KINETICS OF TRITIUM RELEASE FROM THERMAL NEUTRON-IRRADIATED Li_(0.17)Pb_(0.83)

摘要

Tritium release behavior for thermal neutron-irradiated Li_(0.17)Pb_(0.83) eutectic alloy was studied. Main tritium release peak was observed in the temperature just a little higher than melting point in a thermal de-sorption spectrometry (TDS) experiment. Most of tritium release from Li_(0.17)Pb_(0.83) eutectic alloy was found to be governed by diffusion process from the results of isothermal annealing experiments. Tritium dijfusivity in a liquid state of Li_(0.17)Pb_(0.83) eutectic alloy was evalu- ated to be D = 4.7 × 10~(-8) exp(-0.13 eV/kT)m~2s~(-1) Tritium diffusivity was increased by the phase transition of Li_(0.17)Pb_(0.83) eutectic alloy from a solid state to a liquid state, resulting in the sharp tritium release peak that appeared in TDS spectrum. In addition, about 4% of tritium was trapped in Li_(0.17)Pb_(0.83) eutectic alloy as Li-T bond.