IN-SITU TRITIUM RELEASE EXPERIMENT FROM SOLID BREEDER GAMMA-LIALO2 INSWINPC

The first Chinese in-situ tritium release experiment is being carried out in the fission reactor SPRR-300 in the Southwest Institute of Nucl ear Physics and Chemistry (SWINPC). Several runs of the experiment wer e conducted to study tritium generation and release behaviors from Chi na-made gamma -LiAlO2 pellets. The effects of some key operational fac tors (temperature, sweep gas composition and flow rate) upon tritium r elease were studied. The results show that the equilibrium tritium rel ease rate at different temperatures approached the tritium generation rate obtained from neutron calculations. The tritium concentration in the sweep gas decreased with increasing the flow rate. Addition of a s nell quantity of hydrogen greatly enhanced the release of tritium. It was also found that the tritium released in the sweep gas was mostly i n the form of HT. However, when the generated tritium was not purged i n time, the HTC fraction increased gradually. By using the inventory d ifference method, through the special run which lasted 72 hours, we de termined the diffusion coefficient for tritium in gamma -LiAlO2. The o btained diffusivity and its activation energy were compared with those from other experiments. It was found that the value of Q was close to those from LILA and TTTEx experiments, but the value of D-0 was small er.