Emergency shut-off device, in case of leakage of a steam generator tube

Emergency shut-off device in the case of leakage of a tube of a steam generator comprising a jacket containing a tube bundle, within which a liquid metal circulates in contact with the outer surface of tubes of the bundle and applies the heat of vaporization to feed water circulating in each of the tubes two terminal of which portions pass through the jacket and are connected, one to a water supply device and the other to a collector collecting steam formed in the tube, arranged outside the jacket, said device comprising:

• in the terminal portion of the tube connected to the water supply device, a tubular bush inserted in the path of the feed water between the supply device and a portion of the tube entering the jacket, comprising inlet and outlet apertures for the water and containing a valve connected to the bush by a breakable part, in the case of puncture of the breakable part manifested by increased flow rate of water through the bush, said valve being driven into a position of closing the feed water outlet, of the bush,
• and in the terminal portion of the tube connected to the steam collector, a second tubular bush inserted in the path of the steam between the jacket of the steam generator and the steam collector, comprising inlet and outlet apertures for the steam and containing a valve free and movable in the bore of the bush, between an open position where the valve is placed between two sets of apertures, for passage of steam communicating with the steam collector and a closed position of the inlet aperture of the steam into the bush, by movement under the effect of a pressure difference appearing between the inner space of the steam collector and the inside of the bush, in the case of a leakage in the tube.