Pressurizer

A Pressurizer is a component of a pressurized water reactor. The basic design of the pressurized water reactor includes a requirement that the coolant (water) in the reactor coolant system must not boil. Put another way, the coolant must remain in the liquid state at all times, especially in the reactor vessel. To achieve this, the coolant in the reactor coolant system is maintained at a pressure sufficiently high that boiling does not occur at the coolant temperatures experienced while the plant is operating or in an analyzed transient. To pressurize the coolant system to a higher pressure than the boiling point of the coolant at operating temperatures, a separate pressurizing system is required. That is the function of the pressurizer.