Resistance to atmospheric stress corrosion cracking (ESCC) and crevice corrosion
was examined for various candidate canister materials in the spent fuel dry storage
condition using concrete casks. A constant load ESCC test was conducted on the candidate
materials in air after deposition of simulated sea salt particles on the specimen gage
section. UNS S31260 and S31254, highly corrosion resistant stainless steels (SS), did not
fail for more than 46,000 h at 353 K with relative humidity of 35 %, although S30403 SS
and S31603 failed around 500 h by ESCC. Crack growth measurement was done to explain
this result. Cracking on S31603 propagated around 3x10-10 m·s-1 at K values larger than
10MPa·m0.5 at 353K with RH=35%. S31260 SS showed crack growth rate of 4x10-13m·s-1 at
the same condition.