Dose dependences for materials of vver pressure vessels and their support structures

Abstract

The basic equations for structural integrity assessment on brittle fracture criterion are presented. The main mechanisms of radiation and thermal embrittlement of materials used for WWER RPV (15Kh2MFA, 15Kh2NMFA grade steels and its weld metal) and their support structures (St.3, 09G2S grade steels and its weld metal). The main considerations for construction of the trend curves are given and various types of trend curves are presented. The trend curves taken into account metallurgical and operational factors, such as content of alloying and impurity elements, neutron fluence, operating time and irradiation temperature. The analysis of the neutron flux effect under different dominant mechanisms of embrittlement of RPV materials is presented. The effect of irradiation temperature on contribution of different mechanisms of radiation embrittlement typical for materials of WWER RPV and SS is considered.