Westinghouse Electric Corporation

Westinghouse Electric Company LLC

Joseph J Hahn

Michael D Heibel

Eric M Weisel

Kenneth V Margotta

David A Howell

Daniel Walus

Thomas J Schildkamp

Arthur W Kramer

John D Nee

A telescoping guide for extraction and reinsertion support handling of in-core instrument thimble assemblies in the area above the upper support plate in the upper internals of a pressurized water reactor. The telescoping guides extend between the upper ends of the upper internals support columns and an axially movable instrumentation grid assembly which is operable to simultaneously raise the telescoping guides and extract the in-core instrument thimble assemblies from the reactor fuel assemblies.

Method of accessing a core of a nuclear reactor

Upper internals arrangement for a pressurized water reactor

An apparatus for tensioning a hold down beam of a nuclear reactor jet pump inlet mixer is configured to be inserted in a confined annulus between a core shroud and a reactor vessel of a nuclear reactor. The hold down beam includes a beam body, a pair of opposed beam tabs and a pair of opposed beam trunnions extending outwardly from the beam body, and a threaded beam bolt received within a threaded channel extending through the beam body. The tensioning apparatus includes a housing having a lower base plate and an upper support plate positionable over the body of the hold down beam, rotatable trunnion engaging members for engaging the beam trunnions, reciprocating members coupled to the upper support plate and lower base plate for engaging the inlet mixer adjacent to the beam trunnions, and an actuator mounted between the upper support plate and lower base plate and extending through the lower base plate for selectively actuating the trunnion engaging members. Tensioning of the hold down beam is accomplished by positioning the hold down beam on an upper surface of the inlet mixer with each beam tab under an inlet riser bracket of the jet pump. The tensioning apparatus is then placed over the hold down beam, followed by rotating the trunnion engaging members into engagement with the trunnions, extending the reciprocating members to engage the inlet mixer and to force the beam tabs against the inlet riser brackets to thereby extend an opening between the hold down beam and the upper surface of the inlet mixer, rotating the beam bolt to extend the bolt into contact with the upper surface of the inlet mixer, and removing the tensioning apparatus from engagement with the tensioned hold down beam.

Jet pump beam tensioner

A replacement station includes an old split-pin-assembly (OSPA) removal stand and a new split-pin-assembly (NSPA) installation stand. The removal stand includes a saw and a drill. With the guide tube to which the OSPA is secured in the removal stand, the saw severs each OSPA below the flange which engages the base of the lower counterbore in the lower guide tube (LGT) separating the OSPA into a pin fragment and a second fragment including the flange and the remainder of the split-pin with the nut threaded into it. The second fragment remains secured to the LGT after the sawing operation. The guide tube is rotated so that the drill is coaxial with the shank of the pin of the second fragment. The second fragment is separated into a third fragment including the flange and a fourth fragment including the remainder of the pin and the nut both removable from the LGT. The installation stand has NSPA blades in which the new split pins are mounted. The LGT sans the OSPA's is positioned on the installation stand. The new nuts are mounted and torqued into the split pins with a long-handled runner and a torque tool permitting a measured torque to be applied to the new nut. Then the cups on the nuts are crimped by a long-handled crimping assembly which has fixed crimping jaws that produce the crimping by moving parallel to the wall of the cup.

Manual replacement of old split-pin assemblies by new split-pin

The guide tube is mounted on a fixture with the split-pins of each old split-pin assembly straddling a knife edge. The nut of each old split-pin assembly is engaged by a socket of a wrench and a high torque is impressed on the nut. The torque is of sufficient magnitude to shear the weld by which the nut is joined to the split-pin and/or to shear the pin particularly at the edge of a keyway where a button to which the weld is joined is engaged. The knife edge which each split-pin straddles prevents the pin from turning under the torque applied to the nut. After the weld or the pin is sheared the nut or the nut and the pin fragment joined to it is unthreaded from the pin or pin fragment and the separated parts are disposed of. Typically the nut of an old split-pin assembly has diametrically cut slots in its wall. The socket of the wrench is provided with projections which engage the nut in the slots. The torque is applied to the nut through these projections.

Removal of old split-pin assemblies from guide tubes and replacement by

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.

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Pittsburgh, PA, United States of America

Joseph J Hahn