Swelling and void-induced embrittlement of austenitic stainless steel irradiated to 73-82 dpa at 335-365 deg C

Conventional wisdom holds that void swelling of stainless steels falls strongly in swelling rate at temperatures below 400 deg C and should not reach large swelling levels even at high dpa levels. This perception may be incorrect as demonstrated by an irradiation of the Russian steel EI-847 which, in both the annealed and cold worked conditions, reached swelling levels in the BN-350 fast reactor on the order of > = 10% at temperatures of 335-365 deg C and doses of 73-82 dpa. Consistent with expectations based on earlier studies of other steels at these swelling levels, the steel was found to be exceptionally brittle and to have failed with a rather unusual failure mode.