Influence of Lithium Mass Transfer on Tritium Behavior in Pebbles of Li2TiO3 with Excess Lithium

Abstract

• Li 2 TiO 3 with excess Li was heated at 900 °C for 30 days in 1000 Pa H 2 /Ar flow. • Li mass loss was 0.7 wt%, grain size increased and BET surface area decreased. • The majority of evaporative Li was lost by first 3 days. • The influence of the 30 days heating on tritium behavior was not large. • Tritium recovery by isotope exchange with H 2 was effective at 600 °C and 900 °C. Tritium breeding ceramic materials are placed at high temperatures for a long period in a fusion DEMO reactor. Therefore, the understanding of Li mass loss phenomena and its influence on tritium behavior are important. In this study, the pebbles of Li 2 TiO 3 with excess Li were heated at 900 °C for 30 days in a 1000 Pa H 2 /Ar flow and tritium sorption and recovery experiments were carried out. Li mass loss by the heating was evaluated to be 0.7 wt%. The value of Li mass loss was almost same as that for 3 days heating at the same condition. Tritium sorption capacity for the heated pebbles at 600 °C and 900 °C were almost same as that for the pebbles as received. Tritium sorbed in the pebbles could not be recovered effectively by the 1000 Pa H 2 /Ar purge at room temperature and 300 °C but it could be recovered at 600 °C and 900 °C. The influence of the long-time heating on the behavior of tritium sorbed in the pebbles was not large.