Compatibility test between Be12Ti and Li2TiO3

Beryllides have many interesting properties at high temperature and are candidate materials as advanced neutron multiplier for DEMO Reactor blanket developed by JAERI. A new blanket design with mixed pebble packing of neutron multiplier and tritium breeder has been proposed to improve tritium breeding ratio (TBR). Therefore, it is necessary to evaluate the compatibility between the neutron multiplier and the tritium breeder. In this study, the compatibility between Be12Ti and Li2TiO3 was investigated. The compatibility between Be and Li2TiO3 was also investigated for the comparison with the case of Be12Ti. When the Be12Ti specimen was placed in contact with Li2TiO3, neither reaction products nor diffusion of Li in beryllide were found after annealing during 1000 h at 800 °C. In the case of Be specimen in contact with Li2TiO3 no reaction products were observed, however, a diffusion of Li into Be was identified after annealing for more than 300 h at 800 °C. These results show that the compatibility of Be12Ti with Li2TiO3 was higher than that of Be, therefore, from the point of view of compatibility mixed pebble beds of neutron multiplier Be12Ti and tritium breeder Li2TiO3 pebbles can be used in a blanket.