Abstract The basic properties and applications of the alloy Inconel X-750 are described. In addition to a brief survey of damage caused by intergranular stress corrosion cracking on components of the RPV-internals and core-components in LWRs (KWU design and other suppliers), possible damage mechanisms are discussed. Corrective actions to be considered in terms of materials engineering are stress limitations in connection with design changes or replacement by other materials. In conclusion, mention is made of replacements of components performed to date by KWU. The required equipment and a description of the actual replacement activities is given.