Nuclear power facilities

A nuclear reactor facility comprising a primary containment vessel, a reactor pressure vessel installed in the primary containment vessel and accommodating a reactor core in a lower part thereof, a vertical cylindrical wall disposed in a lower part of the primary containment vessel around and spaced from the reactor pressure vessel so as to delimit an annular space therebetween, the vertical cylindrical wall having an upper end disposed at a position higher than an upper end of the reactor core, a diaphragm extending substantially horizontally between the upper end of the vertical cylindrical wall and an inner wall of the primary containment vessel for cooperating with the vertical cylindrical wall to separate a space in the primary containment vessel around the reactor pressure vessel into a pressure suppression chamber and a drywell which includes the annular space, the pressure suppression chamber accommodating therein a pool of liquid coolant wherein a level of the liquid coolant of the pool is higher than the upper end of the reactor core, the vertical cylindrical wall having a plurality of vent passages having an upper part at the upper end of the vertical cylindrical wall and exposed to the drywell and a lower part exposed to the pool of the liquid coolant in the pressure suppression chamber, a submergence line extending from the pressure suppression chamber to the reactor pressure vessel at a position above the upper end of the reactor core and having at least one valve therein for cooperating with the submergence line to introduce the liquid coolant from the pool of the liquid coolant in the pressure suppression chamber to the reactor pressure vessel when the valve is opened for cooling of the reactor core, and a channel member for enabling liquid coolant to flow from the annular space between the vertical cylindrical wall and the reactor pressure vessel in the drywell into the pressure suppression chamber when liquid coolant fills the annular space, the channel member having one end opened at an upper part of the vertical cylindrical wall to the annular space between the vertical cylindrical wall and the reactor pressure vessel and another end exposed to the pool of the liquid coolant in the pressure suppression chamber, the channel member having the one opened end thereof positioned higher than the level of the liquid coolant of the pool in the pressure suppression chamber.