Effects of neutron irradiation on hydrogen isotope permeation on W-Re

•Hydrogen and deuterium permeation behavior for neutron damaged W and W-3 %Re was evaluated by Plasma Driven Permeation method.•Neutron irradiation introduces irradiation defects throughout the sample, which enhanced H and D diffusion toward downstream side.•Increasing the irradiation temperature led to the recovery of irradiation defects and the structural changes have occurred due to Re and Os diffusion. Hydrogen and deuterium permeation behavior for neutron damaged W and W-3 %Re was evaluated using a Plasma Driven Permeation device. For neutron damaged W-3 %Re at 773 K and 1473 K, precipitation of Re and Os was observed by atom probe tomography. Neutron irradiation introduced defect damage throughout the sample and enhanced H and D diffusion toward downstream side. The existence of irradiation damage by neutron irradiation was found to increase hydrogen isotope permeation. Moreover, the existence of Re has suppressed the formation of irradiation defects for hydrogen isotope trapping sites. The recovery of irradiation defects by increasing the irradiation temperature led to the structural changes due to the diffusion of Re and Os, which also affected the hydrogen isotope permeation behavior.