Stress Corrosion Cracking Tests on High-Level-Waste Container Materials in Simulated Tuff Repository Environments

摘要

Types 304L, 316L and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented.