Tritium release property of Li2TiO3-Li4SiO4 biphasic ceramics
Abstract The tritium release experiments of Li4SiO4 pebbles, Li2TiO3 pebbles and Li4SiO4-Li2TiO3 biphasic pebbles were conducted to investigated the tritium release behavior of Li4SiO4-Li2TiO3 biphasic pebbles. The results indicate that the biphasic ceramic pebbles with uniform structure and small grain size exhibit good tritium release performance. The tritium release temperature is around 450 °C, and most of tritium is released in the form of tritiated water. The tritium release behavior of Li4SiO4-Li2TiO3 biphasic pebbles is controlled by the release of both Li2TiO3 and Li4SiO4, and the interfaces between Li2TiO3 and Li4SiO4 can promote the tritium release. Besides, the surface reaction is the key process affected the tritium release of the Li4SiO4-Li2TiO3 biphasic pebbles, because the release behavior is significantly affected by the composition of purge gas. Under 0.1% H2+He purge gas, with the combined effect of the two-phase interface and the isotope exchange reaction, the tritium release properties of the biphasic pebbles are promoted.