BRITTLE-FRACTURE TOUGHNESS - EXPERIMENTAL ESTIMATION OF RPV MATERIALSAND THEIR WELDS CONTAINING SHALLOW CRACKS

This paper presents brittle fracture resistance results for types 15X2 MFA, 15X2NMFA steels and their weldments, produced by submerged are we lding as applied to nuclear reactor VVER-440 and VVER-1000 pressure ve ssels production and maintenance conditions. The fracture toughness/te mperature dependence of these materials was determined for cracks with the depth 0.1 (small) and 0.5 (standard) from specimen thickness. The crack shape (through, semi-elliptical); material state (beginning and end of service life), and the specimen production processing (presenc e or absence of anticorrosive cladding) were also varied. The consider ation of real crack size enables one to sufficiently increase the brit tle fracture resistance of reactor materials and their welded joints. This fact should be used in the performance of control calculations.