Passive residual heat removal system and nuclear power plant equipment

A passive residual heat removal system, comprising:

• a reactor pressure vessel;
• a reactor core placed in the reactor pressure vessel;
• a primary containment vessel including a drywell to surround the reactor pressure vessel, and a suppression chamber internally provided with a suppression pool;
• a vent line connecting the drywell and the suppression pool, the vent line being fitted with a plurality of openings in the suppression pool;
• a coolant pool filled with a coolant and provided above the primary containment vessel;
• a heat exchanger placed under the coolant in the coolant pool;
• a steam suction line connecting the drywell and the heat exchanger;
• a condensate storage tank disposed below the heat exchanger and above an upper end of the reactor core;
• a first condensate discharge line connecting the condensate storage tank and the heat exchanger;
• a non-condensate gas discharge line connected at a first end thereof to an upper section of the condensate storage tank and at a second end thereof to the suppression pool, the second end of the non-condensate gas discharge line being open at a position higher than a highest opening of the vent line in the suppression pool;
• a second condensate discharge line connected at a first end thereof to a position below that section of the condensate storage tank to which the first end of the non-condensate gas discharge line is connected, and at a second end thereof to the suppression pool, the second end of the second condensate gas discharge line being open at a position lower than a lowest opening of the vent line in the suppression pool;
• and
• a condensate return line connected at a first end thereof to a position below that section of the condensate storage tank to which the first end of the second condensate discharge line is connected, and at a second end thereof to a side portion of the reactor pressure vessel, the side portion being above the upper end of the core;
• wherein the open end of the second condensate discharged line, positioned in the suppression pool, is branched into a plurality of horizontal lines, with condensate discharge ports being formed at distal ends of the branched horizontal lines.