ABSTRACT
Spent nuclear fuel at a number of U.S. locations is stored at independent spent fuel storage installations in dry cask storage systems (DCSSs), which commonly consist of a welded austenitic stainless steel canister within a larger concrete vault or overpack. Stress corrosion cracking of welded stainless steel is considered a high-priority technical issue and functional monitoring has been identified as one of the top crosscutting issues concerning performance of various dry cask components.
The work presented in this paper reviews and assesses the current state of technology for directly monitoring stress corrosion cracking, as well as the important environmental conditions—including temperature, humidity, and chloride concentration—that could affect this degradation mechanism. A variety of techniques were identified to be potentially suitable for application to extended storage, ranging from detecting crack initiation and measuring propagation from stress corrosion cracking to measuring the chloride concentration in deliquescent solutions. Some techniques are well developed and commercially available, but some require significant advancement to overcome limitations. Overall, because of geometry, space limitations, and the high ionizing radiation of DCSSs, all the monitoring methods must be modified and tailored for this application.
