Influence of neutron irradiation on H diffusion in Zr-2.5Nb alloy

Deuterium diffusion in Zr-2.5Nb pressure-tube material was measured in- and out-of-flux in the U-2 loop of the NRU reactor at Chalk River Laboratories. The results show that deuterium diffusivity at a neutron flux of about 5x1017 n.m-2s-1 is similar to that measured out-of-flux. This result suggests that deuterium diffusivities determined from out-reactor tests are sufficient for modeling deuterium ingress and its redistribution in pressure tubes and other reactor components made from zirconium alloys. (author)