Anoxic corrosion of various high burnup spent fuel samples

To assess the long-term performance of spent fuel in a repository in saline environments, the effect of iron and sample dimension on the corrosion behavior and radionuclide release from high burnup fuel was studied. Additionally, the release contributions of the highly burned fuel rim and of alpha-recoil transport mechanism was evaluated. Results show that spent fuel is thermodynamically unstable even under reducing conditions (presence of Fe) but the dissolution rates are very slow. Slow dissolution rates are also encountered with powdered fuel, probably resulting from depletion of radiolytic reactants.