Heavy Component Replacement in Nuclear Power Plants

Component replacement is often the most feasible solution to solve the problems associated with primary water stress corrosion cracking of Alloy 600. Even if mitigation and/or repair were a local solution, replacement offers many advantages when addressing the assortment of potentially susceptible parts contained in a major component. This publication focuses on heavy components replacement considered strategic for nuclear power plant life management but not included in current maintenance activities carried out by utilities. The major and heavy components to be considered are: steam generators for pressurized water reactors (PWRs) and pressurized heavy water reactors (PHWRs); reactor vessel heads for PWR plants; reactor internal components for boiling water reactor (BWR) plants; reactor vessel internals for PWR plants; pressurizers for PWR plants; reactor coolant piping/recirculation piping for PWR and BWR plants, and fuel channel and feeder pipes in PHWRs.