Pressure suppression device

Purpose: To suppress the rise of water level caused by the inflow of a non-condensable gas (nitrogen, etc.) at the time of pipe rupture in relation to a pressure suppression chamber of BWR, thereby preventing the application of a great deal of dynamic loads to the wall of the pressure suppression chamber. Constitution: The basic conception of this invention is to provide in a pressure suppression chamber a part which absorbs the volume of a non-condensable gas. As its one method, a partition is provided in the pressure suppression chamber, which is normaly evacuated, and the partition will be opened if a chamber pressure has increased a little due to the inflow of the non-condensable gas. However, this method is of low reliability because it is difficult to maintain the vacuum for a prolonged period of time and therefore a water-soluble gas, for example ammonia, is used for vacuum. That is, the partition and a rupture disk (a pressure differential required for rupture is about 0.5 atm) are provided in the pressure suppression chamber and an ammonia gas at a pressure balanced with the external pressure is filled therein. (Ikeda, J.)