Materials and Corrosion in Light Water Reactors

Since the beginning of nuclear industry, corrosion issues have been a major concern. Less than two years after start-up, stress corrosion cracking occurred on the stainless steel tubing of the steam generator of the prototype for the Nautilus in USA (1953); more recently, in 2022, several French Pressurized Water Reactors were shut down due to stress corrosion cracking of stainless steels pipes in a safety injection circuit. We propose to underline the complex corrosion mechanisms linked to the nuclear reactor environments (high temperature and high-pressure water environments) and to present briefly the three main corrosion phenomena occurring in Light Water Reactors (LWRs), after a short overview of the LWR materials: Finally, the corrosion future will be discussed as LWRs are extending their period of operation up to 60 / 80 years, and even more.