Abstract: A plugging device, such as a tube plug, and method for plugging a tubular member, such as a nuclear steam generator tube, comprises a locking cup for securing together the plurality of members comprising the tube plug. The plugging device may comprise a first member, such as a shell of a tube plug, a second member, such as bolt means of a tube plug and an annular locking cup disposed in a bore of the first member and having outside diameter threads. The outside diameter threads of the locking cup have a deformed portion with a wave-like pattern for providing resistance during threading and unthreading of the locking cup into and out of the first member. At least one of the second member and the locking cup has at least one recess for receiving a deformable portion of the other of the second member and the locking cup for securing the first member, the second member, and the locking cup together.

Abstract: A pin-insertion/torque tool has a blade in a loading tube, which blade is vertically moveable axially by a hydraulic cylinder and can rotate for proper pin alignment. The tool includes a laterally open wrench having splines capable of engaging splines on the new nut. The new split pin is mounted on the blade by a long tube in the end of which the pin is threaded. Once on the blade the tube is unthreaded from the pin. The pin-insertion/torque tool is then moved to a position precisely set by a stop centered along the axis of the hole joining the counterbores in the LGT. The blade is raised thus inserting the new split pin through the lower counterbore and through hole and into the new nut which was deposited in the upper counterbore of the LGT by a pick-and-put tool. The wrench is then repeatedly engaged with the splines in the nut laterally of the "mousehole" into which the nut extends and is rotated, by a hydraulic cylinder and a rack and pinion, over a limited angle.

Abstract: A pick-and-put tool, new-nut hopper and pin-insertion/torque tool for completing the installation of the new split-pin assembly in a lower guide tube under water after the old split-pin assembly has been severed into fragments. One fragment, located in the upper counterbore of the LGT, includes a portion of the old nut and the portion of the pin on which it is threaded. The pick-and-put tool includes a clamp and hydraulic cylinders for moving the clamp between a home position and an advanced position and for pivoting the clamp in each position. There is also a cylinder for raising or lowering the clamp in each position. The pick-and-put tool has stops which stop the movement of the clamp precisely in the home position or the advanced position and in their pivoted positions. The pick-and-put tool is mounted in the pool such that it can properly align with both the LGT and hopper. The clamp is first moved from the home position to the advanced position.

Abstract: A cutting tool is manually operable from above the water level in a reactor cavity pool to sever locking cups from the socket-head cap screws which hold guide tubes to the upper support plate of the upper internals of the reactor. The tool includes a support assembly adapted to be mounted on the guide tube. A motor frame is mounted on the support assembly for limited vertical movement with respect thereto and carries a hydraulic motor coupled by a vertically depending shaft to a tubular cutter for rotating same about its axis. The shaft extends through an opening in the support assembly and through a locating tube which surrounds the cutter and is receivable over the associated locking cup when the support assembly is mounted in place. A drive screw is coupled to the frame and to a shaft which extends up to the coupling tube to a manually operable crank to effect vertical movement of the frame and the cutting means coaxially with respect to the locking cup to sever its top wall from its side wall.

Abstract: The old split-pin assemblies of the lower guide tube of a nuclear reactor are replaced by new split-pin assemblies in a robotic work station under a pool of water. The work station includes a plurality of robotic tools which are remotely actuable from a robotic command center outside of the pool to position the guide tube precisely for a replacement operation, to fragment the old split-pin assemblies and dispose of the fragments under water, and to install a new split-pin assembly. The lower-guide-tube positioning means has a hydraulic cylinder, also remotely actuable externally to the pool, for rotating the guide tube so that it may be oriented properly to be processed by different tools in succession and also so that both split-pin assemblies in each guide tube may be replaced by the same set of tools.