Application of beryllium intermetallic compounds to neutron multiplier of fusion blanket

Beryllium metal is commonest as a neutron multiplier of fusion blanket. However, the application of beryllium metal to DEMO reactor that requires higher temperature (600–900 °C) is very severe, because the melting point is low (1285 °C) and the starting temperature of swelling by neutron irradiation is low (∼500 °C). Therefore beryllium intermetallic compounds that have high melting point have been expected as the advanced material for fusion DEMO blanket. Several R&D concerning the characterization and the fabrication technology for beryllium intermetallic compounds have been performed in Japan that takes a leading part in these R&D. From the results of these R&D, it made clear that beryllium intermetallic compounds had excellent property and the feasibility as the neutron multiplier for fusion DEMO blanket. In addition, fabrication technology for the pebbles was studied.