Development of non-destructive inspection technique for microstructures under irradiation using austenitic stainless steel blocks
江藤 淳二 Junji ETOH 匂坂 充行 Mitsuyuki SAGISAKA 松永 嵩 Takashi MATSUNAGA 礒部 仁博 Yoshihiro ISOBE フランク ガーナー Frank GARNER 沖田 泰良 Taira OKITA
backscatterfast reactorirradiation damagemicrostructurenon-destructive inspectionstructural materialultrasonic
Ultrasonic testing was conducted on two long (218-245 mm), Type 304 stainless steel blocks with a hexagonal cross-section (50 mm face-to-face thickness) that were removed from the reflector region of the decommissioned EBR-II reactor. Ultrasonic testing is one of the widely used non-destructive testing techniques for material characterization. Ultrasonic waves, currently used as a non-destructive technique to detect cracks, change as a result of interacting with microstructural components and can be employed to measure radiation-induced changes in microstructure. The result of quantitative evaluation of the relationship between the microstructure and the ultrasonic signal have a good agreement between ultrasonic measurements and the spatial variations in density changes, as well as swelling arising from microscopy-observed voids. These results clearly demonstrate that ultrasonic techniques can be used to nondestructively measure the microstructures across a thick component.