Narrow annulus permanent canal seal plate
A permanent seal for a refueling canal of a nuclear power plant. The seal includes a support structure and a membrane. The support structure includes a first annular plate with ribs connected to and extending from a lower surface of the annular plate. The support structure is positioned atop the shield wall on the refueling canal floor, encircling and positioned near the annulus. The membrane includes a first end that is connected to the seal ledge and a second end that is connected to the refueling canal floor. The membrane has a stepped profile, with side walls extending substantially perpendicularly from a central annular plate to form a pocket configured to fit over the support structure. Loads imparted to the membrane are transferred through the support structure annular plate and ribs to the refueling canal floor.
1. A permanent seal for providing a liquid barrier over an annular space between a nuclear reactor vessel seal ledge and a surrounding annular ledge, comprising:
a support structure including an annular plate having a first surface and a second surface and a plurality of ribs coupled to said support structure annular plate second surface at first ends thereof and to the annular ledge at second ends thereof; and
a membrane having a first end coupled to the vessel seal ledge, a second end coupled to the annular ledge, and an annular plate extending between said membrane first and second ends, said membrane annular plate having a first surface and a second surface;
wherein said support structure and said membrane are positioned such that said membrane annular plate second surface is adjacent said support structure annular plate first surface.
2. The permanent seal of claim 1 , wherein:
said support structure annular plate has a first radial length;
said membrane annular plate has a second radial length; and
said second radial length is greater than said first radial length such that said membrane annular plate second surface completely overlies said support structure annular plate first surface and extends beyond radial ends thereof.
3. The permanent seal of claim 1 , wherein at least a portion of said ribs are positioned substantially symmetrically about said support structure.
4. The permanent seal of claim 3 , wherein said ribs within said portion are positioned at substantially regular intervals about said structure, said intervals being from 5° to 15°.
5. The permanent seal of claim 1 , wherein said support structure ribs have longitudinal axes and said support structure ribs are coupled to said support structure annular plate such that said longitudinal axes are arranged substantially radially with respect to said support structure annular plate.
6. The permanent seal of claim 1 , wherein said membrane second end is coupled to the annular ledge along a first circumference that completely encircles said support structure.
7. The permanent seal of claim 1 , wherein said support structure further includes a second plurality of ribs coupled to said annular plate second surface at first ends thereof and positioned adjacent to the annular ledge at second ends thereof without being coupled to the annular ledge.
8. The permanent seal of claim 1 , wherein:
said membrane annular plate defines a plurality of resealable port openings therethrough;
said support structure annular plate defines a plurality of holes therethrough; and
said port openings and said holes being substantially aligned.