Tritium permeation behavior in SiC/SiC composites

Measurements of tritium permeation through SiC/SiC composite manufactured by nano-powder infiltration and transient eutectoid (NITE) process were carried out with the use of pure tritium and tritium diluted with hydrogen. Using pure tritium at a pressure of 0.6 Pa on the front side of the composite, the steady-state tritium permeation flux was estimated to be 9.5 × 10−12 mol m−2 s−1. In experiments with tritium diluted with hydrogen, it was found that the steady-state permeation fluxes went down with a decrease of tritium fraction in tritium–hydrogen gas mixture, although the partial pressure of tritium on the front side was fixed at 0.6 Pa.