Abstract: This control rod drive limiter removes the need for piping for extraction drive, increases the reliability of linkage with respect to the control rod, and removes the need of a speed limiter for the control rod, since there is no need to assume that the linkage might be released, thus reducing the building costs.A stop piston 112 is disposed so as to cover a buffer piston 110 and a buffer spring 111 from above, rollers 113 are disposed above this stop piston 112, and the lower end of a piston tube 107 is fixed to a flange 103a in such a manner that the piston tube 107 does not move in the axial and peripheral directions. A collet piston 115, collet fingers 116, and a return spring 117 are disposed between an outer tube 104 and a cylinder tube 105. A guide cap 120 is disposed at the upper end of the outer tube 104. Guide grooves 106c that engage with the rollers 113 are provided in the index tube 106.

Abstract: The reactor-internal equipment handling apparatus (29) can mount and dismount a reactor-internal equipment (5, 70) to and from the reactor pressure vessel (24) quickly. The reactor-internal equipment handling apparatus for a nuclear reactor, hung down from the above the reactor vessel to handle reactor-internal equipment housed in the reactor vessel, comprises: a body frame (31) hung down from above the reactor vessel; a connecting and fixing section (32, 33, 34) provided for the body frame and adapted to be releasably connected to lugs (25) of the reactor-internal equipment; a circular guide rail (28) disposed on the body frame; and a bolt wrench section (36) disposed movably along the circular guide rail.

Abstract: A control rod and fuel supporting member gripping apparatus for gripping a fuel supporting member and a control rod is disposed in a reactor pressure vessel. The fuel supporting member is mounted on a core supporting plate and has fuel assembly supporting holes in which the bottom portions of fuel assemblies are inserted. The control rod is detachably connected with a control rod driving mechanism through a bayonet coupling and is passed through a control rod passage so as to be lifted up and down in order to remove the fuel supporting member and the control rod from the core supporting plate and the control rod driving mechanism.

Abstract: A tool set and a method of using those tools in combination is disclosed that are especially well adapted to the function of rearranging and/or replacing the control rods and fuel supports in a boiling water reactor. The tool set includes a grapple that is capable of simultaneously picking up both a control rod and its associated fuel support. A separate unlatching tool is provided for pulling the control rod's release handle in order to decouple the control rod from a control rod drive. A storage rack that may be mounted in the reactor pressure vessel is provided for storing a fuel support and a pair of control rods when the positions of selected control rods are being shifted about the reactor core area. In the method aspect of the invention, the unlatching tool is used to pull the control rod's release handle. Thereafter, the grapple lifts the control rod and its associated fuel support as a unit.

Abstract: Apparatus for engaging and aligning lower ends of rodlets, or pins, of a nuclear fuel assembly insert. The apparatus facilitates positioning the insert within guide tubes of a nuclear fuel assembly. The nuclear fuel assembly insert rodlet alignment apparatus includes a mounting rack for attachment to a reactor or spent fuel pool edge, a first fixed plate attached to the mounting rack's lower end, and a second sliding plate attached to the first fixed plate. The first and second plates are respectively provided with first and second comb structures each comprised of elongated, linear, pointed teeth arranged in a spaced manner along an edge of a generally flat plate. The lower end of a crank, or rotating shaft, is coupled to the sliding plate by means of suitable linkage permitting the sliding plate to be moved on the fixed plate between a first position wherein the two comb structures are non-overlapping and a second position wherein the two comb structures overlap.

Abstract: A grapple is provided for use with a fuel bundle channel of a nuclear reactor wherein the channel is provided with a pair of gussets in opposite corners of an upper end of the channel, each gusset having a hole therein. The grapple includes a pair of lever arms, each provided with a lifting foot at a lower end of the respective lever arm. The lever arms are movable in opposite directions to a channel lifting position wherein the channel gripper of each lever arm is located under a respective one of the pair of channel gussets. The channel lifting foot of each lever arm includes a pair of laterally spaced lifting elements such that the lifting feet may engage the underside of the gusset on either side of the gusset hole. In addition, each channel lifting foot includes a secondary foot or slider captured between the pair of lifting elements.

Abstract: A tool set and a method of using those tools in combination is disclosed that are especially well adapted to the function of rearranging and/or replacing the control rods and fuel supports in a boiling water reactor. The tool set includes a grapple that is capable of simultaneously picking up both a control rod and its associated fuel support. A separate unlatching tool is provided for pulling the control rod's release handle in order to decouple the control rod from a control rod drive. A storage rack that may be mounted in the reactor pressure vessel is provided for storing a fuel support and a pair of control rods when the positions of selected control rods are being shifted about the reactor core area. In the method aspect of the invention, the unlatching tool is used to pull the control rod's release handle. Thereafter, the grapple lifts the control rod and its associated fuel support as a unit.

Abstract: A latch tool features two elongate arms which extend down along either side of a control rod. Rotatable actuating rods are mounted on the arms. The upper ends of the actuating rods are provided with cranks which engage in slots formed in an actuating disc. As the disc is rotated, the cranks rotate the actuating rods and swing cam-like members, which are fixed to the rods, into position under an unlatching handle. In the preferred embodiments, the actuating disc is threaded onto the exterior of a rotatable input member, so that after the cam-like members are swung into position, the actuating disc threads its way up the input member in a manner which pulls the cam-like members upwardly and pulls the unlatching handle. In addition to the cam-like members which actuate the unlatching handle, lifting cam-like members may additionally be provided to fit in under a lifting handle of the control rod, and facilitate lifting of the control rod out of its position.

Abstract: A device for transferring a poison rod assembly from one fuel assembly to another fuel assembly. The device comprising winch means cooperatively associated with the poison rod assembly for lifting and transferring the poison rod assembly; a tubular member attached to the winch means at one end and adapted to be attached to the poison rod assembly at its other end.for latching onto the poison rod assembly; motor means attached to the winch means for driving the winch means; and actuator means communicating with the tubular member for moving the tubular member in an arcuate motion for latching the tubular member to the poison rod assembly.

Abstract: The spent nuclear fuel rods stored in a wet pit are extracted dry and transported dry to a transport container for dry transportation to a storage area or treatment center. The spent nuclear fuel rods are withdrawn from the wet pit, held within a cask that may be selectively closed at the bottom and transferred while the rod is dry after it is removed from the wet pit and then positioned over a dry container with an open top for a dry transfer of each of the rods to the container. Between the container and the cask is a closure that includes a shield plug and a shielding base that supports the shield plug and allows the shield plug to be moved on guide rails to the position above the open top of the container where the shield plug may then be raised allowing the shielding base to be moved out of position on the rails and the shield plug lowered to close off the container.

Abstract: Elongated coolant pumps suspended under steam generators within containment in a power plant with limited access space, are removed and replaced by an elongated maintenance cart with an elongated opening along one side in which the motor is received. Rollers support the cart for conveying the elongated motor in an upright position out from under the steam generator and onto an elevator. The elevator is lowered to transfer support of the cart and motor through trunnions to saddles straddling the elevator for rotation of the cart to a generally horizontal position. The elevator then raises the horizontally disposed cart carrying the motor to a higher floor where it is rolled off the elevator and out through the auxiliary equipment hatch.

Abstract: Process and device for the positioning of a tool (10) carried by a manipulating arm displaceable in three respectively perpendicular directions of space in relation to the vertical axis of a tube carried by the tube plate of a steam generator for a nuclear reactor. The process involves arranging symmetrically on the arm a set of at least three lighting sources (17) each supplying a light beam directed tangentially towards the periphery of a tube (5), retransmitting, via an optical assembly (18) also carried by the arm, the images of three specific points of the tube illuminated by the sources in the direction of a video monitor, the screen (21) of which comprises three reticles (42, 43, 44) delimiting the actual contour of the tube, and then bringing these images into coincidence with the reticles in order to center the axis (28) of the tools strictly on the axis (35) of the tube.

Abstract: The tool comprises a head (1) for gripping the cluster (2), connected to a handling member (3) slidable in a tool body (4) between an active position in which the head (1) and at least part of the member (3) project from the body (4), and a retracted position in which the head (1), the handling member (3) and at least part of the cluster (2) extend within the body, and combs (5 to 10) for guiding the rods, at an end of the body (4) and displaceable between a retracted position in which they extend along the body (4), and an active position in which they extend perpendicularly to the body, in order to guide the rods. The tool also comprises springs (13) for stressing the combs into the active position and a sleeve (15) for retracting the combs, displaceable between retraction and release positions of the combs, by the head (1) and/or the handling member (3) during their displacement between their active and retracted positions within the body (4).

Abstract: So as to position a device, such as an eddy current probe support inside a cylindrical cavity with radial perforations opening into said cavity, a device (36) is proposed, said device including a pole (50) orientated parallel to the axis of the cavity. This pole may occupy different pre-established indexing positions in rotation and in translation inside the cavity by means of a mechanism (42, 44, 54, 58, 60). In each of these indexing positions, an active head (98), mounted at the extremity of the pole (50) by means of a pantograph (66) and a cladding arm (100), is able to move in a specific active zone on the lower wall of the cavity. To this effect, the active head is clad by the arm (100) and is equipped with autonomous thrustors controlling its movement.

Abstract: A channel box removing apparatus which permits a removal of the channel box from a nuclear fuel assembly while being placed on a fuel rack in a spent fuel storage pool without transferring to a preparation machine. The apparatus includes a pair of pivotally mounted, releasable hooks movable between a latched position where the hooks are in lifting engagement with the undersurfaces of clips provided on a pair of diagonally opposed top corners of the channel box and an unlatched position where the hooks are out of engagement with the associated clips. The apparatus also includes a bail cap mounted thereon for vertical movement and adapted to cooperate with a bail of the fuel assembly to guide the apparatus into an operative position with the fuel assembly during lowering of the apparatus. A locking mechanism is provided for preventing accidental disengagement of the hooks from the associated clips when the channel box is being lifted.

Abstract: A sample of the pressure tube of a CANDU type of nuclear reactor is obtained for deuterium analyses without removing the pressure tube from the reactor. The preferred sampling tool comprises two cutters and means for capturing the removed material, wherein one cutter removes the surface oxide layer, and the second cutter removes a sample for analysis. The cutters and cutting operation are designed to avoid damaging the integrity of the pressure tube to allow it to remain in service. In the preferred embodiment, the sampling tool performs the surface and sample removal operation with the fueling equipment with simple linear movement.

Abstract: A remotely operated device which attaches to an existing internals lifting rig to safely lift and transport nuclear reactor internals structures. The device includes a grapple assembly uniquely formed to maximize the effective bearing surface of an annular shoulder disposed on the grapple assembly to engage the internal structure. The annular shoulder comprises a first outer diameter, the annular shoulder defining a second outer diameter disposed thereabove. The grapple assembly comprises a plurality of fingers circumferentially disposed about an actuator rod which has a diameter essentially equal to a first inner diameter of the grapple assembly. The lower end of the grapple assembly has a second inner diameter smaller than the first and axially adjacent to the annular shoulder.

Abstract: Method for manipulating and/or storing a nuclear reactor fuel assembly including an elongated skeleton structure with fuel rods and a holding device, which includes placing neutron-absorbing material adjacent the fuel rods, fastening a supplemental body with a handle to the skeleton structure, engaging the neutron-absorbing material with the supplemental body, and fitting a coupling part of the holding device to the handle, and a fuel assembly produced according to the method.

Abstract: The present invention provides an apparatus for handling core constituent elements of a reactor that comprises a core having as core constituent elements control rod assemblies each containing a control rod and fuel assemblies each containing nuclear fuel, a small rotating plug rotatably provided on the core, and a control rod drive mechanism provided on the small rotating plug, the control rod drive mechanism being characterized by comprising a plurality of grippers each having a hook projecting inwards so as to be able to engage with a handling head of the control rod and a hook projecting outwards so as to be able to engage with a handling head of each of the core constituent elements as a distance in the longitudinal direction; an operational head for opening and closing the grippers; and a third elevating drive mechanism for vertically driving the operational head; a second elevating frame for supporting the third elevating drive mechanism and the grippers; a second elevating drive mechanism for vertical

Abstract: Concrete support ledges (67) and columns (94) for the upper internals (60) and lower internals (63) structures are poured into the floor (41) and walls (36) of the refueling cavity (33) at the time of initial plant construction. Such concrete supports (67, 94) provide greater stability and do not require any external bracing. A pedestal assembly (100) is associated with each of the concrete supports (67, 94) to provide an adjustable and secure support for the internals structures (60, 63).

Abstract: Apparatus is disclosed for the dry storage of heat-emitting radioactive waste materials. The latter are stored in tubes placed within a room having at least one cold air inlet and a hot air outlet. The distance between adjacent tubes and the distance between a tube and a wall of the room is such that a conically-shaped hot air boundary layer formed by natural convection around a tube is in contact neither with the boundary layer of another tube, nor with the wall of the room.

Abstract: A nuclear reactor having a remotely removable and replaceable thermal insulating shield for the head. Access permitting removal and replacement of the head is thus afforded.The thermal insulating shield includes a vertical frame of insulating material of polygonal transverse cross section encircling the head. A top panel of insulating material is mounted on the top of the frame pivotal by remote actuation between a horizontal position and a retracted position which may be vertical. In the horizontal position, the panels mate to provide thermal shielding for the head.

Abstract: A pressurized water nuclear reactor has a reactor vessel arranged in a pool, which is filled with a neutron absorbing liquid, for example borated water. The reactor vessel is closed except for tubes connecting it with a tray above it. The coolant in the circuit rises from the vessel to the tray, gives up its heat by flashing, and flows back to the bottom of the vessel, driven by natural circulation. The tray is separated from the pool by a vapor-filled bell, which surrounds it. In the bell the vapor gives up its useful heat to a condenser. The relatively low boron content of the cooling circuit, compared to the pool, is achieved by continuous dilution of the condensate from vapor additionally generated out of the pool water. The dilution process is an equilibrium with continuous inflow of the pool water. The inflow is automatically controlled by the pool level, which rises when the pool water is pressed out from below the bell by overproduction of vapor.

Abstract: Apparatus for releasably engaging an elongated member that is releasably connected to the top nozzle of a nuclear reactor fuel assembly. The top nozzle has an adapter plate disposed at its lower end having at least one passageway therethrough through which the elongated member is disposed. The elongated member has a releasable latching structure at one end that is able to be engaged by the apparatus, having at least one latching member movable between a latched position in which the latching member is able to engage said adapter plate and secure the absorber rod in a stationary relationship with respect to the adapter plate and an unlatched position in which the latching member is able to disengage from said adapter plate so that the elongated member be removed from the fuel assembly.

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.

Abstract: A system for remotely repairing nuclear fuel rod assemblies is disclosed herein. Generally, the system comprises a rod handler for gripping, lifting, lowering and ungripping a selected fuel rod, a work station for securing the nuclear fuel rod assembly to be repaired into a desired location, and a positioner device for laterally positioning the rod handler over a selected rod in the fuel assembly secured within the work station. The rod handler includes a contractable collet for gripping and ungripping a desired fuel rod, and a rod sensor concentrically disposed within the collet for sensing when a rod is in a grippable position. The positioner includes a movable carriage which is slidably mounted onto a frame assembly by means of a pair of rail and bearing mechanisms. The system also includes a microcomputer for controlling the manner in which the positioner positions the rod handler, as well as gripping, lifting, lowering and ungripping motions of the handler itself.

Abstract: A control rod driveline and grapple is disclosed for placement between a control rod drive and a nuclear reactor control rod containing poison for parasitic neutron absorption required for reactor shutdown. The control rod is provided with an enlarged cylindrical handle which terminates in an upwardly extending rod to provide a grapple point for the driveline. The grapple mechanism includes a tension rod which receives the upwardly extending handle and is provided with a lower annular flange. A plurality of preferably six grapple segments surround and grip the control rod handle. Each grapple rod segment grips the flange on the tension rod at an interior upper annular indentation, bears against the enlarged cylindrical handle at an intermediate annulus and captures the upwardly flaring frustum shaped handle at a lower and complementary female segment. The tension rods and grapple segments are surrounded by and encased within a cylinder.

Abstract: A control unit for a nuclear reactor constituted by a plurality of sealed vessels (17) communicating with the inside of the tank of the reactor (15) which they extend upwards above its cover (16); each containing a displacement mechanism for a unit absorbing neutrons in the core of the reactor. The drive motors (18) for the mechanisms are positioned in the upper part of the sealed vessels (17) within vertical aeration ducts (32). The control unit includes a supporting and insulating device for the sealed vessels (17) constituted by a vertical structure (23) fast to the cover of the tank (16), a horizontal strengthening plate (27) fixed to the upper part of the vertical structure (23) and a heat-insulating envelope (36) surrounding the sealed vessels (17) to a level below the level of the motors (18). The invention is particularly applicable to pressurized water nuclear reactors equipped with screw and nut mechanisms.

Abstract: An apparatus for posting materials into and out of an enclosure through a port in a wall of the enclosure. A container for the materials has a lid engageable with a door for the port and the container is supported in a cradle. An interlock bar extends between the port and a clamp assembly for the container, the bar being axially displaceable between first and second positions. In the first position of the bar one end thereof arrests movement of a door release mechanism and the bar is locked against axial displacement in the absence of a container in the cradle. In the second position of the bar the opposite end thereof engages and locks the clamp assembly for maintaining the container at the port.

Abstract: An intermediate seismic support system (100) comprises substantially square-shaped seismic support base members (102) which are suspendingly supported from rod position indicator coil assemblies (48) so as to peripherally surround control rod drive mechanism latch housings (20) in order to restrain deflections of the control rod drive mechanisms (12) under seismic conditions. In addition to being remotely installed and removed as a result of being mounted upon the RPI assemblies (48), the seismic supports are also remotely adjustable relative to one another through means of radially movable adjustment blocks (126) which are caused to move radially by means of axially movable actuator blocks (130). The latter blocks (130) are controlled by means of vertically extending actuator rods (134).

Abstract: During unrodded refueling, the drive rods and the control rods and coolant-displacement rods, attached to the drive rods, are removed from a fuel assembly, preliminary to the transfer of the fuel assembly, and are reinserted in the reactor after a replacement fuel assembly has been positioned in the reactor. Prior to the transfer of a fuel assembly, a lifting rig is secured to the upper-internals support. A lift plate is removeably mounted on latches in a lower position of the lifting rig. The latches are released and the lift plate is connected to the drive rods. The lift plate is then raised and removeably mounted on latches in an upper position on the lifting rig. In this position, the control rods and coolant-displacement rods are in the guides in the upper internals of the reactor. During the lift-plate raising operation, the loading on the drive rods is monitored and if the loading exceeds a predetermined magnitude, the excess loading is indicated.

Abstract: An underwater compressing and cutting apparatus for activated or contaminated components of the core of a nuclear reactor by means of which even components of different geometry and different properties can be compressed to reduce their bulk and cut. The apparatus comprises a frame and slidable sleds, one sled having a squeezing jaw and the other sled having a chopping knife which are operated by unidirectional hydraulic cylinders.

Abstract: In the upper internals storage pit of a containment building housing a pressurized water nuclear reactor, there is installed a three-coordinate positioning apparatus which has a frame-like, horizontally oriented base track enclosing an area designed to be occupied by any of the control rod clusters when lowered from the upper internals supported in the storage pit; a mechanism for supporting and vertically displacing the base track in the storage pit; a traversing track supported on the base track for back-and-forth displacement in a first horizontal direction; a mechanism for moving the traversing track in the first horizontal direction; and a carriage supported on the traversing track for back-and-forth displacements in a second horizontal direction perpendicular to the first horizontal direction. The carriage is adapted to receive thereon inspection equipment.

Abstract: A support arrangement is provided for the core modules of a nuclear reactor which provides support access through the control drive mechanisms of the reactor. This arrangement provides axial support of individual reactor core modules from the pressure vessel head in a manner which permits attachment and detachment of the modules from the head to be accomplished through the control drive mechanisms after their leadscrews have been removed. The arrangement includes a module support nut which is suspended from the pressure vessel head and screw threaded to the shroud housing for the module. A spline lock prevents loosening of the screw connection. An installation tool assembly, including a cell lifting and preloading tool and a torquing tool, fits through the control drive mechanism and provides lifting of the shroud housing while disconnecting the spline lock, as well as application of torque to the module support nut.

Abstract: A tool for removing split pin remnants which remain in anchor bores in the upper core plate of a nuclear reactor vessel after removal of guide tube assemblies therefrom, includes an elongated mast having parallel tubular members with handle apparatus at the upper end thereof and carrying at the lower end thereof a ram platform having an upstanding pin removal member. The ram platform is dimensioned to be lowered through any one of the guide tube seating apertures in the upper core plate. A locating plate mounted on the mast above the ram platform seats in the seating aperture and accurately positions the ram platform below the upper core plate with the pin driving member in registry with the pin bore. A hydraulic cylinder is mounted on the mast above the locating plate and has a piston rod extending through the locating plate and fixedly secured to the ram platform for moving it up and down to drive the pin from the bore. Hydraulic fluid is carried to and from the cylinder through the mast tubes.

Abstract: Apparatus for transferring, not only the fuel assemblies, but other component assemblies including control-rod assemblies, thimble-plug assemblies, poison assemblies and the like during refueling of a nuclear reactor. The apparatus includes an outer mast for guiding and protecting the component assemblies which are transferred, an inner mast movable vertically within the guiding mast. The inner mast has grippers for engaging and lifting or lowering fuel assemblies. The outer mast has internal grooved rollers along its length. The inner mast is formed at oppositely facing channels held in a rigid assembly by plates to which the channels are secured. Opposite corners formed by the flanges and the webs of the channels penetrate into the grooves of the rollers and the inner mast is guided and held in position by the rollers. The apparatus also includes an elongated tube within the inner mast movable vertically relative to the inner mast.

Abstract: Gas-cooled high temperature reactor asembly, including a safety container, a chamber disposed in the safety container, a reactor vessel disposed in the chamber for receiving a charge of spherical fuel elements at a given location therein, the reactor vessel being formed of blocks of at least one material from the group consisting of carbon and graphite, a steel shell surrounding the reactor vessel, a metallic base plate supporting the reactor vessel, the base plate having openings formed therein for passing cooling gas blown in the chamber into the given location for a fuel element charge, at least one downwardly extended pipeline having a connection to the base plate for discharging heated gases, the connection being detachable by axial motion of the reactor vessel, a removable cover disposed on top of the chamber, and means disposed on the reactor vessel for connecting the reactor vessel to hoisting apparatus.

Abstract: An improved method and apparatus for transferring nuclear fuel elements between a fluid-filled storage pool and a cask is disclosed. The cask is supported within and is restrained by a tank which is transported between terminal locations of a nuclear facility. Transfer of fuel elements between a storage pool and the cask is accomplished by coupling the tank to a port of the pool. The transporter accurately positions and restrains the tank during transfer. In a preferred embodiment, the cask tank is unweighted from the transporter during transfer and is advanced into a fluid-sealed engagement with a port surface of the pool. In an alternative arrangement, the cask tank remains supported on the transport during its transfer and lifting means mutually engaging the transporter and tank advance the tank toward the port surface for establishing a coupling between the port and the cask.

Abstract: Method of loading or unloading or both loading and unloading a nuclear reactor, wherein control rods of cruciform cross section are at least partly withdrawn, each of the control rods being associated with a respective group of four fuel assemblies respectively having elongated duct tubes of rectangular cross section and being disposed in respective corners of a rectangular mesh of a transverse support grid, the duct tubes forming therebetween a gap-shaped intermediate space of cruciform cross section for accommodating a respective one of the control rods of cruciform cross section, which includes, prior to withdrawing a respective control rod associated with the respective group of four fuel assemblies, unloading from the nuclear reactor at least one of the four fuel assemblies of the group thereof, and inserting a support member into the respective mesh so as to fix in the respective corners of the mesh the ends of two diagonally opposed fuel assemblies of the group remaining in the nuclear reactor; and sup

Abstract: The present invention relates to an installation for replacing a member in a contaminated fluid circuit. It also relates to a process for replacing this member.Installations for treating contaminated fluids, particularly radioactive fluids, comprise pipe systems in which the contaminated fluid flows. These systems or circuits have transfer, distribution, purification and cleaning members and the like, such as pumps, valves, filters, etc. These members are subject to wear, particularly when they have moving parts, and/or dirt or pollutants. It is therefore necessary to replace them by new members or overhaul them at intervals of varying length. Besides such replacements due to wear or pollution, it may be necessary to replace one member by another having different characteristics, e.g. one pump by another pump having different operating principles and/or flow rates.

Abstract: Apparatus is disclosed for decontaminating the wall of a boiling water reactor cavity. A chassis on wheels is rollable on the refueling floor along the cavity curb. A pair of horizontal wheels roll against the curb. A support member extends upwardly and laterally from the chassis to clear the personnel handrail. A mast depends from the support member into the cavity and includes a horizontal reaction wheel bearing against the cavity wall. A vertically positionable carriage is mounted on the mast and carries water spray nozzles directed against the wall.

Abstract: Alignment tool for the remotely controlled recalibration of resilient protruding contact dimples or springs in substantially square spacer grid meshes of nuclear reactor fuel assemblies, including an outer centering tube adapted to the cross section of a spacer mesh and rigid and resilient contact dimples protruding into the interior of the mesh in given directions, the outer centering tube having a window formed therein in the vicinity of the contact dimple, a gripper-actuating tube being concentrically surrounded by and axially movable within the outer centering tube, a pendulum rod having a free end and being disposed in the interior of the gripper-actuating tube and being axially fixed relative to the gripper-actuating tube and able to oscillate in the given protrusion direction of the resilient contact dimple to be recalibrated, a gripper attached to the free end of the pendulum rod, a restoring spring for exerting pressure on the gripper, and a run-on incline formed on the pendulum rod being engageable

Abstract: Device for the underwater disengagement of a nuclear reactor fuel element from a grapnel with at least two articulated fingers. The device is designed to be placed on the end of a duct for positioning fuel elements and includes jacks for adjusting the relative positions of the device and of the grapnel-fuel element unit and for maintaining these positions, further jacks for unfastening the fingers of the grapnel from the body of the grapnel and still further, jacks for tilting the fingers of the grapnel so as to enable the fingers to release their hold on the fuel element.

Abstract: An assembly fixture for cross-shaped control rods of boiling-water nuclear reactors with an upper core grid mesh for holding a core cell formed of four fuel assemblies having a gap therebetween and means disposed beneath the reactor core for driving the control rods in the gap, including a frame having corners formed therein, the frame being substantially the size of a core cell and being disposable on the core grid, templates diagonally oppositely disposed on the frame and extending into the core cell for lateral guidance of the control rods, stops for the control rods disposed on the templates, and a carrying handle having a first portion thereof being pivotable at one of the corners of the frame and a second portion thereof being locked to an opposite corner of the frame in a disassembled condition and swung out of the locked condition in an assembled condition.

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.