Device for the leak-tight assembly of heat exchangers in nuclear reactors

Claim 1

In a nuclear reactor with rapid neutrons cooled by circulation of a liquid metal, comprising a principal tank with a vertical axis, and a primary tank being coaxial with respect to the principal tank and containing the core of the reactor, said tanks being filled with the liquid metal topped by a cover of a neutral gas, the primary tank comprising a transverse notch equipped with openings for communication between the two tanks, receiving bodies of heat exchangers having a vertical axis, being distributed around the core and dipping into the liquid metal, each exchanger comprising at the upper part thereof contained in the primary tank above the tranSverse notch inlet orifices for the liquid metal, and at the lower part thereof in the principal tank below the transverse notch, outlet orifices for said metal, and pumps for circulating the liquid metal discharging from each exchanger and feeding it back into a collector disposed under the core, a regulable sealing device mounted between the primary tank and the principal tank in each of the openings of the transverse notch, said device comprising a cylindrical annular collar surrounding the body of the exchanger traversing each opening, being integral with the notch and open at the upper part thereof in the primary tank, an annular bell having a height substantially equal to that of the collar and being integral with the body of the exchanger, being open at the lower end thereof and outwardly capping and covering said collar and forming an annular space around the entire heat exchanger, and a system for injecting a neutral gas under pressure into said annular space comprised between the bell and the collar for preventing the direct passage of the liquid metal from the primary tank into the principal tank through said annular space.