Stress corrosion cracking of stainless-steel canister for concrete cask storage of spent fuel

The effect of prior cold work on the chloride stress corrosion cracking of 304L austenitic stainless steel under atmospheric conditions

“…In the case of 304L austenitic stainless steel (ASS) one of the most aggressive chemical species is the chloride ion, Cl -, and cracks propagate most often by a transgranular path (TGSCC), rather than an intergranular path (IGSCC), which is more common in ASS with higher C content (~0.08 wt%) [5,6]. Cl-induced SCC is problematic as 304L ASS is widely used as piping material for the primary cooling circuit within a nuclear power plant (NPP), as well as material for canisters used for dry cask storage of spent nuclear fuel ('interim storage') [5,7,8]. Furthermore, both the storage and plant sites are often located close to marine environments, exposing them to a mixture of chloride and sulphate salts.…”

“…Considering that NPP and canisters for spent fuel storage must survive for an extended period of time (at least 40 years), in potentially aggressive atmospheric conditions ([5], it is critical to fully understand the SCC resistance of these materials. It is worth noting that dry storage containers, for nuclear fuel, are usually in contact with the atmosphere, without any filtering of the sea air [8][9][10][11]. The temperatures will also slowly change during their design lives as the decay heat from the fuel exponentially decays [9,12].…”

Stress corrosion cracking of austenitic weld deposits in a salt spray environment

“…Spent nuclear fuel is sealed in the stainless steel canister of the dry cask storage system as an interim storage measure before final disposal [1,2]. AISI 304 SS is one of the candidate materials commonly used for manufacturing the dry storage canister [1,2].…”

“…AISI 304 SS is one of the candidate materials commonly used for manufacturing the dry storage canister [1,2]. It is known austenitic stainless steels (SSs) are susceptible to stress corrosion cracking (SCC) in a chloride-containing environment [3e6].…”

“…As a result, the degradation of the 304SS canister can be complicated by the stress corrosion cracking caused by chloride in the salt deposit and salt solution. It is of technological interest to evaluate the SCC susceptibility of the 304SS by the salt deposit [1] and salt spray [2].…”