Studies of two-phase lithium ceramics Li4SiO4-Li2TiO3 under conditions of neutron irradiation

•Lithium ceramic irradiation up to a neutron fluence of 1.8·1019 n/cm2·s was performed.•Gas release dependences from ceramic under pumping conditions were obtained “in-situ”.•Tritium is released as HT, T2 and HTO molecules.•The ratio of the number of released tritium atoms depends on the concentrations of tritium, hydrogen atoms and adsorbed water molecules on the surface. This work presents the preliminary experimental data on the study of gas release from two-phase lithium ceramics Li4SiO4-Li2TiO3 under neutron irradiation conditions. Experiments were carried out at the WWR-K research reactor (Almaty, Kazakhstan) for ∼4.3 days. The total neutron fluence during the irradiation was ∼1.8·1019n/cm2. In the course of irradiation, two experiments on ceramics heating during irradiation and two experiments with hydrogen isotopes (H2 and D2) supply into the experimental chamber with the sample were performed at a temperature of 680 °C and reactor power of 6 MW. During the entire irradiation, the gas composition in the continuously evacuated ampoule device with samples was recorded. The obtained dependences of the release of tritium-containing molecules and helium during the experiment were qualitatively analyzed.