The effects of He production and heat treatment upon the swelling of steel samples which were irradiated to 51dpa were investigated by using 10B-, 58Ni- and 60Ni-doped specimens. The swelling of tempered steel and steel doped with 10B, when irradiated at 400C, ranged from 0.52 to 1.2%. The swelling of non-tempered steel which was doped with 58Ni or 60Ni was less than 0.02%. At 300C, the swelling in all of the steels was insignificant. In the Ni-doped steel, a high number-density of carbides formed in the matrix. The production of He atoms enhanced the swelling of the steel. However, non-tempering treatments of the steel markedly suppressed swelling. The low swelling of the Ni-doped steel was attributed to the occurrence of a high density of carbides which acted as sinks, or to a decrease in the mobility of vacancies which interacted with C atoms in the matrix.

Effect of Helium Production on Swelling of F82H Irradiated in HFIR. E.Wakai, N.Hashimoto, Y.Miwa, J.P.Robertson, R.L.Klueh, K.Shiba, S.Jistukawa: Journal of Nuclear Materials, 2000, 283-287, 799-805