A numerical comparison of hydrogen absorption behaviors of uranium and zirconium cobalt-based metal hydride beds

In this paper, the hydrogen loading capability of uranium and zirconium cobalt (ZrCo) is numerically compared and evaluated, in order to determine optimum getter materials for the storage of tritium. A three-dimensional hydrogen absorption model is applied to two identically designed cylindrical beds (one with uranium and the other with ZrCo) and hydrogen absorption simulations are then conducted for comparison. The simulation results show different hydrogen loading characteristics between the two beds, with that containing uranium exhibiting superior hydrogen loading performance and easier thermal management capability. This is owing to a lower hydrogen equilibrium pressure for absorption, faster absorption kinetics, lower thermal mass, and a higher thermal conductivity of uranium compared to ZrCo. Detailed analysis of hydrogen absorption behaviors with uranium and ZrCo assists in determining and optimizing proper bed material/design and operating conditions for the storage and delivery system in the International Thermonuclear Experimental Reactor.