Comparative analysis of mechanical properties derived from Japanese PWR surveillance data and MTR data

Toyama, Takeshi; Iwata, Keiko ; Tobita, Toru; Hata, Kuniki ; Suzuki, Masahide; Onizawa, Kunio ; Watanabe, Aiki*; Hojo, Tomohiro*; Funada, Tatsuo*; Sasaki, Haruko*

In recent years, surveillance test data from PWRs in Japan have been accumulated, enabling comparisons with data from domestic and international materials test reactors (MTRs). An evaluation of the relationship between the fracture toughness transition temperature and the related reference temperatures, evaluated from Japanese PWR surveillance data using Japanese regulation and standard, revealed a slightly different trend from that evaluated from MTRs data using the Master Curve method. Therefore, in this study, the fracture toughness transition temperatures of Japanese PWR surveillance data were evaluated using the Master Curve method, and various indicators, i.e., the fracture toughness transition temperature, reference temperatures, chemical composition, and initial material properties, were compared with those for the MTRs data. This allowed for direct comparison in regions with low embrittlement levels. As a result, no significant differences were observed between the PWR surveillance data and the MTRs data for any of the indicators.