In order to predict a time to failure of plant components due to stress corrosion cracking
(SCC), crack initiation and growth behavior must be understood. The crack growth
behavior is generally investigated using a pre-cracked specimen, and the relationship
between stress intensity factor (SIF) and crack growth rate is quantified according to fracture
mechanics. In nuclear power plants, this relation has been utilized to evaluate growth
behavior of cracks detected in operating plants according to fitness-for-service codes [1,2].
On the other hand, it is difficult to grasp crack initiation behavior.