Spectral effects on defect production in the reactor pressure vessel of a pressurized heavy-water reactor

摘要

Embrittlement predictions of reactor pressure vessels of typical pressurized water reactors are conventionally carried out using well established trend curves developed in terms of fast fluence as the correlation parameter. However, such quantification of irradiation damage cannot be applied when large spectral differences appear. We describe an atypical irradiation environment at a pressurized heavy-water reactor (PHWR), where the nature of the damage produced by low-energy neutrons is of importance. We show that at the irradiation position below the core of the PHWR, spectral effects on the primary recoil distribution have a substantial influence on the resulting displacement damage represented in terms of the number of surviving defects. This study illustrates the implications that spectral differences may have when considering the life extension of nuclear power plants. [References: 19]