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 container is provided generally including a first portion configured for containing a first substance and a second portion configured for containing a second substance. The first substance is applied to process, generally for production of a useful byproduct. Further, the second substance may be a useful byproduct of the process, or may be a different byproduct of the process. The volume of the first portion may be variable, the volume of the second portion may variable, or the volumes of the first portion and the second portion may be variable, such that the first portion and the second portion fit within the total volume of the container.

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: When a radioactivated reactor pressure vessel is carried out from a nuclear reactor building of a nuclear power plant, a first opening portion for carrying out the reactor pressure vessel is provided in a roof of the nuclear reactor building, a radiation shield for covering the reactor pressure vessel and shielding radiations is carried into the reactor building through the first opening portion, and installed on a reactor shield wall, lowering a hanger through the first opening portion and a slit provided on an upper lid of the radiation shield, a part of a lid of the reactor pressure vessel and a part of the upper lid of the radiation shield are abutted by hanging up the reactor pressure vessel by the hanger, and the reactor pressure vessel and the radiation shield integrated therewith are raised and carried out of the reactor building, whereby the shield can be easily mounted on the large-sized apparatus in a short time and a dose of radiations exposed to a worker when the shield is mounted can be reduced.

Abstract: A removable rail assembly for use with a spent fuel handling machine, including a support rail, a rail guide carried by the support rail, a rail joint connector supported by the rail guide for coupling the rail guide to adjacent rails, and at least one jacking screw supported by the support rail for lifting the support rail assembly. Another embodiment of the invention includes a second jacking screw received in the top surface of the rail guide. The joint connector is tongue and groove joint with a tapered parting line that permits a tight fit between the removable rail and adjacent fixed rails. During removal of the removable rail, the jacking screw distributes a uniform lifting force along the length of the rail, loosening the joint connector. Once the joint connector is loosened, the rail is coupled to a lifting crane and transported to a storage area.

Abstract: A loading machine for simultaneously transferring fuel elements between a reactor core and a storage rack in a nuclear power station has a mast divided into individual mast parts. Each mast part has its own gripping and guiding devices for gripping and holding the individual fuel elements. The mast is provided on a trolley. At least one of the mast parts is movable horizontally on the trolley and is rotatable about its longitudinal axis. The individual fuel elements can be lifted out of the reactor core simultaneously, their position relative to each other can be changed, and the fuel elements can be set down on a storage rack or a workplace. A method for transferring fuel elements in a nuclear power station is also provided.

Abstract: The extraction tool includes an inner rod pivotally mounting at its distal end a pair of collet sections having mechanical clamping jaws. An outer tube may be advanced and retracted axially relative to the inner rod by a locking tube nut threaded on a sleeve forming part of the inner rod. The inner rod and outer tube are non-rotationally engaged with one another. By axially displacing the outer tube relative to the inner rod, the collet sections are movable between collet-open and closed positions such that the jaws of the collet can respectively grasp and release the barbed end of the end plug of the fuel rod.

Abstract: A transfer device for moving a poison rod assembly between fuel cells in a nuclear fuel storage facility, where the poison rod assembly has a plurality of poison rods depending from a web. The transfer device includes a frame assembly, a poison rod assembly lifting assembly, which is moveable between an upper position and a lower position, a plurality of comb assemblies. The comb assemblies are slidably mounted on the frame so that the comb assemblies slide between an open position and a closed position as the lifting assembly moves from its lower position to its upper position.

Abstract: A cask is lifted from outside of a nuclear reactor building through an opening which is opened at a portion of the nuclear reactor positioned just above a nuclear reactor pressure vessel. By maintaining the cask under a lifted condition a shroud which is an internal structure of the nuclear reactor is transferred and inserted to the cask from the nuclear reactor vessel. After that, an inlet port of the cask is closed, and the cask together with the shroud is lifted outside of the nuclear reactor building through the opening. The internal structure of the nuclear reactor can be speedily carried from the nuclear reactor building with reduced exposure of operators to radioactivity from the radioactive internal structure.

Abstract: A method of handling an internal structure of a nuclear reactor utilizing a receptacle such as a container or a cask. A cask, for example, is lifted from outside of a nuclear reactor building through an opening which is opened at a portion of the nuclear reactor positioned just above a nuclear reactor pressure vessel. While maintaining the cask under a lifted condition, a shroud, which is an internal structure of the nuclear reactor, is transferred and inserted to the cask from the nuclear reactor vessel. Thereafter, an inlet port of the cask is closed so that the cask substantially surrounds the shroud and substantially prevents radiation from the shroud passing therethrough. The cask together with the shroud is lifted outside of the nuclear reactor building through the opening. The internal structure of the nuclear reactor can be speedily carried from the nuclear reactor building with reduced exposure of operators to radioactivity from the radioactive internal structure.

Abstract: A preventive maintenance apparatus for structural members inside a nuclear reactor pressure vessel includes a ring-shaped guide rail having a plurality of lugs which is placed on an upper flange of a core shroud provided inside a reactor pressure vessel. At least some of lugs separately engage with a plurality of guide rods provided on an inner surface of the reactor pressure vessel. A turntable is rotated on the guide rail. A first discharging nozzle moving apparatus placed on the turntable moves a first discharging nozzle for adding compressive remaining stress to an outer surface of the core shroud in a radial direction of the core shroud and in an axial direction of the core shroud. A second discharging nozzle moving apparatus placed on the turntable moves a second discharging nozzle for adding compressive remaining stress to an inner surface of the core shroud in a radial direction of the core shroud and in an axial direction of the core shroud.

Abstract: A rigging system for reactor closure head and reactor internals lifts. The system includes a plurality of latchbox pendants attached to the lifting structure of an overhead crane. A first set of a plurality of lifting lugs is attached to the reactor internals, each of the lifting lugs corresponding to one of the plurality of latchboxes. A second set of a plurality of substantially identical lifting lugs, each of the lifting lugs corresponding to one of the plurality of latchboxes, is attached to a plurality of solid rod lifting pendants attached at one end to the reactor closure head. In operation, the latchbox pendants may be rigged once to the overhead crane for handling reactor internals and left in place throughout the entire rigging sequence without changing to turnbuckle pendants for reactor closure head handling.

Abstract: A fuel assembly locator for guiding and inserting nuclear fuel assemblies into a grid plate of a reactor vessel during reload. In the preferred embodiment, the fuel assembly locator includes a plurality of generally trapezoidal guides each having a multiplicity of serially increasing tiered slope regions for gradually directing the fuel assembly precisely into a grid plate opening. The increasing slope regions allow greater positional tolerance between the exterior of the fuel assembly and the interior opening of the grid plate opening initially, thus requiring less time and precision to align the fuel assembly with respect to the grid plate opening. The tolerance then gradually decreases since the slope of each successive tier is greater than the previous tier, thus precisely directing the fuel assembly into alignment with the grid plate opening for insertion therein.

Abstract: The present invention relates to a method and a device for correction of the movements of a suspension device and positioning thereof in a fluid. The suspension device is provided with a first and a second end, and the first end is suspended from a point (S). A correction device is arranged at the second end of the suspension device and adapted to generate a force which provides an acceleration in the fluid so that the position of the second end of the suspension device is corrected.

Abstract: A camera mast system permits remote inspection of nuclear fuel assemblies and other components of nuclear reactors. The system includes a camera mast assembly mounted on a refueling mast which may be positioned over a selected fuel assembly in the reactor core. An extendable camera mast having a camera mounted thereon moves vertically with respect to a stationary camera mast and the refueling mast in order to allow for visual inspection of various components in the reactor core. The camera mast assembly preferably includes a video cable take-up mechanism for handling the camera video cable as the extendable camera mast is moved up and down. The camera mast assembly is preferably removably mounted on the refueling mast in order to aid in installation and removal. The removable mounting also allows the camera mast assembly to be used independently of the refueling mast.

Abstract: An automatic refueling apparatus has a travel carriage, a traverse carriage and a fuel assembly grappling apparatus composed of a grapple, an extension pipe and a hoist. The automatic refueling apparatus also includes a system for controlling automatic fuel transferring operations, in which a calculation unit and a control unit are provided. After the positions of a start point and a target terminal point of a fuel assembly transfer are input through an input device, the calculation unit determines the shortest route from the start point to the terminal point in a preset fuel transferring permitted region, and the control unit generates driving command signals for moving the fuel assembly grappling apparatus along the obtained shortest route through a simultaneous control along X, Y, Z (Z: an elevation direction vertical to a X-Y horizontal plane of the grapple) and .theta. (a rotation direction in a X-Y horizontal plane of the grapple) axes.

Abstract: An automatic nuclear fuel assembly replacing apparatus has a bridge and a trolley movable in X and Y axis directions, respectively. Mounted on the trolley is a nuclear fuel grapple movable in a Z axis direction and rotatable about the Z axis. A television camera mounting unit is also mounted on the trolley and movable in the Z axis direction. A control system of the apparatus moves the bridge and the trolley so that the center of an underwater television camera supported by the camera mounting unit is centered to a desired target position. Then, calculations are performed on the deviations of the position of the thus positioned camera and a target fuel assembly in the X and Y axis directions and about the Z axis, respectively. The thus calculated results are corrected by a deviation between the fuel grapple and the camera, whereby the position of the fuel grapple is finally controlled to be in alignment with the position of the target fuel assembly in the X and Y axis directions and about the Z axis.

Abstract: A refueling system for a nuclear power plant utilizing a data network to provide for automatic control and enhanced monitoring of the entire fuel transfer process. The refueling system of this invention provides integrated control of the refueling machine within the containment building, the spent fuel handling machine within the fuel storage building, and the fuel transfer system between the buildings. The system provides supervisory control of the overall system operation via a remote control station, while at the same time, having the capability for local on-line control of each element of the system in the event of network failure. The system may automatically identify individual fuel assemblies with an optical scanner. An in-mast sipper connected to the network automatically tests for leaking fuel assemblies. A revised core load pattern and a revised sequence plan can be calculated by the system in the event of the discovery of a leaking fuel assembly.

Abstract: An improved system for transferring fuel bundles and control blades between a fuel storage pool and a fuel core of a nuclear reactor. The transfer system includes a carriage which is movable horizontally along a track which is submerged in a transfer pool. The carriage has a slot for receiving interchangeable baskets of different configurations and capacities. One basket is designed to receive a fuel bundle assembly; another basket is designed to receive a control blade. These baskets have the same mounting hardware. The basic construction of the carriage and baskets is aluminum with accessories of stainless steel. Each basket can be hung on the carriage and locked in place with a bolt. Each basket has a bail for handling with existing grapples. When not in use, the baskets are stored and locked in place on a storage rack.

Abstract: An auxiliary platform has a one-ton hoist which may be used in conjunction with a rigid pole handling system. The positioning of the one-ton hoist, as well as the positioning of a trolley on which the hoist is mounted and the positioning of the platform, is centrally controlled at a control panel. In one embodiment, a new set of tracks are provided on either side of a refueling pool. A pair of cavity platforms are installed over the edges of the reactor cavity to receive the new set of tracks and to thereby allow the auxiliary platform to travel over the reactor cavity. In another embodiment, the existing tracks are extended and a single new track is provided between the equipment pool and the reactor pressure vessel head pedestal and spent fuel cask washdown area. The auxiliary platform is made extendable so that it can travel over the width of the existing tracks and also over width defined by the new track and one of the existing tracks.

Abstract: A nuclear fuel bundle fuel transfer system includes a transfer pool containing water at a level above a reactor core. A fuel transfer machine therein includes a carriage disposed in the transfer pool and under the water for transporting fuel bundles. The carriage is selectively movable through the water in the transfer pool and individual fuel bundles are carried vertically in the carriage. In a preferred embodiment, a first movable bridge is disposed over an upper pool containing the reactor core, and a second movable bridge is disposed over a fuel storage pool, with the transfer pool being disposed therebetween. A fuel bundle may be moved by the first bridge from the reactor core and loaded into the carriage which transports the fuel bundle to the second bridge which picks up the fuel bundle and carries it to the fuel storage pool.

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: The device comprises, in positions adjacent to the bearing surface (15) of the transportable container (1) on the fixed structure, a first member (16) for plugging the central channel (3) of the container (1), and a second member (17) for plugging the upper end of the well (18). These members are arranged inside a zone of contact of at least one o-ring seal (13) with the bearing surface (15). Each of the plugging members (16, 17) comprises a planar surface arranged, in its closing position, in the planar bearing surface (15) of the container or in the planar bearing surface of the fixed structure, respectively. At least one of the plugging members (16, 17) can move in the axial direction of the well (18) and of the central channel (3) of the container (1) and in a transverse direction perpendicular to the axial direction, between its closing position and its opening position.

Abstract: The transfer cupboard (1) comprises a solid body (2) made of a radiation-absorbing material, in which is provided an axially directed receptacle (3) for receiving the assembly (4). The cupboard (1) comprises at least one circuit (15) for cooling the assembly (4) by gas and integrated in the body (2) of the cupboard (1). The cooling circuit comprises at least one main axially directed gas-circulating channel (16) formed in the body (2) of the cupboard, at least one device (18) for the circulation of gas in the cooling circuit (15), and at least one device (17) for purifying the circulating gas, which are arranged in the vicinity of one end of the main channel (16). Two secondary channels (20, 21) formed in the body (2) of the cupboard make it possible to connect each of the ends of the main channel (16) to a corresponding end of the receptacle (3) for the fuel assembly (4), by which the cooling circuit is closed again.

Abstract: A fuel rod alignment template and method for loading fuel rods in a nuclear fuel assembly. Front and rear guide plates are provided with a plurality of holes corresponding to cells in the fuel assembly to be loaded. The guide plates are rigidly connected together by connecting rods that extend beyond the front guide plate and are sized to be received in the guide tubes of the fuel assembly. When attached to the fuel assembly with the front guide plate abutting the guide tubes the holes in the guide plates and cells in the grid assemblies of the fuel assembly are in coaxial alignment. This provides positive guidance to the fuel rods as they are inserted into the fuel assembly to prevent mis-tracking and damage to the fuel assembly.

Abstract: A drive system for propelling first and second drive trucks of a bridge includes a first motor and transmission for driving the first truck, an independent second motor and transmission for driving the second truck and a controller for coordinating the first and second motors for maintaining differential transverse travel between the first and second drive trucks to less than a predetermined maximum. A first closed-loop controls velocity of the first drive truck, a second closed-loop controls velocity of the second drive truck, and an auxiliary closed-loop senses a difference in travel of the first and second drive trucks and adjusts performance of at least one of the first and second closed-loops.

Abstract: A fuel assembly transfer basket for a pool type, liquid metal cooled nuclear reactor having a side access loading and unloading port for receiving and relinquishing fuel assemblies during transfer.

Abstract: A blending/loading system wherein an elongated cylinder or fuel rod is positioned on a turntable underneath a series of hoppers containing the particulates to be blended/loaded. Separate transfer tubes from each hopper are aligned with the cylinder and are subsequently lowered into the cylinder. Upon lowering, the cylinder is rotated and nozzles at the ends of the transfer tubes are activated to discharge, disperse and mix the stored particulates into the rotating cylinder. As the cylinder fills up, the transfer tubes are withdrawn from the rotating cylinder until the desired amount of fill is reached. Afterwards, the nozzles block any additional flow from occurring as they are raised out of the cylinder.

Abstract: An end cap is mounted on a fuel rod gripper to cover the end portions of fingers thereon to minimize impacts with grid cell dimples. The fingers are defined by circumferentially-spaced and longitudinally-extending slots in the gripper which permit the finger end portions to radially expand and retract between corresponding expanded and collapsed conditions. The end cap includes a body having a forward camming portion and a rearward mounting portion. The rearward mounting portion is hollow and configured to fit over and cover the end portions of the gripper fingers with the forward camming portion extending forwardly thereof. Also, circumferentially-spaced and longitudinally-extending attachment flutes are dispsoed internally of the hollow mounting portion of the body and project radially inwardly therefrom.

Abstract: Refueling apparatus for a nuclear reactor including a bridge and a trolley. The bridge is moveable in tracks along the containment of the pit in which the reactor is immersed in water and the trolley moveable in tracks on the bridge at right angles to the tracks on the bridge. The trolley carries a mast assembly for engaging, raising, and lowering a nuclear-reactor component assembly involved in the refueling. The mast includes an elongated member for engaging control-rod and thimble plug assembly and a gripper for raising fuel assemblies. The elongated member is moveable upwardly or downwardly.A TV camera and a light source and reflector are mounted on the gripper assembly at the lower end of the mast assembly. The source and reflector illuminate a selected part of the fuel assembly which is to be transferred and the camera is directed to this part so as to pick up an image of this part. The cooperative TV-receiver monitor on the console on the trolley is provided with cross hairs.

Abstract: Refueling apparatus for a nuclear reactor including a bridge and a trolley movable at right angles to each other over a pit. The trolley carries a mast assembly for engaging, raising, lowering reactor component assemblies.The mast assembly carries electric cables and compressed air hoses from electric and air driven components on the mast and is rotatable relative to the trolley. The cables and hoses are passed from the mast assembly through a flexible cable tray which is oriented with its cable-carrying slot vertically in the configuration generally of an S. The cable tray is connected to the mast at one of its ends, is partly wound around the mast from that end and departs from the mast a predetermined distance at the opposite end. The tray remains fixed at the opposite end as it is wound on or unwound from the mast, so that the cables and hoses as they pass from the opposite end to electrical and air terminals as the trolley remains anchored at the opposite end.

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: A system for transferring fuel assemblies in a nuclear reactor includes a load control system which compares the current load to the more restrictive of fixed overload and underload limits, and instantaneous overload and underload limits continuously calculated from a running average of the measured load. Operation of the refueling machine is terminated if any of these limits are exceeded. The system also accommdates for changes in buoyancy and tension loading applied by spring loaded reels for pneumatic hoses and electrical cables servicing the gripper which engages the fuel assembly as the mast supporting the fuel assembly is raised and lowered in the pool of shielding water covering the reactor core. The current and recent suspended load measurements are displayed relative to the fixed and instantaneous overload and underload limits on a graphic display along with speed and other pertinent data.

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: Refueling apparatus for a nuclear reactor including a bridge and a trolley. The bridge is moveable in tracks along the containment of the pit in which the reactor is immersed in water and the trolley moveable in tracks on the bridge at right angles to the tracks on the bridge. The trolley carries a mast assembly for engaging, raising, lowering a nuclear-reactor component assembly involved in refueling. The mast includes an elongated member for engaging control-rod and thimble plug assembly and a gripper for raising fuel assemblies. The elongated member is moveable upwardly or downwardly.The bridge, trolley and mast assembly each has a pulse generator which produces pulses in accordance with the movement of each. The number of pulses produced when the bridge, trolley or elongated member move to a position at a predetermined distance from a reference position is a measure of the new position of each.

Abstract: A method and an apparatus for controlling a reactor refuelling machine including a plurality of grippers comprised of a plurality of telescopic bars which are telescopically actuatable independently of each other and at least one gripping member mounted to each telescopic bar. A decision is made as to whether the movement of a particular gripper in the Z direction is constrained by a status of the movement of a different gripper. The parallel operation is performed when the movement of the particular gripper in the Z direction is not constrained and when constrained, the particular gripper is placed in condition for waiting.

Abstract: A valve body 10 supports a rotary valve member 20 having a transfer port 22. Sealing between a port 17 of the valve and the member 20 is achieved by a sleeve 30 movable towards and away from the member 20. In a valve closed position seal means in a flat end of the sleeve engage a flat base of a recess in the member 20. The member 20 may be provided with a rotary scraper 41 and heaters located in channels 40 and in this construction the valve is suitable for transferring sodium-cooled nuclear fuel between various localities.

Abstract: Apparatus and process for supervising and controlling the operations of loading and unloading of fuel of a nuclear reactor comprising an information processor 30 formed from several units. A treatment unit 31 receives control signals giving notably the position, the speed, the load of machines 7 and 16 operating the loadings and unloadings of groups in the core 2, the reactor pool 3, and the spent fuel pit 14. A programmable unit 34 furnishes command signals, previously recorded, representing the loading sequence.

Abstract: A fast neutron nuclear reactor having a vessel filled with liquid metal and sealed in its upper part by a box slab having a central opening in which is placed a plug-cover-core overhanging the core of the reactor. The central opening is surmounted by a cell containing the handling and storage mechanism for the plug-cover-core and a mechanism for handling the assemblies. The latter can be moved on annular rails and can be collapsed against the wall of the cell, in order to permit the manipulation of the plug-cover-core. A radial passage connects the cell to a transfer station.

Abstract: The responses of a nuclear reactor refueling machine to commands from a detachable control console are simulated to allow operation of the console for testing and operator training with the console removed from the machine. A simulator, which is connected to the console by the same input and output leads which normally connect the console to the refueling machine, includes a single pulse generator driven by a single three phase A-C motor to simulate movement of the refueling machine bridge, trolley and hoist. The motor drive signals generated on separate console output leads are all connected to the single simulator motor, while the brake release signals energize relays which switch the pulse signals generated by the single pulse generator to the console input leads corresponding to the selected refueling machine component drive motor.

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: A pushing device for removing spent fuel rods from a nuclear reactor fuel assembly comprises a plurality of axially shiftable rods disposed in the same geometric pattern and with the same pitch as the fuel rods. The push rods are mounted at their upper ends to a pressure strip or plate and traverse at their lower ends bores in a guide plate fixed via guide rods to a base plate located on the other side of the pressure plate, the pressure plate being movably secured to the guide rods for linear motion between the base plate and the guide plate. A drive mounted to the base plate is connected to the pressure plate for shifting the latter, while a safety mechanism is provided for interrupting the motion of a push rod if the respective fuel rod is jammed in the fuel assembly.

Abstract: A refueling machine (100) is provided with a latching/unlatching rod (116) which is provided with a hexagonally configured head portion for mated engagement with a hexagonally configured socket (34) defined within a latching/unlatching screw (22) of a fuel assembly (10) whereby the fuel assembly (10) may be securely mechanically connected to the lower core support plate of the reactor internals. The latching/unlatching rod (116) is fixedly connected to a housing (118) which is co-axially disposed within a torque tube (140), the latter of which is fixedly secured to the lower end of a spur gear (130). The spur gear (130) is rotatably engaged with a drive spur gear (148) through means of an idler gear (128), whereby torque is transmitted to the torque tube (140).

Abstract: Fuel handling apparatus for transporting fuel elements into and out of a nuclear reactor and transporting them within the reactor vessel extends through a penetration in the side of the reactor vessel. A lateral transport device carries the fuel elements laterally within the vessel and through the opening in the side of the vessel, and a reversible lifting device raises and lowers the fuel elements. In the preferred embodiment, the lifting device is supported by a pair of pivot arms.

Abstract: A nuclear reactor refueling system for a liquid metal-cooled fast breeder reactor includes a large rotatable plug (18) eccentrically mounted relative to the reactor core (12), and a small rotatable plug (24) mounted within the large plug (18). A fuel handling machine (28) is rotatably mounted upon the small plug (24), and the eccentric mounting of the large plug (18) permits the fuel handling machine (28) to access all areas of the reactor core (12) as well as a fuel transfer station or port (34) located externally of the reactor core barrel (16) yet internally of the reactor pressure vessel. A unique six-fingered star-shaped upper internals structure (36) is eccentrically mounted upon the large plug (18) so as to be concentrically disposed relative to the core (12) when the reactor is in operation yet permitting access to the central-most fuel assemblies (14) of the core (12) as the large rotatable plug (18) is rotated during refueling operations.

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: The mechanism has at least one carrier sprocket wheel (18-19) fixed on a horizontal shaft (15) mounted on the body of a grab (4) with pivoting fingers. An apparatus (14) for actuating the pivoting fingers connected to the shaft allows them to open and close to take up or, alternatively, release the absorbent unit. Drive chain wheels (25-26) allow the portions (20-21) of a chain supporting the carrier pulley (18-19) to be moved, either in synchronism to move the absorbent assembly or with a differential movement to actuate the pivoting fingers of the grab (4). A single differential pinion apparatus (31-32) allows the two kinds of movement to be carried out.The invention can be applied particularly to the control and emergency shutdown of pressurized water nuclear reactors.

Abstract: The safety device consists of doubling a first reel (4) equipped with an operating cable (11) from a carriage (24) for nuclear fuel elements is suspended, by a second reel (5) equipped with an emergency cable (12) connected with the carriage (24) and following the displacement of the carriage in a synchronous manner with the aid of a set of cog-wheels (6 and 7) joined respectively with the reels (4 and 5) by means of reducing gears (2 and 3) and connected with each other by a notched belt (8).To attenuate the impact in case of a rupture of the operating cable (11) and the loading of the emergency cable (12), the carriage (24) is equipped with an attenuating system (22) and an elastic connecting system (20).