PURGE WATER INJECTION SYSTEM OF PRIMARY COOLANT PUMP, AND MOTOR COOLANT SUPPLY SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a purge water injection system or the like of a primary coolant pump for preventing the primary coolant in which crud is mixed from inruding into the inside a motor casing of the primary coolant pump.SOLUTION: A first purge water injection system 50A is equipped with: a primary coolant pump purge water line 55 which is applied to a pressurized-water reactor power-generating plant equipped with a chemical and volume control system 39, extracts a flow rate portion of purge water out of primary coolant 18 extracted from a sealless type primary coolant pump 3 from a position facing an exit of a diffuser 7 positioned on the opposite side of a discharge side piping 25 to be guided to the chemical and volume control system 39, and injects the primary coolant after treatment to surroundings of a drive shaft 12 at a lower side from a pump casing 5; and a purge water flow rate control system for controlling opening of a flow rate regulating valve 58 for regulating the flow rate of the primary coolant flowing to a second flow channel 52 according to an indicated value of a flowmeter 57 which measures the flow rate of the primary coolant through the second flow channel 52.