| 摘要 |
<p>A nuclear core decay heat removal system to be used in a pressurized water reactor including a reactor vessel, a nuclear core, a steam generator, a secondary cooling system, a primary coolant circulation pump, a hot-leg piping for connecting an outlet nozzle of the reactor vessel with an inlet nozzle of the steam generator, and a cold leg piping for connecting an outlet nozzle of the steam generator with an inlet nozzle of the reactor vessel via the primary coolant circulation pump is improved. The improvements reside in that the nuclear core decay heat removal system comprises a first water source (30) disposed higher than the secondary cooling system and communicated with the secondary cooling system via a piping (32) having a valve (31), pressure-reducing means (35) connected to the secondary cooling system, and a second water source (50) disposed higher than the hot-leg piping and the cold-leg piping and communicated with the inside of the reactor vessel via a piping provided with a valve (34), in that the in the case where the steam generator is installed so as to extend in a vertical direction, the inlet nozzle of the steam generator is arranged lower than the outlet nozzle of the reactor vessel, while in the case where the steam generator is installed so as to extend in a horizontal direction, a vent tube is provided in the inlet chamber of the water chamber, and in that the second water source has a water capacity enough to make at least the hot-leg piping and the cold-leg piping submerged under water discharged when the valve included in the piping connected to the second water source is opened.</p> |
