AbstractThe mass transfer coefficient of tritium from molten Li17Pb83 alloy to environmental gas was determined by in-situ tritium release experiments under neutron irradiation in the temperature range from 400 to 700°C. The tritium residence time in the sample in Al2O3 crucible was measured and a tritium release model was applied to obtain the mass transfer coefficient. The mass transfer coefficient decreased with increasing H2 partial pressure in He sweep gas up to 104 Pa at 600°C, and its maximum value was 5.1 × 10−3[m s−1]. At 103 Pa in H2 pressure, it was expressed as follows: KD = 2.5 × 10−3[m s−1] × exp(−30.7[kJ mol−1]/RT). From the dependence of KD on H2 pressure and the value of the activation energy in KD, it was concluded that the rate-controlling process is a liquid film diffusion above 103 Pa in H2 pressure while, below 102 Pa, some surface reaction was considered to be a rate-controlling process.
Tritium recovery from neutron irradiated li-pb alloys