Tritium Release from CTR Solid Blanket

Abstract

In-situ tritium release behavior from Li₂O powder has been investigated under neutron irradiation at high temperatures. It was found that the chemical form of the released tritium depended strongly on the experimental conditions such as pre-treatment (dehumidification) of the sample and the H₂ addition to the sweep gas of helium. Water-soluble component was observed to be a main species from the sample pre-dried in N₂ stream at 800°C for 3 days, while water-insoluble component had fairly large proportion on the sample pre-dried for 5 days. In the case of He-4%H₂ sweep gas, more than 90% of released tritium was water-insoluble even for the sample pre-dried for 3 days. Tritium recovery rate was also accelerated by H₂ addition. These experimental results showed that the oxygen activity of the experimental system essentially affected to tritium release behavior from Li₂O sample.