Reactor cooling device

Purpose: To prevent cooling function from interruption both in normal state and upon earthquakes in a reactor cooling system for use in reactor shutdown or accident. Constitution: A suppression pool is provided to the inside and a water storage tank is provided to the outside of a nuclear reactor building, in which the pool, the tank and the pressure vessel are communicated with water pipes and the water pipes are attached with pumps and valves. Further, an earthquake sensing unit is disposed near the reactor, so that water is fed from the storage tank to the pressure vessel as usual if the magnitude A of the vibrations due to earthquakes is smaller than a predetermined value B for changing the water source (A < B), while on the other hand, the water from the suppression pool is supplied to the pressure vessel by opening or closing the respective valves provided to the water pipe by way of signal circuits in the case of A >= B. (Furukawa, Y.)