Abstract: A bladder mandrel utilizing a sleeve of Pellethane.RTM. to effect tube expansions is disclosed herein. The sleeve which forms the bladder of the mandrel terminates in sealing beads which include fluid-capturing recesses. When the beads of the sleeve are secured within grooves provided in the mandrel body, pressurized fluid flowing through the fluid port of the mandrel enters the fluid-capturing recesses of the beads and sealingly engages these beads within their respective grooves. The sleeve consequently fills with the pressurized fluid, and effects the desired tube expansion. The walls of the sleeve are thinnest at their center portion, and become progressively thicker toward the sealing beads. The use of a Pellethane.RTM. sleeve having a centrally disposed thin-walled section results in a bladder mandrel having a relatively small outer diameter, which in turn allows it to be inserted within a tube without the need for lubricants.

Abstract: A rotopeening apparatus utilizing a flexible spindle for rotopeening the inside wall of tubes of limited access is disclosed herein. The spindle is formed from a flexible, rotatable housing and includes a mandrel having eighteen peening flappers connected thereto along its axis of rotation. The mandrel is rotatably mounted within the housing in an off-center orientation relative to the longitudinal axis of the spindle in order that the peening flapper may rotate and orbit within the tube when the mandrel and the housing are rotated. The apparatus includes a frame plate for detachably mounting the flexible spindle within the open end of the tube to be rotopeened. The spindle is mounted in cantilever off the side of the frame plate to maximize its manipulability in areas of limited access. Additionally, the drive motors of the apparatus are remotely coupled to the peening spindle by means of flexible shafts in order to maximize portability.

Abstract: A method of uniformly rotopeening the inside walls of metallic tubes to a desired final peening intensity by means of at least one rotatable peening flapper is disclosed herein. The method generally comprises the step of simultaneously rotating and orbiting the flapper within the tube while maintaining a selected stand-off distance between the inner edge of the flapper and the inside wall of the tube. The angular speed of the flapper and the stand-off distance are selected so that the slope of the curve defined by peening intensity over time is substantially flat in the vicinity of the desired final peening intensity. The method is particularly useful in uniformly and accurately peening the inside walls of the heat exchange tubes anchored in the tubesheet of a nuclear steam generator in order to relieve tensile stresses in the walls of these tubes which might otherwise lead to stress corrosion cracking in the tube walls.

Abstract: A rotopeening apparatus comprising a plurality of peening spindles, a rotary and orbital drive assembly coupled to the spindles, and an oscillatory drive means for reciprocating the spindles within the interior of an array of tubes is disclosed herein. Each peening spindle includes a rotatable mandrel connected to at least one peening flapper, as well as means for orbiting the mandrel peening flapper around the longitudinal axis of the tube. The rotary and orbital drive assembly includes an orbital driveshaft and a rotary driveshaft which are concentrically disposed with respect to one another and are detachably connectable to the rotatable and orbital mandrel of the peening spindle.

Abstract: Disclosed is an apparatus for overcoming acoustic path angle limitations and transducer coupling problems when an ultrasonic flow measurement method is used to measure water velocity in annular regions such as the downcomer of a nuclear steam generator. In accordance with one embodiment, two axially spaced ultrasonic transducers are coupled perpendicularly to the outer surface of a shell and align respectively with two 45.degree. reflecting surfaces on a structure which is inserted into the downcomer during shutdown. The acoustic path between reflecting surfaces is essentially in line with the fluid flow as desired for best sensitivity and accuracy. Acoustic performance is optimized and transducer mounting is simplified by having the transducers perpendicular to the shell surface. Other embodiments are disclosed for measuring the average flow velocity by angling the acoustic path across the annular region of the downcomer.

Abstract: Steam turbine apparatus is disclosed as comprising first and second turbine sections having respectively an outlet opening and an inlet opening. The first or high pressure turbine section has a plenum wall adjacent its exhaust opening that collects water thereon. A crossover structure is disposed between the outlet opening and the inlet opening for transmitting a steam/water mixture to the second or low pressure turbine section. A hollow member having first and second openings at its respective ends, is associated with the first turbine section such that the first opening is sealed with respect to the outlet opening. The hollow member extends into the first turbine section and its second opening is dimensioned to shadow the outlet opening so that the hollow member captures and discharges the water contacting the adjacent plenum wall and to inhibit the steam/water mixture directed through the outlet opening from stripping and conveying the contacting water to the crossover structure.

Abstract: A flail tube cutter having an elongated cutting head circumscribed by a generally circular cutting blade, a means of rotating this cutting head, and a flexible shaft for coupling the cutting head to the rotating means is disclosed herein. The circular cutting blade of the cutting head includes a serration for defining two cutting teeth. Additionally, the cutting head includes a top portion located above the cutting blade for increasing the impact force of these cutting teeth against the inside wall of the tube being cut. The flail tube cutter of the invention provides a fast-acting tube cutter having a relatively small diameter which is easily snaked through tubes having local restrictions caused by either dents or internally mounted sleeves.

Abstract: An apparatus is disclosed for inspection of tubing, and more particularly, the determination of the extent of erosion in the wall of a heat exchange tube of a nuclear reactor. An ultrasonic transducer assembly is movable axially and rotatably in a helical path for producing both thickness and position signals to provide a map of wall thickness.

Abstract: An apparatus and a method for remotely refurbishing valve seats are disclosed herein. The apparatus generally comprises a welding assembly having a welding head for depositing a bead of metal around the valve seat, and a positioning assembly detachably mountable onto the valve body for angularly and radially moving the welding head around the valve seat at a selected point along the axis of rotation of the seat. Additionally, the apparatus includes a control means operatively connected to the positioning assembly for controlling the movement of the welding head around the valve seat. In operation, the control means, which may include a microprocessor, first angularly moves the welding head 360.degree. around the circumference of the valve seat, then moves the welding head to a different point along the axis of rotation of the valve seat, and then rotates the welding head 360.degree. around the valve seat again for as many cycles as is necessary to rebuild the valve seat.

Abstract: The invention comprises a core barrel plug capable of being remotely installed in a port of a core barrel of a pressurized water nuclear reactor for converting the reactor from a by-pass downflow configuration to a by-pass upflow configuration. The plug comprises a body having an expandable cylindrical portion with a movable mandrel disposed in the body. Remote fluid pressurization causes the mandrel to be advanced thus expanding the body into contact with the port. The plug also comprises a locking mechanism to prevent inadvertent release of the plug.

Abstract: A fiberscope inspection system for a nuclear steam generating plant includes an optical unit and a transport unit respectively coupled to opposite ends of the fiberoptic cable and mounted at spaced-apart points on a trolley beneath the tube sheet, with the fiberoptic cable hanging freely in a catenary between the two units, both of which are coupled by cable to a remote control station. The optical unit is self-contained and includes a light source, a video camera and a focusing mechanism and chain and sprocket remotely-controlled drive means for controlling the focusing mechanism. The transport unit includes a cartridge comprising a coil of a steel drive tape, the leading end of which is welded to a split-sleeve coupling disposed in clamping engagement with the leading end of the fiberoptic cable, the tape being engageable by a drive sprocket for driving same to feed and retract the fiberoptic cable. Position sensing means are provided for monitoring the position of the fiberscope probe.

Abstract: A metal disintegration apparatus for performing work on a portion of a workpiece in a confined location which includes an electrode, and an electrode holder for movably holding, positioning and supporting the electrode at a desired remote location. A vibration feeder is coupled to the electrode so that the electrode can be vibrated relative to the electrode holder while the electrode holder is stationary and the electrode can be advanced to perform cutting. Preferably an air-cushioned reciprocating piston type pneumatic oscillator sends vibrations through a frictionless actuator cable supported by an articulated arm to vibrate the electrode. The vibration feeder is located in a position remote to that of the electrode and therefore the metal disintegration apparatus is ideally suited for work at remote locations such as those encountered in steam generators of nuclear reactors.

Abstract: The sleeving method comprises inserting a metal sleeve within a tube so as to bridge the defective region of the tube. The sleeve is constructed to have annular slots on the outside thereof that are capable of tightly contacting the inside surface of the defective tube and creating a labyrinth-type seal therebetween. The sleeve is also constructed to have an expander member captured therein that may be pulled through the sleeve thereby causing expansion of those portions of the sleeve having the annular slots therein. Once such a sleeve has been inserted into the defective tube, the sleeve is internally expanded in the area of the sleeve wherein the annular slots are located by pulling the expander member through the sleeve. The expansion of the sleeve in the area wherein the annular slots are located causes the lands between each annular slot to closely contact the inside surface of the tube. The other end of the sleeve can then be either similarly attached to the tube or otherwise attached to the tube.

Abstract: A welding apparatus for internally welding sleeves to tubes comprises a central shaft with an electrode attached thereto which are capable of being inserted in a tubular member. A plurality of remotely actuable seals are disposed on the welding apparatus and around the electrode for establishing a sealed chamber in the sleeve in which the welding may take place. The welding apparatus is capable of supplying an inert shielding gas to the sealed chamber for pressurizing the sealed chamber during the welding process and while the electrode completes a weld around the inner circumference of the sleeve. The apparatus may also be used to internally braze the sleeve to the tube.

Abstract: The tool serves to brush the upper and lower counterbores and the channels which interconnect the counterbores in the lower flange of the lower guide tube of a nuclear reactor. The top entrance to the counterbores is partially obstructed by the wall of the guide tube which extends above the flange. The tool includes an upper brush and a lower brush mounted with their axes displaced laterally in opposite directions with reference to the common axis of the counterbores. The mounting is movable linearly and is pivotal about a horizontal axis and includes cam slots engaged by cam followers. When the mounting is moved in one direction (down typically) the upper brush is moved by the cam action into cleaning relationship with the upper counterbore. When the mounting is moved in the opposite direction (up), the lower brush is moved by the cam action into cleaning relationship with the lower counterbore and with the channel between counterbores.

Abstract: An apparatus for simulating and analyzing discontinuities in a tube using eddy current inspection techniques is disclosed. The simulation apparatus includes inner and outer tubular members arranged to define an annular chamber having a predetermined tubular configuration corresponding to the tubular configuration of a tube under investigation. The outer tubular member has an opening through the wall thereof and the inner tubular member defines an axially extending hollow interior. A supply of electrically conductive liquid material is provided in the annular chamber, the quantity of liquid material being such as to substantially and completely fill the annular chamber in the vicinity of the opening through the wall of the outer tubular member. A defect simulation member is supported in the opening in the outer tubular member for movement along a predetermined direction extending transverse to the axis of the inner tubular member.

Abstract: Calibration apparatus for calibrating an ultrasonic transducer array by moving it along an arcuate calibration test member, includes four upright posts interconnected by a rectangular carriage which is slidably movable vertically along the posts. A horizontal pivot shaft is rotatably mounted on the carriage. Fixed to the shaft and depending therefrom are two pendulum arms, interconnected at their lower ends by a pair of cross bars on which is slidably mounted a mounting block. An attachment rod is vertically slidably movable in the mounting block and carries a coupling joint at its lower end for mounting the transducer array. A reversible gearmotor drives the pivot shaft through a chain and sprocket assembly in an oscillating motion. Backlash in the gear train is reduced by a bias weight.

Abstract: A sludge lance nozzle for removing sludge from between the tubes of a nuclear steam generator includes positioning apparatus mounted on top of the nozzle. The tubes are arranged in rows and columns with the axes of the tubes in each column lying in a common column plane. The nozzle is moved perpendicular to the column planes close to one of the rows of tubes. In one embodiment, the positioning apparatus comprises two transmitter/receivers for transmitting signals and receiving reflected signals along axes parallel to the column planes, the axes being spaced apart by odd multiples of one-half tube pitch. The received signals are subtracted to produce a position indicating signal. In another embodiment the positioning apparatus includes a transmitter and a receiver spaced apart in the direction of movement of the nozzle, the transmitter transmitting a signal in a first predetermined direction, and the receiver being responsive only to reflected signals received from a second predetermined direction.

Abstract: The pressure-differential method for sleeve-to-tube joining comprises inserting a sleeve within a tube and joining the sleeve to the tube. An internal heating device is then inserted into the sleeve for bonding the sleeve to the tube. The portion of the sleeve to be joined is then sealed so that the portion of the sleeve to be joined may be internally pressurized. Once the sleeve has been so pressurized, the heating operation may be begun. In the case of welding, as the welding progresses the molten weld pool under the arc is continuously driven by the internal pressure gradient toward the external tube. In this manner the arc force is cushioned by the molten pool at all times thus preventing the weld arc from piercing through the sleeve. In the case of brazing, as the heating progresses the sleeve becomes more pliable such that the internal pressure causes the sleeve and braze material to closely contact the inner surface of the tube.

Abstract: The invention comprises a core barrel plug capable of being remotely installed in a port of a core barrel of a pressurized water nuclear reactor for converting the reactor from a by-pass downflow configuration to a by-pass upflow configuration. The plug comprises a body having an expandable cylindrical portion with a movable mandrel disposed in the body. Remote fluid pressurization causes the mandrel to be advanced thus expanding the body into contact with the port. The plug also comprises a locking mechanism to prevent inadvertent release of the plug and a venting mechanism to prevent inadvertent overpressurization of the plug.