Abstract: A bottom open sled system for exchanging control rod drives in a nuclear reactor is described. The system, in one form, includes a tower forming a control rod drive receiving area, at least one acme screw extends substantially the length of the tower and is mounted within the receiving area. An elevator is coupled to the acme screw and is movable relative to the acme screw. The elevator is configured to engage a portion of the control rod drive and to substantially support the control rod drive. The system further includes a trunnion cart engaged to the tower so that the tower is rotatable relative thereto.

Abstract: An apparatus for cleaning of a reactor pressure vessel head closure stud. The surface of the stud is cleaned by power vacuum brushing. The stud is hung vertically in a cabinet which supports a vertically elevatable spinner housing. The stud is cleaned in a single process using a rotating wire brush system which is rotatably mounted in the spinner housing and has a central opening for passage of the stud. A plurality of wire bushes are arranged in a circular array surrounding the stud. While the wire brushes are rotating in contact with the stud external surface, the spinner housing and wire brush assembly are displaced vertically by an elevator so that the rotating brushes travel along the full length of the stud. The rotating brushes remove accumulated material on the stud surface. The resulting contaminated debris is contained in a volume enclosed by a brush canister and a bellows. The bellows expands or contracts as the elevator travels.

Abstract: A nut runner tool is used to engage, turn, capture and lift the RPV head closure nuts from the RPV studs. The tool is also used to capture, lift and transport the nuts from the storage tray to the RPV head closure studs. The nut runner system enables a single operator to remove and install head closure nuts quickly and safely. The nut runner is powered by a remotely operated air driver. The reaction torque is transferred safely through the tool into the top of the closure stud. The air driver unthreads the nut, then a nut holding device is actuated, and the nut and tool are lifted from the top of the stud with a hoist attached to a trolley. The nut and tool are moved radially from the stud location to the storage position in the nut rack. When positioned over the storage location, the lowering of the nut into the rack is performed by the hoist, eliminating the need to manhandle the nuts into and out of the storage rack.