Abstract: An end effector for supporting an ultrasonic testing probe on a robot arm having a robot mounting bracket for use in a nuclear reactor pressure vessel. The end effector has a wrist assembly with a rotatable wrist axle. The wrist assembly is coupled to the robot mounting bracket and a probe assembly is coupled to the wrist shaft. The ultrasonic testing probe is floatably disposed within the probe assembly.

Abstract: Method and joint for sealing a bare hole in a nuclear heat exchanger tubesheet. The tubesheet has a plurality of holes formed therethrough, wherein at least one of the holes has been left vacant by a heat transfer tube removed from the hole. Such a hole is defined as a bare hole. One embodiment of the method of the invention comprises disposing a sleeve in the bare hole to protect the tubesheet material from the corrosive attack of the heat exchanger primary coolant and sealingly disposing a sleeve plug in the sleeve in order to seal the sleeve. A leak-tight joint is defined as the sleeve plug is sealingly disposed in the sleeve.

Abstract: A method of removing a metal plug from a conduit includes the steps of simultaneously applying a static pull force and repetitive impulses to the plug. The method is particularly suited to removing a plug from a heat exchanger tube in a nuclear powered steam generator. A tool for practicing the method on such plugs includes a first hydraulic actuator for first moving an expansion member out of engagement with an interior plug wall, a second hydraulic actuator capable of attachment to the plug for applying a static pull force to the plug, and an arrangement connecting an air impact tool to the second hydraulic actuator for applying, simultaneously with the static force, high-frequency impulses to the plug entirely through solid members.

Abstract: A method of removing a metal plug from a conduit includes the steps of simultaneously applying a static pull force and repetitive impulses to the plug. The method is particularly suited to removing a plug from a heat exchanger tube in a nuclear powered steam generator. A tool for practicing the method on such plugs includes a first hydraulic actuator for first moving an expansion member out of engagement with an interior plug wall, a second hydraulic actuator capable of attachment to the plug for applying a static pull force to the plug, and an arrangement connecting an air impact tool to the second hydraulic actuator for applying, simultaneously with the static force, high-frequency impulses to the plug entirely through solid members.

Abstract: Tube plug and method for plugging a heat exchanger tube having an inner wall, which tube plug has a reduced susceptibility to stress corrosion cracking. The tube plug includes a shell having a closed end, an open end and an outer wall, the shell defining a chamber therein in communication with the open end of the shell. Disposed in the chamber is an expander member for expanding the outer wall of the shell into sealing engagement with the inner wall of the tube. A sealing member engages the expander member and is disposed across the open end of the shell for sealing the chamber defined by the shell so that fluid can not enter the chamber to corrosively attack the shell.

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 method for removing metallic plugs from conduits such as the heat exchanger tubes in a nuclear steam generator is disclosed herein. In such tubes, plugs formed from a cylindrical shell of Inconel are radially expanded in sealing engagement with the open end of an Inconel tube mounted in a tubesheet by pulling down a cork-shaped expander element disposed in wedging engagement with the shell. The method of the invention removes such plugs by pushing the expander element from the open end back to the closed end of the shell, and then heating the shell to a temperature which substantially lessens its tensile yield while applying a tensile force along the longitudinal axis of the plug shell sufficient to elongate it. In the method, an electrically conductive push-rod is utilized which simultaneously conducts a substantial current of electricity through the plug shell while pushing against the closed end thereof.

Abstract: An improved system for removing a plug from the open end of a heat exchanger tube in a nuclear steam generator is disclosed herein. It is particularly adapted for removing a plug formed from an elongated, cylindrical shell of Inconel.RTM. having a closed end, an open ends, and an expander element that radially expands the shell when axially drawn from the clossed to the open end of the shell. The system comprises an expander remover for axially pushing the expander element from the open end completely through the closed end of the plug shell, and a TIG torch for creating beads along the longitudinal axis of the plug shell which relax the engagement between the plug shell and the tube after the weld beams harden. Finally, the system includes a plug puller for pulling the loosened plug from the tube.

Abstract: Apparatus for restraining the tip of a tube plug from traveling in a tubular member when the tip is fracturedly separated from the plug during the process of extracting the plug from the tubular member. The tube plug includes a shell defining an open cavity therein inwardly tapered from the tip of the plug. Slidably captured in the cavity is a shell expander which has a first bore therein, for expanding the shell into sealing engagement with the tubular member. The apparatus comprises an expansible restrainer, which is disposed in the first bore, for radially expanding the expander into engagement with the shell by radially expansibly engaging the first bore when axially compressed in the first bore. When the restrainer radially expansibly engages the first bore, the expander expansibly engages the shell for restraining the tip of the shell when the tip is fracturedly separated from the shell so that the tip does not travel in the tube and become lodged in or damage the tube.

Abstract: A device for installing a screw-driven, expandable camlock mechanism in a steam generator host tube to effectuate inspections of or repairs to a steam generator tube or tube sheet is disclosed herein. The device comprises a double gimbal camlock installation assembly capable of vertically aligning the camlock mechanism, which has a deformable sleeve disposed thereon, with a steam generator host tube and capable of installing the camlock mechaism in the steam generator host tube. The installation assembly includes a double gimbal having a pivotal first ring disposed in and connected to a pivotal second ring which is disposed between and connected to the tines of a U-shaped fork. Attached to the first ring is a housing having a rotation device disposed therein, which rotation device engages a threaded rod that is connected to the camlock mechanism.

Abstract: A nozzle dam for providing a fluid-tight seal across a primary fluid nozzle in the plenum of a nuclear steam generating vessel includes two fluid-impermeable seals, each comprising a circular three-section foldable seal plate covered with a flexible diaphragm and circumferentially encompassed by an inflatable seal member disposable in frictional sealing engagement with the inner surface of the nozzle. The center sections of the two seals are interconnected by tubular coupling means. The diaphragms are disposed on the high pressure sides of the seal plates, and the sections of each seal plate are hinged on the high pressure side. The center section of each seal plate carries two pairs of support tabs attached to the low pressure side thereof and respectively projecting from opposite ends thereof in cantilever fashion for supported engagement with a frustoconical portion of the inner surface of the nozzle.

Abstract: An elbow and process for fabrication for use in particulate material conveyancing comprising a curved outer pipe, a curved inner pipe having the same radius of curvature as the outer pipe, concentric with and internal to the outer pipe, comprising an outer layer comprised of a first material and an inner layer comprised of a second material wherein said first material is characterized by high erosion resistance when impinged by particulate material and wherein said second material is characterized by high tensile strength and flexibility, and an inner pipe supporting means for providing support to said inner pipe, disposed between said inner pipe and said outer pipe.