[en] We have measured solubility constants for hydrogen and deuterium in the Zr-Al alloy to be: K/sub H/ = exp (11.1(5) - 16900(600)/T9 (Torr/[Torr-1/g]²) and K/sub D/ = exp (12.2(8) - 16800(600)/T) (Torr/Torr-1/g]²) respectively, where K is defined implicitly by P = Kq² with P the equilibrium pressre (in Torr) and q the bulk concentration (in Torr-l/g). These values, in conjunction with a model for the solubility, predict that the constant for tritium, K/sub T/ approx. 4 K/sub H/. Consequently, the regeneration of tritium will be faster by a factor of four over that for hydrogen at the same temperature, or the tritium regeneration temperature can be reduced approx. 50⁰K compared to hydrogen for the same regeneration time