With Coolant Flow Bypass Means Patents (Class 376/444)
  • Patent number: 10991473
    Abstract: A method of manufacturing a fuel assembly for use in a core of a nuclear power reactor. The method includes manufacturing each of a plurality of elongated fuel elements by mixing powdered fuel material with powdered metal non-fuel material. The mixed powdered fuel material and metal non-fuel material is sintered to create a fuel core stock, the fuel core stock is surrounded with a cladding material, and the fuel core stock and cladding material are co-extruded to create the fuel element. The fuel element has a spirally twisted, multi-lobed profile that defines a plurality of spiral ribs. The multi-lobed profile includes lobe tips and intersections between adjacent lobes. The cladding is thicker at the tips than at the intersections. The plurality of elongated fuel elements are mounted to a frame of the fuel assembly. A moderator:fuel ratio in a region of the fuel elements is 2.5 or less.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: April 27, 2021
    Assignee: THORIUM POWER, INC.
    Inventors: Sergey Mikhailovich Bashkirtsev, Valentin Fedorovich Kuznetsov, Valery Vladimirovich Kevrolev, Alexey Glebovich Morozov, Michael H. Montgomery
  • Patent number: 9922732
    Abstract: A moderating fuel rod for a boiling water reactor may include a nuclear fuel section; a neutron moderator section including a metal hydride; and a threaded connector joining the nuclear fuel section and the neutron moderator section. By including one or more moderating fuel rods in a fuel bundle, the neutron moderation within the fuel bundle may be improved, thereby allowing energy to be more efficiently extracted from the entire length of the fuel bundle.
    Type: Grant
    Filed: October 7, 2014
    Date of Patent: March 20, 2018
    Assignee: Global Nuclear Fuel-Americas, LLC
    Inventors: John Christopher Hannah, Gerald Dean Kvaall, Jr.
  • Patent number: 9484118
    Abstract: A nuclear fuel assembly for a boiling water reactor is provided. The nuclear fuel assembly includes a base, a head and a bundle of full length fuel rods and partial length fuel rods. The bundle extends longitudinally between the base and the head, at least one partial length fuel rod having a lower end received in a housing provided in the base and delimited by a closed bottom larger than the lower end. The housing is further delimited by a peripheral wall surrounding the lower end and the partial length fuel rod rests freely on the bottom.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: November 1, 2016
    Assignee: AREVA NP
    Inventors: Jens Schäfer, Juris Kronenberg
  • Patent number: 9053825
    Abstract: A fuel assembly for a nuclear boiling water reactor is provided. The reactor comprises a plurality of such fuel assemblies and a plurality of control rods. Each control rod is insertable between the fuel assemblies. The fuel assembly has a longitudinal center axis and includes a plurality of elongated fuel rods and an elongated channel box. The channel box has inner sides, facing the fuel rods, and outer sides. Each inner and outer side has a longitudinal center line extending in parallel with the center axis and along the length of the channel box. A number of protrusions are distributed along the center line of at least two of the outer sides. The protrusions are configured to ensure a minimum distance between the outer side and an adjacent control rod and to enable the control rod to easily slide over and on top of the protrusions.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: June 9, 2015
    Assignee: Westinghouse Electric Sweden AB
    Inventors: Lars Hallstadius, Mats Dahlback, Anders Soderlund
  • Patent number: 8559586
    Abstract: A reactor fuel bundle includes both full-length fuel rods and part-length fuel rods. The part-length rods are clumped in two groups—a first rod group surrounds one or more water passages which are generally centrally disposed in a channel of the fuel bundle, and a second rod group is distributed about an inner perimeter wall of the channel.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: October 15, 2013
    Assignee: Global Nuclear Fuel-Americas, LLC
    Inventors: Lukas Trosman, Cary L. Kunz, Russell E. Stachowski, Russell M. Fawcett, Shingo Fujimaki, Daisuke Goto
  • 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: 8238511
    Abstract: A protector bottom grid for a nuclear fuel assembly that includes three laterally staggered and horizontally oriented protrusions that extend into the fuel rod cell of a support grid below a vertically oriented spring. The three staggered protrusions extend into the cell a distance that maintains a space between the protrusions and the fuel rod. The vertically oriented spring biases the fuel rod against a dimple extending from the opposite cell wall that is at an elevation just above the spring. The protrusions below the spring trap incoming debris in the area of the fuel rod end cap and protect the fuel rod cladding from fretting.
    Type: Grant
    Filed: June 9, 2009
    Date of Patent: August 7, 2012
    Assignee: Westinghouse Electric Company LLC
    Inventors: Hua Jiang, Paul Evans
  • 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: 7215729
    Abstract: A resistance member (e.g., fuel holding portion of the lower tie plate) is provided at the lower end of the fuel assembly. Provision is made of a coolant ascending path in which said water rods have coolant inlet ports that are open in a region lower than the resistance member to upwardly guide the coolant, and a coolant descending path which has a coolant delivery port that is open in a region higher than the resistance member to downwardly guide the coolant. The coolant ascending path and the coolant descending path are communicated with each other at their upper end portions.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: May 8, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Osamu Yokomizo, Yuichiro Yoshimoto, Yoshiyuki Kataoka, Shinichi Kashiwai, Yasuhiro Masuhara, Akio Tomiyama, Akihito Orii, Kotaro Inoue, Takaaki Mochida, Tatsuo Hayashi
  • Patent number: 6888911
    Abstract: Transverse vibrations of the pellet columns included in the fuel rods of fuel elements are limited by elastically mounting the fuel rod jacket tubes in the mesh of spacer grids. When the fuel rods are supported in this way, flexural vibrations of a higher order occur that lead to damage to the jacket tubes caused by fretting. These vibrations are the less dampened the more rigid the fixture of the fuel rod is. These vibration conditions are more easily excited and more strongly dampened when the pellet columns are more mobile, thereby removing vibration energy from the fuel element and avoiding damage caused by fretting. The mobility of the columns can be increased by increasing the gap between the pellet and the jacket tube, or by using constructions in which a torque M?10 N mm on the fuel rod leads to a tilting angle ??0.1°.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: May 3, 2005
    Assignee: Framatome ANP GmbH
    Inventors: Jürgen Stabel-Weinheimer, Mingmin Ren
  • Patent number: 6885722
    Abstract: A fuel assembly attains high burnup and increases reactor shut-down margin when loaded into a reactor core wherein a water gap width on a control rod side and a water gap width on a side opposite to the control rod side are almost equal to each other. The fuel assembly has a plurality of fuel rods arranged in a square lattice pattern, each fuel rod being filled with nuclear fuel pellets and also has at least one neutron moderator rod shifted toward one corner where a control rod is inserted, away from a cross sectional center of the fuel assembly.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: April 26, 2005
    Assignee: Hitachi, Ltd.
    Inventor: Ryoji Masumi
  • Patent number: 6765979
    Abstract: Separation devices are disposed in the vent volume above part-length rods and above one or more of the spacers above the upper ends of the part-length rods. The separation devices preferably comprise swirlers located above the lattice openings which would otherwise receive the rods but for the underlying part-length rods. In this manner, flow is directed laterally outwardly onto the surfaces and into the interstices of the full-length fuel rods for improved power performance while simultaneously adverse pressure drops across the spacers are minimized.
    Type: Grant
    Filed: November 21, 1997
    Date of Patent: July 20, 2004
    Assignee: General Electric Company
    Inventors: Gary E. Dix, Bruce Matzner
  • Patent number: 6735268
    Abstract: The spacer/water rod retention assembly includes a clip secured to the spacer having a slot perimetrically bounded both axially and laterally spaced portions of the clip. A resilient tab projects from one side portion into the slot. A water rod has a projecting tab which, upon relative rotation of the spacer and water rod, engages and deflects the clip tab to enable the water rod tab to reside in the clip slot. When the clip tab returns to its initial position, substantial relative rotation between the water rod and spacer is precluded and axial connection between the spacer and water rod is assured. In another form, the water rod tab projects into a slot of the clip. An adjacent water rod prevents rotation of the water rod tab in the opposite direction, thereby capturing the spacer and water rod and preventing relative axial movement.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: May 11, 2004
    Assignee: General Electric Company
    Inventors: Russell P. Higgins, David G. Smith
  • Patent number: 6735267
    Abstract: A fuel assembly in accordance with the present invention comprises a plurality of first fuel rods and a plurality of second fuel rods having a length shorter than a length of the first fuel rod, and these two kinds of fuel rods are arranged in a fuel rod array of 10 rows by 10 columns. Two water rods are arranged in regions capable of arranging 8 fuel rods. The second fuel rods are not arranged in the outermost tier of the fuel rod array. Which satisfies the following conditions, that is, B≧60  (Equation 1) 15≦n≦20(n: integer)  (Equation 2) Awr/Ach≦0.149  (Equation 3) Lp/Lf≧11/24  (Equation 4) Awr/Ach≧(3.00×10−4×n2+6.00×10−4×n−1.2×10−2)×(Lp/Lf−1)+1.75×10−1  (Equation 5) Awr/Ach≦(8.63×10−4×n2−6.09×10−2×n+1.33×10−1)×(Lp/Lf−8.
    Type: Grant
    Filed: August 26, 2002
    Date of Patent: May 11, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Akihito Orii, Junichi Koyama, Koji Nishida, Masao Chaki, Toru Kanazawa
  • Patent number: 6643350
    Abstract: A fuel assembly attains high burnup and increases reactor shut-down margin when loaded into a reactor core wherein a water gap width on a control rod side and a water gap width on a side opposite to the control rod side are almost equal to each other. The fuel assembly has a plurality of fuel rods arranged in a square lattice pattern, each fuel rod being filled with nuclear fuel pellets and also has at least one neutron moderator rod shifted toward one corner where a control rod is inserted, away from a cross sectional center of the fuel assembly.
    Type: Grant
    Filed: April 2, 2002
    Date of Patent: November 4, 2003
    Assignee: Hitachi, Ltd.
    Inventor: Ryoji Masumi
  • Publication number: 20030194045
    Abstract: The spacer/water rod retention assembly includes a clip secured to the spacer having a slot perimetrically bounded both axially and laterally spaced portions of the clip. A resilient tab projects from one side portion into the slot. A water rod has a projecting tab which, upon relative rotation of the spacer and water rod, engages and deflects the clip tab to enable the water rod tab to reside in the clip slot. When the clip tab returns to its initial position, substantial relative rotation between the water rod and spacer is precluded and axial connection between the spacer and water rod is assured. In another form, the water rod tab projects into a slot of the clip. An adjacent water rod prevents rotation of the water rod tab in the opposite direction, thereby capturing the spacer and water rod and preventing relative axial movement.
    Type: Application
    Filed: April 10, 2002
    Publication date: October 16, 2003
    Inventors: Russell P. Higgins, David G. Smith
  • Patent number: 6600800
    Abstract: In a boiling water fuel assembly, some of the fuel rods are shortened. It is necessary to establish a sufficiently high maximum power for transition to boiling. To optimize this power, spacers are at a constant distance at a bottom and are at a shorter distance at a top. The spacers belonging to upper group have turbulence-generating vanes which, however, do not project above the shortened fuel rods.
    Type: Grant
    Filed: June 18, 2001
    Date of Patent: July 29, 2003
    Assignee: Framatome ANP GmbH
    Inventors: Dieter Bender, Otmar Bender, Hans-Joachim Lippert, Walter Übelhack
  • Patent number: 6598029
    Abstract: An auction service is provided that stimulates competition between energy suppliers (i.e., electric power or natural gas). A bidding moderator (Moderator) receives bids from the competing suppliers of the rate each is willing to charge to particular end users for estimated quantities of electric power or gas supply (separate auctions). Each supplier receives competing bids from the Moderator and has the opportunity to adjust its own bids down or up, depending on whether it wants to encourage or discourage additional energy delivery commitments in a particular geographic area or to a particular customer group. Each supplier's bids can also be changed to reflect each supplier's capacity utilization. Appropriate billing arrangements are also disclosed. The technology required to facilitate forward delivery transactions, in which a buyer and seller agree to the terms of a transaction today but schedule the delivery for a future time, would be helpful to end users, resellers and suppliers.
    Type: Grant
    Filed: April 4, 2000
    Date of Patent: July 22, 2003
    Assignee: Geophonic Networks, Inc.
    Inventors: Jack J. Johnson, William F. Coyle
  • Patent number: 6516043
    Abstract: A fuel assembly includes a plurality of fuel rods placed in a square lattice array of 9-rows/9-columns and at least one water rod. In this fuel assembly, the fuel rod pitch of the plurality of fuel rods is in a range of 14.15 mm to 14.65 mm, and means for offsetting and holding a fuel bundle composed of the fuel rods and the water rod is provided in such a manner that the center in a cross section of the fuel bundle is offset from the center in a cross section of the lower tie plate toward the channel fastener side. With this configuration, it is possible to provide a fuel assembly for a D-lattice core, which is capable of achieving the fuel economy comparable to that of a C-lattice core without reducing the thermal margin, and of using the existing fuel spacers.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: February 4, 2003
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Masao Chaki, Koji Nishida, Motoo Aoyama, Junichi Koyama, Katsumasa Haikawa, Yasuhiro Aizawa
  • Patent number: 6516042
    Abstract: The invention relates to a fuel assembly for a boiling water reactor which is adapted, during operation of the reactor, to allow water to flow upwards through the fuel assembly while absorbing heat from a plurality of fuel rods, whereby part of the water is transformed into steam. The fuel assembly comprises a steam channel through which the steam flows through the fuel assembly. The steam channel (16a, 16b, 16c, 16d) consists of an empty volume which at least extends through part of the fuel assembly. The fuel assembly is designed such that the water and the steam are brought to rotate around the steam channel whereby the water is thrown away from the steam channel whereas the steam which is separated from the water flows upwards through the steam channel.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: February 4, 2003
    Assignee: Westinghouse Atom AB
    Inventor: Sture Helmersson
  • Patent number: 6510192
    Abstract: A boiling water type nuclear reactor core, in which a plurality of fuel assemblies, each enclosed in a channel box, are loaded and a plurality of control rods, each having control blades, are arranged between the channel boxes. Long blade control rods, each having control rod blades which extend in four directions, are arranged between channel boxes on diagonals of square bundle regions each formed by a plurality of fuel assemblies, and short blade control rods, each having a control rod blade length of about half of the width of one of the square bundle regions, are arranged between the channel boxes in the center of each of the square bundle regions.
    Type: Grant
    Filed: November 2, 2000
    Date of Patent: January 21, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Junichi Yamashita, Kumiaki Moriya, Katsumasa Haikawa, Yasuhiro Masuhara, Taichi Takii, Akihiro Yamanaka, Takao Kondo, Motoo Aoyama, Masao Chaki
  • Patent number: 6487266
    Abstract: A fuel bundle assembly for a boiling water nuclear reactor comprising a plurality of fuel rods having respective fuel columns therein, and arranged in an ordered array, extending between upper and lower support structures, the plurality of fuel rods enclosed within a hollow, open-ended channel member at least partially enclosed by the open-ended channel member; at least one water rod supported on the lower tie plate and extending upwardly toward the upper tie plate, the at least one water rod having an upward flow path including at least one inlet at a lower end of the upward flow path, and a downward flow path including at least one outlet at a lower end of the downward flow path, the at least one outlet located about midway along the fuel columns within the fuel rods.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: November 26, 2002
    Assignee: General Electric Company
    Inventors: Gary E. Dix, James C. Shaug
  • Patent number: 6434210
    Abstract: A fuel assembly attains high burnup and increases reactor shut-down margin when loaded into a reactor core wherein a water gap width on a control rod side and a water gap width on a side opposite to the control rod side are almost equal to each other. The fuel assembly has a plurality of fuel rods arranged in a square lattice pattern, each fuel rod being filled with nuclear fuel pellets and also has at least one neutron moderator rod shifted toward one corner where a control rod is inserted, away from a cross sectional center of the fuel assembly.
    Type: Grant
    Filed: June 18, 1999
    Date of Patent: August 13, 2002
    Assignee: Hitachi, Ltd.
    Inventor: Ryoji Masumi
  • Patent number: 6337892
    Abstract: In each of a number of fuel assemblies loaded in a core of a boiling water reactor, a fuel holding portion of a lower tie plate holds lower end portions a plurality of fuel rods and at least one water rod. The water rod includes a rising pipe opened to a space in the lower tie plate below the fuel holding portion and introducing upward a coolant introduced to the rising pipe, and a falling pipe communicated with the rising pipe and introducing downward the coolant introduced through the rising pipe. The falling pipe has a coolant outlet opened to a second coolant passage defined between the fuel rods above the fuel holding portion. The rising passage is filled with the coolant during a period of rated power operation of the reactor, and a surface of the coolant is formed in the rising pipe during a period of non-rated power operation in which a flow rate of the coolant supplied to the fuel assemblies is lower than that during the period of rated power operation.
    Type: Grant
    Filed: September 6, 2000
    Date of Patent: January 8, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Masao Chaki, Koji Nishida
  • Patent number: 6333957
    Abstract: A tool kit for adjusting the angular orientation of water rods about respective axes in a nuclear fuel bundle includes a washer wrench, socket, orientator wrenches, orientator gauges and an orientator cap. The washer wrench has opposed jaws having parallel surfaces and reliefs at junctures between the surfaces and the base of the jaws to inhibit rounding off corners of tie bars connected to the water rods. The socket has a corresponding D-shaped recess as the tie bar ends to facilitate rotational adjustment thereof. Orientator wrenches have witness notches for aligning the flats of the tie bars. The orientator gauges comprise a series of gauge bodies each having a pair of axially parallel openings with stepped margins to the openings such that one opening is axially offset from the margin defining the entrance to the other opening.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: December 25, 2001
    Assignee: General Electric Company
    Inventors: William C. Peters, David G. Smith, Edward G. Apple, Jr.
  • Patent number: 6301321
    Abstract: A new design concept of boiling water reactor fuel assembly water channels is disclosed. The new design utilizes parallel flow paths guided inside an outer conduit without reversing flow. The different flow paths discharge water into the coolant stream, which is the objective of this invention, and resulting in improvements in thermal efficiency and stability of the fuel assembly. The thus diverted flow paths discharge water evenly into the coolant stream, which is the objective of this invention, with the result of improving the thermal efficiency and stability of the fuel assembly.
    Type: Grant
    Filed: July 14, 1999
    Date of Patent: October 9, 2001
    Inventor: Yousef M. Farawila
  • Patent number: 6285729
    Abstract: The spacer/water rod retention assembly includes a clip secured to the spacer having a slot perimetrically bounded both axially and laterally spaced portions of the clip. A resilient tab projects from one side portion into the slot. A water rod has a projecting tab which, upon relative rotation of the spacer and water rod, engages and deflects the clip tab to enable the water rod tab to reside in the clip slot. When the clip tab returns to its initial position, substantial relative rotation between the water rod and spacer is precluded and axial connection between the spacer and water rod is assured. In another form, the water rod tab projects into a slot of the clip. An adjacent water rod prevents rotation of the water rod tab in the opposite direction, thereby capturing the spacer and water rod and preventing relative axial movement.
    Type: Grant
    Filed: May 7, 1999
    Date of Patent: September 4, 2001
    Assignee: General Electric Company
    Inventors: Russell P. Higgins, David G. Smith
  • Patent number: 6278757
    Abstract: A resistance member (e.g., fuel holding portion of the lower tie plate) is provided at the lower end of the fuel assembly. Provision is made of a coolant ascending path in which said water rods have coolant inlet ports that are open in a region lower than the resistance member to upwardly guide the coolant, and a coolant descending path which has a coolant delivery port that is open in a region higher than the resistance member to downwardly guide the coolant. The coolant ascending path and the coolant descending path are communicated with each other at their upper end portions.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: August 21, 2001
    Assignee: Hitachi, LTD
    Inventors: Osamu Yokomizo, Yuichiro Yoshimoto, Yoshiyuki Kataoka, Shinichi Kashiwai, Yasuhiro Masuhara, Akio Tomiyama, Akihito Orii, Kotaro Inoue, Takaaki Mochida, Tatsuo Hayashi
  • Patent number: 6236701
    Abstract: A fuel assembly for a boiling water reactor comprising at least one rotary cell (13a-13d) which has fuel rods (4) arranged in a number of concentric rings with a substantially circular shape, and a steam conducting channel (17a-17d) arranged in the centre of the concentric rings through which steam flows upwards through the fuel assembly. At least certain of the fuel rods in the rings are arranged such that their upper ends are displaced in relation to their lower ends in the tangential direction such that water and steam are brought to rotate around the steam conducting channel.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: May 22, 2001
    Assignee: ABB Atom AB
    Inventor: Olov Nylund
  • Patent number: 6226343
    Abstract: A water rod for a fuel assembly of a boiling water nuclear reactor has a first end and a second end, wherein at least one of the first and second ends is directly attachable to a tie plate of the fuel assembly without an end plug. The structure of the present invention simplifies the manufacturing process and reduces the cost of the fuel assembly in the boiling water nuclear reactor. The water rod according to the invention has one or both of its ends configured to be directly attachable to the tie plate of the fuel assembly.
    Type: Grant
    Filed: April 23, 1997
    Date of Patent: May 1, 2001
    Assignee: General Electric Company
    Inventors: Christian D. Frederickson, Harold B. King
  • Patent number: 6205196
    Abstract: A boiling water type nuclear reactor core, in which a plurality of fuel assemblies, each enclosed in a channel box, are loaded and a plurality of control rods, each having control blades, are arranged between the channel boxes. Latitudinal long blade control rods, each having control rod blades which extend latitudinally in four directions, are arranged between channel boxes on diagonals of square bundle regions each formed by a plurality of fuel assemblies, and latitudinal short blade control rods, each having control rod blades which extend latitudinally in four directions with each control rod blade having a latitudinal length of about half of the width of one of the square bundle regions, are arranged between the channel boxes in the center of each of the square bundle regions. The long blade control rods have a latitudinal blade length which is about twice as long as the latitudinal blade length of the short blade control rods.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: March 20, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Junichi Yamashita, Kumiaki Moriya, Katsumasa Haikawa, Yasuhiro Masuhara, Taichi Takii, Akihiro Yamanaka, Takao Kondo, Motoo Aoyama, Masao Chaki
  • Patent number: 6181763
    Abstract: A fuel bundle assembly for a boiling water nuclear reactor comprising a plurality of fuel rods having respective fuel columns therein, and arranged in an ordered array, extending between upper and lower support structures, the plurality of fuel rods enclosed within a hollow, open-ended channel member at least partially enclosed by the open-ended channel member; at least one water rod supported on the lower tie plate and extending upwardly toward the upper tie plate, the at least one water rod having an upward flow path including at least one inlet at a lower end of the upward flow path, and a downward flow path including at least one outlet at a lower end of the downward flow path, the at least one outlet located about midway along the fuel columns within the fuel rods.
    Type: Grant
    Filed: June 8, 1998
    Date of Patent: January 30, 2001
    Assignee: General Electric Company
    Inventors: Gary E. Dix, James C. Shaug
  • Patent number: 6175606
    Abstract: A fuel assembly (1) for a boiling water nuclear reactor comprising a plurality of vertical fuel rods (3) which are arranged in spaced relationship between a bottom tie plate (6) and a top tie plate (5). The bottom tie plate (6) is provided with through-holes (6a) for the passage of a coolant (F). Further, the fuel assembly (1) comprises a bottom support (10) which is formed substantially from a downstream and an upstream flat surface (12, 13) and four side surfaces (14). The flat surfaces (12, 13) and the side surfaces (14) form a parallelepiped which surrounds a cavity. A filtering member is arranged in the upstream flat surface (13) and comprises a plurality of through-holes (11).
    Type: Grant
    Filed: July 26, 1999
    Date of Patent: January 16, 2001
    Assignee: ABB Atom AB
    Inventor: Håkan Söderberg
  • Patent number: 6148054
    Abstract: A support rod 14 carrying one or more separation devices 12, e.g., swirlers, is releasably secured in a fuel bundle. The support rod and separation devices are sized to pass through openings in the spacers S otherwise containing full length fuel rods. The lower end of the support rod is releasably connected to the upper end of a part-length fuel rod PLR which in turn is releasably connected to the lower tie plate. The support rod, separation devices and part-length rod may be installed and removed relative to the fuel bundle as an integral assembly with the part-length rod and separation devices passing through the openings in the spacers. When installed, the separation devices lie above upper spacers in the vent volumes to flow liquid on and into the interstices of the surrounding fuel rods.
    Type: Grant
    Filed: November 9, 1998
    Date of Patent: November 14, 2000
    Assignee: General Electric Company
    Inventors: David G. Smith, Harold B. King
  • Patent number: 6141397
    Abstract: In each of a number of fuel assemblies loaded in a core of a boiling water reactor, a fuel holding portion of a lower tie plate holds lower end portions a plurality of fuel rods and at least one water rod. The water rod includes a rising pipe opened to a space in the lower tie plate below the fuel holding portion and introducing upward a coolant introduced to the rising pipe, and a falling pipe communicated with the rising pipe and introducing downward the coolant introduced through the rising pipe. The falling pipe has a coolant outlet opened to a second coolant passage defined between the fuel rods above the fuel holding portion. The rising passage is filled with the coolant during a period of rated power operation of the reactor, and a surface of the coolant is formed in the rising pipe during a period of non-rated power operation in which a flow rate of the coolant supplied to the fuel assemblies is lower than that during the period of rated power operation.
    Type: Grant
    Filed: June 17, 1999
    Date of Patent: October 31, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Masao Chaki, Koji Nishida
  • Patent number: 6088420
    Abstract: In a reactor core, there is charged a number of fuel assemblies composed of a channel box and a fuel bundle disposed therein, in which fuel rods adjacent to each other are arranged so as to provide a triangular shape and a ratio of a coolant channel cross section to a fuel cross section is set to be 1 or less.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: July 11, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsugio Yokoyama, Ritsuo Yoshioka, Yasushi Tsuboi
  • Patent number: 5995577
    Abstract: A nuclear fuel bundle has full-length and part-length fuel rods, the latter defining vent volumes interspersed among the full-length fuel rods. The vent volumes afford critical power enhancement by efficiently transferring liquid to adjacent full-length fuel rods. Except for full-length fuel rods adjacent unheated surfaces, for example, the channel and water rods, each fuel rod lies face adjacent a steam vent volume and full-length fuel rods diagonally adjacent a steam vent volume lie face adjacent at least one other steam vent volume whereby, except for full-length fuel rods adjacent non-heat generating surfaces, enhanced critical power performance is applicable to all full-length fuel rods notwithstanding diagonal location of full-length fuel rods relative to a steam vent volume.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: November 30, 1999
    Assignee: General Electric Company
    Inventor: Bruce Matzner
  • Patent number: 5949839
    Abstract: A fuel assembly for a boiling water reactor where the fuel assembly during operation is arranged vertically in the core of the reactor. The fuel assembly comprises a plurality of vertical fuel rods (22) arranged in one or more fuel bundles, wherein at least the majority of the fuel rods comprise a stack of fuel pellets (7) surrounded by a cladding tube (8b) and a plenum tube (23) which is connected to the upper part of the cladding tube (8b), the plenum tube having a cross-section area which is smaller than the cross-section area of the cladding tube.
    Type: Grant
    Filed: April 9, 1998
    Date of Patent: September 7, 1999
    Assignee: Asea Brown Boveri AB
    Inventor: Olov Nylund
  • Patent number: 5914995
    Abstract: A nuclear reactor fuel assembly includes a fuel assembly base, a fuel assembly head and mutually parallel fuel rods containing nuclear fuel and extending between the fuel assembly head and the fuel assembly base. A water tube having first and second open ends extends parallel to the fuel rods. The first end of the water tube grips and is held at the fuel assembly base. An elongated extension body has first and second ends. The second end of the extension body grips and is held at the fuel assembly head. The second end of the water tube is screwed into the first end of the elongated extension body, or the first end of the elongated extension body is screwed into the second end of the water tube. The elongated extension body has two mutually coaxially disposed partial bodies. One of the partial bodies has the second end of the extension body and the other of the partial bodies has the first end of the extension body. One of the partial bodies is screwed into the other of the partial bodies.
    Type: Grant
    Filed: February 27, 1996
    Date of Patent: June 22, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventors: Werner Meier, Peter Rau
  • Patent number: 5872826
    Abstract: A channel box for a nuclear-reactor fuel assembly (MOX fuel assembly) containing plutonium, capable of properly controlling the excess reactivity without mixing neutron absorber or burnable poison into a fuel rod, and a channel box for a nuclear-reactor fuel assembly which does not form any gap between the channel box and members containing burnable poison in the channel box and in which the burnable poison does not directly contact with reactor water.
    Type: Grant
    Filed: June 25, 1997
    Date of Patent: February 16, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Tadashi Fujieda, Masahisa Inagaki, Iwao Takase, Yoshitaka Nishino, Junichi Yamashita, Akihiro Yamanaka, Kenichi Ito, Junjiro Nakajima, Takehiro Seto
  • Patent number: 5859888
    Abstract: In a fuel bundle for a boiling water nuclear reactor comprising a plurality of fuel rods secured within an array and extending between upper and lower tie plates, and including at least one additional fuel rod extending from the lower tie plate but terminating short of the upper tie plate, an improvement wherein a removable extension rod secured to the at least one additional fuel rod and extending substantially to the upper tie plate. The removable extension rod is in the form of a hollow tube having a plurality of openings therein and an internal flow path over an axial portion of the hollow tube, the flow path serving to cause coolant in the hollow tube to be deposited on adjacent fuel rods.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: January 12, 1999
    Assignee: General Electric Company
    Inventors: Robert B. Elkins, Harold B. King
  • Patent number: 5809101
    Abstract: A fuel bundle assembly for a nuclear reactor includes a modified channel and a handle unit that improves pressure drop performance. With the modified channel, one approach is to vary the outside dimension of the fuel channel along the length of the channel, but maintain a constant channel wall thickness. Another approach is to maintain the external dimensions of the fuel channel and vary the wall thickness along the length of the channel. The handle unit is formed including a handle member and a separate rod support member releasably engageable with the handle member. The handle member includes channels for receiving latch pin assemblies, coolant rods and a spacer assembly. The rod support member includes a plurality of fuel rod support chambers providing lateral support for the fuel rods of the fuel assembly. The rod support member also includes a main chamber that is sized to receive a portion of the handle member in a friction fit.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: September 15, 1998
    Assignee: General Electric Company
    Inventors: Thomas G. Dunlap, Gerald M. Latter, Mark J. Colby, Michael R. Stepp
  • Patent number: 5787140
    Abstract: A fuel bundle assembly for a nuclear reactor includes a modified channel that improves pressure drop performance and a handle assembly that includes structure for preventing a broken end plug from escaping the fuel bundle. In modifying the channel, one approach is to vary the outside dimension of the fuel channel along the length of the channel, but maintain a constant channel wall thickness. Another approach is to maintain the external dimensions of the fuel channel and vary the wall thickness along the length of the channel. The handle assembly replaces the conventional upper tie plate and is provided with structure for preventing debris such as a broken fuel rod end plug from escaping the fuel bundle. The structure preferably includes a plurality of gridwork cross members forming a substantially square grid including gridwork windows that are sized smaller than the fuel rod end plugs.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: July 28, 1998
    Assignee: General Electric Company
    Inventors: Thomas G. Dunlap, Gerald M. Latter, Mark J. Colby, Michael R. Stepp
  • Patent number: 5748695
    Abstract: A latch pin assembly is configured to enable selective engagement with at least one of the fuel assembly channel and the coolant rod such that the fuel assembly channel and the coolant rod can be selectively utilized to support the fuel assembly load, thereby eliminating the need for fuel tie rods. The latch pin assembly includes a latch pin selectively engageable with the fuel assembly channel and the coolant rod, and an anchoring assembly cooperating with the latch pin, wherein the anchoring assembly anchors the latch pin in a selected position such that the latch pin engages at least one of the fuel assembly channel and the coolant rod. The latch pin may be alternatively engageable with the fuel assembly channel and the coolant rod or simultaneously engageable with the fuel assembly channel and the coolant rod.
    Type: Grant
    Filed: November 7, 1995
    Date of Patent: May 5, 1998
    Assignee: General Electric Company
    Inventors: Thomas G. Dunlap, Robert B. Elkins, Mark J. Colby
  • Patent number: 5671261
    Abstract: A lifting assembly is configured to facilitate attaching of the lifting bar to a load bearing water rod in a nuclear fuel assembly. A connecting member is rigidly secured to the water rod and is provided with one of a male engaging portion and a female receiving portion. A lifting member including the lifting bar is engageable with the connecting member and includes the other of the male engaging portion and the female receiving portion. The male engaging portion and the female receiving portion are correspondingly shaped, and after insertion of the connecting member into or about the lifting member, the connecting member and lifting bar can be rotated relative to each other to prevent disassembly of the lifting assembly. A spring is disposed between the lifting bar and the water rod and urges the male engaging portion toward a locked position. The lifting assembly facilitates the attaching and detaching of the lifting bar to a load bearing water rod.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: September 23, 1997
    Assignee: General Electric Company
    Inventor: Christian D. Frederickson
  • Patent number: 5663993
    Abstract: In a nuclear fuel rod assembly including a plurality of fuel rods and at least one water rod held together in a bundle, and wherein end plugs at the lower ends of the fuel rods and the at least one water rod engage a lower tie plate, an improvement wherein the end plug at the lower end of the at least one water rod is hollow and includes a multi-diameter flow metering bore for regulating coolant flow into the water rod.
    Type: Grant
    Filed: October 12, 1995
    Date of Patent: September 2, 1997
    Assignee: General Electric Company
    Inventors: David W. Danielson, Robert B. Elkins, Thomas G. Dunlap
  • Patent number: 5646973
    Abstract: A fuel bundle assembly for a nuclear reactor includes a lower tie plate; a transition piece underlying the lower tie plate; a plurality of fuel rods and at least one water rod seated on the lower tie plate and extending in substantially parallel relationship toward an upper end of the fuel bundle assembly, wherein a fuel bundle assembly lifting load is carried by load bearing members including certain of the fuel rods or by the at least one water rod; a plurality of spacers axially spaced along the at least one water rod and including means for laterally supporting each of the fuel rods; and a handle bar assembly at the upper end of the fuel bundle assembly connected to the load bearing members such that the plurality of non-load bearing fuel rods are supported only by the lower tie plate and the plurality of spacers.
    Type: Grant
    Filed: October 12, 1995
    Date of Patent: July 8, 1997
    Assignee: General Electric Company
    Inventors: Richard A. Proebstle, Christian D. Frederickson, Thomas G. Dunlap, Edward A. Croteau
  • Patent number: 5640435
    Abstract: The lower end of each of a plurality of fuel rods is supported by a fuel supporting portion of a lower tie plate. The fuel supporting portion includes a plurality of second coolant paths for supplying a coolant from below the fuel supporting portion to a first coolant path defined above the fuel supporting portion and between the fuel rods. The total cross-sectional area of all the second coolant paths is smaller than the cross-sectional area of the first coolant path.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: June 17, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Hideki Kurosaki, Junjiro Nakajima, Hajime Umehara, Shozo Nakamura, Satoshi Kanno, Koji Nishida, Yasunori Bessho, Masahisa Inagaki, Osamu Yokomizo, Yuichiro Yoshimoto
  • Patent number: 5627865
    Abstract: A nuclear fuel assembly for a boiling water reactor, comprising an outer channel having a substantially square cross-sectional area, and fuel rods arranged with a predetermined pitch in an array of 10.times.12 where the centers of the fuel rods are located at the vertices of equilateral triangles.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: May 6, 1997
    Assignee: Siemens Power Corporation
    Inventors: Harold E. Williamson, Kenneth V. Walters
  • Patent number: 5627866
    Abstract: A fuel assembly for a nuclear reactor vessel includes a plurality of fuel rods, at least one coolant rod, a lower tie plate supporting the fuel rods and coolant rod, and a channel surrounding the fuel rods, coolant rod and tie plate. The lower tie plate is supported by the channel such that the channel carries a load of the fuel assembly. In one aspect of the invention, an upper tie plate includes two spring loaded latch pins engageable with corresponding apertures in the channel. A transition member supports the lower tie plate and is rigidly secured to the channel. Thus, when lifting the fuel assembly from the reactor, the channel bears the load of the fuel assembly. End gussets or clips are welded to the channel and inserted into the transition member, which serve as a secondary support for the transition member in the event that its primary connection to the channel fails. A channel guide member is secured to the, upper tie plate and includes two ears that are received in ear apertures in the channel.
    Type: Grant
    Filed: October 12, 1995
    Date of Patent: May 6, 1997
    Assignee: General Electric Company
    Inventors: Thomas G. Dunlap, Robert B. Elkins, Christian D. Frederickson, Russell P. Higgins