Sealing device for a component vertically disposed within the primary vessel of a nuclear reactor

Claim 1

A sealing device for a component vertically disposed within a primary vessel of a nuclear reactor and having an upper cylindrical part forming a flange whose diameter is greater than the diameter of the component, said component resting by said flange on a horizontal closing plate of the primary vessel around a hole for the component to pass through the plate and held in place by an annular anti-flyoff flange, one part of which rests on the upper surface of the flange of the component and another part of which has devices for fixing and clamping the flange of the component on the plate, said sealing device comprising: (1) a seal-bearing ring disposed around the flange of the component and resting on the plate of the reactor below the anti-flyoff flange; (2) a first set of annular seals disposed on said sealing ring ensuring sealing between the inner side surface of the seal-bearing ring and the outer side surface of the flange of the component at the part thereof located above the plate; (3) a second set of annular seals ensuring sealing between the base surface of the ring and the plate; (4) a clamping ring disposed above the seal-bearing ring includes an inner rim coming to bear at the interior of a seal-bearing seating disposed between the seal-bearing ring and the flane of the component, on at least one of the seals for applying pressure on this seal allowing its radial dilatation; (5) a means for applying a backing force vertically downward on the clamping ring and thus on the seal-bearing ring, fixed on the anti-flyoff flange at the part thereof located above the seal-bearing ring; and (6) a means for injecting an isolating gas between the flange of the component and the plate to ensure isolation of the interior of the vessel independently of the seals of the seal-bearing ring, said sealing device being entirely removalble for fitting and removal of the component.