Achievements and further plans for the OECD Halden reactor project materials programme

The materials programme at Halden, in addition to cladding corrosion studies, is aimed also at addressing the effects of operating conditions and water chemistry variables on core materials behaviour, particularly as related to reactor pressure vessel integrity and irradiation assisted stress corrosion cracking (IASCC), the materials degradation phenomenon which affects the structural integrity of stainless steel and nickel based components. The aim of the experimental work is to improve the understanding of materials ageing processes, to demonstrate the benefits of mitigation measures and to evaluate properties of materials, which have been subjected to long in-reactor service. While a number of the studies are performed in loops, which simulate light water reactor environments in terms of thermal-hydraulic, radiation and water chemistry conditions, dry irradiation facilities are also utilised, particularly in relation to studies aimed at determining the effects of fluence on material integrity.