Installation for the vapourization of the two-phase mixture contained in a cooling system during a scheduled depressurization

摘要

An evaporator vessel encloses an array of heating tubes through which the primary coolant of a pressurised water-cooled nuclear reactor is directed during a depressurising operation, from hot duct to cold duct, causing water in the main part of the vessel to boil. The steam is released from the top of the vessel through control valve to collector, and a connection between the downstream ends of the tubes and the vessel interior allows limited flow of relatively cold water into the vessel to maintain the level. The evaporation of a fraction of the coolant water in vessel cools the main flow of coolant, which continues to circulate through the reactor core.