Pressurizer

The pressurizer is a system which allows the water in the reactor coolant system to be kept in liquid form, despite a temperature in excess of 300 °C.
It is placed on one of the loops of the reactor coolant system and keeps it a pressure of 155 bar. It also serves as an expansion vessel to absorb the dilatation of the water or its compression under variations in load. It is also equipped with valves to protect the reactor coolant system against overpressure.