Development of beryllium material for reflector lifetime expansion

Dorn, C. K.*; Tsuchiya, Kunihiko ; Hatano, Yuji*; Chakrov, P.*; Kodama, Mitsuo*; Kawamura, Hiroshi

The JMTR has used beryllium reflector since it began operation in 1968. Beryllium has been used as the reflector element material in the reactor, specifically S-200F structural grade beryllium in JMTR. As a part of the reactor upgrade, the Japan Atomic Energy Agency (JAEA) has carried out the cooperation experiments to extend the operating lifetime of the beryllium reflector elements. Thus, three kinds of beryllium metals such as S-200F, S-65H and I-220H were selected at the viewpoints of production methods, impurities and grain size of beryllium starting powders, mechanical properties. Now, data of the material properties and interaction between pure water and these beryllium grades are accumulated under un-irradiated. Additionally, irradiation tests have been prepared and development of PIE technologies has been performed. In this paper, the results of various properties and irradiation test plan for lifetime expansion of beryllium are described for material testing reactors.