Recent progress on granulation technologies and characterization of advanced fusion functional materials

Kim, Jae-Hwan; Nakamichi, Masaru

Beryllium intermetallic compounds with pebble type have been investigated as an advanced neutron multiplier in demonstration (DEMO) fusion reactors, in Japan and the EU in the DEMO R&D of the International Fusion Energy Research Centre (IFERC) project as part of Broader Approach (BA) activities from 2007 to 2016. Beryllide is well-known as the most promising candidate for advanced multipliers in demonstration fusion reactors. However, due to its brittleness, it is difficult to fabricate not only a block-type but also a pebble-type beryllide. Recently, beryllide pebbles has been successfully fabricated by combinational method, plasma sintering and rotating electrode method. Here, we report on synthesis and analysis of beryllide blocks as well as pebbles with different chemical compositions. On the other hand, in order to clarify the effect of the content of Ti on the fabrication of beryllide pebbles, a rotating electrode method was applied using a plasma-sintered beryllide rod jointed by two beryllide blocks and powder. In this study, overview of R&D on synthesis and granulation technologies of not only binary but also ternary beryllides as advanced neutron multipliers is reported from viewpoints of optimization and characterizations. In addition to R&D on this multiplier material, new approach of beryllides as H storage materials will be briefly introduced.