson.