Materials science: Increased nuclear waste storage corrosion at material interfaces

The corrosion of glass and ceramic nuclear waste forms is accelerated when in contact with metallic canisters, according to a study in Nature Materials. This interaction between dissimilar materials could significantly affect the service life of nuclear waste storage packages.

Deep geological disposal is considered a solution for the management of high-level nuclear wastes. Some radioactive wastes will be immobilized in glass or ceramics and then enclosed in metallic canisters to prevent interaction with the environment, and then stored in a repository deep underground. However, over the long period of performance, the repository environment will eventually penetrate to the waste. The current safety and performance evaluation models only assess the corrosion of individual material groups independently, neglecting the potential interactions between different materials that are used together for a repository system.

Gerald Frankel and colleagues pressed stainless steel against model nuclear waste immobilization materials (a borosilicate glass and titanate-based ceramics) and studied the corrosion under simulated repository conditions. The authors found that the corrosion of both glass and ceramics are enhanced at the contact area with stainless steel.

The authors suggest that such an accelerating effect on corrosion may exacerbate the release of radionuclide into the environment. They conclude that this should be considered carefully in assessing the safety of waste disposal and the selection of compatible barrier materials for improving the performance.