Prevention device for LOCA and nuclear reactor having the same

A prevention device for loss of coolant accident (LOCA), the prevention device comprising:

• a nozzle portion integrally formed in a reactor vessel and having a communication hole communicating with the inside of the reactor vessel;
• a nozzle finishing portion assembled to the nozzle portion and an injection line for injecting a fluid to the inside of the reactor vessel respectively on both sides of the nozzle finishing portion in a communicating manner;
• and
• a check valve mounting portion installed to be embedded inside the nozzle portion and having at least one check valve opened by flow such that the fluid is injected into the reactor vessel,
• wherein the check valve blocks outflow of a reactor coolant from the reactor vessel in case of failure of the injection line,
• wherein the check valve mounting portion has a first insertion portion including dual check valves disposed to be spaced apart from each other in a longitudinal direction of the nozzle portion and a second insertion portion including an outflow blocking portion opening the communication hole when the first insertion portion is mounted and blocking the communication hole when the first insertion portion is drawn out, and
• wherein the second insertion portion includes a second casing disposed inside the nozzle portion to surround the first insertion portion, and the outflow blocking portion has one side hinged to an upper side within the second casing and the other side rotated to open and close the communication hole according to insertion or withdrawal of the first insertion portion.