Patent Number: 
Section: claims

1. A system for reducing tritium migration comprising:a spent nuclear fuel pool comprising a body of tritiated water having an exposed surface; anda cover comprising:a sheet having an inner surface opposite an outer surface and a side surface extending between the inner and outer surface, the inner surface facing the exposed surface of the body of tritiated water, the sheet-further comprising a vapor impermeable membrane that includes:a first vapor impermeable layer;a radiation shielding layer; anda thermal insulating layer; anda frame comprising a base, whereby the first vapor impermeable membrane wraps around at least a portion of the base;wherein the first vapor impermeable membrane layer extends continuously from the inner surface of the sheet across the side surface of the sheet to outer surface of the sheet. 2. The system of claim 1, wherein the sheet a continuous sheet. 3. The system of claim 1, wherein the vapor impermeable membrane further includes a second vapor impermeable membrane, wherein the radiation shield layer and the thermal insulating layer are sandwiched between the first and second vapor impermeable layers. 4. A system for reducing tritium migration comprising:a spent nuclear fuel pool comprising a body of tritiated water having an exposed surface;a cover comprising:a sheet having an inner surface opposite an outer surface and a side surface extending between the inner and outer surface, the inner surface facing the exposed surface of the body of tritiated water, the sheet-further comprising a vapor impermeable membrane that includes a first vapor impermeable layer;a radiation shielding layer; anda thermal insulating layer;wherein the first vapor impermeable membrane layer extends continuously from the inner surface of the sheet across the side surface of the sheet to outer surface of the sheet;a frame comprising a base, whereby the first vapor impermeable membrane wraps around at least a portion of the base; anda gasket that forms a closed perimeter about the spent nuclear fuel pool, and the first vapor impermeable layer is located between the gasket and the base. 5. A system for reducing tritium migration comprising:a spent nuclear fuel pool comprising a body of tritiated water having an exposed surface;a cover comprising:a sheet having an inner surface opposite an outer surface and a side surface extending between the inner and outer surface, the inner surface facing the exposed surface of the body of tritiated water, the sheet-further comprising a vapor impermeable membrane that includesa first vapor impermeable layer;a radiation shielding layer; anda thermal insulating layer;wherein the first vapor impermeable membrane layer extends continuously from the inner surface of the sheet across the side surface of the sheet to outer surface of the sheet;a frame comprising a base, whereby the first vapor impermeable membrane wraps around at least a portion of the base;wherein the vapor impermeable membrane further includes a second vapor impermeable layer, wherein the radiation shield layer and the thermal insulating layer are sandwiched between the first and second vapor impermeable layers, and the second vapor impermeable membrane contacts at least a portion of the base of the frame.