Solubility of hydrogen and deuterium in yttrium

This paper presents the study of absorption capacity and reaction rate of hydrogen and deuterium in yttrium for the purpose to investigate the method of deuterium and tritium recovery. At first, a solubility equation was derived from the dilute interstitial solid solution model. The measurements of adsorption and reaction rate were made by the constant-volume pressure method. The yttrium sample was yttrium powder of the purity of 99%. The absorption reaction reaches to the equilibrium within a few minutes. The relation between the solubility and pressure can be expressed by the law of Sieverts. The absorption and desorption of hydrogen are almost reversible, and the recovery of the solubility of hydrogen isotopes in yttrium can be made by keeping the absorber at about 800 degree C for a few minutes at 10-6 Torr. The ratio of the solubilities of hydrogen isotopes is close to the mass ratio, and is close to one in atomic ratio. Accordingly, tritium would be absorbed in yttrium as well as hydrogen and deuterium. (Kato, T.)