Abstract: Disclosed is an assembly fixture and method useful for the assembly and fabrication of metal grids such as used to support and position the fissionable fuel rods of a nuclear fuel assembly. The grid assembly fixture uses a grid assembly plate (1) and a plurality of toggle clamp assemblies (9) and clamping pads (12) attached thereto to temporarily hold the four peripheral or border grid straps (7) in proper position and alignment against the four sides of the grid assembly plate (1). A strap retention assembly (13) is then placed around the four peripheral or border grid straps (7) to hold them in proper position and alignment during the further fabrication and welding of the grid straps (7).

Abstract: A modular grid welding fixture for a spacer grid that facilitates full grid laser welding of a spacer grid in one setup. The modular design allows for partial implementation of each weld type. A base plate is used for mounting to the positioning/rotational plate of the welding system. A removable sub-plate received in the base plate is used to position the grid strips for proper location for welding. A top fixture plate is aligned with the base plate and provides for mounting of a second sub-plate if required. Side plates with spring loaded pressure pads that are hinged to the top fixture plate apply uniform pressure to the outer grid strips during processing. The base plate, top plate, side plate, and pressure pads are provided with a plurality of through holes to allow access of the laser beam for welding. Corner clips are used to insure contact of the overlapping sections of the outer grid strips for proper corner welding.

Abstract: In an automated final weld apparatus, a transporter conveys nuclear fuel-loaded cladding tubes successively to a check station to verify the presence of a plenum spring in the open end of each cladding tube, a reader station where a unique first end plug serial number is read, an evacuation/backfill station where the cladding tube is backfilled with helium, a seam welding station where a final end plug is welded to the cladding tube open end, and a seal weld station where the tube is pressurized with helium through a pressurization hole in the final end plug, whereupon the pressurization hole is welded closed. After checking for helium leakage, the seam weld is inspected in a succession of inspection stations, and, depending on inspection results, the finished nuclear fuel rods are sorted into accepted and rejected lots.

Abstract: An apparatus for inserting U shaped tubes in a heat exchange core includes a track which includes a pair of parallel channels for receiving the limbs of the tubes and for guiding the limbs on three sides, a slide for pushing the tubes along the track and into the heat exchange core, and restraining means for closing the fourth side of the channels to guide the limbs, the restraining means being adapted to move out of the track as the head of the tube and the slide pass along the track.

Abstract: A key member, a method for insertion and/or removal of the fuel rods in a nuclear fuel assembly using the key member and a method of disassembling the nuclear fuel assembly using the same key member are disclosed. The key member has first projections and second projections formed on the opposite faces of an elongated key body. In the insertion or removal of the fuel rods or in the disassembling the nuclear fuel assembly, the key member is inserted into the grid and rotated to bring the first projections and the second projections into engagement with the straps of the grids and the springs on the straps to thereby the springs are deflected in a direction away from the dimples opposing to the springs. In this situation, the insertion and removal of the fuel rods can be carried out.

Abstract: A mechanical tube expander for simultaneously expanding plural hairpin tubes into interlocked relationship with plural fins which includes a frame on which is provided a receiver to support the bent portions of the hairpin tubes in an assembly of fins loosely stacked on the straight leg portions of the hairpin tubes. A support structure is also provided on the frame for engaging and supporting a first endmost fin that is oriented immediately adjacent to but spaced from the receiver. A pressure plate carrying a plurality of expander rods is provided and each of the expander rods is aligned with the hairpin tubes. A stripper plate structure having plural guide openings therethrough is also provided. The expander rods extend through the guide openings. Structure is provided on the stripper plate for engaging a second endmost sheet of the assembly of fins at an end thereof which is remote from the receiver.

Abstract: A radioactive source is mounted at one end of a rod and a ball-shaped coupler is disposed at the other end of the rod. An apparatus for handling a plurality of radioactive sources respectively mounted at one end of a plurality of rods having a ball-shaped coupler disposed at the other end of each said rod includes a shaft having a canister at one end of the shaft and a clip at another position on the shaft. The canister defines a plurality of compartments for respectively receiving a plurality of said mounted radioactive sources. The clip defines a plurality of chambers for respectively receiving a plurality of the ball-shaped couplers. The rods are flexible and semirigid and the distance between the canister and the clip is such in relation to the distance between the radioactive source and the ball-shaped coupler on the rod that the rods must be flexed after the radioactive sources are received in the compartments in order to insert the ball-shaped couplers into the chambers of the clip.

Abstract: Apparatus for extracting a heat exchanger tube assembly from a heat exchanger shell includes an extractor frame, an extractor body moveable with respect to the frame, and powered extraction members for literally moving the extractor body with respect to the frame. A plurality of rollers are provided each supporting the extractor frame and extractor body, and a plurality of respective drive motors each power one of the rollers for manipulating the apparatus relative to the heat exchanger shell. Both forward and reverse rotation of a respective roller and pivotable rotation of the roller with respect to the frame for steering capability of the apparatus may be provided by control means positioned such that the operator need not be carried by the assembly. A plurality of hydraulic cylinders each secured to the extractor frame are provided for elevating the extractor body to a desired position with respect to the heat exchanger shell for extraction and reinsertion of the tube assembly.

Abstract: A tool for use in installing O-ring seals in the removable head of a nuclear reactor pressure vessel. Disclosed are two embodiments of the tool. One embodiment is adapted to fit within the stud bolt holes of the flange of the removable head of the pressure vessel. The other embodiment is adapted to be magnetically attached to the underside of the flange of the removable head of the pressure vessel. The tool uses a movable support arm to properly position and support the O-rings in their respective grooves machined in the underside of the flange of the removable head.

Abstract: An apparatus for deforming, splitting and chopping of contaminated, or potentially contaminated, heat exchanger tubes into short tubes segments that easily may transported to an off-site location for decontamination or disposal. The invention has particular utility in dismantling potentially contaminated tubes from a tube bundle that is part of a condenser for a BWR or PWR nuclear power plant. The invention involves first gripping and deforming the exterior periphery of a potentially contaminated tube with opposed transverse forces sufficient to travel the tube longitudinally out of the tubesheets in a deformed condition, and then splitting the deformed tube into first and second wall sections which are chopped into short length wall segments. The deformation preferably flattens the tube so that the short wall segments are substantially planar, with exposed inner and outer surfaces.

Abstract: Apparatus (100) for pulling a projecting tube (14) from a tube sheet (12), along the tube axis (18), comprising a base (200) for engaging the tube sheet and a jacking assembly (300) mounted on the base and actuable by a first fluid pressure variation between extended and retracted positions (302) away from and toward the base respectively. A substantially annular gripper assembly (400) is connected to the jacking assembly for extended and retracted movement therewith and adapted to coaxially receive the tube. The gripper assembly includes a housing (404) having a gripper piston chamber (410) in which a second fluid pressure variation can be introduced into the gripper piston chamber. A gripper piston 420 is situated for movement in the gripper piston chamber in response to the second fluid pressure in the chamber.

Abstract: In a brain irradiating system a large number of Cobalt 60 radiation sources are carried in ports in a heavy primary shield. After the normal ten year useful life of such radiation sources, they are often difficult to remove because due to corrosion, etc, the aluminum source holders become fused in their ports. The apparatus herein includes a hollow collet which grasps the head of the source holder surrounded by and, preferably, splined to a mechanical puller which securely holds the collet around the source holder cap. Liquid nitrogen is caused to flow into the hollow collet and against the cap of the source holder, causing the aluminum source holder to shrink more than the surrounding steel of the primary shield. The source holder and the Cobalt 60 source may then be either pulled out or, if threadedly engaged with the primary shield, turned out of its port.

Abstract: A tool is disclosed for assembling or disassembling an endcap into or out of a housing. The housing includes a distal end, an intermediate portion, and a receptacle disposed in the distal end. The tool includes a hook removably joinable to the endcap, and a clamp removably joinable to the housing intermediate portion. The hook is jacked relative to the clamp for translating the endcap relative to the receptacle for either assembling or disassembling the endcap into or out of the housing.

Abstract: An automated fuel assembly loader, capable of patterned loading, moves nuclear fuel rods in a loading direction between a fuel rod skeleton defining an array of receptacles for the fuel rods, and a fuel rod magazine supplying or receiving the fuel rods. A table supports the fuel rod skeleton at a loading position. A movable carriage having a line of individual fuel rod engaging devices moves a subset of fuel rods along the line forward in the loading direction. The rods are selected via a pattern stored in a controller. Selection devices such as pneumatic clamps mechanically couple the selected engaging devices to the carriage for movement while others are left behind. A ball screw carriage drive arrangement moves the carriage parallel to the loading direction and a jack screw positioning drive displaces the carriage perpendicular to the line of fuel rods.

Abstract: An apparatus and method are provided for servicing an irradiated nuclear control rod underwater in a reactor building servicing pool. A turntable containing a plurality of spaced apart tools is positioned adjacent to the control rod. A first tool aligns the turntable relative to the radioactive roller mounted to the control rod by a radioactive pin therethrough. The turntable is indexable to position a second tool adjacent to the radioactive roller and pin, with the second tool being effective for freeing the radioactive pin from the control rod. The turntable is indexable for positioning a third tool adjacent to the radioactive roller and pin for removing the radioactive pin and the roller from the control rod. In further embodiments of the invention the turntable is further indexable for positioning a fourth tool adjacent to the control rod for reaming the pin aperture through which the radioactive pin was mounted.

Abstract: A method and assembly for securing a cylindrical centering pin in a bore formed in a plate includes introducing an end of a centering pin to be secured to a plate into a bore formed in the plate until at least part of a coaxial, radially deformable wall portion of the end to be secured protrudes beyond the plate; and generating pressure in a closed hollow space surrounded by the wall portion with a pressure fluid until the wall portion radially expands and anchors the centering pin. According to another method and assembly, the end is introduced into the bore until at least part of the end to be secured, which has a periphery and an interior with radial slits formed therein, protrudes beyond the plate; and a mandrel-like tool is partially brought into the slits in the interior of the end of the centering pin and radially expands the end of the centering pin with the tool for anchoring the centering pin.

Abstract: The device comprises a support (9) provided with means (12) for its demountable fastening to the reactor structure (1) above and vertically in line with the component (3), a turret (10) mounted rotatably on the support (9) about its vertical axis, a device for taking up forces (11), on which the lower end of the turret (10) is mounted rotatably, an arm (18) mounted movably on the turret (10) in a radial direction, a first cutting unit (20) mounted on the movable arm (18), a trolley (25) mounted movably on the turret (10) in the vertical direction, a vertical second cutting unit mounted on the trolley (25) and a means for handling (30) fragments of the component (3).

Abstract: Device for the simultaneous positioning of a plurality of threaded connecting elements (1) carried by a supporting member (8) and intended for fastening a component (2) placed on an appliance (3), the component (2) having open-ended bores (5) for the passage of the threaded connecting elements (1), and the appliance having tapped holes (4) corresponding to the open-ended bores (5) and capable of receiving the threaded connecting elements (1), including provision for permanent checking and correction of the position of the axes of the threaded connecting elements (1) in relation to the axes of corresponding tapped holes (4), and of the horizontality of the supporting member (8), and a lifting beam.

Abstract: A method and apparatus for repairing a heat-exchanger of the type having a tube sheet in which the extremities of exchanger tubes are mounted. The method involves unrolling tubular insert stock from a supply roll, straightening the unrolled insert stock by passing it through a straightening device which has its output disposed substantially in alignment with one of the exchanger tubes to be repaired and at a location adjacent the mounted extremity of the exchanger tube, and forcibly pulling the straightened insert stock into the one exchanger tube. The pulled-in insert stock is then cut to length, and the ends radially expanded against the inner walls of the exchanger tube, and sealed to the tube sheet.

Abstract: A plug and method for plugging a penetration in a pressure vessel wall having a sleeve protruding through the penetration. The sleeve is cut at a point between the interior and exterior surfaces of the pressure vessel wall. The cut portion of the sleeve extending beyond the exterior surface of the pressure vessel wall is removed. A plug sized to fit within the penetration is inserted into the penetration so that one end of the plug is flush with the exterior surface of the pressure vessel wall. A weld pad is deposited on the end of the plug and the exterior surface of the pressure vessel wall.

Abstract: Process and apparatus are disclosed for removing and replacing the hold down beams of fluid circulating jet pumps mounted in a nuclear reactor. The disclosed process and apparatus are operable from a position such as the refueling bridge remote from the reactor and while the refueling cavity surrounding the reactor is flooded with moderator fluid.

Abstract: A tool positioning assembly for receiving tooling for repairing heater penetrations at the lower end of a pressurizer supported on its end by a support skirt between the pressurizer and a base with the pressurizer having a surge line extending vertically into the apex of the lower spherical end of the pressurizer. A pair of circular tracks are mounted so as to be concentric with the pressurizer. The inner track is mounted to the surge line and the outer track is mounted so as to be below the outer periphery of the pressurizer. A carriage is movably mounted between the tracks so as to be movable therebetween and around the pressurizer. Cross slides mounted on the carriage provide horizontal movement. A vertical slide mounted on the upper cross slide provides vertical movement and is also rotatable around its own vertical axis for clearance purposes when maneuvering around the heater penetration nozzles.

Abstract: In a boiling water nuclear reactor having its core, fuel support casting, and control rod guide tubes removed to expose the core plate, an apparatus and method for the submerged welding repair and replacement of the control rod drive housing at the bottom extremity of the reactor vessel is disclosed. The apparatus registers to a hole in the core plate and its corresponding guide pin. A mating fixture on the depending extremity of the shaft of the apparatus precisely fits and mates to the top of the control rod drive housing. The alignment device includes cross electronic levels sealed for submersion which levels remotely transfer through attached wiring the precise angularity between the top of the control rod drive housing on one hand and the corresponding and overlying hole in the core plate on the other hand. For the welding repair process herein, a welding cylinder apparatus fits over the depending end of the shaft of the alignment device.

Abstract: Apparatus for cutting a cruciform shaped radioactive control rod into three separate cut sections, the cruciform shaped radioactive control rod being of the type having four substantially equidistantly spaced sheaths extending from and along a large portion of the length thereof, each sheath containing at least one radioactive rod, and a velocity limiter at one end thereof, the apparatus including a first cutting device for cutting the velocity limiter away from the remainder of the control rod to form a first one of the cut sections; and a second cutting device for simultaneously cutting the remainder of the control rod along the lengthwise direction thereof and substantially transverse to the first cutting device, to form two chevron shaped sections as the remaining two of the cut sections.

Abstract: Apparatus for screwing on and off a clamp nut (5) and an extension piece (13) facing the clamp nut. The extension piece (13) of each of plurality of connection members (2) cooperates with a ring (1) for simultaneously tensioning the connection members. The apparatus includes a carriage (20) for guiding and displacing the apparatus around the ring (1) tensioning the connection member (2), a disengageable system (30) for displacing and rotationally driving the extension piece (13) which is to be screwed on or off, and a disengageable system (40) for rotationally driving the clamp nut (5) which is to be screwed on or off. These systems are supported by the carriage (20) and are displaceable along an axis parallel to the axis of the connection member (2) and at a speed identical to that of the nut (5) or of the extension piece (13) in the course of its screwing or unscrewing.

Abstract: A method for installing a heater unit assembly (52, 54) in a reactor pressure vessel (2) for performance of an annealing treatment on the vessel (2), the vessel (2) having a vertical axis, being open at the top, being provided at the top with a flange (6) having a horizontal surface, and being provided internally, at a location below the flange (6), with orientation elements (8) which are asymmetrical with respect to the vertical axis, by the steps of:providing an orientation fixture (10) having an upwardly extending guide member (18) and orientation elements (14, 16) and installing the orientation fixture (10) in the vessel (2) so that the orientation elements (14,16) of the orientation fixture (10) mate with the orientation elements (8) of the pressure vessel (2) in order to establish a defined position of the orientation fixture (10) in the pressure vessel (2), and so that the guide member (18) projects above the pressure vessel (2) flange (6);placing a seal ring (30) in a defined position on the pressure

Abstract: A hand held tool for removing a hollow locking tube from a locking position in the upper end portion of a guide thimble includes an elongated hollow tubular assembly having a lower end portion insertable in the locking tube and an actuator assembly mounted through the tubular assembly for axial movement therealong and having a lower end portion for actuating a set of lifting members of the lower end portion of the tubular assembly to extend and retract their catch elements through and from apertures in the tubular assembly for engaging with and disengaging from a lower edge of the locking tube. The lower end portion of the tubular assembly includes a guide member composed of a hollow tubular element and a guide element interfitted with an open end of the tubular element and having a body portion projecting therefrom. The tubular element has the apertures through which the catch elements on the lifting members can be extended to engage the lower edge of the locking tube.

Abstract: A system is directed for remotely securing a canopy seal about a broken omega seal site between the control drive mechanism and the adapter tube of a nuclear reactor vessel so as to contain any radioactive leakage therebetween. The system includes a stalk measuring device for initially measuring the diameter of the adapter tube, a split canopy installation fixture which is adjusted according to the measurement detected by the stalk measuring device to position a two-piece canopy seal about the omega seal site, and a robotic weld arm for performing the upper and lower radial welds about the canopy seal as well as C-shaped vertical welds between the two-piece canopy seal.

Abstract: An apparatus and method are provided for remotely inserting and feeding a sleeve within a selected tube to be serviced mounted in a tubesheet of a nuclear steam generator, so as to relieve reverse forces generated during the insertion and feeding of the sleeve and to reduce operator interaction. The device includes a tool having a frame, at least one gripper unit having gripping fingers which extend from a top plate of the tool for detachably suspending the frame from a tube in close proximity to the selected tube. The gripper unit also includes a hydraulically actuated cylinder for retracting the gripping fingers toward the top plate of the tool to forcibly position the tool against the underside of the tubesheet. An advancing assembly supported by the frame is also provided for remotely inserting and feeding the sleeve into the selected tube. This advancing assembly is vibrated by way of a vibrator mounted thereon.

Abstract: An apparatus for the inspection and/or repair of tubes discharging into a chamber of a heat exchanger includes a tube sensor. A manipulator provides remote-controlled positioning of the tube sensor. A plurality of mouthpieces disposed on the manipulator introduces the sensor into tubes of a heat exchanger. Tube connectors communicate with the mouthpieces and have two ends. One of the ends of the tube connectors is coaxially attachable to orifices of the tubes of the heat exchanger. The other of the ends of the tube connectors are bundled into a circular group at an adaptor. A distributor plate has orifices into each of which a respective one of the tube connectors discharge. A parallel turntable is supported on the distributor plate. A guide hose is introduced into the turntable for guiding the tube sensor. Incremental rotation of the turntable selectively aligns the axis of the guide hose with the axis of one of the orifices in the distributor plate.

Abstract: An apparatus for loading cylindrical fuel pellets into tubular fuel rods includes pellet segregation means for detecting and segregating an undersized pellet prior to its entry into a fuel rod. The segregation means includes a pair of laterally separated guide rails adapted to support the lateral side edges of the advancing pellets, and such that a pellet of undersized diameter will drop to a level below that of the properly sized pellets. A lateral shoulder is positioned at the downstream end of the guide rails for engaging and holding any dropped pellet so that it cannot advance into the fuel rod. Also, a pellet deflecting plate is positioned at the upstream end of the guide rails, to interrupt the contact between adjacent pellets and thus assure that an undersized pellet is not carried along the guide rails by the adjacent pellets.

Abstract: A machine for remotely lining the inside of a heat exchanger tube end (13) received in a tube plate (14). The machine includes a flexible tube (15) connecting a push-pull device to a motorized unit (16) for driving tools used for fixing the sleeve in the heat exchanger tube. The machine also includes a tool loader (25, 26) at the head of a cable (20) which is driven by the push-pull device and means for applying the end of the flexible tube to the end of any of the heat exchanger tubes which may need lining. The motorized unit (16) includes two superposed fluted hubs (30, 33) one of which is driven by a low speed electric motor while the other is driven by a high-speed pneumatic motor.

Abstract: In a nozzle dam assembly wherein a circular dam faces into a nozzle adjacent its opening and a support frame abuts the backside of the dam and is removably affixed across a ring encircling the opening, apparatus for selectively locating the dam at its optimum sealing position within the nozzle notwithstanding the particular longitudinal profile of the nozzle or eccentricity of the ring-relative to the nozzle opening comprising apparatus for adjusting the dam relative to the frame along the nozzle axis and also vertically and horizontally perpendicular to the nozzle axis.

Abstract: A workstation within a containment cell is provided with a services-supply module or unit by means of which a range of services such as electrical power, hydraulics, pneumatics etc are made available for in-cell use. The services are provided by means of a number of replaceable and exchangeable services-connection cartridges which sealingly engage in the unit and provide continuity between out-of-cell supply lines connectible to adaptors and in-cell supply lines connectible to adaptors. The cartridges are replaceable without breaking cell containment conditions with the aid of a tool (by which a replacement cartridge is fed forwardly to displace in nose to tail relationship the cartridge to be replaced.

Abstract: Process and apparatus are disclosed for removing and replacing the hold down beams of fluid circulating jet pumps mounted in a nuclear reactor. The disclosed process and apparatus are operable from a position such as the refueling bridge remote from the reactor and while the refueling cavity surrounding the reactor is flooded with moderator fluid.

Abstract: A method for replacing bolts on core components of nuclear reactors includes machining away a bolt fastened at an installation site in a core component as well as the entire fastening of the bolt with an electroerosion machine. Machined-away bolt material is removed and caught with a filter. The bolt is then ejected from the core component with a closed force system. The installation site of the bolt is remachined with an accurate fit and a new bolt is subsequently inserted. An apparatus for replacing bolts on core components of nuclear reactors includes rails. An auxiliary platform is supported on the rails on both sides of a reactor pressure vessel. An auxiliary crane is disposed on the auxiliary platform and adjustable transverse to the rails. A tool carrier is guided on the auxiliary platform and suspended from the auxiliary crane. A tool is disposed on the tool carrier for replacing bolts on core components.

Abstract: A curved structure (20) with two flat side flanges and a curved bottom (23') connecting the flanges, each of which is associated with a curved guiding slide (24a,24b)is used for lining a peripheral tube of a steam generator. A trolley (21) having wheels (25, 26) interacting with the guiding slides moves in the curved structure and is guided along the inner wall of the water box of the steam generator. A rigid roller-expanding tool (24) is connected to a drive mechanism carried by the trolley by a flexible cable, and is guided by a guiding device after it leaves the curved structure.

Abstract: A dispersion strengthened ferritic steel cladding tube for use in a nuclear reactor and having a double-layer structure is provided. The cladding tube comprises a tube body made of a dispersion strengthened ferritic steel having a ceramic dispersed therein and containing 8 to 13% by weight of chromium. The inner surface of the tube body is lined with a ferritic steel containing 18 to 30% by weight of chromium. The cladding tube has not only excellent compatibility with a mixed oxide fuel but also excellent high temperature strength and swelling resistance.A method of producing the cladding tube using powder metallurgy is also provided.

Abstract: The invention is directed to an apparatus for performing the remotely-manlated installation and removal of a pass-through conduit unit into and out of a channel formed in a partition wall. A feed assembly is part of the apparatus and includes a plurality of parts assembled to form an elongated body in the channel. An articulated coupling such as a ball joint couples the conduit unit to the elongated body. A drive is operatively connected to the elongated body for displacing the latter in the channel. A crane has a holder for holding and remotely manipulating the conduit unit as the latter is installed or removed from the channel.

Abstract: To form longitudinally spaced pairs of angularly spaced stops in the walls of fuel rod-positioning ferrules utilized in nuclear fuel bundle spacers, the ferrules, cut from tubular stock, are longitudinal oriented in a first station and angularly oriented in a second station using a reference notch cut in one ferrule edge. Successive ferrules are picked from the second station and placed in a die of a punch press. Ferrule exterior surface back-up is provided by the die upon closure, and interior surface back-up is provided by a mandrel inserted in the ferrule bore as the punches converge into stop-forming engagement with the ferrule wall. Formed ferrule discharge is induced by placement of the next ferrule in the die.

Abstract: A workstation within a containment cell is provided with a services-supply module or unit by means of which a range of services such as electrical power, hydraulics, pneumatics etc. are made available for in-cell use. The services are provided by means of a number of replaceable and exchangeable services-connection cartridges which sealingly engage in the unit and provide continuity between out-of-cell supply lines connectible to adaptors and in-cell supply lines connectible to adaptors. The cartridges are replaceable without breaking cell containment conditions with the aid of a tool (by which a replacement cartridge is fed forwardly to displace in nose to tail relationship the cartridge to be replaced.

Abstract: In a two-arm type manipulator, it is very rare that two arms develop trouble simultaneously due to malfunction of motors and/or cables. In view of the above fact, motors for actuating manipulator joint mechanisms and cables connected between the motors and the manipulator frame are removably mounted on the shoulder section of the frame of the manipulator. Further, the first arm is so arranged as to be accessible to the second shoulder section or the second arm is so arranged as to be accessible to the first shoulder section. Therefore, it is possible to allow an access of one manipulator arm to the other disabled manipulator elements (motors and/or cables) for removal and replacement of the disabled elements with new elements without aid of another manipulator, in particular, where the manipulator is equipped in atomic facilities which refuse access, thus saving equipment investment.

Abstract: A liner (12) is inserted into the water box (3) through the manhole (9) vertically in line with the manhole, and then the liner (12) is moved as far as a position situated vertically in line with the tube (8) to be lined. The operations of inserting the liner (12) into the tube (8), of diametral expansion and of roller-expanding are performed by inserting a corresponding appliance into the water box (3) and using this appliance from an operating station outside the water box, where the drive for the appliance is situated.

Abstract: The fuel element comprises a plurality of modular capsules (5) arranged in sequence axially within a sheath (2). Each of the capsules (5) comprises a tubular case (10) closed at both ends by a porous element (13, 14) and enclosing a stack of pellets (11) in contact with the inner surface of the case (10) without radial clearance. The outside diameter of the capsules (5) is such that a very small radial clearance exists between the outer surface of the capsule (5) and the inner surface of the sheath (2).

Abstract: To assemble nuclear fuel bundle spacers comprised of a multiplicity of rod-positioning ferrules, automated apparatus is provided comprising an indexing table mounting a plurality of identical, angularly spaced ferrule fixtures which are successively positioned at a first station for receipt of a pair of properly oriented ferrules. The table is indexed to present the ferrule pairs in turn to a second station where a spring is loaded in pre-assembly relation thereto. At the next table index position, a third station manipulates the successive fixture-mounted ferrule pairs to interlock the spring with each ferrule pair as a subasssembly which is then indexed in turn to a fourth station for assembly into a spacer fixture.

Abstract: The device comprises a handling arm (21) arranged inside the water box of the steam generator and permitting the assembly for fitting and withdrawing a plug (22) to be placed in the alignment of the tubes of the steam generator bundle. The device additionally comprises an endless screw (35) for moving the tubes in the axial direction, which is fastened to the handling arm (21), a support (44) fastened to the endless screw (35), movable in the axial direction, a linking member (51) carried by the support (44) for removable fastening to the plug body, and a sliding rod (55) actuated by a jack integral with the support (44). The rod (55) actuated by the jack permits, a thrust to be exerted on the plug held by the connecting member (51), in order to produce its extension and facilitate its withdrawal.

Abstract: Apparatus for loading fuel rods in a desired enrichment pattern includes a carrousel, an elongated fuel rod storage magazine, and a fuel rod verify and feed workstation and a magazine holder and indexing mechanism disposed between the carrousel and the magazine. The carrousel has a plurality of gondolas movable mounted thereon for stocking fuel rods of known enrichments. The magazine defines a matrix of elongated slots open at their forward ends for receiving fuel rods. The workstation defines a fuel rod feed path extending between the carrousel and the magazine and is adapted to receive successively one at a time along the feed path at its upstream end fuel rods from selected ones of the carrousel gondolas.

Abstract: A controller for an apparatus for installing a mechanical tube plug includes a controller having a controller console remote from the tube installation site and a solenoid assembly located proximate to that site. The console includes switches and indicators for providing a rotation control signal to the apparatus. The solenoid assembly includes a circuit for receiving a torque indication signal from the apparatus and an alarm circuit for setting the torque at a predetermined upper limit in response to a signal input at said controller console. The circuit operates to terminate rotation control and disable the apparatus when said limit is reached. Other features of the controller are also disclosed.

Abstract: An apparatus for mounting and demounting a lid of a vessel on and from a body thereof. The lid and the body are fastened to each other by a plurality of stud bolt and nut assemblies. A turntable is supported on a sling to be fixed to the lid, for turning movement in a horizontal plane about a vertical axis passing through a center of the lid. A plurality of operating units are supported by the turntable and are arranged in circumferentially spaced relation on a circle having a diameter equal to that of a pitch circle of the stud bolts. Each of the operating units includes a device for transporting the nuts to and from the stud bolts, and a device for attaching and detaching the stud bolts to and from an end flange of the body of the vessel. A positioning arrangement is provided for moving the turntable in the horizontal plane relatively to the sling so as to bring the operating units into vertical alignment with the stud bolts.

Abstract: A remotely controlled tooling apparatus is disclosed for supporting and selectively disposing a tool with respect to a workpiece illustratively taking the form of a core barrel of a nuclear reactor. Illustratively, a core barrel is of a substantially cylindrical configuration and has a plurality of flow holes disposed therethrough. The remotely controlled apparatus comprises a tool carriage, a support table carried thereby for receiving the tool, a strongback assembly for supporting and guiding the tool carriage with respect to the core barrel, and a pair of clamps affixed to the strongback assembly for engaging the core barrel for suspending the strongback assembly upon the core barrel. The tool carriage and its support table carried thereby are selectively disposed with respect to the core barrel, whereby the tool may be engaged and disengaged with and from the core barrel.