Patent Number: 056339011
Section: claims

1. A permanent pool cavity seal for a containment arrangement including a wall defining a refueling pool floor and a refueling pool cavity extending about a nuclear reactor vessel having an annular flange thereabout, said permanent pool cavity seal comprising: an annular inner seal ring mounted on, and extending about, said nuclear reactor flange;  an annular outer seal ring mounted on, and extending about, said refueling pool floor;  an annular support ring upstanding from said outer seal ring,  an annular seal plate having its outer periphery sealingly connected to said support ring and its inner periphery disposed above and closely adjacent said inner seal ring;  a plurality of support arms disposed beneath said seal plate and extending radially from said refueling pool cavity wall to engage said seal plate at an intermediate transverse location of a bottom side thereof; and  an annular flexible seal operative to accommodate thermally induced axial and radial expansion and contraction of said nuclear reactor vessel with respect to said refueling pool cavity wall, said flexible seal having a cross-section of substantial J-shape and being disposed substantially completely beneath said seal plate, said flexible seal being sealingly weldedly attached about one peripheral edge to said bottom side of said seal plate and about its other peripheral edge to said inner seal ring. 2. The permanent pool cavity seal according to claim 1 in which each of said seal plate, said support ring and said J-shaped flexible seal are formed from a plurality of circumferentially arranged arcuate members. 3. The permanent pool cavity seal according to claim 1 including a plurality of access holes extending through said seal plate at circumferentially spaced locations thereabout, and an access hole cover removably attached to each said access hole. 4. The nuclear containment arrangement of claim 1 wherein each support arm has at least a leveling screw to adjust the level of said seal plate.