Chloride-induced stress corrosion cracking in Austenitic steels for SNF storage canisters - Recent understanding and advances in mitigation and repair

Abstract

Chloride-induced stress corrosion cracking (CISCC) is a critical threat to stainless steel (SS) spent nuclear fuel (SNF) and radioactive materials storage canisters currently in service worldwide. In the past decade, extensive research has been conducted to understand fundamental mechanisms of CISCC, as well as to develop effective repair and mitigation methods to prevent catastrophic failure of the SNF canisters from CISCC. This review article aims to: (1) summarize recent progress from fundamental studies of CISCC in SS, and (2) present state-of-the-art developments in CISCC mitigation and repair techniques that may be especially well-suited for SNF storage applications, including cold spray (CS), friction stir welding (FSW), friction surfacing (FS), laser shock peening (LSP), and ultrasonic nanocrystal surface modification (UNSM). Knowledge gaps in current understanding of CISCC and roadmaps for deployment of the repair techniques are also discussed.