Tritium storage development. Progress report No. 13, July--September 1977

Engineering-scale operation was started on hydriding of zirconium for application to tritium storage systems. Eight runs were made with commercial-grade zirconium sponge at 338/sup 0/ to 499/sup 0/C and 0 to 770 torr, hydrided to hydrogen-to-zirconium atom ratios up to 2. Reaction rates were determined for hydrogen flow rates of 2.72 to 9.24 cm/sup 3/ at STP/g Zr-min. For each run, hydrogen pressure was plotted on a semilog scale against time and H/Zr atom ratio to elucidate the reaction mechanism in terms of reaction kinetics, diffusion, and equilibrium hydrogen vapor pressure. Lack of consistency in some of the runs is probably due to difference in the extent of the diffusion barrier formed on the metal because of reaction with oxygen and other contaminants. Static leach testing of zirconium sponge and rod in distilled water was continued; leach rates ranged from 8.9 x 10/sup -7/ to 1.7 x 10/sup -6/ cm/day for the 166 to 208 day leach period