The invention, so as to pass through the air inside the storage part having a first circulation passage communicating with the said storage part and the blood equivalent to pay through the heat exchanger to suppress the pressure increase inside the storage portion cools the air inside the storage part cooling system, driven residual heat removal system having a second cyclic flow passage which passed through the primary system fluid or secondary system fluid, and cooling the primary system fluid or secondary system fluid through the heat exchanger to remove decay heat of the sensible heat and the core of the reactor coolant system , and while maintaining the pressure boundary the provided channels are arranged in each other, separated on the plate to guide the heat exchange between the fluid and to cool by passing through the air, wherein the primary system fluid or secondary system fluid to said channel a first circulation path and discloses a passive safety system and nuclear power plant having this comprising a plate type heat exchanger which is connected to said second circulation conduit.