Primary circuit
Nuclear reactors for naval propulsion

The primary circuit is organized as follows:

• parallel steam generators at the core outlet;

• parallel primary pumps on the cold branch, downstream of the steam generators. A non-return valve prevents reverse flow in the event of a pump stoppage (a static hydraulic suction valve is preferred to a mechanical valve);

• a pump bypass circuit is often used to improve natural circulation operation when the primary pumps are shut down.

Various configurations of the primary circuit are shown in figures 11, 12,