2. Metallic materials used for PWR components

In pressurized water reactors, the structures must, on the one hand, withstand the pressure, temperature, and stresses generated by the circulation of primary water at approximately 330 °C (or even up to approximately 345 °C for certain parts of the pressurizer) and 15.5 MPa (155 bar) during normal operation, power fluctuations, hydraulic tests, and potential accidents. On the other hand, they must also prevent or minimize the presence of particles in the water flowing through the reactor core, to prevent these particles from becoming activated upon contact with the fuel elements and subsequently depositing throughout the primary circuit, which would significantly complicate maintenance operations. To this end, all areas in contact with the primary coolant that are susceptible to general or localized corrosion are made of stainless steel alloys. The internal components of the vessels, the...