Abstract: A reactivity control device for storing nuclear fuel includes a top tube sheet, plurality of neutron absorber rods fixedly attached to the sheet, and a floating guide plate slideably mounted on the absorber rods for upward and downward movement between a lower position and an upper position. The reactivity control device is insertable into a spent fuel assembly in either wet storage in a spent fuel pool or dry storage in a canister. The absorber rods are inserted into empty guide tubes when the fuel assembly is removed from the nuclear fuel core normally occupied by control rods when in the reactor vessel. During installation, the device is lowered to insert the absorber rods into the guide tubes. The guide plate first engages the fuel assembly as the rods continue to slide through the plate until the tube sheet then engages the plate signaling the device is fully installed.

Abstract: A fuel assembly handling tool that can be lowered onto the top nozzle of a fuel assembly, positively latch the top nozzle, unlatch from the top nozzle, and be raised off the top nozzle of the fuel assembly. The tool head, that interfaces with the top nozzle has load bearing grippers that latch onto the fuel assembly, that are located in a storage position up within the tool while the tool is lowered onto the fuel assembly. The gripper fingers are then lowered into position during the latching process, and are raised back to the storage position during the unlatching process. In the storage position, the gripping fingers are spaced above the fuel assembly top nozzle when the tool head is resting on the nozzle.

Abstract: Disclosed is a fuel rod auto-loading apparatus for a nuclear fuel assembly, which disposes fuel rods in a fuel rod case in a bundle to assemble the fuel rods into the nuclear fuel assembly. The fuel rod auto-loading apparatus includes a fuel rod storage unit having a plurality of stacked racks for fuel rods, a fuel rod loading unit raised/lowered to the racks and transferring the fuel rods, a feeding unit placing the fuel rods in rows and loading the fuel rods into the fuel rod case, a fuel rod unloading unit selectively unloading some of the fuel rods stored in the fuel rod storage unit and transferring the fuel rods to the feeding unit, a fuel rod assembly lifter which is disposed parallel to the feeding unit, and a controller controlling driving of the fuel rod loading unit, the feeding unit, and the fuel rod unloading unit.

Abstract: A telescoping rod control cluster assembly change tool for moving control rod assemblies among fuel assemblies in a nuclear facility. The operation of the tool is completely mechanical and the telescoping feature enables the tool to have a relatively low profile when it is being moved and stored without housing a control rod assembly. Rigidly supported alignment cards guide a gripper that attaches to the control rod assembly as the control rod assembly is withdrawn into the tool with the alignment cards preventing any lateral or rotational movement of the gripper.

Abstract: A reactor installation tool and method for installing a reactor unit in a reactor tube. A reactor installation tool including a movable assembly and a fixed assembly linked together such that the movable assembly can be adjusted relative to the fixed assembly. The movable assembly including a reactor sleeve attachment means for releasably securing a reactor sleeve loaded with a reactor unit to the tool. The fixed assembly including an expandable clamping unit for releasably securing the tool to a reactor tube. A reactor unit can be installed in the reactor tube by adjusting the movable assembly to extract the reactor unit from the reactor sleeve as the fixed assembly is rigidly secured to the reactor tube. The fixed assembly can be released from the reactor tube and the reactor installation tool can be removed from the reactor tube.

Abstract: A handling tool (100) for securely handling a radioactive source (204) comprises a first securing device and a second securing device. The first securing device comprises a chamber (103), and an opening mechanism (105, 106) for opening the chamber (103). The opening mechanism opens the chamber when the chamber is brought in proximity with a source pocket that may contain a radioactive source (204), and the opening mechanism closes the chamber when the chamber is withdrawn from the source pocket (200). The second securing device comprises a gripping device (111, 112, 113, 114, 115, 116, 117) to grip and release a radioactive source (204), and a positioning mechanism (109, 110, 116) for positioning the gripping device in the source pocket (200) or inside the chamber (103) of the first securing device.

Abstract: An automated machine for loading nuclear reactor fuel, BP, or APSR pellets from small trays having rows of pellets into reactor rods of long length wherein the pellets are individually counted and loaded into rows of a loading tray according to the desired number of pellets per row and total number of pellets per tray with the loading tray controls being moved to a que tray where they may be weighted and there from to an unloading tray for sequential row loading into the reactor rod.

Abstract: A retaining tool for a telescoping refueling arm in a nuclear reactor, the retaining tool includes a plurality of support members coupled to a plurality of plates. The retaining tool includes a first plate having a first and a second side, a second plate spaced apart from the first plate, and a third plate having a first and a second side The third plate is spaced apart from the second plate so that the second plate is located between the first and third plates. The second side of the first plate engages the roller housings of the mast outer tube assembly, and the first side of the third plate engages the roller housings of one of the intermediate tube assembly to prevent the intermediate tube from extending and thus permitting the inner tube of the mast to fully extend.

Abstract: A fuel rod extracting machine which can extract the fuel rods one by one from a Korean type 17×17 Light Water Reactor fuel assembly comprises a multi-functional rotary head including a camera for measuring the positions of the fuel rods and securing nuts being fastened on the bottom end piece of fuel assembly, an impact wrench for unfastening the securing nuts, and a gripper for gripping and extracting the fuel rods one by one. All of these are installed on a single rotary disc, which is driven by a tool rotating motor, at intervals of 90 degrees. To improve the reliability and safety in using the multi-functional rotary head, a load cell and a remote compliance center are installed at the rear of the gripper. The load cell monitors a state of insertion of the fuel rod into a collet and measures a fuel rod extracting force. The remote compliance center provides the smooth insertion of the fuel rod onto the collet, even though there exists a small misalignment between them.

Abstract: A lifting fixture includes a housing; a plurality of jaws movable radially in and out of the housing to secure the fixture to a component to be lifted; at least one lifting bail extending from on end of the housing; and a screw mechanism operatively connected to the plurality of jaws for moving the jaws radially between an inward retracted position and an outward locking position. A related lifting and flipping process is also disclosed.

Abstract: An extraction tool for removing a partial length fuel rod from a fuel bundle assembly, wherein the partial length fuel rod has an upper end plug, the tool comprising an extension rod having a pair of gripper jaws mounted at one end thereof, the gripper jaws shaped and sized to engage the upper end plug; and a locking tube slidably received over the extension rod and engageable with the gripper jaws to lock the gripper jaws to the upper end plug.

Abstract: The inventive apparatus for remotely handling bar-like components which define a longitudinal direction includes a gripper mechanism for gripping the component including first and second gripper members longitudinally fixedly spaced from each other and oriented parallel to each other in planes transverse to the longitudinal direction. Each gripper member includes a jaw having at least one V-groove with opposing surfaces intersecting at a base and extending radially relative to the longitudinal direction for receiving the component in an open end between the opposing surfaces. The V-grooves on the jaw plate of the first and second gripper members are aligned in the longitudinal direction to support the component in the first and second gripper members.

Abstract: Apparatus for the remote grasping and safe transporting of an article and r remote coupling of an electrical plug connection comprises a first adapter device which is suitable for connection to a crane block and includes at least one load latch, adapted to be locked by a locking device, as well as a centrally arranged first plug member. It further comprises a second adapter device which is suitable for connection to an article to be transported and includes a pin member, adapted to be engaged with the load latch, as well as a second plug member disposed centrally within the pin member.

Abstract: The grab (1) comprises a tubular body (2) connected to a lifting means and a slide (3) mounted axially movably in the tubular body (2), so as to ensure the actuation of gripping pawls (20) carried by the tubular body (2). The tubular body (2) has a bell-shaped open end part (16), within which the slide (3) is connected to the inner surface of the tubular body over its entire periphery by means of an axially deformable gas-tight elastic member (30). The gripping pawls (20) are arranged within the bell-shaped end part (16) of the tubular element between the elastic member (30) ensuring its closure and its open end (16a). During the introduction of the lower part of the tubular body (2) into the liquid metal (8) in order to carry out the pick-up and displacement of an object (15), gas is trapped inside the bell (16) and forms a reserve, in which the gripping pawls (20) and their control means are located during the pick-up and displacement of the object (15) below the level (8a) of the liquid metal.

Abstract: A drive unit for gripping and rotating a fuel rod during inspection of the fuel rod. A housing has a drive motor mounted at its first end with a spindle rotatably mounted in the housing and directly coupled to the drive motor. A recess at one end of the spindle adjacent the second end of the housing receives a substantially donut shaped rubber bladder. A flanged port that extends radially from the bladder and is in fluid communication with the interior of the bladder provides a means for pressurizing the bladder. This causes radial inward expansion of the bladder for gripping a fuel rod to be inspected.

Abstract: The device comprises a vertical pole (11) having a manipulating handle (14) at its upper end and a gripper (22) fastened to one end of a gripper support (20) mounted pivotally about a horizontal axis (21) at the end of the pole (11). Springs (25, 29) make it possible to return the gripper into a grasping position distant from the vertical axis ZZ' of the pole (11). A mechanism (24) for controlling the gripper in order to open and close it is carried by the gripper holder (20). This mechanism is connected to a remote-actuation mechanism by a flexible transmission element (37).

Abstract: The crane operated lifting apparatus for safely gripping and holding obje (11) includes a plurality of movable pawls (3) which enter into a groove, aperture, or bore (14) of an object (11) which is to be transported. To move the pawls (3), a driving member (4) is provided which is displaceable in a basic body (1). The lifting apparatus also includes comprises two holding members (2,5) the first of which is firmly attached to the basic body (1) while the second one is connected to the driving member (4) for a tilting or pivoting motion. Thus, the hook of a crane may selectively grasp either one of the two holding members (2,5) or both of them (2,5) together, and it may also selectively swing the second holding member, (5). In this manner it is possible to have all the functions, such as locking, unlocking, and conveying, accomplished by the hook of a crane alone.

Abstract: A spent fuel rack for storing fresh fuel assemblies, or spent fuel assemblies removed from a nuclear reactor, which includes a base plate having multiple cells of modular construction welded at their bottom ends to the plate. The cells are formed of L-shaped sections having walls which support neutron absorbing material, and the walls of one cell are common to the adjacent cells. The base plate includes openings primarily for receiving the bottom nozzle of a fuel assembly, but they further serve as access openings for apparatus used for leveling the base plate and for lifting and transferring the base plate with or without cells thereon, to a different area.

Abstract: A gripping tool for a device for the remote-controlled removal of samples in housings with heads from a container includes a mast having a first coupling part. A second coupling part is opposite and associated with the first coupling part. A guide bar elastically bears on the second coupling part in a telescoping manner with pivots disposed on the guide bar. At least two catches of a two-armed lever are disposed on the pivots and have guide grooves formed therein. A bushing surrounding the guide bar has guide pins each engaging a respective one of the guide grooves. At least one remotely controlled linear drive moves the bushing in the direction of the longitudinal axis of the bushing for surrounding the head of the sample housing with the catches like tongs.

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: A tool for gripping a remotely located article includes an elongated tubular housing, a tool actuating assembly connected to one end of the housing, and a jaw support member connected to the other end of the housing. A first jaw member having a gripping surface is supported on the jaw support member by a first pair of arms, and a second jaw member having a gripping surface is supported on the jaw support member by a second pair of arms so that the gripping surfaces of the jaw members are disposed in parallel, confronting relation. The two pairs of arms are slidingly and pivotably connected to the jaw support member so that the gripping surfaces of the jaw members may be moved between a first, open position and a second, closed position for gripping an article. When moving between the first and second positions the gripping surfaces move in parallel relation to one another. The tool actuating assembly includes an over-center toggle mechanism so that the jaws are held locked when in the gripping position.

Abstract: An absorber rod for nuclear reactors with a pile of spherical fuel elements, which is inserted directly into the pile, in order to affect the prevailing neutron flux by absorber material located in an annular gap between two concentric cylindrical rod elements. The absorber rod has concentric rod elements arranged in pairs, a common rod tip and common connecting pieces. The rod elements are cooled by flow of gas and the inner cylindrical rod element performs the support function, i.e., it absorbs and transmits forces and moments originating in the movements of the rod during insertion and extraction.

Abstract: The invention is directed to an apparatus for pulling a plurality of fuel ds out of a fuel element structure and has a gripping device which is capable of clamping the fuel rods. To reliably pull the fuel rods from an irradiated nuclear reactor fuel element, the apparatus includes an upper guide rod and a lower tension rod which lie horizontally and are arranged one above the other. The rods extend through a plurality of clamping plates in a direction perpendicular to the latter. The clamping plates are mounted so as to be parallel to each other and spacers are arranged between each two mutually adjacent ones of the clamping plates. The spacers are arranged on both rods with the width of the spacers on the lower rod beign slightly less than the diameter of a fuel rod. The clamping plates are pressable together by means of a tensioning device. The apparatus of the invention enables the gripping device to be placed on the fuel element in a simple manner.

Abstract: A thimble grip fuel assembly handling tool (20) for transporting fully loaded fuel assemblies (52) is disclosed. The tool (20) comprises an elongated mast (23) slidingly disposed within an elongated cylinder (113), the cylinder being of a length less than the mast (23) such that the tool defines a mast fill-up position (126) and a mast full-down position (128). A cage (110) assembly acts to protect the gripping means (32) when the tool is transported in the mast full-up position (126). The gripping means (32) is comprised of a plurality of gripping members (49) which grip the inside diameter of control rod guide thimbles (50). The load path is distributed in the tool such that when the fuel assembly (52) secured to the gripping means (32) is raised, the weight of the fully loaded fuel assembly (52) acts to increase the gripping force on the fuel assembly.

Abstract: During the dismantling of a nuclear reactor fuel assembly, there is a simultaneous gripping of all the rods (a) arranged in square grid form in said assembly using a device (10) which effects a clamping or locking at the end of the rows of rods. For this purpose, device (10) has passageways (26) penetrated by the ends of two adjacent rows of rods (a). In said passage ways are trapped mobile members (34, 34') arranged in such a way that each rod is placed between two adjacent members. By applying a locking force on the mobile end members in each passageway (26), each rod is gripped between two members (34, 34'). Preferably, the mobile members (34, 34') are provided with abutments limiting the locking or clamping force individually applied to each rod. For filling the gaps of the grid of rods (a) corresponding to the locations occupied by the guide tubes in the assemblies, rollers (78) are placed in the passageways (26) at the corresponding locations.

Abstract: A latching assembly for use in latching a cable to and unlatching it from a given object in order to move an object from one location to another is disclosed herein. This assembly includes a weighted sphere mounted to one end of a cable so as to rotate about a specific diameter of the sphere. The assembly also includes a static latch adapted for connection with the object to be moved. This latch includes an internal latching cavity for containing the sphere in a latching condition and a series of surfaces and openings which cooperate with the sphere in order to move the sphere into and out of the latching cavity and thereby connect the cable to and disconnect it from the latch without using any moving parts on the latch itself.

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 method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water-storage pool. The individual rods are moved from a fuel assembly and through a transition funnel by movable grippers at opposite ends of the funnel. One movable gripper reciprocates between gripping and release positions in a gap between the fuel assembly and the transition funnel. A stationary gripper can be located in the gap at the entry side of the funnel to hold the fuel rods while the movable gripper returns from a release position to the gripping position. Both grippers include members which can be pressed into frictional engagement with the spaced apart array of fuel rods. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the transition funnel and emerge as a bundle.

Abstract: In order to automatically initiate without any intermediate instrumentation chain the drop of absorbing members into the core of a nuclear reactor, in the of a drop in the cooling liquid level to below a given threshold and, optionally, a rise in the pressure to beyond a maximum permitted value, between each absorbing member and the bar supporting said member is provided an apparatus, which comprises tongs formed by at least two fingers, said tongs normally being locked in a gripping position by locking members, such as balls. A float mounted in the bar controls the unlocking of the tongs in either of the two conditions requiring the dropping of the absorbing members.

Abstract: A nuclear fuel rod loader for pulling fuel rods into a fuel assembly skeleton has a rod gripper with slots defining fingers. The rod gripper passes through the grids of the skeleton on its way to a fuel rod magazine. An inner shaft of the rod gripper spreads open the fingers to engage a groove in the cavity of the end plug of the fuel rod. The rod gripper is retracted, pulling the coupled fuel rod into the fuel assembly skeleton. The rod gripper has a chamfer surface at the closed slot end of each slot to avoid the rod gripper damaging a dimple during entry into the grids of the fuel assembly skeleton. The rod gripper has a stress relief surface at the closed slot end of each slot to avoid failure in the flexing fingers.

Abstract: An apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water-storage pool. The individual rods are moved from a fuel assembly and through a transition funnel by movable grippers at opposite ends of the funnel. One movable gripper reciprocates between gripping and release positions in a gap between the fuel assembly and the transition funnel. A stationary gripper can be located in the gap at the entry side of the funnel to hold the fuel rods while the movable gripper returns from a release position to the gripping position. Both grippers include members which can be pressed into frictional engagement with the spaced apart array of fuel rods. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the transition funnel and emerge as a bundle.

Abstract: A method for testing vertically disposed fuel rods combined in fuel rod clusters or fuel assemblies in rack positions of a fuel assembly rack of a water-cooled nuclear reactor includes inserting a holding device into first and second unoccupied rack positions while maintaining an unoccupied third rack position therebetween, inserting a fuel assembly to be tested into the third rack position with a lifting device, locking the fuel assembly to the holding device while the fuel assembly is in the third rack position, moving the fuel assembly vertically upward with the holding device, interrupting the upward motion of the fuel assembly, subsequently inserting a probe with a test device into spaces between the fuel rods in a testing operation, moving the fuel assembly vertically downward with the holding device after completing the testing operation until the fuel assembly is deposited in the third rack position, removing the fuel assembly with the lifting device, and depositing another fuel assembly to be tested

Abstract: A handling apparatus which is intended primarily for operations involving pulling and pushing nuclear fuel rods which are carried out when dismantling assemblies, comprising a handling head in which there are provided a plurality of cylinders (6) in which grippers are slidable, formed by two coaxial parts (4, 10) by means of pistons (4a, 4b) which are fixed with respect thereto. Said pistons define three annular spaces (A, B, C) which are supplied by three individually controllable hydraulic fluid circutis (La, Lb, Lc). Such fluids provide for opening and sliding movement of the grippers with respect to the head as well as control of the maximum admissible force in respect of traction or compression on the grippers.At the upper end of each gripper two travel limit switches give the individual situation of each thereof.

Abstract: A gripper with leaf springs having fingers near their ends to engage and disengage work. The springs are respectively connected in an annular array to the end of a cylindrical support. The springs are diverged or expanded to cause the fingers to engage the work and are converged or collapsed to cause the fingers to disengage the work. During the diverging and the converging each spring is pivoted about its junction with the support. The diverging and the converging of the springs is effected by an actuator or mandrel including a rod having a nose at its outer end. The actuator is reciprocable within the springs between advanced and retracted positions. Near its outer end the rod has a conical cam surface which engages cooperative internal cam-follower surfaces on the springs to diverge the springs when the actuator is in advanced position. The nose has a skirt which engages the outer ends of the springs, i.e. the fingers, to converge the springs near the ends when the actuator is in retracted position.

Abstract: A method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water storage pool. The individual rods are drawn upwardly through a transition funnel from the fuel rod assembly into a fuel rod container. Individual pulling elements extend through the fuel rod container and through the transition funnel. The pulling members each includes a renewable metal cap and an electrode for welding the cap to the top end of an individual fuel rod within a fuel rod assembly. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the fuel rod container.

Abstract: An improved end plug for attachment on an end of a cladding tube of a nuclear fuel rod facilitates using a gripper tool for loading the fuel rod into a nuclear fuel assembly. The end plug includes an inner portion adapted to be inserted into the end of the tube and an outer portion adapted to extend from the end of the tube when the inner portion is inserted therein. The outer plug portion has a body part disposed adjacent the tube end and a leading part disposed remote from the tube end. The leading part of the outer plug portion has a hollow interior cavity defined therein, an exterior annular truncated surface defined on a terminal end thereof and an exterior annular tapered surface defined on a lateral side thereof. The exterior tapered surface extends between and merges with the body part and the exterior truncated surface and provides sufficient angular inclination so as to facilitate insertion of the end plug when mounted on the fuel rod tube end into the fuel assembly.

Abstract: A method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water-storage pool. The individual rods are moved from a fuel assembly and through a transition funnel by movable grippers at opposite ends of the funnel. One movable gripper reciprocates between gripping and release positions in a gap between the fuel assembly and the transition funnel. A stationary gripper can be located in the gap at the entry side of the funnel to hold the fuel rods while the movable gripper returns from a release position to the gripping position. Both grippers include members which can be pressed into frictional engagement with the spaced apart array of fuel rods. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the transition funnel and emerge as a bundle.

Abstract: A device for moving a cluster of nuclear reactor control elements, more especially usable for changing the moderation rate of a nuclear reactor, comprising a vertical shaft having nippers cooperating with grabs integral with sub-clusters. Each grab comprises resilient fingers engageable with the nippers and lockable by snap fitting on the fixed upper structure. Each nipper is formed so as to engage resilient fingers and unlock them from the upper structure when the nipper is raised above the position which causes locking of the grab on the structure. A fixed lower structure is provided for causing forced disengagement of the nipper when this latter is lowered beyond the rest position of the grab on this structure. Raising of the nipper then drives the grab by simple bearing force.

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: In a system for inspecting fuel assembly guide thimbles, an apparatus for handling drag gages insertable within the guide thimbles includes a spider rotatably mounted to an upright support structure and supporting drag gages in a series of angularly-displaced storage positions about the support structure, and a drive operable to rotate the spider relative to the support structure and thereby moving the gages about an endless path to dispose a selected one thereof at a retrieval-and-return station. An elongated track mounted to the support structure extends outwardly above the spider, and a trolley is movable along the track between a remote position overlying a work station containing the fuel assembly to be inspected and a position adjacent to the support structure and overlying the drag gage retrieval-and-return station.

Abstract: A tool (78) for grasping a multiplicity of nuclear fuel rods (42) to remove them from a nuclear fuel assembly (32) and relocate them, preferably, into a fuel consolidation device (86). The tool has a gripper head (200) reciprocably guided within a shroud (80). A distinct jaw mechanism (216) for grasping each of the multiplicity of fuel rods is carried by a common frame (214) and actuated and controlled by a distinct means (232, 234, 242). A key feature of the gripper head is that each jaw mechanism (216) has an neck portion (244) to offset the actuation means (232, 234) from the moving jaw portion (220). The shroud carries alignment means (82, 206) for precisely orienting the tool relative to a targeted group of rods within the assembly, so that the spacing of the rods is maintained as they are pulled up into the shroud by the gripper head.

Abstract: Apparatus for removing irradiated clips from an irradiated fuel assembly comprises a remotely operated tool including hydraulic or pneumatic jaws operable for withdrawing a clip from fuel rods, while supporting the portions of the fuel rods both above and below the clip to avoid damaging the rods during removal of a clip, and further including a support tube held captive in a carriage mechanism for moving the tool into positions for either clip removal, or for ejection of a removed clip from the tool into a clip disposal basket.

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: The invention relates to an apparatus for handling nuclear fuel assemblies, as well as to an assembly for use with such an apparatus.The apparatus comprises a vertically axed guide tube in which is displaced a grapnel, suspended on a flexible connection such as a chain, under the action of a reduction gear. As the grapnel is immobilized in rotation in the guide tube, an assembly is gripped by means of a bayonet system by controlling the rotation of the guide tube-grapnel assembly by a reduction gear. The apparatus can in particular be suspended on the small and/or large rotary plug of a fast neutron nuclear reactor. It can also be used in a handling hod under gas.

Abstract: A gravity actuated gripper includes two concentrically interleaved shells ich are displaceable with respect to one another in two positions for gripping molds containing radioactive material, with the fill opening or upper edge of the molds being provided with a circumferential carrying ring behind which engage balls to perform the gripping. The gripper is intended to be particularly robust and assure high operational reliability under all conditions. For this purpose, a special control is provided for the two positions, the control including a switching ring which corresponds with rings of crown teeth attached to both shells. Due to the special configuration of the teeth and an up-and-down movement of the switching ring, the two shells can take on a gripping position and a release position.

Abstract: A gripper device (24) for attachment to the inside of a tube (12) has a shaft member (26) including an upper tapered portion (30) surrounded by a generally cylindrical sleeve member (34) having at least two holes (38) opposite the tapered portion of the shaft. The sleeve outer diameter is slightly less than the inner diameter of the tube targeted for attachment. A spring (32) is connected between the shaft member and the sleeve member, for biasing the tapered shaft downwardly relative to the sleeve. A round bearing or hard ball (36) is located in each hole such that downward motion of the shaft relative to the sleeve urges the balls outwardly to protrude from the sleeve surface against the tube wall. The device is installed by pushing on stem (28) at the lower end of the shaft member to insert the device into the tube. A flange (44) is formed at the lower end of the sleeve to limit the sleeve insertion into the tube.

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 safety device to be applied to the vertical displacement of, for example, the control rods of a nuclear reactor, comprises the combination of a stator placed on the outside upper part of an impervious, nonmagnetic cylinder within the inside of which a rotor is mounted about its shaft, free in axial translation, with the shaft rotatable with the rotor but fixed in translation, and with the rotation of the shaft transferred to a hollow threaded rod which will transfer rotation to a nut slidable vertically inside the cylinder, supporting the control rods therebelow; the rotor also controlling the opening and closing of a jaw for holding and releasing the hollow threaded rod.

Abstract: A suspension grapple adapted especially for use in transferring nuclear fuel assemblies to a reactor core, a fuel pool and the like. It includes a hook swingable into and out of engagement with the fuel assembly, a first lock mechanism for automatically locking the hook in lifting engagement with the fuel assembly, and a remotely operable mechanism for disabling the first lick mechanism to disengage the hook from the assembly. A second lock mechanism is provided to lock the hook out of engagement with the fuel assembly. The grapple further includes an automatic release mechanism which operates to release the hook from that out-of-engagement position and move it into lifting engagement with the fuel assembly upon the grapple abutting the assembly in a predetermined positional relationship therebetween when being lowered to engage the assembly.

Abstract: A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing.