pressurized water reactor

A pressurized water nuclear power station. Water at high pressure is circulated around the reactor vessel where it is heated. The hot water is pumped to the steam generator where it boils in a separate circuit; the steam drives the turbines coupled to the electricity generator. This is the most widely used type of reactor. More than 20 countries have pressurized water reactors.

Nuclear reactor design used in nuclear power stations in many countries, and in nuclear-powered submarines. In the PWR, water under pressure is used in a closed system, as a coolant, passing through the reactor to the generator. Boric acid is added as a moderator. The pressurized water circulates through a steam generator, where its heat boils water to provide steam to drive power turbines.