Abstract: A method for decommissioning a nuclear facility includes: floating a nuclear reactor pressure vessel above a cavity; positioning a mounting device on bio-protective concrete to cover the cavity with the mounting device; mounting a lower portion of the nuclear reactor pressure vessel on the mounting device; and cutting and decommissioning the nuclear reactor pressure vessel mounted on the mounting device.

Abstract: A method for decommissioning a heavy water reactor facility includes: removing the plurality of guide tubes from a plurality of through-holes; installing a plurality of shielding stoppers in the plurality of through-holes; removing the shielding stopper installed in one through-hole of the plurality of through-holes, and inserting a cutting device into a lower portion of the reactivity mechanism deck through the one through-hole to cut a connection portion between the reactivity mechanism deck and the calandria vault by using the cutting device; and separating the reactivity mechanism deck from the calandria vault.

Abstract: Devices position inspection and operation tools in a nuclear reactor without use of a bridge or other maintenance structure well above the reactor core. Devices can selectively join to in-reactor structures like steam dams through clamping that permits limited movement. Positioning assemblies may be supported by the devices. The positioning assembly includes a mast that moves relative to the positioning assembly. Rollers of the positioning assembly may so move the mast. The positioning assembly may be rotated with a sun gear having an exterior surface about which the mast and rollers can revolve. A local motor or external drive may provide power for this rotation and/or revolving as well as rotation of the rollers to move the mast and assembly. Devices are useable underwater or submerged in fluid and may include instruments with powering lines or mechanical extensions that permit powering or direct interfacing from operators outside the reactor.

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 device for turning a container about a turning axis is provided. The device includes a stationary holding member and two bearing members which are spaced apart along the turning axis on each side of a space for receiving a container, and which are capable of being used for bearing on the container while enabling the rotation of the container about the turning axis relative to the bearing members. The device includes a movable holding member that is mounted onto the stationary holding member so as to rotate about the turning axis, at least one bearing member being supported by the movable holding member while being mounted onto the movable holding member so as to rotate about the drive axis, the or each bearing member supported by the movable holding member not rotating about the turning axis relative to the stationary holding member when the movable holding member rotates about the turning axis relative to the stationary holding member.

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: 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: Systems and methods for refueling a nuclear reactor that has a reactor core in a reactor pool having a plurality of elongated reactor core components, a fuel pool for storing core components, and a transfer channel connecting the fuel pool to the reactor pool. The method includes retrieving a replacement core component from the fuel pool, and securing the replacement core component in a first compartment of a handover assembly in a vertical position. The method also includes retrieving a spent core component from the reactor core, and securing the spent core component in a second compartment of the handover assembly in a vertical position. The replacement core component is retrieved from the first compartment and installed into the reactor core. The spent core component is retrieved from the second compartment and stored in a storage rack in the fuel pool.

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: A shielded rack loader makes use of a loading rack movable between a shielding structure and a storage tube. A shield plug seals the storage tube. A hoist moves the shield plug and the loading rack. A shield plug cart and a material transfer cart mate with receiving flanges of the rack loader and permit temporary storage and movement of the shield plug and of canisters of transuranic material.

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: Methods and apparatus for moving fuel bundles in a reactor pressure vessel (RPV) of a nuclear reactor are described. In one embodiment of the apparatus, a support tube facilitates the positioning of a multiple channeled magazine within the RPV, especially at locations adjacent fuel bundles. In the one embodiment, the support tube extends in the reactor pressure vessel into the area above the top guide. A magazine assembly is coupled to the support tube, and includes a magazine having a plurality of fuel bundle receiving channels. The magazine extends from the support tube so that it is adjacent the fuel bundles and the top guide. Grapples extend through the magazine channels, engage the fuel bundles, and retract the bundles into the magazine channels. The magazine and support tube, and thus the bundles, are then moved.

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: A dry transfer system for spent nuclear fuel (SNF) assemblies includes a transfer container with a sliding sleeve for vertical translation therein. The sliding sleeve includes a number of compartments for receiving a corresponding number of fuel assemblies. The container includes an integral and remotely controllable hoist with a number of individually actuated grapples for latching onto a corresponding number of fuel assemblies. The system further includes a loading stand with an elevator for raising and lowering a fuel basket that also includes a number of compartments for moving fuel assemblies up to and in alignment with the sleeve of the transfer container that is landed on the loading stand.

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

Abstract: The present invention presents an apparatus to facilitate the loading of specific fuel rods into the specific grid cells of the grids of a fuel assembly. The loading apparatus utilizes air-pressure operated loading cylinders to push out the specific fuel rods from a fuel rod magazine into the corresponding grid cells. The loading apparatus operates in conjunction with a series of fuel rod support rollers which provide support to the fuel rods, being charged into the grids, from the underside of the fuel rods to prevent sagging of the tip end, thus avoiding scraping against the straps of the grids when entering the grid cells, and causing potentially harmful surface scratches on the fuel rods.

Abstract: There are disclosed an assembling apparatus and an assembling method of a nuclear fuel assembly by which flaws or scratches to be formed on the surfaces of the fuel rods can be reduced. The fuel rods are inserted into the grid cells of the supporting grids under the state where the supporting grids are disposed in proximity to each other. Therefore, it is possible to remarkably reduce the fall-down movement of the tip portion of the fuel rod. Conventionally, the tip portion or lower surface of the fuel rod inevitably comes in contact with the grid cell of the supporting grid, so that the scratches might be formed on the surface of the fuel rod, which deteriorates the quality of the fuel assembly. However, according to the present method and apparatus, it is possible to avoid the interference between them so that the scratches to be formed on the surface of the fuel rods can be reduced remarkably.

Abstract: The present invention relates to a pull-in rod type loader for loading fuel rods efficiently and conveniently from a fuel rod magazine to a fuel assembly. The control rod pipes and fuel rods are held in assigned grid cells, respectively termed pipe-cells and fuel-rod-cells, in each quadrant section of a grid. The control rod pipes are disposed in a quadrant so that the locations of the pipe-cells assigned for the guide pipes in one quadrant are symmetrical with respect to a central rotational axis of the apparatus. The grid cells and the pull-in loader are both aligned with respect to a central rotational axis. To load the fuel rods into the fuel assembly, only the pull-in rods need to be operated for every 90 degree rotation of the loader about the central axis, because the locations of the pull-in rods correspond exactly with the grid cells assigned to hold fuel rods.

Abstract: The present invention is made to provide an assembling machine for nuclear fuel assembly, having a simple mechanical construction, in which the time required for inserting the fuel rod can be reduced.In the prior-art machine, the pull-in rod and its drive mechanism and the like are required to perform the operation for inserting the fuel rod into the supporting grid, thus, the mechanical construction must be complicated. Further, a relatively long time must be required to perform the operation for holding the fuel rod by the pull-in rod, which makes the whole working hours longer. In the machine according to the present invention, a drive mechanism is provided to drive a stopper, by which the regulation of the stopper for regulating the fall-down movement of the fuel rod can be released with ease. Thus, the fuel rod is fallen down by its own weight, so that the fuel rod can be inserted into the grid cell of the supporting grid which is supported by the supporting post.

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 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: 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).

Abstract: The present invention relates to a device for handling a load, particularly an immersed load, by means of a shaft having a polygonal cross-section.The shaft, which can move along its axis, is maintained by a bearing connected to rotation means, so that a rotation of the bearing about the axis of the shaft leads to an identical rotation of the latter. The supply fluid for the bearing can be that in which the load to be manipulated is immersed.Application to the control and inspection of fuel rods.

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.