Diffusion-controlled tritium release from neutron-irradiated γ-LiAlO 2

Abstract

Thermal release behavior of tritium produced in neutron-irradiated γ-LiAlO 2 crystals has been studied with emphasis laid on the tritium release rate. All of the tritium produced in γ-LiAlO 2 was released on heating to 1170 K under vacuum. The predominant tritium species released was tritiated water (HTO). The HTO(g) release rate was controlled by diffusion of tritium (T +) and the diffusion coefficient determined in the temperature range from 630 to 930 K was D = 2.1 × 10 −5 exp( −90.3 RT )cm 2s −1 , where probable errors were ± 1.0 kJ mol −1 for the activation energy and ± 0.1 for the logarithm of the pre-exponential term. The diffusion coefficient for tritium in γ-LiAlO 2 was nearly two orders of magnitude smaller than that in Li 2O crystals.