Patent Number: 040640035
Section: claims

1. In the intermediate heat transport system of a sodium-cooled nuclear reactor incorporating an intermediate sodium-to-sodium heat exchanger, sodium-to-water heat exchangers, a pump and a drain line, the improvement comprising a device for rapidly draining the heat transport system including a body having a cylindrical side wall, a conical bottom and a cover, an outlet line leading to a dump tank penetrating the side wall, said drain line penetrating said body vertically through the apex of the conical bottom and terminating in an enlarged portion within the interior of the body, a diaphragm welded to the end of the drain line and held thereagainst by a clamp ring threaded onto the enlarged portion of the drain line and having a circular groove therein of slightly less diameter than the drain line, a punch having a circular shearing edge thereon of the same diameter as said groove and having sharp projections thereon resting in said groove, said punch having an axial recess in the bottom thereof, a stem connector disposed in said recess fixedly connected to said diaphragm and attached to the punch by a lost motion connection and means for actuating said punch to cut a circular opening in the diaphragm and for withdrawing the punch thereby removing the sheared-out portion of the diaphragm from the opening cut in the diaphragm. 2. In the intermediate heat transport system for a sodium-cooled nuclear reactor including an intermediate sodium-to-sodium heat exchanger, sodium-to-water heat exchangers, a pump and a drain line, the improvement comprising a device for rapidly draining sodium from the heat transport system including a body having a cylindrical side wall, a conical bottom and a cover, an outlet line leading to a dump tank penetrating the side wall, said drain line penetrating the body vertically through the apex of the conical body and terminating in an enlarged portion within the interior of the body, a rupturable member seated on the end of the drain line consisting of a solid head including a portion approximately the same diameter as the drain line, an elongated transition portion of lesser diameter, an actuating stem, and a rim extending circumferentially around the solid head, said rim being welded to the end of the drain line and held thereagainst by a clamp ring, the inner circumference of which constitutes a shearing edge, said rim having a circular groove therein of slightly less diameter than the drain line, the shearing edge of the clamp ring having three sharp projections thereon 120.degree. apart adapted to rest in the groove, the bottom of the rupturable member being convex and extending into the drain line, and means for pulling the rupturable member upwardly against the shearing edge of the clamp ring to clear the throat of the drain line for outflow of sodium therethrough. 3. A device for rapidly draining sodium from a piping system having a drain line therein comprising a body including a cylindrical side wall, a conical bottom and a cover, an outlet line leading to a dump tank penetrating the side wall, said drain line penetrating said body vertically through the apex of the conical bottom and terminating within the interior of the body, a rupturable member comprising a diaphragm extending across the end of the drain line and welded thereto, and means for shearing an opening in said rupturable member approximately the size of the throat of the drain line and for positively removing the sheared-out portion of the rupturable member from the opening cut therein comprising a punch having a circular shearing edge thereon approximately the size of the drain line, a stem fixedly attached to the diaphragm and attached to the punch by a lost motion connection and means for actuating the punch to cut a circular opening in the diaphragm and for retracting the punch whereby the sheared-out portion of the diaphragm is removed from the opening in the metal diaphragm. 4. A device for rapidly draining sodium from a piping system having a drain line therein comprising a body including a cylindrical side wall, a conical bottom and a cover, an outlet line leading to a dump tank penetrating the side wall, said drain line penetrating said body vertically through the apex of the conical bottom and terminating within the interior of the body, a rupturable member extending across the end of the drain line, said rupturable member including a solid head having a portion approximately the same diameter as the throat of the drain line having a rim extending peripherally therearound seated on the open end of the drain line, the rim being welded to the end of the drain line and clamped thereagainst by a clamp ring having an interior shearing edge, the bottom of the solid closure head being convex and extending into the drain line and means for pulling the rupturable member upwardly against the shearing edge of the clamp ring to clear the throat of the drain line for outflow of sodium therethrough.