RPV胴板の内部亀裂に対する構造健全性評価
概要
When quasi-laminar defects are detected in the RPV shell, these defects are modeled to single circular crack with a diameter of 2a and an angle of ? from RPV wall enveloping these micro-defects like as the model used in the structural integrity assessment for Doel-3. An acceptable crack size is investigated for fracture assessment and initial crack size considering the fatigue crack growth by 60 years operation due to the JSME Fitness-for-Service (FFS) code. It was found that the initial crack with 2a of 4% smaller than the acceptance crack for fracture at the same location is accepted to exist. Although some discrepancies between Appendices E-1 and E-5 of the JSME FFS code exist for the treatment of internal crack, the structural integrity assessment can be performed for internal crack with some conservative assumptions.
