Tritium Permeation Performance with Pd/Ag Alloy Membrane Based on Hydrogen Isotope

Pd/Ag alloy membrane can be used to separate and purify HT/T₂ from the offgas of TMSR. In this paper, a Pd/Ag alloy membrane with thick of 80 μm was chosen to separate H₂, which can simulate the separation of tritium. The separation effect of Pd/Ag alloy membrane in pure H₂ and H₂-Ar gas mixture was studied. The results indicate that the diffusion of atomic hydrogen through a membrane is the controlling mechanism and rate determine step of hydrogen permeation. In the condition of H₂-Ar gas mixture, the H₂ permeation flux reduces remarkably due to the influence of concentration polarization of Ar. Through the analysis of the membrane surface under SEM, the ratio of Pd in the alloy membrane increases and the grain boundary can be found, which could be inferred to the influence of H₂ permeation.