Development of non-destructive inspection technique for microstructures under irradiation using decommissioned materials(2) An theoretical approach
江藤 淳二 Junji ETOH 匂坂 充行 Mitsuyuki SAGISAKA 松永 嵩 Takashi MATSUNAGA 枝川 文哉 Humiya EDAGAWA 礒部 仁博 Yoshihiro ISOBE 沖田 泰良 Taira OKITA
backscattering echodepth distributionmicrostructurestainless steelultrasonic inspectionvoid
Abstract It is desired to develop an ultrasonic inspection technique non-destructively measuring various forms of irradiation-induced degradation in structural components of nuclear reactors. In order to evaluate the depth distributions of ir radiation-induced microstructural changes, we have developed a numerical simulation model of ultrasonic wave changes caused by microstructural changes in austenitic stainless steel based on the developed theory of ultrasonic wave propagation for comparison with experimental results. In this simulation we focused primarily on simplified distributions of void swelling which was found to dominate the microstructures of the EBR-II thick blocks. This simulation produced results that were consistent with the experimental results, providing confidence that this technique can indeed be used to interrogate reactor internal components to measure not only the bulk-averaged swelling but also the depth distribution of swelling.