EMBRITTLEMENT AND FRACTURE TOUGHNESS OF HIGHLY IRRADIATED AUSTEN1TIC STEELS FOR VESSEL INTERNALS OF WWER TYPE REACTORS. PART 3. ANALYSIS OF CRACK PROPAGATION CONDITIONS

摘要

One of the most significant operating factors that have an influence on the materials of internals of fast neutron reactors (FN) or water-moderated, water-cooled reactors (WWER) is the intensive neutron irradiation. Specifically, the intensity of the damaging neutron dose (dD/dt) for some components, e.g., internals, is as high as 1 dpa/year for FN reactors, 1 dpa/year for WWER-440 reactors and 1.5-2 dpa/year for WWER-1000 reactors. The intensive irradiation has dictated the choice of materials - austenitic chromium-nickel steels - for the reactor pressure vessel (RPV) internals. For FN and WWER reactors the internals are made of steels Khl8N9 and Khl8N10T, respectively.