機械学会維持規格クラス2, 3フェライト鋼管の評価不要欠陥寸法

抄録

The flaw evaluation methods for Classes 2 and 3 components have been provided in JSME fitness-for-service rule for nuclear power plants. Articles EC-2000 and ED-3000 in the code prescribe the acceptance standards for Classes 2 and 3 components, respectively. For austenitic stainless steel, the acceptance standards for Classes 2 and 3 piping is the same as those for Class 1 piping since the fracture toughness is assumed adequately high. In contrast, Classes 2 and 3 Ferritic piping has wide range of fracture toughness, therefore, specific acceptance standards are prepared in consideration of the level of fracture toughness. In this paper, a case study to configure allowable flaw sizes for Classes 2 and 3 with realistic material properties was conducted. The margins of the allowable flaws against failure were also examined.