Developing a Novel Sensor to Detect Stress Corrosion Cracking of Spent Nuclear Fuel Storage Containers

A significant portion of the Unites States’ annual energy demand is provided by nuclear power. Safe storage of radioactive spent nuclear fuel is an essential part of the fuel life-cycle. Currently, spent fuel is stored at the reactor site in stainless-steel dry storage containers where the loaded containers are welded shut and backfilled with helium. Since the storage containers are passively cooled with air from the ambient environment, the canisters may become susceptible to atmospheric induced corrosion damage, particularly in the weld sensitized region. To ensure the integrity of the storage containers we are developing a sensor to determine the presence and extent of corrosion damage as well as provide a viable indicator for the future condition of these containers. We have developed a miniature stress corrosion cracking test fixture to provide an early warning signal at the initiation of corrosion damage. These fixtures use a three point bend test configuration to stress stainless steel samples while collecting resistance measurements over time. Sample failure is signaled by a sudden jump in resistance across the sample. The data these sensors provide can help predict the future health of the current storage containers and ensure long-term safe storage.