Abstract: Fuel elements are moved between an upper pool and a lower pool of a nuclear plant by a conveyor tube having an upper end at the upper pool and a lower end at the lower pool and extending at an acute angle to the vertical between the ends. A plurality of transport baskets can move through the conveyor tube, each holding at least one of the fuel. An upper transfer device at the upper end in the upper pool loads the fuel elements into or unloads them from the transport baskets. A lower transfer device in the lower pool loads fuel elements into or unloads them from the transport baskets. Each transfer device can hold two of the transport baskets that are displaceable for positioning above or below the conveyor tube and movable during displacement through the tube between a vertical transfer position and an angled transport position.

Abstract: A storage container is carried into a nuclear-reactor containment, and then, the core structure is housed in the storage container. In this process, a bottom cover is carried to a storage-container body by using a moving device. The storage-container body and the bottom cover are positioned by adjusting the position of the bottom cover on the moving device while the bottom cover is supported by free bearings. The bottom cover is then attached to the storage-container body.

Abstract: A refueling apparatus for charging nuclear fuel in a reactor vessel, the refueling apparatus including: a refueling unit loading new nuclear fuel to a core or extracting spent nuclear fuel from the core; and a waveguide sensor unit including an ultrasonic wedge to form a Lamb wave, a waveguide with an end connected to the ultrasonic wedge and with another end transmitting the Lamb wave into the reactor vessel, and an ultrasonic sensor connected to the ultrasonic wedge and sensing a reflection signal reflected from an inside of the reactor vessel, the waveguide being formed in a plate shape and mounted in an end of the refueling unit. The waveguide integrally moves with the refueling unit, and the waveguide sensor unit detects a condition of the inside of the reactor vessel, while the refueling unit refuels the fuel assembly in the reactor vessel.

Abstract: A method of aligning a nuclear fuel bundle and handling selected fuel rods within the fuel bundle located in a spent fuel pool of a nuclear power plant. The bundle includes water rods, full-length and part-length fuel rods extending through a plurality of fuel spacers provided between top and bottom ends of the bundle, each spacer having a plurality of cells accommodating corresponding fuel and water rods. The method includes insertion of a rod grapple tool into a top end of a fuel bundle and down to a desired location within the bundle. A guide pin retrieval tool inserts into a side of the fuel bundle to remove a guide pin from a distal end of a gripper of the rod grapple tool, allowing the guide pin retrieval tool to grip a part-length fuel rod within the fuel bundle.

Abstract: Provided is a sliding support and a system using the sliding support unit. The sliding support unit may include a fulcrum capture configured to attach to a support flange, a fulcrum support configured to attach to the fulcrum capture, and a baseplate block configured to support the fulcrum support. The system using the sliding support unit may include a pressure vessel, a pedestal bracket, and a plurality of sliding support units.

Abstract: In a spent fuel pool of a nuclear power plant, there is provided a system for aligning a nuclear fuel bundle and handling selected fuel rods within the fuel bundle. The bundle includes water rods, full-length and part-length fuel rods extending through a plurality of fuel spacers provided between top and bottom ends of the bundle, each spacer having a plurality of cells accommodating corresponding fuel and water rods. The system includes a bundle alignment system for aligning the fuel rods and water rods, a rod grapple tool to extract selected part-length rods from the bundle, and a fuel rod guide block slidable onto the top end of the bundle for protecting an uppermost fuel spacer of the bundle, and for aligning fuel rods within individual cells of all the fuel spacers in the fuel bundle.

Abstract: A rear door system for transferring hot cell equipment into or out of a hot cell is disclosed. The rear door system of the present invention includes a rear door, which is provided to a rear wall of the hot cell so as to be movable to open or close the rear wall of the hot cell, and a vertical moving table, which is provided at a predetermined position on the lower portion of the front surface of the rear door so as to be movable upwards or downwards. The rear door system further includes a drive unit, which is provided at a predetermined position in the lower end of the rear door to move the rear door, and a stationary working table, which is disposed above the vertical moving table and is fixed in the hot cell in a horizontal orientation. The rear door system further includes a removable table, which is removably coupled at a predetermined position to the stationary working table, and a hot cell crane hook and a service area crane hook, which are respectively provided inside and outside the hot cell.

Abstract: In a spent fuel pool of a nuclear power plant, there is provided a system for aligning a nuclear fuel bundle and handling selected fuel rods within the fuel bundle. The bundle includes water rods, full-length and part-length fuel rods extending through a plurality of fuel spacers provided between top and bottom ends of the bundle, each spacer having a plurality of cells accommodating corresponding fuel and water rods. The system includes a bundle alignment system for aligning the fuel rods and water rods, a rod grapple tool to extract selected part-length rods from the bundle, and a fuel rod guide block slidable onto the top end of the bundle for protecting an uppermost fuel spacer of the bundle, and for aligning fuel rods within individual cells of all the fuel spacers in the fuel bundle.

Abstract: The invention relates to a method for transferring an article from a fluid-filled first vessel into a fluid-filled second vessel or in the opposite direction. The vessel is connected by a connecting element, in which there is a transport device for moving the article. A fluid flow flowing out of the first vessel is maintained in one part of the connecting element, while the article is transported through the connecting element. An apparatus for transferring an article, in particular a nuclear fuel element, between the vessels is also described, in which an extraction device for the discharge of fluid is located on the connecting element.

Abstract: A method and apparatus is disclosed for smoothly inserting a fuel rod loader through the skeleton of a fuel cell and then for pulling an attached fuel rod into the fuel rod skeleton while keeping the fuel rod under constant tension and preventing the bowing of the fuel rod. The pulling mechanism comprises a smooth collet with a smooth bullet end cap for guiding the puller mechanism into and through the skeleton where the bullet end cap is removed and the fuel rod is attached with a unique ball and slide mechanism actuated by a long puller rod that grabs the end of the fuel rod by a forward motion of the puller rod and is easily removed from the fuel rod by reversing this motion once the fuel rod is in place.

Abstract: The invention relates to a method for transferring an article from a fluid-filled first vessel into a fluid-filled second vessel or in the opposite direction. The vessel is connected by a connecting element, in which there is a transport device for moving the article. A fluid flow flowing out of the first vessel is maintained in one part of the connecting element, while the article is transported through the connecting element. An apparatus for transferring an article, in particular a nuclear fuel element, between the vessels is also described, in which an extraction device for the discharge of fluid is located on the connecting element.

Abstract: An instrument (1) is lowered into a tank with a narrow opening (4) guided by an articulated arm (11) mounted on a mobile trolley on the periphery of the opening. The rotation of the arm consecutive to this movement and the pivoting of the lower section (13) around the articulation (14) place the instrument (1) vertically above the required place, by means of a simple control if expressed in polar co-ordinates. Application to taking samples and inspections in tanks containing dangerous waste.

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 present invention is used in fuel handling for lifting of fuel assemblies and/or control rods out of/into a reactor vessel in a nuclear reactor. The reactor vessel comprises a reactor core with a plurality of fuel assemblies and control rods. A fuel pool is arranged adjacent the reactor vessel. A cassette comprising a plurality of storage positions for fuel assemblies and/or control rods is arranged near the reactor core, whereupon fuel assemblies and/or control rods are lifted out of the reactor core and arranged in the cassette. The cassette is then transported to the fuel pool for temporary storage.

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: 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: A transfer system moves fuel assemblies along a track extending through a transfer tube within a containment wall in a nuclear power plant between the auxiliary building side and the containment building side. A car carries a basket for the assemblies. Two winches are located on the auxiliary building side above the water level existing over the track during refueling operations. The winches operate respective pairs of cables, driving the car in either direction. Four sheaves respectively direct the cables to the horizontal direction along the track. One pair of cables is secured to a yoke on the car to drive the car away from the containment building. Two horizontal sheaves are located near the containment end of the transfer tube. The other two cables extend horizontally along the track from the vertical sheaves to the horizontal sheaves, redirecting them to extend horizontally in the reverse direction. These return cables are secured to the yoke to drive the car toward the containment building.

Abstract: An emergency device for the control of the displacement of a conveying carrier for a nuclear fuel assembly, in which the conveying carrier (6) moves under the effect of a push-pull chain (15) actuated by a driving mechanism causing, according to the direction, its winding on itself in spiral so as to pull the carrier, or its unwinding by forming then a carrier rigid pushing element, including a connecting member between the chain and the carrier, formed of two portions (27,38) connected to each other by a pin which can be broken when required in order to disconnect the two portions and to free the carrier from the chain.Breaking of the pin is due to the effect of a traction exerted remotely from the carrier on a control cable (16) such that, after breaking, the cable can apply a traction on the carrier so as to bring it back freely, independently of the chain, to a predetermined position.

Abstract: A diverter assembly for diverting a pneumatically conveyed holder for a radioactive material between a central conveying tube and one of a plurality of radially offset conveying tubes includes an airtight container. A diverter tube having an offset end is suitably mounted in the container for rotation. A rotary seal seals one end of the diverter tube during and after rotation of the diverter tube while a spring biased seal seals the other end of the diverter tube which mvoes between various offset conveying tubes. An indexing device rotatably indexes the diverter tube and this indexing device is driven by a suitable drive. The indexing mechanism is preferably a geneva-type mechanism to provide a locking of the diverter tube in place.

Abstract: Method and apparatus for assisting the loading of a reactor core with new and/or irradiated elongated fuel assemblies which includes inserting a fuel assembly with a fuel assembly carrier from a storage pit into a grid position of a reactor core with a refueling machine having propelling equipment, supplying an actual position of the fuel assembly carrier to the propelling equipment of the refueling machine during movement of the refueling machine between the storage pit and the reactor vessel, comparing the actual position of the fuel assembly carrier with a desired position of the fuel assembly carrier to find a deviation, and carrying out a correction of the deviation in the travelling movement of the refueling machine based upon the comparison.

Abstract: In an installation for handling assemblies between the main vessel of a fast neutron nuclear reactor and an adjoining vessel, use is made of a transfer hood formed by a thick tube whose inclined axis can be moved alternatively into the prolongation of the axes of two inclined ramps opening into the main vessel and adjoining vessel respectively, by the rotation of a platform of vertical axis bearing the hood and also two flaps which close the ramps when the reactor is operating, so that an assembly-transferring pot can be guided isostatically inside the ramps and the hood, the platform also possibly comprising a spare flap.Application to all assemblies forming a reactor core, such as fuel assemblies, lateral neutron screening assemblies and absorbing assemblies.

Abstract: A structure for the storage of core assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the core assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot core assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the core assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.

Abstract: A cable-driven arm-reciprocating system particularly useful for transferring nuclear fuel bundles from a nuclear reactor pool to a spent fuel storage pool, wherein an arm-retracting cable extends from a winch drum around fixed and movable-axis sheaves to a retracting anchor device and an arm-extending cable extends from the same winch drum also around fixed and movable-axis sheaves to an extending anchor device, each anchor device including spring means for maintaining and allowing for variations in cable tension.

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: Installation for handling the assemblies of a fast neutron nuclear reactor comprising a core located in a vertically axed vessel and constituted by a group of assemblies positioned in a supporting grid, a horizontal slab over the vessel, a large rotary plug in the slab, a small rotary plug in the large rotary plug and off-centered with respect to the latter, and a handling pot or container making it possible to remove the fuel elements from the vessel, wherein the small rotary plug has a handling poker and the large rotary plug positioned coaxially with respect to the core has a handling arm, the poker making it possible to reach a fraction of assemblies, particularly those in the central part of the core and to transfer them into a take-up station of the supporting grid, the assemblies placed in the take-up station, as well as those in the peripheral area downwardly accessible to the handling arm being deposited by the latter in the handling pot or container.

Abstract: A manipulator for transferring fuel assemblies between inclined fuel chutes for a liquid metal nuclear reactor.Hoisting means are mounted on a mount supported by beams rotatably attached by pins to the mount and to the floor. Rotation of the beams can be impelled by a one dimensional movement causing the manipulator to accomplish a complicated, two dimensional transfer.

Abstract: Apparatus for the transfer and positioning of targets in an irradiation installation equipped with an access lock of axis Z.sub.3 Z.sub.4 and within which there is a high vacuum, the installation being located in a protective enclosure defined by a shielded wall, including a telescopic assembly of axis X.sub.1 X.sub.2 located within the protective enclosure, the telescopic assembly having a free end able to carry the target to be positioned and being located on a support, and the support can be given a movement enabling it to move between a first target handling position in which the satisfactory operation of its components can be checked and a second position in which the X.sub.1 X.sub.2 axis of the telescopic assembly coincides with the Z.sub.3 Z.sub.4 axis of the access lock and the free end introduced into the lock.

Abstract: Apparatus for loading and unloading fuel assemblies, for fast neutron nuclear reactors, and in particular for groups of fast neutron nuclear reactors cooled by liquid sodium located on one and the same site. The apparatus is removable as a unit and comprises a lock chamber (25) in the form of a removable and transportable vessel. The vessel (25) contains a pivoting ramp (35) allowing transfer of assemblies between the primary ramp (28) and the secondary ramp (29) of the nuclear reactor. Apertures (26) and (27) corresponding to the ramps (28) and (29) respectively are provided in the wall of the vessel (25) and connecting and isolating apparatuses (30) and (31) allow the lock chamber to be placed in communication with the ramps of the reactor, or conversely to be separated from the reactor and isolated.

Abstract: A dismountable and movable device for the transfer of fuel assemblies for a breeder nuclear reactor, comprising a platform (11) mounted for rotation on a support (12) resting on the structure of the reactor. The platform is provided with apertures (19, 20) and carries a hopper (23) which can contain a fuel assembly (5) in vertical position, at the level of one of the apertures (19). The apertures can be brought into correspondence with vertical shafts (14, 15) permitting access to storage (5a) and evacuation (5b) positions for the assemblies (5). The hopper (23) contains a winch (37) for the vertical displacement of the assemblies in the hopper and the shafts when they are in correspondence. The shafts and the platform comprise complementary connecting and sealing devices to assure the connection between the hopper and the shafts. The device is particularly useful for reactors grouped on one and the same site where transport of the assemblies is effected by modules displaced on the site.

Abstract: A nuclear reactor containing assemblies having two caps and a framework inside which fuel rods are disposed vertically is reloaded by first inverting the assembly to be removed into a vertical position permitting the then lower cap to be demounted. The spent fuel rods are then identified and removed in sets and deposited in a suitable storage area, and replacement rods are placed in sets in the framework of the fuel assembly. Finally, the lower cap is replaced and the assembly is conveyed into the reactor vessel at its new location.

Abstract: In an installation for a nuclear power station comprising a "reactor building" with a first swimming pool for handling of fuel units and a fuel building with a second swimming pool for the transfer, storage and deactivation of the units, the second swimming pool is located at a lower level than that of the first and is connected to the first by an intermediate auxiliary chamber filled with water and located under the first swimming pool. The auxiliary chamber is connected by a vertical pipeline to the first swimming pool and by a horizontal connecting pipeline to the second swimming pool. Each of the pipelines is provided with a shut-off valve, with interlocking means which prevents the simultaneous opening of the two valves. There is negligible dead space around a conveyor basket for fuel units when it is in the vertical or horizontal pipelines.

Abstract: The invention relates to an assembly for passage through a containment slab for transferring irradiated nuclear fuel, comprising a sleeve passing through the slab and fast therewith and a guide ramp passing through the sleeve and in which moves a handling pot carrying the fuel, wherein said assembly further comprises a device for evacuating the residual heat dissipated by the fuel, this device comprising a bundle of caloducts disposed parallel to the ramp over a length at least equal to that of the sleeve, and means for evacuating the flow of heat directed above the slab by the caloducts.

Abstract: A reusable thermally actuated linkage arrangement includes a first link member having a longitudinal bore therein adapted to receive at least a portion of a second link member therein, the first and second members being sized to effect an interference fit preventing relative movement therebetween at a temperature below a predetermined temperature. The link members have different coefficients of thermal expansion so that when the linkage is selectively heated to a temperature above the predetermined temperature, relative longitudinal and/or rotational movement between the first and second link members is enabled. Two embodiments of a thermally activated linkage are disclosed which find particular application as actuators for a grapple head positioning arm in a nuclear reactor fuel handling mechanism to facilitate back-up safety retraction of the grapple head independently from the primary fuel handling mechanism drive system.

Abstract: A pool type nuclear fission reactor has a core, with a plurality of core elements and a redan which confines coolant as a hot pool at a first end of the core separated from a cold pool at a second end of the core by the redan. A fuel handling system for use with such reactors comprises a core element storage basket located outside of the redan in the cold pool. An access passage is formed in the redan with a gate for opening and closing the passage to maintain the temperature differential between the hot pool and the cold pool. A mechanism is provided for opening and closing the gate. A lifting arm is also provided for manipulating the fuel core elements through the access passage between the storage basket and the core when the redan gate is open.