Leakage control device in a main steam isolating valve

Object: To return all of leaked steam into a reactor receiving container despite the state of trouble to minimize the discharge of radioactive material at the time of trouble. Structure: A leakage control system for main steam isolating valves communicating the main steam isolating valves disposed in a main steam pipeline with a pressure control chamber, the system including a condenser and an ejector, the condenser being communicated with the ejector through a pump, the condenser causing the isolating valves to be negative pressure, non-condensed gases contained in condensation and leaked steam being fed to the pressure control chamber through the pump and ejector. (Kamimura, M.)