Containment vessel and nuclear power plant therewith

A containment vessel for containing a reactor pressure vessel, a reactor core, and a steam generator of a pressurized water reactor, the containment vessel comprising:

• a main body equipped with a polar crane;
• a diaphragm set above the polar crane,
• wherein the diaphragm partitions the main body into an upper vessel and a lower vessel,
• wherein the diaphragm is configured to provide the partition before and after a loss-of-coolant accident (LOCA),
• the upper vessel being located higher than the lower vessel,
• the upper vessel including a dome part thereof,
• wherein an open space is in the dome part,
• the lower vessel being configured to contain all of an equipment and piping constituting a reactor pressure boundary,
• the equipment and piping including the reactor pressure vessel and the steam generator of the pressurized water reactor,
• wherein the diaphragm isolates the upper vessel from the lower vessel;
• a pressure suppression chamber having a suppression pool and a gas phase,
• the suppression pool being configured to store water,
• the gas phase of the pressure suppression chamber is in fluid communication with the open space in the dome part;
• a LOCA vent pipe fluidly connecting the suppression pool to the lower vessel;
• and
• a vacuum breaker configured to equalize a pressure of the upper vessel and a pressure of the lower vessel,
• the vacuum breaker is configured to open and allow gas flow from the upper vessel to the lower vessel when a pressure difference between the upper vessel and the lower vessel exceeds a preset value.