Improvement of the Soundness Assessment Technique for Reactor Internals with Cracks based on Inspection Data

In this study, improvement of soundness assessment method of Japanese Code and Guideline in Ref. [1] and [2] were studied by combination of FEM analysis and fracture test using 1/5 scale mock-up. 18 cases of collapse analyses were performed by FEM analysis to various crack locations. In 4 cases of all 18 cases, the fracture tests were performed in order to evaluate the validity of collapse analyses. As a result of comparison of load-displacement curves by collapse analyses with the fracture tests, both curves were close to each other. Therefore it is considered that the validity of collapse analyses has been confirmed. (author)