Abstract: A method for installing a header cap on a water header both positioned on a stator coil. The method includes the steps of creating a generally smooth surface on the water header for providing a mating surface on the water header. A seal is interposed between the mating surface of the water header and the header cap for providing a material used to provide a sealed boundary between the cap and mating surface. The header cap and the mating surface of the water header are placed in abutting relationship with the seal for forming a layered, contiguous connection. A pressure device is attached in operative association with the header cap for operatively applying a pressure to the header cap. A spring which is received by the pressure device is compressed for applying a constant and unidirectional pressure to the pressure device which, in turn, transmits the constant and unidirectional pressure to the header cap.

Abstract: An improved apparatus for impact testing stator wedge tightness in an electrical generator includes a base assembly that has a vibration sensor mounted thereon and is adapted to temporarily attached to a stator core lamination in an electrical generator, an impact assembly for creating an impact against the stator core lamination; and a mounting system for mounting the base assembly to the impact assembly. The mounting system includes an isolating system for vibrationally isolating the base assembly from the impact assembly during use, so that the vibration sensor will receive vibrations from the stator core lamination, and not said impact assembly. The method of use is also disclosed.

Abstract: A header cap and the mating surface of a water header are placed in abutting relationship with a seal for forming a layered, contiguous connection. A pressure device is attached in operative association with the header cap for operatively applying a pressure to the header cap. A spring which is received by the pressure device is compressed for applying a constant and unidirectional pressure to the pressure device which, in turn, transmits the constant and unidirectional pressure to the header cap. The connection is finally heated for brazing the header cap and water header together and for forming a seal.

Abstract: A system and method for testing an electrical generator of the type having a rotor (14) and a stator (12) includes or utilizes a movable carriage (22) having testing equipment which is sized to fit between the rotor (14) and stator (12) and is positionable over a selected stator (12) slot so as to be able to axially traverse the selected stator (12) slot, at least one sensor for sensing whether the movable carriage (22) is centered in an optimum position with respect to the selected stator (12) slot; and structure for centering the movable carriage (22) with respect to the optimum position if the sensor indicates the movable carriage (22) is not so centered, whereby accuracy of any testing by the testing equipment is optimized.

Abstract: A stator testing device for a dynamoelectric machine formed from a plurality of laminations defining a plurality of substantially parallel stator teeth each extending over a preselected length of the stator. The stator testing device includes a housing having a bottom face adapted to be disposed adjacent the stator teeth and a face cover extending outwardly from said bottom face. A chattock coil for detecting stator axial currents is disposed within said housing. The chattock coil has a pair of end portions with bottom surfaces each extending to the bottom face of said housing. A pair of brackets are removably attached to the face cover of said housing, and a magnet is removably attached to each bracket. The magnets are located on the brackets so that the bottom surfaces of the pair of magnets are positioned adjacent to selected corners of adjacent stator teeth and remain in positional relationship to the selected corners as the housing is moved over a preselected length of said stator.

Abstract: Method and apparatus for performing remote impact testing for generator stator wedges and ripple springs. An improved low profile carriage is utilized for correlating wedge displacement data with the force required to displace the wedge. A calibrated test stand, in which exemplary wedges are placed under a known loading via a hydraulic load cell, provides means for generating calibration curve sets. From the graphed forcedisplacement curves generated from wedges placed under a known loading, force and displacement data generated during actual stator testing can be analyzed to measure the tightness or looseness of stator wedges, coils and ripple springs. In the preferred embodiment of the low profile carriage of the present invention, a capacitive sensor is used to directly measure the displacement or vibration of stator wedges as a result of being struck by an impact hammer with a known force.

Abstract: The internal structure of an apparatus with internal passages such as a steam turbine is inspected without dismantling by inserting a compact robotic carriage device into a steam pipe and remotely controlling the carriage to carry a video probe to a restricted passage such as a nozzle block and to extend the probe relative to the carriage to inspect features within the restricted passage such as turbine blades. Separate motor drives for each side of the carriage include drive wheels of slightly greater diameter than a timing belt which serves as a tractor tread to drive the carriage over obstacles not bridged by the wheels. A large permanent magnet between the wheels is retained within the carriage by front and rear axles and secures the carriage to the pipe walls in all orientations. The fixed size of the device is minimized by housing a motor for extending the probe relative to the carriage in a module cantilevered from the carriage by a preloaded compression spring.

Abstract: An inspection system inspects the interior of the stator of an electric generator for the existence of several problems. The inspection apparatus is mounted on a carriage that travels along the slots defined by the stator. An indexer is mounted to the rotor of the generator and can travel around the circumference of the rotor to deliver the carriage to the desired slot. An indexer plate is mounted to the indexer and can be registered with the desired slot to insure that the carriage can enter the slot from the indexer. An associated motor controller disables the motor if an electrical fault is disclosed.

Abstract: Apparatus for measuring ripple spring deflection to determine stator wedge tightness in an electric generator without removing the rotor includes a low profile carriage insertable in the gap between the rotor and stator. A probe is aligned longitudinally and laterally with holes in the stator wedges with the aid of a miniature television camera on the carriage and extended through an aligned hole to contact the ripple spring. The probe is connected through a cable to the core of a linear variable differential transformer mounted on the carriage which provides an accurate measurement of probe extension. The probe is extended and retracted by an arrangement of cables and springs providing a lost motion coupling which accommodates for seating of the probe against a ripple spring at less than full extension.

Abstract: An inspection system inspects the interior of the stator of an electric generator for the existence of several problems. The inspection apparatus is mounted on a carriage that travels along the slots defined by the stator. An indexer is mounted to the rotor of the generator and can travel around the circumference of the rotor to deliver the carriage to the desired slot. An indexer plate is mounted to the indexer and can be registered with the desired slot to insure that the carriage can enter the slot from the indexer. An associated motor controller disables the motor if an electrical fault is disclosed.

Abstract: A low profile remotely controlled carriage which is inserted between the rotor and stator of an electric generator carries an impactor which can be preloaded to strike the stator wedges in all orientations around the stator with a selected high impact force which causes the stator wedge to vibrate. A detector seismically isolated from the impactor measures the deflections in the vibrating stator wedge. Preferably, the detector includes an eddy current coil positioned to measure the distance to a wedge follower which vibrates with the wedge. In one embodiment, the wedge follower is a vacuum cup secured to the wedge. In another, the eddy current coil measures the distance to a foot spring biased against the vibrating wedge. Preferably, the detector is seismically isolated by mounting it on a separate carriage disposed in an aperture in the low profile carriage.

Abstract: An inspection system inspects the interior of the stator of an electric generator for the existence of several problems. The inspection apparatus is mounted on a carriage that travels along the slots defined by the stator. An indexer is mounted to the rotor of the generator and can travel around the circumference of the rotor to deliver the carriage to the desired slot. An indexer plate is mounted to the indexer and can be registered with the desired slot to insure that the carriage can enter the slot from the indexer. An associated motor controller disables the motor if an electrical fault is disclosed.

Abstract: A method for reparing bent mixing vanes in a nuclear reactor fuel assembly is described, including the steps of introducing an apparatus having movable blades below a grid with a mixing vane; opening the blades; withdrawing the apparatus so that a blade abuts and straightens the bent mixing vane; closing the blades; and fully extracting the apparatus from the fuel cell.

Abstract: An improved system for repairing and reconstituting a fuel rod assembly in the spent fuel pool of a nuclear power plant is disclosed herein. The improved system includes a height-adjustable elevator and carriage assembly for lifting and inverting a pair a fuel assemblies with their bottom ends adjacent one another, a length-adjustable rod handling tool having a gripper for gripping, lifting, lowering and ungripping a fuel rod, and a dual-axis tool positioner mountable over the bottom ends of the inverted, adjacent fuel assemblies. The tool positioner includes a funnel-shaped tool guide that is movable over the bottom ends of the fuel assemblies for receiving and positioning the gripper of the rod handling tool. The improved system may be adjusted for use in spent fuel pools of substantially different dimensions and water levels without the need for additional parts, and may be operated by only two technicians.

Abstract: Apparatus for performing inspections in difficult to access locations. The device includes remotely controlled transport apparatus upon which is mounted a camera and illumination lamps. The transport apparatus is maneuvered, through the remote control system, to the location where a visual inspection is to be performed. The associated camera then transmits a picture of the area in the vicinity of the camera back to a remote television monitor where it may be viewed.

Abstract: A moveable magnetic carriage on which is mounted inspection equipment for inspecting the stator of an electrical generator without removal of the generator rotor. An associated positioning device positions the carriage on the generator.

Abstract: An inspection device which permits inspection of the interior of a turbine for metal integrity. The inspection device is mounted on a sensor assembly that engages a turbine blade and rests on the turbine disc. Metal integrity sensors are mounted on the sensor assembly and inspect various areas of turbine blades and turbine rotor steeples. The associated coil assembly provides a coil of wire and magnetic shielding which improves the sensitivity of the metal integrity sensors. The associated method provides for proper positioning of the apparatus and inspecting the turbine for metal integrity.

Abstract: An apparatus for repairing bent mixing vanes in a nuclear reactor fuel assembly is provided, including a unique tool and a related tool handling device. The tool is an elongated tube with a housing containing two sets of opposing, high-strength blades movable between closed and opened positions. The tool is inserted into a fuel cell detected as having a grid with a bent mixing vane to a location below the damaged grid with the blades in the closed position. The blades are then remotely opened and the tool is withdrawn. As the tool is withdrawn, one blade abuts the bent mixing vane and bends it back close to its original position. The blades are then closed and the tool is fully extracted from the fuel cell. Once the tool is fully extracted, the fuel rod can again be reliably inserted into the repaired fuel cell.

Abstract: The guide tube is disconnected and removed from the upper internals of the reactor to a work station in a pool of borated water. The work station includes a clamp-and-index tool, a metal-disintegration-machining (MDM) tool, pick-and-put tool, a brush tool, a nut hopper, a pin-insertion/torque tool, and a crimping tool. These tools are hydraulically operable. The clamp-and-index tool positions and, by repeated centering maintains the guide tube in precise position for removal and replacement of its split pins, the MDM burns through an old pin-and-nut assembly severing it into readily removeable fragments. This pin fragment is removed by an expeller on the clamp-and-index tool. This pick-and-put tool removes the burned nut fragment and replaces it with the new nut. The pin-insertion/torque tool inserts the new pin and torques the new nut onto the new pin. The crimping tool crimps a locking cap secured to the nut onto the pin. The tools are controlled from a command center external to the pool.

Abstract: A system for removing debris from a nuclear fuel assembly includes a work platform disposable on the fuel assembly racks in a spent fuel pol. A support stand is mounted on the work platform and has a sliding support plate movable between a support position engageable with the lower end of the fuel assembly, and a retracted position permitting lowering of the fuel assembly through an opening in the work platform into one of the racks. A tool manipulation assembly is disposable on the platform and includes a rotatable turret-type tool mount carrying four different cleaning tools, including a pick, a brush, a water lance and a water-actuated tweezers. The tool manipulating assembly includes drive means for effecting X-Y-Z movement of the tool mount for working on the fuel assembly. Each tool is resiliently mounted in a tool holder which yields if the tool engages the fuel assembly in a given direction with a predetermined force, generating an alarm signal to prevent damage to the tool assembly.