Abstract: A passive safety system includes a containment, a reactor in the containment, a plurality of safety injection tanks connected with the reactor and having water and nitrogen gas to supply water thereof into the reactor through a safety injection line communicating to the first safety injection line upon a loss of coolant accident, a plurality of core makeup tanks connected with the reactor to supply water thereof into the reactor through a second safety injection line communicating to a safety injection line upon the loss of coolant accident, and a plurality of passive residual heat removal systems to remove residual heat from the reactor upon the loss of coolant accident or a non-loss of coolant accident. The water in each of the safety injection tank is stably supplied to the reactor for many hours by a differential head resulting from gravity or gas pressure.

Abstract: A passive safety system includes a containment, a reactor in the containment, a plurality of safety injection tanks connected with the reactor and having water and nitrogen gas to supply water thereof into the reactor through a safety injection line communicating to the first safety injection line upon a loss of coolant accident, a plurality of core makeup tanks connected with the reactor to supply water thereof into the reactor through a second safety injection line communicating to a safety injection line upon the loss of coolant accident, and a plurality of passive residual heat removal systems to remove residual heat from the reactor upon the loss of coolant accident or a non-loss of coolant accident. The water in each of the safety injection tank is stably supplied to the reactor for many hours by a differential head resulting from gravity or gas pressure.

Abstract: Disclosed are a nuclear reactor adapted for mitigating a loss-of-coolant accident and a mitigation method thereof. The nuclear reactor includes a nuclear reactor vessel, a first pipe part connected to the nuclear reactor vessel to supply or drain fluid, and a first opening/closing part connected to the first pipe part. When the first pipe part is broken, the first opening/closing part closes the first pipe part to stop discharge of coolant. A supplementary coolant injection part is connected to the nuclear reactor vessel through a second pipe part. When the second pipe part is broken, a second opening/closing part closes the second pipe part to stop discharge of coolant.