Irradiation effect on mechanical properties in structural materials of fast breeder reactor plant

Nagae, Yuji ; Takaya, Shigeru  ; Wakai, Eiichi  ; Aoto, Kazumi 

Proper evaluation of neutron irradiation damage on structural materials is important to ensure long life of fast breeder reactor plants (FBR). In this study, the effects of dose, helium content, and the ratio of helium content to dose on tensile and creep properties have been investigated in the assumed irradiation damage range of FBR structural materials. The assumed irradiation damage range is up to about 1 displacement per atom (dpa) and about 30 appm for helium content. Austenitic stainless steel and high-chromium martensitic steel are considered as FBR structural materials. As a result, it is shown that dose is a promising index for evaluating neutron irradiation damage.