Abstract: Both a closed system and method for cooling a submersible propulsor unit for a water vehicle is provided for a unit of the type that includes a submersible motor having a shaft connected to a propeller, and a housing containing the motor. The system comprises a motor cooling assembly that includes a shaft seal for conducting the shaft outside of the housing while preventing ambient water from entering the housing, a liquid contained within the housing for cooling the motor, a heat exchanger for thermally connecting but mechanically isolating the liquid from the ambient water, an impeller (102) for recirculating the liquid through both the motor and the heat exchanger, and a bellows (128) for equilibrating any pressure differentials between the cooling liquid and the ambient water. A filter assembly (129) mounted within the bellows relieves any pressure differential that is not relieved by the bellows when ambient water pressure is greater than that of the cooling liquid in the housing.

Abstract: A deep beam head for a nuclear reactor and an improved reactor containing such a head where the upper horizontal support plate of a calandria in the reactor forms a sealing plate for the reactor vessel. The sealing plate has a ring member about the upper periphery thereof that is secured to the top of the pressure vessel cylindrical wall and reinforcing members extend across the sealing plate and are welded to the ring, while transverse cross-members extend across the sealing plate and are welded to the reinforcing members. The calandria may be removed from the reactor while attached to the ring member to provide ready access to the reactor internals.

Abstract: Disclosed is a garden canopy having a frame for supporting a plurality of parallel spaced elongate panels. The panels are positioned on the frame to provide a light and moisture aperture therebetween. The panels are formed from uniform wall thickness material and each have a flat bottom with curved or arcuate edges.