brine

Abstract. Deaerated 5 M NaCl soluti n is irradiated in the presence of UO2 pellets with a-radiation from 238Pu. Experiments are conducted with 238Pu doped pellets and others with 238Pu dissolved in the brine. The radiolysis products and yields of mobi-lized U and Pu from the oxidative dissolut on of UO2 are determined. Results found for radiolysis products and for the oxidation/dissolution of pellets immersed in Pu containing brine are similar to results for Pu doped pellets, where the radiation chemi-cal processes occur only in the liquid layer of some 10mm thickness adjacent to the pellet. The yield of radiolysis products is comparable to earlier results, that of mobi-lized U from the pellets is < 1 % of the total amount of oxidized species. Thus, the radiation chemical yield (G-value) for mobilized hexavalent U is < 0×01 ions/ 100 eV. In spite of the low radiation yield for the corrosion, the rate of UO2 dissolu-tion is higher than expected for the concentrations of long-lived oxidizing radiolysis compounds found in the solutions