Correlation between annihilation of irradiation defects and tritium release in neutron-irradiated lithium zirconate

摘要

Recently, we have investigated the annihilation behavior of the radiation defects and the tritium release behavior in/from some neutron-irradiated ceramic breeder materials. In the present study, correlation between the tritium release and the annihilation of irradiation defects were investigated for neutron-irradiated Li_2ZrO_3. The annihilation of irradiation defects consisted of two processes, the fast and the slow processes. The activation energies for these processes were determined to be 0.32 ± 0.01 and 0.80 ± 0.01 eV, respectively. The E'-center of irradiation defects was found to act as a tritium trapping site by comparison between the annihilation of irradiation defects and tritium release. From the present and the previous works, the annihilation process of oxygen vacancies such as E'-center and F~+ -center could play an important role in tritium behavior. The results of the present and previous studies suggest that there appears to be similar correlation between annihilation of irradiation defects and tritium release for several ceramic breeder materials.