DISSOLUTION OF IRRADIATED FUEL - A RADIOLYTIC MASS-BALANCE STUDY

We have studied the production of H-2,O-2 and H2O2 by radiolysis of th e leach solution in a closed system containing fragments of irradiated PWR fuel and distilled water purged with argon. The experimental data Is not reflected in the release of U(VI) to the solution, clearly ind icating that most of the oxidant production has been taken up by the U O2 spent fuel surface. This proves that the UO2 surface constitutes a major redox buffer capacity to prevent radiolytic oxidation under repo sitory conditions.