Passive protective system in the event of accidental escape of the heat carrier (heat-carrying medium) of a nuclear power plant having a water-cooled nuclear reactor

摘要

In order to guarantee the safety of a nuclear power plant having a water-cooled nuclear reactor in the event of accidental escape of the heat carrier, a passive protective system is provided in which the hermetic chambers of the primary coolant circuit are connected to a condensation system with bubble passage, which is connected in turn to a hermetic monolithic chamber. The condensation system consists of tubes immersed at different depths from the water surface of a water chamber and each fitted with a flat nozzle. These flat nozzles are embraced in each case by a channel with a converger and diffuser, the channel having a flat cross-section. The hermetic chamber can have a variable volume, for which purpose it is provided with a water seal and a movable cover. In this case, its volume increases even under minimum increase in pressure, and this makes it possible to dimension for substantially smaller design pressures. The different tube lengths and the design of the immersed tube ends with flat nozzles provide the preconditions that some of the tubes will be operated under stationary conditions even in the case of a relatively low throughput of the steam/air mixture. IMAGE