Novel granulation process of beryllide as advanced neutron multipliers

Advanced neutron multipliers with low swelling and high stability at high temperatures are desired for pebble bed blankets of demonstration fusion power (DEMO) reactors. Beryllium intermetallic compounds (beryllides) are the most promising advanced neutron multipliers. In order to fabricate the beryllide pebbles, beryllide with shapes of block and/or rod is necessary when a melting granulation process is applied such as a rotating electrode method. A plasma sintering method has been proposed as new technique which uses a non conventional consolidation process. It was clarified that the beryllide could be simultaneously synthesized and jointed by the plasma sintering method in the insert material region between two beryllide blocks. Beryllide rod of Be12Ti with 10 mm in diameter and 60 mm in length has been successfully fabricated by the plasma sintering method. Using this plasma-sintered beryllide rod, fabrication of prototype beryllide pebble was performed by a rotating electrode method as one of the melting methods. The prototype pebbles of Be12Ti with 1 mm in average diameter were successfully fabricated.

► Fabrication technology of beryllide has been developed as advanced neutron multipliers. ► A plasma sintering method has been proposed as new technique of beryllide synthesis. ► Beryllide rod has been successfully fabricated by the plasma sintering method. ► The plasma-sintered beryllide rod was granulated by a rotating electrode method. ► The prototype pebbles with 1 mm in average diameter were successfully fabricated.