COMPARISON OF МАSTER CURVE WITH NORMATIVE METHOD OF ESTIMATING WWER-1000 REACTOR PRESSURE VESSEL METAL FRACTURE TOUGHNESS

The paper considers the generalized temperature dependence of the stress intensity factor K JC in the WWER-1000 reactor pressure vessel metal, which was derived based on the surveillance test data for fracture toughness. The consistency of the shape of the Master curve and 95 % upper and lower confidence bounds with the experimental dependence of crack resistance parameters on temperature was studied. From the point of view of the level of conservatism and acceptability, a comparison of the normative curves of fracture toughness according to NPRR (Nuclear Power Rules and Regulations) G-7-002-86 and SOU NNEGC (Standard of organization of Ukraine, National Nuclear Energy Generating Company) 177:2019 with a 5 % confidence bound of the Master curve was carried out. The possibility of using RT 0 temperature as a temperature index instead of T K for the normative fracture toughness curve of SOU NNEGC 177:2019 was considered.