Nuclear power plants are now storing spent nuclear waste in onsite dry storage containers because of
the limited room in spent fuel storage pools. Some of these dry storage containers are located in
chloride-rich environments near coastal areas. Because many of the dry storage containers are made
of austenitic stainless steels, a potential concern is the susceptibility of the canisters to undergo
chloride-induced stress corrosion cracking. The objective of this work is to evaluate if atmospheric
stress corrosion cracking can develop in stainless steel cask. To that end, types 304, 304L, and 316L
stainless steel U-bend samples were fabricated and placed in an environmental chamber. Simulated
sea salt was deposited on the surface of the samples, using a salt fog procedure. The U-bend samples
were heated to various temperatures and subjected to accelerated corrosion, involving cyclic changes
in relative humidity. Cracking was observed in all the samples, except for those where the temperature
remained equal to or above 85 °C [185 °F].
Keywords: Stress Corrosion Cracking, Atmospheric Corrosion, Stainless Steel, Dry Storage Containers