Material development of beryllium reflector in materials testing reactors

Tsuchiya, Kunihiko ; Longhurst, G.*; Chakin, V.*; Tazhibayeva, I.*; Druyts, F.*; Dorn, C. K.*; Kawamura, Hiroshi

Beryllium has been utilized as a moderator and/or reflector in a number of material testing reactors. In fact, the nuclear properties of beryllium are its low atomic number, low atomic weight, low parasitic capture cross section for thermal neutrons, readiness to part with one of its own neutrons (n, 2n), and good neutron elastic scattering characteristics. Various problems of beryllium utilization are introduced for nuclear reactors and two points are proposed for the solution of irradiated beryllium wastes. Thus, it will be necessary to consider fundamental changes to the frame design, starting with the choice of beryllium material grade. Additionally, irradiation tests are planned for the design modification of beryllium materials. Beryllium material grades are selected for material modification and irradiation tests have been discussed. New measurement procedures in PIEs are also proposed for evaluation of lifetime extension. In this presentation, status and future plan of beryllium reflector development are introduced.