Cooling system for primary containment vessel in nuclear power plant and component for use in said cooling system

摘要

Pipes are mounted horizontally on an outlet portion of a gas vent pipe in a condenser-type heat removal system, and have-openings which are formed only in a portion below a horizontal plane in which axes of these pipes lie, thereby enlarging a region where uncondensed steam is mixed with water in a suppression pool. With this arrangement, a surface portion of the water of the suppression pool is prevented from becoming hot, and the temperature of this pool water is uniformed. As a result, the temperature of the water surface of the suppression pool is lowered, thereby decreasing the pressure within a primary containment vessel. This enhances the reliability of the primary containment vessel, and reduces a design strength of the primary containment vessel.