Tritium release from neutron-irradiated Li2O sintered pellets: porosity dependence

The tritium release behaviour from sintered Li2O pellets of various densiti es (71-98.5% theoretical density, T.D.) has been investigated by heating te sts at a constant rate. It is shown that :he tritium release rate depends o n porosity at densities above 87% T.D., while no dependence was observed at densities below 86% T.D. The tritium release process is thought to consist of three stages described as follows: (1) the liberation of tritium trappe d at point defects due to their recovery (peak at around 570 K); (2) the ad vection through interconnected pores via adsorption and desorption on their inner walls and diffusion in the gas phase of interconnected pores (peak s et around 620 K); (3) the dissolution and release of tritium trapped in clo sed pores (peaks at around 700, 830 and 1000 K). (C) 2000 Elsevier Science B.V. All rights reserved.