The corrosion of radioactive waste disposal canisters based on in situ tests

Abstract The safe disposal of high-level waste and spent fuel requires the development of disposal canisters with lifetimes of several thousand years. Since iron and copper alloys are the primary canister materials under consideration, corrosion is the main time-dependent degradation mechanism leading to canister failure. In situ corrosion experiments conducted in various underground research laboratories during the past 30–40 years have highlighted the importance of the experimental design, as relatively small differences in design can lead to unexpected phenomena. For example, the importance of confinement in order to decrease microbial activity and achieve low corrosion rates has been shown repeatedly. Furthermore, in situ corrosion experiments have provided insight to repository design and optimization that would not have been possible if the tests were not done in the actual host rock. On the other hand, in order to maximize the usefulness of the obtained results, corrosion-specific experiments with well-defined exposure conditions are needed.