Removal of hydrogen isotopes in an inert gas stream with particle beds of metal hydrides

For removal of hydrogen isotopes from a gas mixture in a fuel clean-up system of a D-T fusion reactor or purification of recycling gas in a tritium-handling glove box, a bed packed with metallic particles is one of the most promising ways. In this study a particle bed of yttrium is comparatively tested using two kinds of the removal modes: a once-through mode and a circulating one. Variations of hydrogen concentrations at inlet and outlet of the bed for both the modes are in good agreement with numerical solutions to mass transfer equations of hydrogen in each mode. Optimum operating conditions of the bed based on the solutions save both an amount of metallic particles and the time required for the removal of hydrogen isotopes by absorption. The obtained results may be also useful for an engineering design of the tritium removal system in the D-T fuel cycle.