Preliminary characterization of plasma-sintered beryllides as advanced neutron multipliers

先進中性子増倍材料としてのプラズマ焼結ベリライドの予備的特性評価

中道 勝; 金 宰煥; 宗像 健三*; 柴山 環樹*; 宮本 光貴*

Nakamichi, Masaru; Kim, Jae-Hwan; Munakata, Kenzo*; Shibayama, Tamaki*; Miyamoto, Mitsutaka*

Advanced neutron multipliers with low swelling and high stability at high temperature are desired for pebble bed blankets. Beryllium intermetallic compounds (beryllides) are the most promising advanced neutron multipliers. Development of advanced neutron multiplier has been started between Japan and the EU in the DEMO R&D of the International Fusion Energy Research Centre (IFERC) project as a part of the Broader Approach activities. The plasma sintering method has been selected as a new beryllides synthesis method. The plasma sintering results in starting powder particle surface activation that enhances sinterability and reduces high temperature exposure. The plasma sintering shows that the intermetallic compound beryllide such as BeTi, BeTi and BeTi can be directly synthesized from mixed elemental powders of Be and Ti at a temperature lower than the melting point. In this report, the preliminary characterization of plasma sintered Be-Ti beryllide was carried out such as reactivity with water vapor, microstructure analysis by ion irradiation effect and deuterium retention property compared with beryllium (Be) metal. From the result of the preliminary characterization, it revealed that plasma sintered Be-Ti beryllide sample has a good performance as a neutron multiplier. This beryllide sample has enough oxidation resistance, high radiation resistance and low deuterium retention property more than Be metal.