Hydrogen solubility and absorption kinetics were studied in samples which had been irradiated with neutrons to fluences of up to 5.4 x 1024/m2. It was found that the absorption of H could be treated as a diffusion-controlled process. The rate constant for H absorption was different to that for desorption, and the difference was attributed to the effects of trapping sites. After neutron irradiation to 1.9 x 1024/m2 (about 0.2dpa), the H solubility was 20 to 50 times higher than that in non-irradiated samples. The increase in H solubility saturated above a damage level of about 0.3dpa. The H diffusivity was decreased by neutron irradiation to fluences of up to 1.9 x 1024/m2. It then increased at higher fluences. This behavior was attributed to the production of H trapping sites and to an increase, in the distance between basal planes, that was caused by neutron irradiation.

H.Atsumi, M.Iseki, T.Shikama: Journal of Nuclear Materials, 1992, 191-194, 368-72