Verification to recover tritium in neutron-irradiated Li by Y plate

The recovery of tritium from neutron-irradiated Li by an Y plate was experimentally investigated for tritium removal in a Li loop of IFMIF. The molar fraction of tritium included in neutron-irradiated Li ranges from 0.007 to 0.04 ppm. The Y plate at 400–500 °C successfully recovered the low concentration of tritium dissolved in Li. Although HTO as well as HT remained in Li without T recovery, the main chemical species of tritium remaining in Li after recovery was HT, and HT and HTO was released from Y after T recovery. SEM-EDX analysis revealed the transfer of not only tritium or hydrogen but also oxygen originally included in Li. The treatment of Y by a HF acid solution was effective to remove oxides formed on the Y plate and to enhance its hydrogenating rate.