Overview of structural materials in water-cooled fission reactors

Nuclear power currently provides a fraction of non-carbon-emitting power generation in the United States and around the world. The existing fleet of water-cooled reactors continues to improve on operations and reliability, as ensuring public safety and environmental protection is a prerequisite, whether water reactor, advanced reactor, or fusion. Materials are important during all phases of a reactor’s lifetime and must perform reliably for their entire expected lifetime. Unfortunately, nuclear reactors of all designs present a challenge for component service and material performance, as exemplified in water reactors. Components within a reactor must tolerate the harsh environment of high-temperature water, stress, vibration, and, for those components in the reactor core, an intense neutron field. Degradation of materials in this environment can lead to reduced performance and, in some cases, sudden failure. This chapter will provide an overview of the key water reactor designs, their features, and materials of construction. In addition, this chapter will introduce some of the key degradation modes facing materials for nuclear power reactors, including irradiation effects and corrosion. Finally, this chapter will provide an introduction to the key materials of construction, their use, and key characteristics.