| 摘要 |
PURPOSE:To assure the adequate water injection rate meeting the pressure of a nuclear reactor and to make contribution to the improvement in safety and the reduction of cost by forming a pressure accumulation water injecting system into multistage constitution and dividing the same to a system for injecting water in a high-pressure state and a system for injecting the water in a middle-pressure state. CONSTITUTION:The high-pressure accumulation water injecting system 25 consists of a pressure accumulation tank 18, a water injecting valve 19 and a water injecting piping 23. The valve 19 is designed to be opened by a LOCA signal. The middle-pressure accumulation water injecting system 24 consists of a pressure accumulation tank 20, a check valve 21, and a stop valve 22. The valve 22 is opened by the LOCA signal. The cooling water in the tank 20 is injected into a reactor core part 3 by the automatic opening of the valve 21 when the pressure in the reactor drops sufficiently. The opening valve of the high-pressure accumulation water injecting system, is opened to inject the cooling water into the reactor by the LOCA signal when LOCA is generated at this time. The cooling water in the pressure accumulation tank is injected into the core part when the reactor pressure, the regulating valve of which is opened by the LOCA signal, drops below the holding pressure of the middle- pressure accumulation water injecting system. The water injection by a gravity fall type ECCS is executed when the pressure drops sufficiently thereafter. |
