[2A15-21] Reactor Pressure Vessel Steels

[2A20] Development of high temperature material property equation for base metal and welded joints of reactor pressure vessel steels

*Kenta Shimomura¹, Takuya Yamashita¹, Yuji Nagae¹ (1. JAEA)

Keywords:high temperature, creep, tensile, RPV

Since the reactor pressure vessel (RPV) may have been damaged in the accident at the Fukushima Daiichi Nuclear Power Plant, we have been estimating the damage condition of the RPV by evaluating the coupled thermal - structural analyses. Since the RPV is exposed to high temperature (>600°C) during an accident, material property equations for RPV materials in the high temperature range are required. In particular, there are various welds in RPV, but there is no data on high temperatures (above 600°C) in the existing knowledge, and analytical evaluation including welds could not be performed. In this study, welded joints using RPV materials were fabricated, high-temperature (>600°C) material data were obtained, base metal and joint strength were compared, and material property equations that can be applied up to high temperature ranges were developed. As a result of the test, it was confirmed that there was no difference in strength between the base metal and the joint, and the elastic - plastic stress-strain relationship, creep-strain equation, and creep rupture equation were developed as material property equations.