Trial fabrication tests of advanced tritium breeder pebbles using sol–gel method

Lithium titanate (Li2TiO3) is one of the most promising candidates among tritium breeding materials because of its good tritium release characteristics. However, the mass of Li2TiO3 decreased with time by Li evaporation in a hydrogen atmosphere and by Li burn-up. In order to prevent the mass decrease at high temperatures, Li2TiO3 with added Li (Li2+xTiO3+y) have been developed as one of advanced tritium breeders. Li2TiO3 with added Li was synthesized from proportionally mixed LiOH·H2O and H2TiO3 with a Li/Ti ratio of 2.2, and then the sol–gel method were selected as the candidate for the pebble fabrication technique of advanced tritium breeders. In this study, trial fabrication of pebbles was performed by the sol–gel method. The diameter of the pebbles is 1.18 mm, and the sphericity is 1.04. The density of the pebbles is about 89%T.D analyzed by mercury intrusion technique. Molar ratio (Li/Ti) of the sintered pebbles evaluated by inductively coupled plasma atomic emission spectrometry (ICP-AES) is 2.12. These results show that the pebble fabrication using the sol–gel method is a promising production technique for mass production of the advanced tritium breeder pebbles.