Abstract: Downcommer coupling apparatus and methods for replacing a core spray line downcommer pipe coupled to a shroud T-box are described. In one embodiment, the coupling apparatus includes a wedge flange, a wedge, a wedge housing, a pipe seal, a cylindrical pipe, an elbow, a lower flange, and a shroud seal. The downcommer pipe is connected to the coupling apparatus by extending the pipe through the wedge flange, the wedge, and the wedge housing. The wedge has a plurality of flexible thinned segments that extend into the wedge housing to secure the downcommer pipe to the wedge housing. Wedge flange bolts extend through the wedge flange, the wedge, and the wedge housing to rigidly secure the downcommer pipe to the coupling apparatus. Dowel bolts extend through the wedge housing and the downcommer pipe to provide vertical and torsional load transfer from the downcommer pipe to the coupling apparatus. The lower flange is configured to receive the shroud T-box.

Abstract: A fuel handling system for nuclear reactor plants comprising an improved underwater grapple means for transferring fuel units while submerged within a water containing reactor vessel. Wherein a novel structure is provided which allows for direct viewing downward for operating the grapple hooks.

Abstract: A refueling mast for a reactor complex includes four generally cylindrical tubes. Each inner tube has vertical grooved tracks formed therein. Each outer tube has a guide roller mounted thereon with grooves which mate with track grooves of a respective track on the adjacent inner tube. Track grooves are cold formed moving a roller die tool up and down each inner tube, while increasing pressure on the incorporated die rollers. This process flattens the inner tube where the tracks are being formed. The grooved tracks and the associated flattening provide the torsional rigidity required on the mast tubes for precise positioning and orientation of fuel elements.