Isotopic exchange between hydrogen and deuterium in the process of permeating through Li_(0.17)Pb_(0.83)

摘要

The permeation process of hydrogen isotopes through Li_(0.17)Pb_(0.83) has been investigated experimentally. We obtained the overall D permeation rates that take into consideration of the effects of the H-D isotopic exchange reaction on the surface and diffusion in the Li-Pb layer. It was proved that the rate-determining step was not the surface reaction but the diffusion in the Li-Pb bulk. We proposed a system of gas-liquid counter-current extraction using a packed column for continuous tritium recovery. The concentration profiles through the column and tritium extraction rates are calculated. It is estimated that the column height of 5 m is sufficient to achieve the tritium recovery ratio of 99.999%. This counter-current extraction method is easy to operate and efficient to recover tritium from Li-Pb.