Safety injection device and nuclear power plant having the same

A nuclear power plant comprises a safety injection device, and wherein the safety injection device comprising:

• a containment building;
• a reactor coolant system provided inside the containment building and accommodating a reactor coolant formed to carry heat energy generated according to fission of fuel;
• a cooling water storage section accommodating cooling water injected into the reactor coolant system;
• a power producing section producing power with steam discharged from the reactor coolant system in case of an accident;
• a steam supply pipe transmitting steam discharged from the reactor coolant system to the power producing section;
• a steam discharge pipe discharging steam drove the power producing section;
• and
• a safety injection line supplying cooling water accommodated in the cooling water storage section to the inside of the reactor coolant system,
• wherein cooling water accommodated in the cooling water storage section is supplied to the inside of the reactor coolant system on the basis of driving power produced by the power producing section through a cooling water inlet pipe connecting the cooling water storage section and the power producing section, a cooling water discharge pipe connecting the power producing section and the safety injection line, and the safety injection line.