Plural Fuel Segments Or Elements Patents (Class 376/426)
  • Patent number: 9020091
    Abstract: An improved grid for a nuclear reactor fuel assembly that has an egg-crate base grid as the primary support structure with each support cell of the base grid that supports a fuel rod having a lock-support sleeve that is rotatable within the support cell between a first and second orientation. In the first orientation the lock-support sleeve fits loosely within the support cell of the base grid and respectively, loosely receives the fuel rods that are loaded therein. The lock-support sleeves are then rotated to a second orientation that locks the fuel rods axially within the support cells.
    Type: Grant
    Filed: April 14, 2008
    Date of Patent: April 28, 2015
    Assignee: Westinghouse Electric Company LLC
    Inventors: Yong Lu, Xiaoyan Jiang
  • Patent number: 8867693
    Abstract: A grid (13) for supporting nuclear fuel pencils (3) for a nuclear fuel assembly (1) comprising a peripheral belt (17), the peripheral belt (17) comprising on at least one of its edges (35, 37) guide fins (33) is disclosed. The edge (35, 37) of the peripheral belt (17) has between the adjacent guide fins (33) recesses (39) towards the inside of the grid (13). The invention is applicable, for example, to pressurized water reactors.
    Type: Grant
    Filed: October 27, 2005
    Date of Patent: October 21, 2014
    Assignee: Areva NP
    Inventors: Pascal Burfin, Michel Bonnamour, Gilles Margier, Jürgen Stabel-Weinheimer, Mingmin Ren
  • Publication number: 20140307845
    Abstract: A fuel rod for a nuclear fission reactor is disclosed and claimed. The fuel rod includes an elongate hollow cladding configured to retain a nuclear fuel therein. The cladding includes an elongate hollow tube. Fiber layers are positioned around the outside surface of the tube or within the tube forming an integral part thereof. Both the tube and the fibers are formed of a ceramic material. A fuel assembly including a plurality of such fuel rods is also disclosed and claimed.
    Type: Application
    Filed: April 10, 2014
    Publication date: October 16, 2014
    Inventor: Mihai G. M. Pop
  • Patent number: 8855261
    Abstract: A spacer for holding fuel rods includes cells formed by a sleeve having an upper edge and a lower edge and a number of abutment surfaces. The lower edge has a wave shape with wave peaks aligned with a respective one of the abutment surfaces, and wave valleys located between two adjacent ones of the abutment surfaces. The upper edge has a wave shape with wave peaks, which are aligned with a respective one of the abutment surfaces, and wave valleys located between two adjacent ones of the abutment surfaces. Each of the abutment surfaces extend from a respective one of the wave peaks of the upper edge to a respective one of the wave peaks of the lower edge. The sleeves abut each other in the spacer along respective connection areas to make the abutment surfaces rotatable with respect to a center point of the connection area.
    Type: Grant
    Filed: August 21, 2013
    Date of Patent: October 7, 2014
    Assignee: Westinghouse Electric Sweden AB
    Inventors: Sture Helmersson, Leif Larsson, Olov Nylund, Hakan Soderberg
  • Patent number: 8842802
    Abstract: A fuel rod for a nuclear reactor includes the fuel rod having a first axial zone positioned proximate to a bottom end, a second axial zone positioned adjacent to the first axial zone in the intermediate region, and a third axial zone positioned proximate to a top end. The first axial zone has an enrichment greater than the second axial zone and the second axial zone has an enrichment greater than or equal to the third axial zone. Also includes fuel assemblies having a plurality of fuel rods and methods of designing and manufacturing of fuel rods and fuel assemblies.
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: September 23, 2014
    Assignee: Global Nuclear Fuel-Americas, LLC.
    Inventors: William Earl Russell, II, Robert Haughton
  • Patent number: 8831166
    Abstract: Zirconium-based metal alloy compositions comprise zirconium, a first additive in which the permeability of hydrogen decreases with increasing temperatures at least over a temperature range extending from 350° C. to 750° C., and a second additive having a solubility in zirconium over the temperature range extending from 350° C. to 750° C. At least one of a solubility of the first additive in the second additive over the temperature range extending from 350° C. to 750° C. and a solubility of the second additive in the first additive over the temperature range extending from 350° C. to 750° C. is higher than the solubility of the second additive in zirconium over the temperature range extending from 350° C. to 750° C. Nuclear fuel rods include a cladding material comprising such metal alloy compositions, and nuclear reactors include such fuel rods. Methods are used to fabricate such zirconium-based metal alloy compositions.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: September 9, 2014
    Assignee: Battelle Energy Alliance, LLC
    Inventor: Robert Dominick Mariani
  • Patent number: 8824621
    Abstract: A filter including a plurality of flow ducts extending in a longitudinal direction and each delimited between one pair of walls is provided. The filter includes deflectors protruding into each duct alternately from the pair of walls with overlapping in the longitudinal direction to define a zigzag shaped flow channel and provided with at least one set of holes aligned in the longitudinal direction to define through the overlapping deflectors a passage for accommodating a lower end pin of a fuel rod.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: September 2, 2014
    Assignee: Areva NP
    Inventor: Reazul Huq
  • Patent number: 8817942
    Abstract: The present invention relates to a nuclear reactor, in particular a pool-type nuclear reactor cooled with liquid metal (for example, a heavy metal such as lead or lead-bismuth eutectic) or with sodium or molten salts, having a core formed by a bundle of fuel elements and immersed in a primary fluid circulating between the core and at least one heat exchanger; the fuel elements extend along respective parallel longitudinal axes and have respective bottom active parts immersed in the primary fluid to constitute the core, and respective service parts that extend at the top from the active parts and emerge from the primary fluid; the fuel elements are mechanically supported via respective top end heads anchored to supporting structures and can be operated via handling machines.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: August 26, 2014
    Assignees: Del Nova Vis S.r.l.
    Inventor: Luciano Cinotti
  • Patent number: 8774345
    Abstract: This bottom end-piece includes nozzles for directing the flow of water of the reactor along the lower ends of the fuel rods, the nozzles being arranged at nodes of the substantially regular network of the fuel rods, and an anti-debris device which delimits water flow channels. At least some of the water flow channels are arranged at nodes of the substantially regular network. Direction nozzles are arranged at least partially in the channels in order to delimit water passages therewith, and at least one water passage includes a first section and a second section which are mutually offset radially relative to the corresponding node of the network in order to form a baffle.
    Type: Grant
    Filed: December 5, 2007
    Date of Patent: July 8, 2014
    Assignee: Areva NP
    Inventors: Michel Verdier, Eric Labarriere
  • Patent number: 8711997
    Abstract: A reactor core is immersed in a liquid metal coolant in a core barrel of a liquid metal cooled reactor. The reactor core includes a plurality of fuel assemblies contained in the core barrel, a neutron absorber that absorbs a neutron in the reactor core, and a neutron moderator that moderates a neutron therein so as to control a reactivity of the reactor core. The neutron absorber and the neutron moderator constitute a mixture contained in reactivity control assemblies of the reactor core in the liquid metal coolant prior to immersion of the reactor core. The neutron moderator is composed of zirconium hydride.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: April 29, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsugio Yokoyama, Hisato Matsumiya, Yasushi Tsuboi
  • Patent number: 8705685
    Abstract: The geometric dimensions and shape of a device for removing solid particles from the cooling medium that is circulated in the primary circuit of a nuclear reactor, in particular a boiling water nuclear reactor, are such that the device can be inserted in lieu of a fuel element or fuel assembly into an empty fuel element or assembly position of the reactor core of the nuclear reactor.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: April 22, 2014
    Assignee: Areva GmbH
    Inventors: Hartmut Lelickens, Reazul Huq, Werner Meier, Jochen Heinecke
  • Patent number: 8699654
    Abstract: The invention concerns a method comprising measurement on a fuel channel (14) of fuel assemblies (8) for nuclear boiling water reactors. The method comprises that: the measurement is done by the use of a non-destructive inductive eddy current measurement method, the measurement is done on a fuel channel (14) which has been used at least a certain time during operation in the core of a nuclear boiling water reactor, the measurement is done when the fuel channel (14) is located in water, the measurement is done on different places on the fuel channel (14), wherein through the method at least the hydride content of the fuel channel (14) at said places is determined. The method can be used in order to find out how shadow corrosion from a neighboring control rod influences the properties of the fuel channel (14).
    Type: Grant
    Filed: June 8, 2009
    Date of Patent: April 15, 2014
    Assignee: Westinghouse Electric Sweden AB
    Inventors: Kurt-Åke Magnusson, Holger Wiese, Björn Andersson, Göran Jergeus
  • Patent number: 8693611
    Abstract: A liquid-metal cooled fast reactor core having a nuclear fuel assembly constituted of nuclear fuel rods with varying cladding thicknesses in reactor core regions, in which: the nuclear fuel assembly (1) of a liquid-metal cooled fast reactor includes nuclear fuel assemblies (1a, 1b and 1c) in inner, middle and outer reactor core regions, respectively, and is installed in a hexagonal duct (3) with nuclear fuel materials (2-2a, 2-2b and 2-2c) surrounded by respective claddings (2-1a, 2-1b and 2-1c), and the claddings (2-1a, 2-1b and 2-1c) of a nuclear fuel rod (2a) in the inner reactor core region, a nuclear fuel rod (2b) in the middle reactor core region and a nuclear fuel rod (2c) in the outer reactor core region are formed at different thicknesses. The reactor core can flatten power distribution using a single-enrichment nuclear fuel in the liquid-metal cooled fast reactor.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: April 8, 2014
    Assignees: Korea Atomic Energy Research Institute, Korea Hydro & Nuclear Power Co., Ltd.
    Inventors: Ser Gi Hong, Yeong-Il Kim, Sang Ji Kim, Do-Hee Hahn
  • Patent number: 8693612
    Abstract: A spacer grid for nuclear fuel rods includes a plurality of unit spacer grids stacked one on top of another. Each unit spacer grid includes a plurality of unit spacer grid straps disposed at regular intervals in a row, and a plurality of fixing grid straps connected to respective opposite ends of the unit spacer grid straps so as to fix the unit spacer grid straps. Each unit spacer grid strap has convexities alternating with each other on opposite sides thereof at regular intervals, and at least one of the convexities has a diameter greater than the others. The unit spacer grids are rotated in one direction by a 90 or 180 degree angle when being stacked.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: April 8, 2014
    Assignee: Korea Atomic Energy Research Institute
    Inventors: Young Ho Lee, Kang Hee Lee, Jae Yong Kim, Kyung Ho Yoon, Hyung Kyu Kim, Chang Hwan Shin, Dong Seok Oh, Wang Ki In, Tae Hyun Chun, Kun Woo Song
  • Patent number: 8681921
    Abstract: An embodiment of the present invention takes the form of a system that allows for simultaneously assembling or disassembling multiple segmented nuclear fuel rods (hereinafter “segmented rods”). An embodiment of the present invention, may receive, secure, and move the segmented rods into a position that allows for performing the tasks of either assembly or disassembly, allowing for an operator to use a tool to complete the aforementioned tasks.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: March 25, 2014
    Assignee: GE-Hitachi Nuclear Energy Americas, LLC
    Inventors: Bradley D. Bloomquist, David Grey Smith, David P. Ketcham, William Earl Russell, II
  • Patent number: 8681929
    Abstract: A fuel assembly for a nuclear reactor that employs dissimilar materials for the fuel assembly grid and the control rod guide thimbles. The guide thimbles are secured to the grid employing a through grid cell sleeve that is welded to the grid and spot weld rings that are secured over the sleeve and welded directly to the guide tube through windows in the sleeve.
    Type: Grant
    Filed: January 15, 2008
    Date of Patent: March 25, 2014
    Assignee: Westinghouse Electric Company LLC
    Inventors: Paul M. Evans, Harry A. Pearce, Michael A. Marzean, David A. Boatwright
  • Patent number: 8654917
    Abstract: Fuel elements are supported by fuel assemblies configured for use in land-based nuclear reactors such as the VVER-1000. The fuel elements include a kernel having a multi-lobed profile that forms spiral ribs that include fissionable material (e.g., uranium or plutonium), a central metal displacer extending along a longitudinal axis of the kernel, and a metal cladding (e.g., zirconium and/or other refractory metals) enclosing the kernel. The fuel element may be fabricated by joint extrusion of the displacer, kernel, and cladding through a die to metallurgically bond the kernel and cladding.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: February 18, 2014
    Assignee: Thorium Power, Inc.
    Inventors: Sergey Mikhailovich Bashkirtsev, Valentin Fedorovich Kuznetsov, Valery Vladimirovich Kevrolev, Alexei Glebovich Morozov, Michael H. Montgomery
  • Patent number: 8644446
    Abstract: A spacer grid for a nuclear fuel assembly for a light water reactor delimits a substantially regular array of cells housing nuclear fuel rods. The spacer grid further including supporting members which project into the cells from the peripheral belt of walls. The inner surface of at least one supporting member has before irradiation a concave shape in a plane transverse to the longitudinal direction. The inner surface of the contact part of the supporting member also has a convex shape in a longitudinal plane orientated radially with respect to the central axis of the corresponding cell before irradiation.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: February 4, 2014
    Assignee: Areva NP
    Inventors: Berenger D'Uston De Villereglan, Claude Bois, Bruno Bonnamour, Michel Bonnamour
  • Patent number: 8625733
    Abstract: A neutron source rodlet assembly having a separate source capsule assembly that is not encapsulated within the neutron source rodlet assembly. The neutron source rodlet assembly is made up, at least in part, of a neutron source positioning rodlet assembly and the source capsule assembly configured such that assembly together is feasible at a remote site and they can be shipped separately. The source capsule assembly has outer and inner capsules with the outer capsule having a threaded stud at one end that mates with a complimentary threaded recess on the neutron source positioning rodlet assembly. The inner capsule contains a neutron source. The neutron source positioning rodlet assembly and the source capsule assembly are locked together at their interface when the threaded joint is completely tightened. A secondary neutron source material may also be encapsulated within a hollow portion of the neutron source positioning rodlet assembly.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: January 7, 2014
    Assignee: Westinghouse Electric Company LLC
    Inventors: Ashutosh Chahande, Thanh Do
  • Publication number: 20130322591
    Abstract: Nuclear fuel assemblies include fuel elements that are sintered or cast into billets and co-extruded into a spiral, multi-lobed shape. The fuel kernel may be a metal alloy of metal fuel material and a metal-non-fuel material, or ceramic fuel in a metal non-fuel matrix. The fuel elements may use more highly enriched fissile material while maintaining safe operating temperatures. Such fuel elements according to one or more embodiments may provide more power at a safer, lower temperature than possible with conventional uranium oxide fuel rods. The fuel assembly may also include a plurality of conventional UO2 fuel rods, which may help the fuel assembly to conform to the space requirements of conventional nuclear reactors.
    Type: Application
    Filed: May 11, 2011
    Publication date: December 5, 2013
    Applicant: THORIUM POWER, INC.
    Inventor: Tatjana Ivanovna Kuznetsov
  • Patent number: 8599994
    Abstract: In various embodiments, a spacer grid for a nuclear reactor fuel bundle is provided. The grid includes a plurality of interstitial dividers that form an array of cells. Each cell is structured to retain a respective one of a plurality of fuel rods to thereby form an array of equally spaced fuel rods. The grid additionally includes a perimeter band that peripherally surrounds the dividers and is connected to opposing ends of each divider. The perimeter band includes a plurality of spring tabs formed along and extending from an edge of the perimeter band. The spring tabs extend from the edge at an angle away from the dividers such that a distal end of each spring tab will contact an interior surface of a respective one of a plurality of walls of a channel in which the arrayed fuel rods can be inserted to form the fuel bundle.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: December 3, 2013
    Assignee: General Electric Company
    Inventor: Russell Patrick Higgins
  • Patent number: 8599991
    Abstract: A boiling water reactor has a core disposed in the reactor pressure vessel and loaded with a plurality of fuel assemblies including transuranic nuclides. A ratio of Pu-239 in all of the transuranic nuclides included in the fuel assembly, which is loaded in the core, with a burnup of 0 is 3% or more but 45% or less. In the fuel assembly having a channel box and a plurality of fuel rods disposed in the channel box, a transverse cross section of a fuel pellet in the fuel rod occupies 30% or more but 55% or less of a transverse cross section of a unit fuel rod lattice in the channel box.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: December 3, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Renzo Takeda, Junichi Miwa, Kumiaki Moriya
  • Patent number: 8576977
    Abstract: A method for design of a fuel assembly for nuclear reactors, including structural components made from zirconium alloy: the mean uniaxial tensile or compressive stress to which the components are subjected during the assembly life is calculated, the zirconium alloy of which the components are made is selected according to the following criteria: those components subjected to an axial or transverse compressive stress of between ?10 et ?20 MPa are made from an alloy with a content of Sn between Sn=(=0.025??0.25)% and Sn=?0.05?%: those components subjected to such a stress of between 0 et ?10 MPa are made from an alloy the Sn content of which is between Sn=traces and Sn=(0.05?+1)%: those components subjected to such a stress of between 0 and +10 MPa are made from an alloy the Sn content of which is between Sn=0.05% and Sn=(0.07?+1)%: and those components subjected to such a stress of between +10 and +20 MPa are made from an alloy the content of SN of which is between 0.05% and 1.70%.
    Type: Grant
    Filed: December 7, 2007
    Date of Patent: November 5, 2013
    Assignee: Areva NP
    Inventors: Pierre Barberis, Véronique Rebeyrolle, Jean-Jérôme Vermoyal
  • Patent number: 8571168
    Abstract: A fuel assembly for a light water reactor contains a fuel rod cluster and a spacer that has a number of cells, bounded by webs for laterally holding fuel rods. A damaged region including at least one damaged cell is present in an edge region of a spacer. There being fastened above or below the damaged region on the spacer with the aid of at least one connecting part is a replacement assembly that contains at least a number of cells that corresponds to the number of the damaged cells, at least a portion of the cells being traversed by fuel rods. A method for repairing the light water reactor fuel assembly in the case of which fixed above or below the damaged region on the spacer is a replacement assembly that takes over the holding function at least of one defective cell.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: October 29, 2013
    Assignee: Areva GmbH
    Inventors: Franz Josef Fraundorfer, Gregor Münsterjohann, Erhard Friedrich
  • Patent number: 8565367
    Abstract: Example embodiments are directed to fuel assembly components and nuclear fuel bundles including the fuel assembly components. Example embodiments of a fuel assembly component may include a cylindrical device having first and second ends and a mounting assembly on the first end of the cylindrical device configured to attach to and detach from a partial length fuel rod. Example embodiments of a nuclear fuel bundle may include an upper tie plate, a lower tie plate, at least one full-length fuel rod, at least one partial length fuel rod, and a fuel assembly component.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: October 22, 2013
    Assignee: Global Nuclear Fuel-Americas, LLC
    Inventor: Daniel Reese Lutz
  • Patent number: 8548113
    Abstract: Example embodiments are directed to upper tie plates for debris mitigation and fuel bundles that use the upper tie plates. Example embodiment tie plates may include a plurality of debris capture elements that overlap each other so as to create debris traps for particulate debris that would fall onto the fuel bundle. Example embodiment fuel bundles may use the upper tie plates for debris mitigation.
    Type: Grant
    Filed: August 28, 2009
    Date of Patent: October 1, 2013
    Assignee: Global Nuclear Fuel - Americas, LLC
    Inventors: Michael T. Kiernan, Michael S. DeFilippis
  • Patent number: 8542789
    Abstract: Example embodiments and methods are directed to irradiation target positioning devices and systems that are configurable to permit accurate irradiation of irradiation targets and accurate production of daughter products, including isotopes and radioisotopes, therefrom. These include irradiation target plates having precise loading positions for irradiation targets, where the targets may be maintained in a radiation field. These further include a target plate holder for retaining and positioning the target plates and irradiation targets therein in the radiation field. Example embodiments include materials with known absorption cross-sections for the radiation field to further permit precise, desired levels of exposure in the irradiation targets. Example methods configure irradiation target retention systems to provide for desired amounts of irradiation and daughter product production.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: September 24, 2013
    Assignee: GE-Hitachi Nuclear Energy Americas LLC
    Inventors: William Earl Russell, II, Heather J. Hatton, Melissa Allen, Melissa L. Hladik, Samuel John Lafountain, Luis Alberto Torres, Erick W. Dittmer
  • Patent number: 8520795
    Abstract: An intermediate end plug assembly for a segmented fuel rod can stably support the fuel rod to the end of its cycle even if an interval between the fuel rods becomes narrow due to application of a dual-cooled fuel rod, and reduce excess vibration induced by flows of interior and exterior channels of the dual-cooled fuel rod for obtaining high burnup and output. To this end, the fuel rod has a segmented structure so as to make its length short. A lower intermediate end plug includes at least one channel hole, through which a coolant flows into an internal channel of the fuel rod, so that a possibility of causing departure from nuclear boiling ratio (DNBR) of the dual-cooled fuel rod is reduced.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: August 27, 2013
    Assignee: Korea Atomic Energy Research Institute
    Inventors: Kyung Ho Yoon, Jae Yong Kim, Young Ho Lee, Kun Woo Song, Tae Hyun Chun, Dong Seok Oh, Wang Ki In, Hyung Kyu Kim, Chang Hwan Shin, Kang Hee Lee
  • Patent number: 8509377
    Abstract: Example embodiment fuel bundles use multiple types of spacers within the same fuel bundle. The type for each spacer location may be determined based on the axial position of the spacer, the characteristics of the spacer type, and the location and coolant characteristics for the particular example fuel bundle including the spacers. Historic performance data for the particular bundle location, predictive modeling, etc. may be used to determine what spacer types at which locations result in the best operating conditions and margins for example fuel bundles.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: August 13, 2013
    Assignee: Global Nuclear Fuel—Americas, LLC
    Inventor: Birol Aktas
  • Patent number: 8503600
    Abstract: A fuel element for a nuclear reactor has a fuel rod bundle, at least one spacer with cells defined by at least one web section made from a first material and several guide tubes each running through a cell and axially fixed thereto made from a second material. The first and second materials have differing thermal expansion coefficients. The connection between the guide tube and the spacer is embodied as follows: first and second projections are directly or indirectly fixed to the guide tube. The first projections are disposed in a first axial position and the second projections are arranged at a second axial position and the projections each engage in an opening through the web section to give an axially-acting undercut.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: August 6, 2013
    Assignee: Areva GmbH
    Inventors: Matthias Rudolph, Hans-Peter Fuchs, Erhard Friedrich
  • Patent number: 8416912
    Abstract: The nuclear fuel assembly means a group of nuclear fuel rods disposed in a substantially regular array together with a support skeleton (5), the assembly having: two nozzles; guide tubes interconnecting the nozzles; and spacer grids secured to the guide tubes for holding the rods. The assembly includes at least one support skeleton reinforcing device disposed between two successive spacer grids and secured to guide tubes. The reinforcing device is disposed inside the group of rods and presents a transverse extent that is smaller than the transverse extent of the array of nuclear fuel rods.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: April 9, 2013
    Assignee: Areva NP
    Inventors: Guy Gentet, Angelo Beati, Jacques Gauthier
  • Patent number: 8369475
    Abstract: A nuclear fuel assembly support grid formed from an array of a plurality of orthogonally arranged straps in an egg-crate configuration with angled trailing and/or leading edges that are designed to break the correlation of vortices shed from the edges of the grid straps by varying the phase of the vortices to avoid resonant vibration of the straps.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: February 5, 2013
    Assignee: Westinghouse Electric Company LLC
    Inventors: Yong (Roger) Lu, Xiaoyan (Jane) Jiang, Michael E. Conner, Paul M. Evans
  • Patent number: 8363776
    Abstract: A ratio of the number of fuel assemblies loaded on a core to the number of control rod drive mechanisms is 3 or more. The fuel assembly itself contains mixed oxides of a low enrichment concentration uranium oxide containing 3 to 8 wt % in the average enrichment concentration of the fuel assembly, or mixed oxide containing not less than 2 wt %, but less than 6 wt % in the average enrichment concentration of fissile plutonium of. In the burner type BWR core on which the fuel assemblies are loaded, an average weight density of uranium, plutonium and minor actinides is 2.1 to 3.4 kg/L as a conversion at the value of unburned state.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: January 29, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Renzou Takeda, Motoo Aoyama, Junichi Miwa, Tomohiko Ikegawa, Kumiaki Moriya
  • Patent number: 8345815
    Abstract: A fuel assembly for a pressurized water nuclear reactor contains a multiplicity of fuel rods which are guided in a plurality of axially spaced spacers which in each case form a square grid, composed of grid webs, with a multiplicity of cells arranged in rows and columns. In each case one control rod guide tube is guided through a number of these cells. At least one spacer is configured to be mechanically stronger in a first partial region than in a second partial region. In this second partial region, the spacer is provided with at least one resisting element which protrudes into a flow sub-channel formed between the fuel rods and increases the flow resistance. The resisting element counteracts a reduction associated with the mechanically weaker configuration, in the flow resistance in the second partial region and in this manner effects a homogenization of the hydraulic behavior of a spacer which is mechanically inhomogeneous on account of the varying mechanical configuration.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: January 1, 2013
    Assignee: Areva NP GmbH
    Inventors: Jürgen Stabel, Udo Borsdorf
  • Publication number: 20120263271
    Abstract: A nuclear fuel pellet design that is a cylindrical axial profile with either a larger radius or conical shaped ends such that the as built diameter at the ends of the pellet are slightly smaller than at the middle and at normal operating conditions, the diameter at the ends is nearly the same as at the middle. Preferably, there are short chamfers at the axial ends of the pellet.
    Type: Application
    Filed: April 14, 2011
    Publication date: October 18, 2012
    Applicant: WESTINGHOUSE ELECTRIC COMPANY LLC
    Inventors: Yuriy Aleshin, David B. Mitchell
  • Publication number: 20120189089
    Abstract: A method is provided for operating a nuclear reactor. The method includes operating the nuclear reactor for at least one plutonium equilibrium cycle during which the core contains plutonium-equilibrium nuclear fuel assemblies; subsequently, operating the reactor for transition cycles, at least some of the plutonium-equilibrium nuclear fuel assemblies being progressively replaced with transition nuclear fuel assemblies and then with uranium-equilibrium nuclear fuel assemblies; and then operating the nuclear reactor for at least one uranium equilibrium cycle.
    Type: Application
    Filed: July 21, 2010
    Publication date: July 26, 2012
    Applicant: AREVA NP
    Inventors: Dorothee Henras, Song Hui Zheng
  • Publication number: 20120002777
    Abstract: The present invention relates to nuclear fuel compositions including triuranium disilicide. The triuranium disilicide includes a uranium component which includes uranium-235. The uranium-235 is present in an amount such that it constitutes from about 0.7% to about 20% by weight based on the total weight of the uranium component of the triuranium disilicide. The nuclear fuel compositions of the present invention are particularly useful in light water reactors.
    Type: Application
    Filed: June 17, 2011
    Publication date: January 5, 2012
    Applicant: WESTINGHOUSE ELECTRIC COMPANY LLC
    Inventors: Edward J. Lahoda, Radu Pomirleanu, Sumit Ray, Lars Hallstadius
  • Publication number: 20110222643
    Abstract: A cladding tube for nuclear fuel made from metal and including concave dimples on its external surface. A nuclear fuel assembly includes at least a plurality of nuclear fuel rods provided with such cladding tubes. The cladding tube is advantageously manufactured by pilgrim rolling, the dimples being formed during the pilgrim rolling.
    Type: Application
    Filed: September 29, 2009
    Publication date: September 15, 2011
    Inventors: Jean-Luc Doudoux, Eric Galban, Yves Charbonnier, Jérôme Boussin, Matthieu Ponce, Jan Patrice Simoneau, Jörg Peucker, Holger Schmidt, Klaus L. Nissen
  • Publication number: 20110206174
    Abstract: The invention refers to a nuclear fuel, a fuel element, a fuel assembly and a method of manufacturing a nuclear fuel. The nuclear fuel is adapted for use in a water cooled nuclear reactor, including light water reactors LWR, such as Boiling Water Reactors BWR and Pressure Water Reactors PWR. The nuclear fuel comprises an uranium-containing compound consisting of UN. The uranium content of the uranium-containing compound comprises less than 10% by weight of the isotope 235U. The nuclear fuel comprises an additive substantially consisting of at least one element, in elementary form or as a compound, selected from the group consisting of Zr, Mo, Si, Al, Nb and U.
    Type: Application
    Filed: February 22, 2010
    Publication date: August 25, 2011
    Applicant: WESTINGHOUSE ELECTRIC SWEDEN AB
    Inventors: Lars HALLSTADIUS, Edward J. LAHODA, Janne WALLENIUS, Mikael JOLKKONEN, Radu POMIRLEANU, Sumit RAY
  • Publication number: 20110013739
    Abstract: Example embodiments are directed to methods and apparatuses for generating desired isotopes within water rods of nuclear fuel assemblies. Example methods may include selecting a desired irradiation target based on the target's properties, loading the target into a target rod based on irradiation target and fuel assembly properties, exposing the target rod to neutron flux, and/or harvesting isotopes produced from the irradiation target from the target rod. Example embodiment target rods may house one or more irradiation targets of varying types and phases. Example embodiment securing devices include a ledge collar and/or bushing that support target rods within a water rod and permit moderator/coolant flow through the water rod. Other example embodiment securing devices include one or more washers with one or more apertures drilled therein to hold one or more example embodiment target rods in a water rod while permitting coolant/moderator to flow through the water rod.
    Type: Application
    Filed: July 15, 2009
    Publication date: January 20, 2011
    Inventors: David Grey Smith, William Earl Russel, II
  • Patent number: 7804930
    Abstract: The nuclear fuel assembly having nuclear fuel rods and a support skeleton having two nozzles, guide tubes interconnecting the nozzles, and spacer grids for holding the rods, the grids being secured to the guide tubes. The assembly further has at least one lattice reinforcing device for reinforcing the support skeleton. The reinforcing device is placed between two spacer grids and is secured to the guide tubes. The invention is applicable to fuel assemblies for pressurized water reactors.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: September 28, 2010
    Assignee: Areva NP
    Inventors: Angelo Beati, Thierry Muller, Jean-François Rondemerre
  • Publication number: 20100128835
    Abstract: An intermediate end plug assembly for a segmented fuel rod can stably support the fuel rod to the end of its cycle even if an interval between the fuel rods becomes narrow due to application of a dual-cooled fuel rod, and reduce excess vibration induced by flows of interior and exterior channels of the dual-cooled fuel rod for obtaining high burnup and output. To this end, the fuel rod has a segmented structure so as to make its length short. A lower intermediate end plug includes at least one channel hole, through which a coolant flows into an internal channel of the fuel rod, so that a possibility of causing departure from nuclear boiling ratio (DNBR) of the dual-cooled fuel rod is reduced.
    Type: Application
    Filed: April 9, 2009
    Publication date: May 27, 2010
    Applicants: Korea Atomic Energy Research Institute, Korea Hydro and Nuclear Power Co., Ltd.
    Inventors: Kyung Ho Yoon, Jae Yong Kim, Young Ho Lee, Kun Woo Song, Tae Hyun Chun, Dong Seok Oh, Wang Ki In, Hyung Kyu Kim, Chang Hwan Shin, Kang Hee Lee
  • Publication number: 20090274260
    Abstract: Example embodiments and methods are directed to irradiation target retention devices that may be inserted into conventional nuclear fuel rods and assemblies. Example embodiment devices may hold several irradiation targets for irradiation during operation of a nuclear core containing the assemblies and fuel rods having example embodiment irradiation target retention devices. Irradiation targets may substantially convert to useful radioisotopes upon exposure to neutron flux in the operating nuclear core and be removed and harvested from fuel rods after operation.
    Type: Application
    Filed: May 1, 2008
    Publication date: November 5, 2009
    Inventors: William Earl Russell, II, David Grey Smith, Michael S. DeFilippis
  • Patent number: 7587018
    Abstract: A nuclear fuel and a method to produce a nuclear fuel wherein a porous uranium dioxide arrangement is provided, the arrangement is infiltrated with a precursor liquid and the arrangement is thermally treated such the porous uranium dioxide arrangement is infiltrated with a precursor liquid, followed by a thermal treating of the porous uranium dioxide arrangement with the infiltrated precursor liquid such that the precursor liquid is converted to a second phase.
    Type: Grant
    Filed: January 8, 2007
    Date of Patent: September 8, 2009
    Assignee: Areva NP Inc.
    Inventor: John Kevin McCoy
  • Publication number: 20090175402
    Abstract: Exemplary embodiments provide automated nuclear fission reactors and methods for their operation. Exemplary embodiments and aspects include, without limitation, re-use of nuclear fission fuel, alternate fuels and fuel geometries, modular fuel cores, fast fluid cooling, variable burn-up, programmable nuclear thermostats, fast flux irradiation, temperature-driven surface area/volume ratio neutron absorption, low coolant temperature cores, refueling, and the like.
    Type: Application
    Filed: December 12, 2008
    Publication date: July 9, 2009
    Inventors: Roderick A. Hyde, Muriel Y. Ishikawa, Nathan P. Myhrvold, Lowell L. Wood, JR.
  • Patent number: 7526058
    Abstract: A rod assembly for a fuel bundle of a nuclear reactor may include an upper end piece, lower end piece and a plurality of rod segments attached between the upper and lower end pieces and to each other so as to form an axial length of the rod assembly. The rod assembly may include an adaptor subassembly provided at given connection points for connecting adjacent rod segments or a given rod segment with one of the upper and lower end pieces. The connection points along the axial length of the rod assembly may be located where the rod assembly contacts a spacer in the fuel bundle. One (or more) of the rod segments may include an irradiation target therein for producing a desired isotope when a fuel bundle containing one (or more) rod assemblies is irradiated in a core of the reactor.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: April 28, 2009
    Assignee: General Electric Company
    Inventors: Russell Morgan Fawcett, Randy Peter Gonzales, Russell Patrick Higgins, Robert Bryant James, Michael Thomas Kiernan, William Earl Russell, II, Steven Bruce Shelton, David Grey Smith, Russell Edward Stachowski, Lukas Trosman
  • Patent number: 7430267
    Abstract: The present invention relates to a multi-core fuel rod for research reactor and, more particularly, to a multi-core fuel rod for research reactor in which monolithic fuel cores made of uranium-molybdenum alloy are disposed in an aluminum matrix in a multi-core form. The multi-core fuel rod in accordance with the present invention provides a minimized contact surface area between nuclear fuel and aluminum, and reduces the formation of pores and swelling by restraining formation of reaction layer to avoid excessive reaction between the fuel and aluminum. Therefore, improved stability of nuclear fuel can be obtained by minimizing temperature rise as well as achieving high density and thermal conductivity of the fuel.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: September 30, 2008
    Assignees: Korea Atomic Energy Research Institute, Korea Hydro & Nuclear Power Co., Ltd.
    Inventors: Chul Gyo Seo, Ho Jin Ryu, Chang Kyu Kim, Yoon Sang Lee, Jong Man Park, Don Bae Lee, Seok Jin Oh
  • Patent number: 7349518
    Abstract: A ratio of the number of fuel assemblies loaded on a core to the number of control rod drive mechanisms is 3 or more. The fuel assembly itself contains mixed oxides of a low enrichment concentration uranium oxide containing 3 to 8 wt % in the average enrichment concentration of the fuel assembly, or mixed oxide containing not less than 2 wt %, but less than 6 wt % in the average enrichment concentration of fissile plutonium of. In the burner type BWR core on which the fuel assemblies are loaded, an average weight density of uranium, plutonium and minor actinides is 2.1 to 3.4 kg/L as a conversion at the value of unburned state.
    Type: Grant
    Filed: March 16, 2006
    Date of Patent: March 25, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Renzou Takeda, Motoo Aoyama, Junichi Miwa, Tomohiko Ikegawa, Kumiaki Moriya
  • Patent number: 6744842
    Abstract: A fuel assembly for a pressurized-water reactor includes fuel rods held in cells of spacers, control rod guide tubes, and a headpiece and a foot piece, by which it is fixed to upper and lower core grids, respectively. A spacer having a first part, which lies on a radially outer side with respect to a longitudinal center axis of the fuel assembly, and a second part, which lies on a radially inner side and is completely surrounded by the first part are included to reduce the size of gaps between fuel assemblies. The second part is formed of Zircaloy. The first part is made of a metallic material, and when compared to the Zircaloy of the second part, has a lower growth in the radial direction, caused by neutron radiation and a higher coefficient of thermal expansion.
    Type: Grant
    Filed: September 19, 2002
    Date of Patent: June 1, 2004
    Assignee: Framatome ANP GmbH
    Inventors: Norbert Schmidt, Peter Rau, Erika Herzog
  • Patent number: 6327324
    Abstract: A fuel assembly for a boiling water reactor comprising a plurality of fuel units (3a, 3b, 3c, 3d), stacked on top of each other, each one comprising a top tie plate (5), a bottom tie plate (6) and a plurality of fuel rods (4a, 4b, 4c) arranged between the top tie plate and the bottom tie plate. The fuel units are surrounded by a fuel channel (9) with a substantially square cross section. At least some of the fuel units comprise fuel rods with different diameters and different fuel quantities. The fuel rods are adapted such that fuel quantity and lattice space are optimized laterally and axially in the fuel assembly.
    Type: Grant
    Filed: February 10, 1999
    Date of Patent: December 4, 2001
    Assignee: Westinghouse Atom AB
    Inventor: Olov Nylund