Emergency cooling system for reactors

The present invention relates to a reactor emergency cooling system for flooding the reactor at the onset of an accident. The present invention provides a reactor emergency cooling system for solving technical problems associated with mounting an opening which admits a large quantity of water. The summary of the present invention is as follows: a bulkhead is provided between a reactor room and a tank which introduces water into the reactor room at the onset of an accident; an opening is provided in the bulkhead to connect the reactor room to the tank; a valve-body is provided on the reactor room side to close the opening, the valve body is secured to the bulkhead by a piston which moves through a small tube connected to the tank; a weak spot which is destroyed by a pressure increase in the reactor room at the time of accident is provided to extinguish the said pressure and release the valve. Thus, the present invention allows a large diameter opening to be uncovered by the destruction of the small diameter weak spot, whereby functional reliability and the large diameter opening allow the core to be cooled rapidly, preventing fuel fusion. (Ishida, M.)