Welcome to the BURGMANN Sealing World
Pressurized water reactor

A thermal nuclear power station which used light water (light water reactor nuclear reactor) at pressures up to approximately 170 bar. The water employed to dissipate the heat of nuclear fission and to retard the neutrons released by splitting nuclei (moderation) is demineralized and treated with chemicals to enable it to serve as coolant for the reactor. Proper coordination of system pressure and temperature prevents the coolant from vaporizing, enabling the intensive cooling effect of the pressurized water to be utilized to the full.
Main coolant pumps
located outside the reactor pressure vessel convey the coolant in several closed circuits through the steam generator (primary circuit). The feed water fed to the steam generator on the secondary side absorbs the heat of the primary circuit and vaporizes. In each comparable power station, this steam is conveyed to and drives the turbine.

 


After the feed water condenses in the condenser, it is recycled to the steam generators (secondary circuit). Separating the reactor cooling circuit (primary circuit) and the water steam circuit (secondary circuit) is an advantage (as compared with e. g. boiling water reactors) for pumps and their mechanical seals, because far fewer of them – only those of the primary circuit are contaminated (radioactively). The feed water pumps, booster pumps, and main and secondary condensate pumps (condensate pumps) are among those pumps which remain uncontaminated. All pumps in a pressurized water reactor are equipped with mechanical seals.
Schematic presentation of a pressurized water reactor with its principal pumps