Abstract: A servicing machine for a steam generator is accurately set up in the generator channel head with a pivoted arm mounted for rotation in a plane parallel to the tubesheet. The angular position of the arm, the longitudinal position of a carriage mounted on the arm and the vertical position of a platform on the carriage are remotely controlled to maneuver a probe used in mapping the precise location of the thousands of holes in the tubesheet. Various operations are then performed at each precise hole location by tools carried by the arm mounted carriage to prepare for installation of new tubing. The operation of a pair of remotely controlled pivoted arms, one on each side of the channel head divider plate, is coordinated to automatically position the ends of U-shaped tubes in corresponding holes in the tubesheet on opposite sides of the divider plate and to secure the same in place.

Abstract: A digital computer performs a complete eddy current analysis of the tubes of a steam generator from data input to generation of a final report. The computer extracts signatures generated by various structural features and tube defects from the data, breaks down composite signatures into their component parts and classifies each such signature by applying thereto a cascading set of experience based rules. Signatures classified as structural features are examined closely for the presence of colocated tube defects. A post processor correlates the location of the indication identified from the time based eddy current data with the known physical location of the structural features so that the position of the defects can be presented in terms of distances from fixed structures.

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: An apparatus for expanding a tube against the walls of a circumscribing bore, or a sleeve within a tube to effect an interference joint therebetween, is described herein. The tube expansion apparatus generally comprises a fluid mandrel connected to a hydraulic expansion unit for applying a radially expansive force to the tube or sleeve, and a control circuit electrically connected to the expansion unit and fluidly connected to the mandrel for sensing fluctuations in the pressure of the fluid discharged from the mandrel during the elastic and plastic deformation of the tube or sleeve during the expansion process, computing a final swaging pressure on the basis of these pressure fluctuations, and deactuating the hydraulic expansion unit when this final swaging pressure is attained within the tube or sleeve. The invention is particularly adapted for minimizing or eliminating the clearance between the heat exchange tubes of a nuclear reactor, and the baffle plate bores through which they extend.

Abstract: A servicing machine for a steam generator is accurately set up in the generator channel head with a pivoted arm mounted for rotation in a plane parallel to the tubesheet. The angular position of the arm, the longitudinal position of a carriage mounted on the arm and the vertical position of a platform on the carriage are remotely controlled to maneuver a probe used in mapping the precise location of the thousands of holes in the tubesheet. Various operations are then performed at each precise hole location by tools carried by the arm mounted carriage to prepare for installation of new tubing. The operation of a pair of remotely controlled pivoted arms, one on each side of the channel head divider plate, is coordinated to automatically position the ends of U-shaped tubes in corresponding holes in the tubesheet on opposite sides of the divider plate and to secure the same in place.

Abstract: Control for the operation of a mechanical handling and gauging system for nuclear fuel pellets. The pellets are inspected for diameters, lengths, surface flaws and weights in successive stations. The control includes, a computer for commanding the operation of the system and its electronics and for storing and processing the complex data derived at the required high rate. In measuring the diameter, the computer enables the measurement of a calibration pellet, stores that calibration data and computes and stores diameter-correction factors and their addresses along a pellet. To each diameter measurement a correction factor is applied at the appropriate address.The computer commands verification that all critical parts of the system and control are set for inspection and that each pellet is positioned for inspection. During each cycle of inspection, the measurement operation proceeds normally irrespective of whether or not a pellet is present in each station.

Abstract: The identity of a cantilevered end effector support member and its angular position on the platform member of a carriage movable along an arm which is rotatable in a plane parallel to a steam generator tubesheet, are supplied to a tubesheet servicing machine control system in the form of a discrete pattern of electrical signals which is used to determine the offset required in aligning the end effector with a particular point on the tubesheet. The discrete pattern of electrical signals is generated by at least two sensor elements mounted on one of the members, preferably at different radial distances from the pivot axis of the support member. At least two trigger elements are mounted on the other member in such a pattern as to trigger selected sensor elements to produce the discrete pattern of signals.

Abstract: A steam generator tubesheet is serviced by end effectors mounted on a slew table cantilevered from a carriage slidable along an arm rotatable in a plane parallel to the tubesheet. In servicing a selected hole in the tubesheet, the rotatable arm and the carriage arm are driven to positions which allow the cantilevered slew table to be slewed to a predetermined angle associated with the selected hole. The arm and carriage are then driven to positions which place the end effector under the selected hole taking into account the offset of the slew table. Alternatively, a determination is first made whether the arm and carriage can be positioned within preset limits to place the end effector under the selected hole using the existing slew angle. If so, the existing slewed angle is used but, if not, the table is slewed as mentioned above.

Abstract: A servicing machine for a steam generator is accurately set up in the generator channel head with a pivoted arm mounted for rotation in a plane parallel to the tubesheet. The angular position of the arm, the longitudinal position of a carriage mounted on the arm and the vertical position of a platform on the carriage are remotely controlled to maneuver a probe used in mapping the precise location of the thousands of holes in the tubesheet. Various operations are then performed at each precise hole location by tools carried by the arm mounted carriage to prepare for installation of new tubing. The operation of a pair of remotely controlled pivoted arms, one on each side of the channel head divider plate, is coordinated to automatically position the ends of U-shaped tubes in corresponding holes in the tubesheet on opposite sides of the divider plate and to secure the same in place.

Abstract: Apparatus and method for positioning either one of a pair of automatically controlled remote mechanisms for properly positioning the two opposed ends of a common heat exchanger tube within a tube sheet of a steam generator and having a tool for securing the tube therein. The apparatus includes a pair of microswitches precisely positioned closely adjacent the tool on each of said pair of mechanisms. The first switch is actuated upon initial engagement of the tube end and the tool to indicate which of the opposed tube ends is first engaged, and the second switch is actuated upon proper positioning of the tube end within the tube sheet. The method of operation is such that the tube end nearest the tube sheet of the two opposed tube ends to be engaged is the first tube end to be positioned and secured within the tube sheet.

Abstract: A segmented manipulator arm for a nuclear reactor vessel inspection device is disclosed. The several segments of the arm are linked in a manner which permits independent movement of each segment in a different plane of motion. The transducer array which is utilized to conduct the examination of any appropriate point in the reactor vessel is cooperably linked to the final or most forward segment of the manipulator arm.The first segment of the manipulator arm is appropriately coupled to the main column of the inspection device for independent movement in one of three planes relative to the main column. Additional segments are employed and cooperatively linked to the first segment to yield a total of nine planes of movement for one or more of the segments. In addition, brackets are used to constrain segment movement in parallel or predetermined planes as desired.

Abstract: A positionally variable mounting assembly for transducers used to interrogate a nuclear reactor vessel is disclosed. Means are provided for clamping each transducer of an array about its flange in a central restraining block. The central restraining block is, in turn, pivotally mounted in a yoke.The yoke is movable secured to bars or rails bolted to the transducer plate and, by loosening appropriate bolts, can be moved along the ways or pivoted about one of them. Further, the restraining block can be removed from the yoke and pivotally clamped in a different orientation to upstanding brackets attached to the transducer array plate, or rotated through 90.degree. and then secured again in the yoke.

Abstract: An air pressurized coaxial cabling system is disclosed for carrying electrical cables and air simultaneously to and from underwater junction boxes and electrical elements employed in a nuclear reactor vessel inspection device. An electrical cable is routed to a sealed junction box which is also supplied from a source with pressurized air. The electrical cable and air exit the junction box coaxially and are routed therefrom to an underwater junction box wherein the pressurized air prevents water seepage and allows the use of ordinary electrical connectors and components.