Current Status of the Fabrication of Li4SiO4 and Beryllium Pebbles for CN HCCB TBM in SWIP

Abstract

Tritium breeder and neutron multiplier as functional materials play an important role not only in ITER test blanket module (TBM) but also in fusion reactor. The paper describes the status of the fabrication of the two materials in Southwestern Institute of Physics (SWIP). Li4SiO4 pebbles were fabricated by melt-spraying method. Most of the pebbles with the diameter of 1.0 mm are well spherically shaped. The properties of the pebbles have been investigated. The results show that the pebbles produced by this method have a high density of 93% TD (theoretical density). It was also found that the open/closed porosity will be decreased after thermal treatment, but the average crush load will be increased to 7 N. The rotating electrode process (REP) has been adopted to produce beryllium pebble for impurity control and mass production. The pebbles with the diameter of 1.0 mm were produced by REP. The beryllium pebbles produced by REP look almost perfectly spherical with a very smooth surface and a high density of 98% TD. The test results indicate that REP method has excellent prospects for the fabrication of beryllium pebbles and the attractiveness of their properties.