Damage Evaluation Techniques for FBR and LVVR Structural Materials Based on Magnetic and Corrosion Properties along Grain Boundaries

Hoshiya, Taiji; Takaya, Shigeru  ; Nagae, Yuji ; Abe, Yasuhiro; Aoto, Kazumi ; Ueno, Fumiyoshi*  

Japan Atomic Energy Research Institute and Japan Nuclear Cycle Development Institute have begun The cooperative research of novel evaluation techniques of structural material degradation in Fast Breeder Reactor (FBR) and Light Water Reactor (LWR), which based on magnetic and corrosion properties along grain boundaries Magnetic method has been proposed as the one of the innovative non-destructive detection techniques on the early stage of creep-damage before crack initiation for aged structural materials of FBRs. On the other hand, corrosion properties and magneto-optical characteristics of ion-irradiated stainless steel in the vicinity of grain boundaries were estimated by AFM. These degradations were induced by changes in characteristics in the vicinity of grain boundaries, such as chromium depletion. It is found that the initial level of progressing process of damage can detect changes in magnetic and corrosion properties along grain boundaries of aged and degraded nuclear