Pressure suppression device

Purpose: To moderate the rapid increase in pool water and load exerted on the pool bottom by supporting the entire weight of vent tubes on the building mat. Constitution: Vent tubes having a plurality of small apertures perforated at the side immersed in pool water are directly mounted at one ends to a diaphragm floor and mounted in a closed state to the mat of a suppression chamber. Thus, the fluid in the drywell (nitrogen and steams) flown into the vent tubes are discharged through the small apertures as small gas bubbles into the pool water to suppress the rapid increase in the level of the pool water and the load exerted on the mat, as well as the load exerted on the diaphragm floor can be decreased since the weights of the vent tubes are supported on the mat. (Kawakami, Y.)