JP2916841B

PURPOSE:To reduce operating pressure at a heat exchanger pipe so as to prevent leaks from a heat exchanger by forcing low-temperature, low-pressure and nonradioactive cooling water to pass through non-regenerative heat exchanger pipes, and forcing a high-temperature, high-pressure, radioactive primary coolant to pass through shells. CONSTITUTION:A high-temperature, high-pressure primary coolant in a reactor pressure vessel 1 is extracted using circulating pumps 35a, 35b by a predetermined amount to be purified and is allowed to pass through regenerative heat exchanger pipes 51a-51c and then pass through non-regenerative heat exchanger shells 80a-80d as a heating medium and flow into a filtering demineralizer 40. Cooling water for reactor auxiliary machinery cooling facilities is allowed to return to a post-water chamber via a non- regenerative heat exchanger pipe side inlet nozzle, a pre-water chamber and a heat transfer pipe and flow out of an outlet nozzle. The temperature of the primary coolant is therefore lowered and the coolant is purified to predetermined water quality by the filtering demineralizer 40. The primary coolant purified is then allowed to pass through the regenerative heat exchanger shells 60c-60a as a cooling medium and is heated and then flows into feedwater facility piping 17, joins with water fed from the feedwater facilities and again flops into the vessel 1 as primary coolant.