Completely passive cooling system for reactor core after accident of large-scale pressurized water reactor nuclear power plant

A completely passive cooling system for a reactor core after an accident of a large-scale pressurized water reactor nuclear power plant, comprising:

• a shield building having an outer wall and a through air inlet arranged on an upper part of the outer wall;
• a water tank arranged at an upper part of the shield building;
• a cooling water distribution plate arranged above a top of a containment within the shield building;
• a spray pipe arranged at an inside of the top of the shield building and having a water inlet end and a water outlet end, wherein the water inlet end is connected to a bottom of the water tank and the water outlet end is extended to be above the cooling water distribution plate;
• and
• an air deflector arranged between the shield building and the containment and having an upper end connected to an inside of the top of the shield building,
• wherein a smokestack is arranged on a top of the shield building with a steel-concrete composite structure,
• wherein the water tank is arranged around the smokestack, and
• wherein the top of the shield building comprises a double-layer structure, a double-layer steel-concrete composite structure top is formed on an upper end of the cylindrical steel-concrete composite structure, while a cylindrical steel-concrete air flow passage is formed on the top, and the double-layer steel-concrete top forms the water tank.