Mass loss of Li_2TiO_3 pebbles and Li_4SiO_4 pebbles

摘要

It has been known that water vapor is released from ceramic breeder materials into the purge gas due to desorption of adsorbed water under dry atmosphere and due to the water formation reaction under hydrogen atmosphere. However, an effect of water vapor in the purge gas to Li mass loss has not been understood. In this study, mass loss of Li_2TiO_3 (NFI) and Li_4SiO_4 (FzK) under hydrogen atmosphere (1000 Pa H_2/Ar), and mass loss of Li_2TiO_3 (NFI) and Li_2TiO_3 with additional Li which is in a developmental stage (JAEA) under water vapor atmosphere (50 Pa H_2O/Ar) were compared, respectively. It was found that under hydrogen atmosphere Li mass loss of Li_4SiO_4 and Li_2TiO_3 is same degree although the amount of water vapor released from Li_4SiO_4 is larger than that from Li_2TiO_3. It was clarified with regard to Li_2TiO_3 that Li mass loss in water vapor atmosphere is larger than that in hydrogen atmosphere. Mass loss of Li_2TiO_3 with additional Li (JAEA) was larger than that of Li_2TiO_3 (NFI). It was observed by X-ray analysis that Li deposits formed on the inner wall of the quartz tube contain Li_2TiO_3.