Tritium release from neutron-irradiated Li2O sintered pellets: isothermal annealing of tritium traps

Tritium release rate from Li2O (71–86% T.D.) is found to follow the stretched exponential form, dF/dt=exp(−(t/τ))β. The values of β are about 0.8 near 500 K and about 0.5 near 580 K. The activation energy of tritium release is calculated as approximately 92 kJ/mol at 493–533 K and 139 kJ/mol at 543–583 K. It is suggested that the rate controlling process of tritium release is detrapping from the irradiation defects that serve as trapping sites for tritium, and the recovery behavior of such irradiation defects significantly affects the tritium release behavior. No porosity dependence of tritium release was observed for these densities of Li2O.