Features of the in-situ experiments on studying of tritium release from lithium ceramic Li2TiO3 using vacuum extraction method

Highlights: • The neutron irradiation of Li2TiO3 was performed by vacuum extraction method. • A qualitative analysis of the experimental results is presented. • Almost no tritium is released in the form of tritium water vapor,. • The processes associated with t interaction with H2O vapor can be excluded from the consideration. • A significant amount of tritium is released as T2 molecule. The paper presents the results of reactor experiments with lithium ceramic Li₂TiO₃ performed at the WWR-K research reactor (Almaty, Kazakhstan). A qualitative analysis of the experimental results is presented. The following general results are obtained from the experiments performed by the vacuum extraction method:• Almost no tritium is released in the form of tritium water vapor, and the processes associated with tritium interaction with water vapor can be excluded from the consideration; • a significant amount of tritium is released as T₂ molecule; • in long-term irradiation, a significant growth of tritium release in the form of T₂ molecule with the time of irradiation is observed. It was concluded that the experiments performed by vacuum extraction allow elimination of a number of surface interactions of tritium (for example, with water vapor) and significantly facilitate understanding of the mechanisms of tritium release due to its transfer in the bulk of the material. In particular, it allows us to propose simpler models describing the release process and to evaluate the effect of tritium interaction processes with traps that arise in the material during irradiation.