文摘
Out-of-pile tritium release experiments were performed on Li4SiO4 pebbles produced from lithium hydroxide under various compositions of sweep gas (He, 1.1% H2/He) and environmental moisture conditions. The experimental results indicate that tritium gas can be released directly from “dry-Li4SiO4 under pure He gas. This phenomenon did not happen on “wet-samples, which means that the chemical form of released tritium is sensitive to moisture. Adding H2 to sweep gas may increase the overall desorption rate of tritium gas through H2 isotope exchange reaction, which occurs at a lower temperature than those of directly released tritium gas. Yet, the threshold of the H2 isotope exchange reaction is higher than the desorption reaction of tritiated water. Consequently, the effect of H2 isotope exchange reaction would reduce significantly on water adsorbed Li4SiO4 samples.