Including Handling Of A Second Different, Diverse Reactor Component (e.g., Control Element, Moderator Element, Vessel Cover Removal) Patents (Class 376/262)
  • Patent number: 10020079
    Abstract: A core of a light water reactor has a plurality of fuel assemblies. The fuel assemblies include a plurality of fuel rods in which a lower end is supported by a lower tie-plate and an upper end is supported by an upper tie-plate. The fuel rods form plenums above a nuclear fuel material zone and have a neutron absorbing material filling zone under the nuclear fuel material zone. Neutron absorbing members attached to the upper tie-plate are disposed between mutual plenums of the neighboring fuel rods above the nuclear fuel material zone. The neutron absorbing members have a length of 500 mm and are positioned at a distance of 300 mm from the nuclear fuel material zone. Even if the overall core is assumed to become a state of 100% void, no positive reactivity is inserted to the core.
    Type: Grant
    Filed: April 24, 2015
    Date of Patent: July 10, 2018
    Assignee: HITACHI-GE NUCLEAR ENERGY, LTD.
    Inventors: Renzo Takeda, Junichi Miwa, Kumiaki Moriya
  • Patent number: 9666313
    Abstract: A nuclear reactor includes at least: a pressure vessel including an upper vessel section and a lower vessel section connected by a mid-flange and containing primary coolant; a nuclear reactor core disposed in the lower vessel section and immersed in the primary coolant; and upper internals suspended from the mid-flange of the pressure vessel. The upper internals include at least internal CRDMs immersed in the primary coolant and control rod guide frames. To refuel, the nuclear reactor is depressurized. The upper vessel section is disconnected and removed while leaving the mid-flange in place with the upper internals remaining suspended from the mid-flange. The mid-flange is then removed with the upper internals remaining suspended from the mid-flange. The fuel is replaced, the mid-flange is placed back onto the lower vessel section with the upper internals remaining suspended from the mid-flange, and the upper vessel section is placed back and re-connected.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: May 30, 2017
    Assignee: BWXT mPower, Inc.
    Inventors: Scott J Shargots, Matthew W Ales, James B Inman
  • Patent number: 9449722
    Abstract: A system for gripping an inner tube and locking/unlocking it into and from an outer tube concentric with the inner tube. The system according to the invention is provided with one or more catching devices which allow both sealed locking/unlocking of the inner tube to the gripper member and of the inner tube in the outer tube, achieving this with only a translational movement of the gripper member over a travel A or a travel B. The system according to the invention advantageously constitutes a system for inserting and extracting a specimen holder tube intended to house a specimen of nuclear materials, such as nuclear fuels, into and from a measurement instrumentation holder tube intended to house measurement sensors and a cooling system.
    Type: Grant
    Filed: December 4, 2013
    Date of Patent: September 20, 2016
    Assignee: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
    Inventors: Sebastien Gay, Niels Peyre
  • Patent number: 8995603
    Abstract: A control rod/fuel support handling apparatus that is used in the case where a control rod and a fuel support are held, removed and lifted in a reactor and then are transported into the reactor in a periodical inspection of a BWR and in the case where the control rod and the fuel support are attached and mounted again into the reactor, the control rod/fuel support handling apparatus including: a fuel support gripper that holds the fuel support with a support gripping member; a control rod gripper that includes a vertically movable and rotatable elevating/rotating unit, holds the control rod with a control rod gripping member, disconnects and connects the control rod and a control rod drive mechanism, and allows removal and attachment of the control rod; and a control panel that controls automatically controls the control rod gripper in response to the instructions from an operation pendant.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: March 31, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Tomatsu, Koichi Soma, Kaoru Takagi
  • Patent number: 8737558
    Abstract: A system includes at least one body, a link for suspending the body for movement with gravity from a first elevation position to a second elevation position, and an electrical energy generator coupled with the body through the link to drive the generator to generate electricity upon movement of the body with gravity from the first to the second elevation position. The at least one body has a mass of at least approximately 100 tonnes; the first and the second elevation positions define a distance therebetween of at least approximately 200 meters; and/or the system further includes an operator configured to operate the link to controllably move the at least one body against gravity from the second to the first elevation position to increase a gravitational potential energy of the at least one body, and to maintain the gravitational potential energy of the at least one body.
    Type: Grant
    Filed: April 26, 2012
    Date of Patent: May 27, 2014
    Assignee: Launchpoint Technologies, Inc.
    Inventor: O. James Fiske
  • Patent number: 8718222
    Abstract: An apparatus for reinforcing a jet pump riser includes: an elbow upper clamp for covering a riser elbow coupled to a thermal sleeve from an upper side thereof; an elbow lower clamping member for clamping the riser elbow from a lower side thereof; an elbow vertical portion clamping member for covering a vertical portion of the riser elbow; and an elbow horizontal portion clamping member for covering a horizontal portion of the riser elbow. These members are disposed in different orientations with respect to the elbow upper clamp so as to fix the thermal sleeve, the riser elbow and the riser pipe.
    Type: Grant
    Filed: August 16, 2007
    Date of Patent: May 6, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masakazu Abura, Toshihiro Yasuda, Kazuo Sudo, Haruhiko Hata, Yasushi Kanazawa, Kunihiko Kinugasa, Hajime Mori
  • Patent number: 8599989
    Abstract: Provided is a modular reactor head area assembly. The modular reactor head area assembly is installed on a reactor head, and includes: a seismic support structure that performs functions of lifting, moving and reinstallation of the reactor head and control rod driving apparatuses, cooling of the control rod driving apparatuses, shielding of missile parts, and supporting with respect to a seismic load, and disperses a load applied to the control rod driving apparatuses; an upper module that is an assembly of components located at an upper portion of the seismic support structure for the control rod driving apparatuses; and a lower module that is an assembly of components located at a lower portion of the seismic support structure for the control rod driving apparatuses. The upper module and the lower module are 252 detachably coupled to each other so that maintenance of the control rod driving apparatus can be performed easily.
    Type: Grant
    Filed: December 31, 2007
    Date of Patent: December 3, 2013
    Assignee: Korea Power Engineering Company, Inc.
    Inventors: Tae-Kyo Kang, Hyun-Min Kim, Young-Ju Kwon, Kwang-Hee Cho, Ki-Seok Yoon, In-Yong Kim, Yeon-Ho Cho, Myoung-Goo Lee
  • Publication number: 20130301779
    Abstract: A nuclear reactor includes at least: a pressure vessel including an upper vessel section and a lower vessel section connected by a mid-flange and containing primary coolant; a nuclear reactor core disposed in the lower vessel section and immersed in the primary coolant; and upper internals suspended from the mid-flange of the pressure vessel. The upper internals include at least internal CRDMs immersed in the primary coolant and control rod guide frames. To refuel, the nuclear reactor is depressurized. The upper vessel section is disconnected and removed while leaving the mid-flange in place with the upper internals remaining suspended from the mid-flange. The mid-flange is then removed with the upper internals remaining suspended from the mid-flange. The fuel is replaced, the mid-flange is placed back onto the lower vessel section with the upper internals remaining suspended from the mid-flange, and the upper vessel section is placed back and re-connected.
    Type: Application
    Filed: April 12, 2013
    Publication date: November 14, 2013
    Inventor: Babcock &Wilcox mPower, Inc.
  • Patent number: 8576973
    Abstract: A cask for loading at least one nuclear fuel assembly in a transport container, including a body with a longitudinal axis (X) capable of sealably covering an upper end of a container, at least one aperture (10) for letting through a fuel assembly, at least one means for connecting to pneumatic confinement means and at least one means (56) capable of maintaining a means (58) for sealing a chamber of the container inside the cask and at a distance from an entrance of said chamber during loading, wherein the maintaining means (56) includes a first arm (60) rotationally mobile around a first axis and a second arm (62) attached to the first arm (60) and rotationally mobile relatively to the first arm, said cask also including external means for controlling the arms (68,86), and wherein the second arm (62) includes a housing (76) for receiving the sealing means.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: November 5, 2013
    Assignee: Areva NC
    Inventor: Serge Fantini
  • Patent number: 8437445
    Abstract: A method of predicting stresses on a BWR steam dryer that includes creating an analytical acoustic model of a BWR steam system; generating pressure estimations by inputting empirical data into the analytical acoustic model of the BWR steam system; creating an analytical structural model of the BWR steam dryer; and predicting stresses on the BWR steam dryer using the analytical structural model and the pressure estimations.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: May 7, 2013
    Assignee: General Electric Company
    Inventors: David Galbally, Daniel Verne Sommerville, Matthew Christopher O'Connor, Daniel Charles Pappone, Hardayal Mehta, Leslie Wellstein
  • Patent number: 8254516
    Abstract: An outer filter removal tool for a boiling water reactor control rod drive that uses a mechanical advantage obtained through the use of lead screw threads to pull the outer filter off of the control rod drive. Fingers on the tool are closed around the upper flange of the outer filter by sliding a collar over the outwardly biased fingers. A shaft extending through the tool is rotated which in turn extends a push plate against the control rod drive index tube causing the fingers to pull against the upper flange on the outer filter until the filter is freed from the control rod drive. The tool will hold the filter in place until affirmatively released for proper disposal.
    Type: Grant
    Filed: September 22, 2009
    Date of Patent: August 28, 2012
    Assignee: Westinghouse Electric Company LLC
    Inventors: David P. Ketcham, Stafford L. Turner, Robert T. Fells
  • Patent number: 8189731
    Abstract: The machinery system and its application herewith, intended to create an opening in the roof of a Reactor Primary Containment of Generation II and III Nuclear Power Electric Generating Station. This opening is necessary to replace an aging nuclear reactor with a new, safer and more efficient reactor. Generation II and III Nuclear Power Electric Generating Stations include General Electric (GE) Boiling Water Reactor BWR/2, 3, 4, 5 and BWR/6 located in Mark II, and Mark III wet containments and Pressurized Water Reactors manufactured by Westinghouse, Combustion Engineering and Babcock and Wilcox located in dry containments. Until this time, existing reactor replacement was not possible due to Reactor Primary Containment structural enclosure configuration. The Dual Head Vertical Milling Machine System will remove a Reactor Primary Containment Dome Segment thus providing an opening, allowing reactor replacement and the electric generating station to remain operational for an other 40 years and beyond.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: May 29, 2012
    Inventor: John Jugl
  • Patent number: 8143592
    Abstract: Systems, devices, and methods for filling containers with radioactive materials are described. In certain embodiments, the systems comprise a shielding material that substantially defines a chamber and, preferably, substantially blocks radioactivity, a conduit extending through the shielding material into the chamber, and a securing unit that is disposed in the chamber proximal to the conduit and is adapted to receive a container through the conduit.
    Type: Grant
    Filed: April 29, 2010
    Date of Patent: March 27, 2012
    Assignee: DRAXIMAGE General Partnership
    Inventor: Daniel Tartaglia
  • Publication number: 20110317797
    Abstract: A control rod/fuel support handling apparatus that is used in the case where a control rod and a fuel support are held, removed and lifted in a reactor and then are transported into the reactor in a periodical inspection of a BWR and in the case where the control rod and the fuel support are attached and mounted again into the reactor, the control rod/fuel support handling apparatus including: a fuel support gripper that holds the fuel support with a support gripping member; a control rod gripper that includes a vertically movable and rotatable elevating/rotating unit, holds the control rod with a control rod gripping member, disconnects and connects the control rod and a control rod drive mechanism, and allows removal and attachment of the control rod; and a control panel that controls automatically controls the control rod gripper in response to the instructions from an operation pendant.
    Type: Application
    Filed: December 18, 2009
    Publication date: December 29, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tsutomu Tomatsu, Koichi Soma, Kaoru Takagi
  • Patent number: 7986760
    Abstract: A method and apparatus for the permissive control of a mast and fuel grapple to be used in the movement of reactor fuel components, including fuel assemblies, single blade and double blade guides, to be used in a Boiling Water Reactor (BWR) nuclear reactor. The Permissive Control System reduces the chance of human error associated with the movement of reactor components by assisting in controlling the location (plant coordinate) of the mast for picking-up and dropping-off reactor components, the sequence of reactor component movements, the orientation (angular rotation) of the mast and fuel grapple, the raising and lowering of the grapple, and the opening and closing of the fuel grapple.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: July 26, 2011
    Assignee: GE-Hitachi Nuclear Emergy Americas, LLC
    Inventor: Michael Johnson
  • Patent number: 7873137
    Abstract: A fast reactor including a reactivity control assembly including a reactor shutdown rod and neutron absorbers, a reactor shutdown rod drive mechanism, and units of neutron absorber drive mechanism. The reactor shutdown rod drive mechanism causes an inner extension tube to fall and release the reactor shutdown rod by a gripper section by turning off the power supply to a holding magnet at the time of scram. When grasping the neutron absorbers, an outer extension shaft is pulled up to allow both of the extension shafts to be inserted. After the outer extension tube gets to a handling head section of the neutron absorber, the outer extension shaft is pushed down to grasp the neutron absorber externally by latch fingers of the gripper section so that the neutron absorber can be moved up and down.
    Type: Grant
    Filed: February 8, 2007
    Date of Patent: January 18, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiyuki Suzuki, Koji Matsumoto, Kenzo Koizumi, Yasushi Tsuboi
  • Publication number: 20100284505
    Abstract: The present invention provides an apparatus for detecting and/or repositioning annulus spacers used to maintain the position of a pressure tube withm a calandria tube of a nuclear reactor. The method comprises the steps of: vibrationally isolating a section of the pressure tube; vibrating the wall of said pressure tube within said isolated section; detecting vibration of the wall at a minimum of two axial positions within said isolated sections; and detecting the reduction in vibration level of the wall at one or more of said axial positions in comparison to the remaining axial positions. The apparatus comprises a tool head to be inserted into the pressure tube, the tool head comprising a first end and a second and a clamping block m each of said ends. The clamping blocks are used to vibrationally isolate a section of the pressure tube located between said ends.
    Type: Application
    Filed: September 10, 2008
    Publication date: November 11, 2010
    Inventors: James M. King, Bruce A.W. Smith, Paul Feenstra
  • Patent number: 7809098
    Abstract: A system for exchanging a control rod drive of a nuclear reactor is provided. The system may include an integrated drive exchange assembly system (IDEAS). The IDEAS may include a trunnion cart attached to a tower assembly. The tower assembly may include an integrated extension carriage assembly. The IDEAS may also include a control rod drive adapter; and a lead cart connected to the trunnion cart assembly.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: October 5, 2010
    Assignee: General Electric Company
    Inventors: Veronica Salazar, James Burner, Mark W. Broaddus
  • Patent number: 7787583
    Abstract: An apparatus and method for manufacturing a handling pole including a pole section, a pole adapter connected to one end of the pole section, a spade member connected to the other end of the pole section, and a nut assembly for connecting adjoining poles. The pole adapter may include an upper sleeve and the spade member may include a lower sleeve.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: August 31, 2010
    Assignee: General Electric Company
    Inventors: Gregory A. Francisco, Robert W. Whitling
  • Publication number: 20090129528
    Abstract: A method and apparatus for the permissive control of a mast and fuel grapple to be used in the movement of reactor fuel components, including fuel assemblies, single blade and double blade guides, to be used in a Boiling Water Reactor (BWR) nuclear reactor. The Permissive Control System reduces the chance of human error associated with the movement of reactor components by assisting in controlling the location (plant coordinate) of the mast for picking-up and dropping-off reactor components, the sequence of reactor component movements, the orientation (angular rotation) of the mast and fuel grapple, the raising and lowering of the grapple, and the opening and closing of the fuel grapple.
    Type: Application
    Filed: November 15, 2007
    Publication date: May 21, 2009
    Inventor: Michael Johnson
  • Publication number: 20080205576
    Abstract: A light water reactor, comprising: a reactor pressure vessel; a core disposed in the reactor pressure vessel and loaded with a plurality of fuel assemblies including transuranic nuclides; and a coolant supplying apparatus for supplying a coolant to said core, wherein 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; and ratios of a plurality of isotopes of the transuranic nuclides being present in the fuel assembly taken out of the core are substantially the same as ratios of the plurality of isotopes present in the fuel assembly with the burnup of 0, which is to be loaded in the core.
    Type: Application
    Filed: January 24, 2008
    Publication date: August 28, 2008
    Inventors: Renzo TAKEDA, Junichi Miwa, Kumiaki Moriya
  • Patent number: 7386087
    Abstract: The invention relates to a method and a device for loading a fuel assembly into the core of a nuclear reactor. The inventive method consists in: inserting a dummy assembly (4) into the loading location (3) of the fuel assembly (5), said dummy assembly essentially having the same shape and dimensions as the loading location (3) and comprising smooth side walls; fixing the position of at least one fuel assembly (5) that is adjacent to the loading location (3), in the presence of the aforementioned dummy assembly (4), in relation to at least one second assembly (5) of the core, using at least one fuel assembly support tool (11); removing the dummy assembly (4) from the loading location (3); introducing the fuel assembly (5) which is being loaded into the loading location (3); and removing the fuel assembly support tool(s) (11).
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: June 10, 2008
    Assignee: Framatome ANP
    Inventor: Patrice Jublot
  • Patent number: 7289590
    Abstract: A device for handling a guide tube assembly. The assembly has an upper tube and a lower tube in each of which there are fixed horizontal guide plates arranged such that they are spaced apart in an axial direction. The handling device itself includes a gripper having a tubular body and two opposing arms located at one end of the tubular body and moveable between a retracted position and a deployed position, the arms bearing against a lower surface of a contacted guide plate when in the deployed position. A control member is located at an opposite end of the tubular body for controlling the arms. The length of the tubular body of the gripper selected to be: a) greater than the distance between an upper end of the upper tube and a first guide plate of the lower tube; and b) less than the distance between the upper end of the upper tube and a third guide plate of the second tube.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: October 30, 2007
    Assignee: Framatome ANP
    Inventors: S├ębastien Joly, Daniel Grypczynski, Gilles Morel
  • Patent number: 7239683
    Abstract: A device and method to move a fuel assembly of a nuclear reactor, wherein the device eliminates the potential for dropping the fuel assembly due to stress corrosion cracking of the upper guide thimble sleeves that attach the top nozzle to guide thimbles.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: July 3, 2007
    Assignee: Framatome ANP, Inc.
    Inventors: George S. Pabis, Darel R. Clark, Anthony A. Pugh, Raymond A. King
  • Patent number: 7158605
    Abstract: A head assembly for a reactor pressure vessel includes a removable closure head, an array of control rod drive mechanisms, a seismic support platform, a missile shield assembly and a cooling system for drawing atmospheric air across electromagnetic coil stack assemblies. The cooling system includes: a lower shroud surrounding the coil stack assemblies with an end open to the atmosphere around the CRDMs; a plurality of extending internal ducts disposed within the array of CRDMs upwardly to an upper plenum disposed above the seismic support platform and a plurality of fan assemblies disposed on the upper plenum. The missile shield is disposed within the upper plenum. The cooling system effectively cools the coil stack assemblies during fuel cycles and does not hinder access to the CRDMs during an outage. The head assembly has lift legs for transporting either the entire head assembly as an integral unit or the structure above the seismic support platform a subassembly.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: January 2, 2007
    Assignee: Westinghouse Electric Co LLC
    Inventors: Alexander W. Harkness, Michael G. Ball, Gregory E. Gontis
  • Patent number: 6853697
    Abstract: An apparatus, transfer cask, system, and method for defueling a nuclear reactor and transferring spent nuclear fuel from a spent nuclear fuel to a storage cask for long terms storage. In one aspect, the invention is an apparatus for use in transferring a canister of spent nuclear fuel from a transfer cask to a storage cask, the apparatus comprising a radiation absorbing shield surrounding a portion of a hole through which the canister can pass; means for securing the apparatus to the top surface of the storage cask; means for securing the bottom surface of the transfer cask to the apparatus; wherein the transfer cask securing means and the storage cask securing means are positioned on the apparatus so that when the apparatus is secured to both the transfer cask and the storage cask, the cavity of the transfer cask, the hole, and the cavity of the storage cask are substantially aligned; and means for moving the bottom lid in a horizontal direction once the bottom lid is unfastened from the bottom surface.
    Type: Grant
    Filed: June 3, 2003
    Date of Patent: February 8, 2005
    Assignee: Holtec International, Inc.
    Inventors: Krishna P. Singh, Stephen J. Agace
  • Patent number: 6788755
    Abstract: A system and method for moving a canister of spent nuclear fuel from a first location, which may be within a nuclear power generation facility to a second location such as a storage cask that is used for short-term or long-term storage of spent nuclear fuel includes a first lifting mechanism for engaging a transfer cask and a second lifting mechanism for engaging and lifting the canister of spent nuclear fuel. Preferably, the method is practiced by first positioning a canister of spent nuclear fuel within the transfer cask and then engaging the transfer cask with the first lifting mechanism. The canister is engaged with the second lifting mechanism. The transfer cask having the canister positioned within is moved to the vicinity of a storage cask, and the canister is lowered from the transfer cask into the storage cask by the second lifting mechanism without disengagement of the first lifting mechanism from the transfer cask.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: September 7, 2004
    Assignee: American Crane & Equipment Corporation
    Inventors: David P. Weber, Oddvar Norheim
  • Patent number: 6744841
    Abstract: A method of carrying equipment out of a nuclear reactor building that, in carrying equipment rendered radioactive out of a nuclear reactor building, makes it possible to shorten the operating time and reduce the number of casks to be used, wherein the structures of a nuclear power plant that are outside the equipment installed in the nuclear power plant are removed and these removed structures are then stored in the space in the equipment and carried out of the building.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: June 1, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Masataka Aoki, Takahiro Adachi, Katsumi Kobayashi, Mitsuo Kuroha, Kazunori Izumi
  • Patent number: 6731715
    Abstract: One of methods for carrying out a reactor vessel according to the present invention comprises the steps of removing an overhead traveling crane in a reactor containment vessel of a pressurized water reactor, or the steps of, in an area where an overhead traveling crane is installed, operating the overhead traveling crane to move aside for creating a space, through which the reactor vessel is able to pass, and then carrying out the reactor vessel through an opening provided in a top portion of the reactor containment vessel. With the present method, the reactor vessel of the pressurized water reactor can be carried out in a short time with high efficiency.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: May 4, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Masataka Aoki, Kouichi Ushiroda, Takahiro Adachi
  • Patent number: 6665364
    Abstract: Nuclear fuels are taken from a nuclear reactor pressure vessel, a rail for running is mounted under the reactor pressure vessel drain piping in parallel with a horizontal portion of the reactor pressure vessel drain piping inside a pedestal positioned on the lower side of the reactor pressure vessel, an inspection apparatus is mounted on the-rail, and the inspection apparatus is moved along the rail to inspect the reactor pressure vessel drain piping, whereby the reactor pressure vessel drain piping can be surely inspected while reducing radiation exposure to an inspector.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: December 16, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yuuichirou Mizumachi, Makiko Miyauchi, Masakazu Hisatsune, Fuminobu Takahashi
  • Patent number: 6654436
    Abstract: A stud enclosure for protecting a stud extending upwardly from a nuclear reactor pressure vessel (RPV) flange has a cylindrical can with a capped end and an open end. The capped end has an axially extending hole with a screw extending therein for fastening the stud enclosure to the stud. A seal ring is disposed adjacent the open end of the cylindrical can for sealing the ring on the RPV flange. A gas valve is disposed in the capped end of the cylindrical can for pressurizing the interior portion of the can with air. The stud enclosure is used to protect the RPV studs after the RPV head has been removed in order to permit access to the interior portions of the RPV.
    Type: Grant
    Filed: October 8, 2001
    Date of Patent: November 25, 2003
    Assignee: Westinghouse Electric Company LLC
    Inventors: Mark A. Marra, Reginald R. Dulaney
  • Patent number: 6643349
    Abstract: In order to carry out a radioactivated reactor pressure vessel from a nuclear reactor building of a nuclear power plant, a first opening portion for carrying out the reactor pressure vessel is provided in a roof of the nuclear reactor building. A radiation shield for covering the reactor pressure vessel and shielding radiations is carried into the reactor building through the first opening portion, and installed on a reactor shield wall. A hanger is lowered through the first opening portion and a slit provided on an upper lid of the radiation shield. A portion of a lid of the reactor pressure vessel and a portion of the upper lid of the radiation shield are abutted by hanging up the reactor pressure vessel by the hanger.
    Type: Grant
    Filed: August 1, 2002
    Date of Patent: November 4, 2003
    Assignees: Hesco Technology Co., Ltd., ICC Co., Ltd.
    Inventors: Masataka Aoki, Norihito Saito, Takahiro Adachi
  • Patent number: 6625248
    Abstract: A process for the treatment of radioactive graphite which includes the following steps: (i) reacting the radioactive graphite at a temperature in the range of from 250° C. to 900° C. with superheated steam or gases containing water vapor to form hydrogen and carbon monoxide; (ii) reacting the hydrogen and carbon monoxide from step (i) to form water and carbon dioxide; and (iii) reacting the carbon dioxide of step (ii) with metal oxides to for carbonate salts. The process enables radioactive graphite, such as graphite moderator, to be treated either in-situ or externally of a decommissioned nuclear reactor.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: September 23, 2003
    Assignee: Studsvik, Inc.
    Inventors: J. Bradley Mason, David Bradbury
  • Patent number: 6625245
    Abstract: A method of carrying out a reactor vessel according to the present invention includes removing an overhead traveling crane in a reactor containment vessel of a pressurized water reactor. Alternatively, in an area where an overhead traveling crane is installed, operating the overhead traveling crane to move aside for creating a space, through which the reactor vessel is able to pass. Then the reactor vessel is carried out through an opening provided in a top portion of the reactor containment vessel. With the present method, the reactor vessel of the pressurized water reactor can be carried out in a short period of time with high efficiency.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: September 23, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masataka Aoki, Kouichi Ushiroda, Takahiro Adachi
  • Patent number: 6556641
    Abstract: There are provided a control rod holding unit 16 for releasably holding a control rod 7 which is loaded in a reactor vessel 1, and fuel support/control rod guide tube holding unit 17 for releasably holding a fuel support 8 which supports a bottom end of a fuel assembly 10 and a control rod guide tube 6 on which the fuel support 8 is placed at top end. The control rod holding unit 16 and the fuel support/control rod guide tube holding unit 17 are fitted to a main body frame 26 which can be hoisted down inside the reactor vessel 1. Accordingly, there can be provided a reactor-internal equipment handling apparatus and method which are capable of reducing a term of work which is required for operations to load/unload the control rods, the fuel supports, and the control rod guide tubes.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: April 29, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Maehara, Koichi Soma, Kazuo Sakamaki
  • Patent number: 6501813
    Abstract: A control rod/fuel support grapple is provided which is capable of pulling up simultaneously a control rod and a fuel support from a reactor and also uncoupling the control rod and control rod drive mechanism. The control rod/fuel support grapple comprises a control rod holding unit for holding a control rod's hoist handle, a fuel support holding unit for holding a fuel support, and a coupling releasing unit or uncoupling the control rod and the control rod drive mechanism, coupled by virtue of a spud coupling. These three units are attached to a main body frame which is lowered into a reactor pressure vessel.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: December 31, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Soma, Kazuo Sakamaki
  • Patent number: 6452993
    Abstract: When a radioactivated reactor pressure vessel is carried out from a nuclear reactor building of a nuclear power plant, a first opening portion for carrying out the reactor pressure vessel is provided in a roof of the nuclear reactor building, a radiation shield for covering the reactor pressure vessel and shielding radiations is carried into the reactor building through the first opening portion, and installed on a reactor shield wall, lowering a hanger through the first opening portion and a slit provided on an upper lid of the radiation shield, a part of a lid of the reactor pressure vessel and a part of the upper lid of the radiation shield are abutted by hanging up the reactor pressure vessel by the hanger, and the reactor pressure vessel and the radiation shield integrated therewith are raised and carried out of the reactor building, whereby the shield can be easily mounted on the large-sized apparatus in a short time and a dose of radiations exposed to a worker when the shield is mounted can be reduced.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: September 17, 2002
    Assignees: Hitachi, Ltd., HESCO Technology Co., Ltd., ICC Co., Ltd.
    Inventors: Masataka Aoki, Norihito Saitou, Takahiro Adachi
  • Patent number: 6327321
    Abstract: Extruded Borated Aluminum rodlets of extended length are formed to maximize neutron absorption surface area while minimizing weight. They are located in the empty cells of a new or spent fuel assembly previously used by control rods and instrumentation with a length equal to that of a fuel rod or guide tube and control the reactivity of the fuel assembly during storage and shipment of the spent fuel assembly.
    Type: Grant
    Filed: April 20, 1999
    Date of Patent: December 4, 2001
    Assignee: Framatome ANP, Inc.
    Inventor: Peter L. Holman
  • Patent number: 6327322
    Abstract: A transfer device for moving a poison rod assembly between fuel cells in a nuclear fuel storage facility coupleable to an overhead crane. The poison rod assembly has a plurality of poison rods disposed in rows. The device includes an elongated outer member, an inner member, and a gripper assembly supported by the inner member. The inner member is slidably disposed within the elongated outer member. The overhead crane is coupled to the inner member for sliding said inner member between an upper position and a lower position. An interlock assembly selectively couples the inner member and elongated outer member. Thus, moving the crane, which is coupled to the inner member either moves the inner member relative to the elongated outer member when the interlock is not engaged, or, moves both the inner member and the elongated outer member when the interlock is engaged.
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: December 4, 2001
    Assignee: Westinghouse Electric Company LLC
    Inventors: Christopher Marc Burton, David John Stefko, Louis Joseph Tylman
  • Patent number: 6295329
    Abstract: A reactor-internal equipment handling apparatus which is capable of reducing work required to load/unload control rods, fuel supports, and control rod guide tubes, includes a control rod holding unit (16) for releasably holding a control rod (7) which is loaded into a reactor vessel (1), and fuel support/control rod guide tube holding unit (17) for releasably holding a fuel support (8) which supports a bottom end of a fuel assembly (10) and a control rod guide tube (6) on which the fuel support (8) is placed. The control rod holding unit (16) and the fuel support/control rod guide tube holding unit (17) are fitted to a main body frame (26) which can be hoisted down inside the reactor vessel (1).
    Type: Grant
    Filed: April 27, 1999
    Date of Patent: September 25, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Maehara, Koichi Soma, Kazuo Sakamaki
  • Patent number: 6282254
    Abstract: A transfer device for moving a poison rod assembly between fuel cells in a nuclear fuel storage facility, where the poison rod assembly has a plurality of poison rods depending from a web. The transfer device includes a frame assembly, a poison rod assembly lifting assembly, which is moveable between an upper position and a lower position, a plurality of comb assemblies. The comb assemblies are slidably mounted on the frame so that the comb assemblies slide between an open position and a closed position as the lifting assembly moves from its lower position to its upper position.
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: August 28, 2001
    Assignee: Westinghouse Electric Company LLC
    Inventors: Christopher Marc Burton, David John Stefko, Louis Joseph Tylman
  • Patent number: 6240155
    Abstract: A method of performing maintenance on a structural member inside a reactor pressure vessel includes lowering an annular guide rail having a second lug until the guide rail rests on an upper flange of a core shroud provided inside the reactor pressure vessel, detachably mounting the second lug of the guide rail to a first lug mounted on the core shroud, positioning a discharging nozzle at a position at which compressive remaining stress is added to a surface of the core shroud by moving the discharging nozzle in a radial direction and an axial direction of the core shroud by a discharging nozzle moving apparatus mounted on a turnable revolving on the guide rail and discharging water to add compressive remaining stress to a surface of the core shroud from the discharging nozzle.
    Type: Grant
    Filed: August 4, 1999
    Date of Patent: May 29, 2001
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Koichi Kurosawa, Eisaku Hayashi, Sadato Shimizu, Minoru Ootaka, Fujio Yoshikubo, Ren Morinaka, Masayuki Nishino, Noboru Chiba, Kunio Enomoto, Kazunori Sato
  • Patent number: 6108391
    Abstract: Apparatus for supporting the lower elbow assembly of a jet pump in a reactor pressure vessel (RPV) of a nuclear reactor are described. The clamp apparatus includes a lower clamp element and an upper clamp element. The upper and lower elements are configured to be positioned at the interface between the thermal sleeve and the jet pump riser elbow. The upper and lower elements include extended ridges that are configured to fit in circumferential grooves precisely machined into the sleeve-elbow assembly on opposing sides of the interface.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: August 22, 2000
    Assignee: General Electric Company
    Inventors: Gerald A. Deaver, David B. Drendel, Siamak Bourbour, Leonard John Sharpless, Arunachalam Mahadevan
  • Patent number: 6047037
    Abstract: A multi-lift tool and method for moving control rod assemblies in a nuclear reactor. The multi-lift tool comprises a frame having an upper end and a lower end. A control rod grapple is supported by the frame for engaging a lifting handle of a control rod. The control rod grapple is movable along a length of the frame for raising and lowering the control rod relative to the frame. A fuel support piece grapple is secured to the lower end of the frame for engaging and lifting a fuel support piece together with the control rod. A blade guide grapple is secured to the upper end of the frame for engaging and lifting a blade guide together with the fuel support piece and the control rod. An unlatching grapple is supported near the lower end of the frame for engaging and lifting an unlatching handle of the control rod. The unlatching grapple is movable along a length of a lower portion of the frame for raising the unlatching handle of the control rod relative to the frame.
    Type: Grant
    Filed: May 19, 1997
    Date of Patent: April 4, 2000
    Assignee: Combustion Engineering, Inc.
    Inventor: Adrian Peter Wivagg
  • Patent number: 5999584
    Abstract: A rigging system for reactor closure head and reactor internals lifts. The system includes a plurality of latchbox pendants attached to the lifting structure of an overhead crane. A first set of a plurality of lifting lugs is attached to the reactor internals, each of the lifting lugs corresponding to one of the plurality of latchboxes. A second set of a plurality of substantially identical lifting lugs, each of the lifting lugs corresponding to one of the plurality of latchboxes, is attached to a plurality of solid rod lifting pendants attached at one end to the reactor closure head. In operation, the latchbox pendants may be rigged once to the overhead crane for handling reactor internals and left in place throughout the entire rigging sequence without changing to turnbuckle pendants for reactor closure head handling.
    Type: Grant
    Filed: February 23, 1998
    Date of Patent: December 7, 1999
    Assignee: Framatome Technologies, Inc.
    Inventors: Larry A. Adams, James E. McCann
  • Patent number: 5970109
    Abstract: A method for disposing of a component located in a reactor pressure vessel of a nuclear reactor plant. The component is, in particular, a lower core structure of a pressurized water reactor plant. An upper part of a container provided for further transport is disposed above an opened and flooded reactor pressure vessel. The upper part is provided with a lower orifice. The component is raised through the orifice into the upper part of the container and is subsequently transported to an upwardly open lower part of the container. The upper part is assembled together with the lower part to form the container, so that the component is enclosed and shielded in the container.
    Type: Grant
    Filed: September 15, 1998
    Date of Patent: October 19, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventors: Konrad Meier-Hynek, Gerd Reimer
  • Patent number: 5930318
    Abstract: The present invention provides a method and apparatus for fuel handling in a nuclear reactor. The nuclear reactor has a reactor vessel comprising a reactor core with a plurality of fuel assemblies and control rods. A fuel pool is arranged adjacent to the reactor vessel. A group comprising at least a plurality of fuel assemblies is simultaneously lifted out of or into the reactor vessel with a single gripper, the gripper having a plurality of gripping devices. The group is transported between the reactor vessel and the fuel pool by means of the gripper.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: July 27, 1999
    Assignee: ABB Atom AB
    Inventors: Bengt Baversten, Karl-Erik Nystrom, Anders Rosengren, Antti Suvanto
  • Patent number: 5896430
    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.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: April 20, 1999
    Assignee: ABB Atom AB
    Inventors: Bengt Baversten, Karl-Erik Nystrom, Anders Rosengren, Antti Suvanto
  • Patent number: 5802127
    Abstract: An in-core monitor protector intended for use during in-vessel services while work is being performed in the reactor core region of a BWR. The purpose of the protector is to prevent damage to or displacement of the in-core monitors, which could be caused by the installation or removal of various types of equipment through the top guide of the core during an outage. This protection is accomplished by partly surrounding the in-core monitor with the protector. The primary component is an aluminum channel of such size as to surround the monitor on three sides and of such length as to extend from the bottom of the top guide to the top of the fuel support castings. The closed sides of the channel prevent direct contact between servicing tools and the monitor. A top subassembly is used to secure the protector to the top guide. A bottom subassembly is used to secure the protector to the fuel support castings.
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: September 1, 1998
    Assignee: General Electric Company
    Inventor: Neal J. Goldberg
  • Patent number: 5778034
    Abstract: This control rod drive limiter removes the need for piping for extraction drive, increases the reliability of linkage with respect to the control rod, and removes the need of a speed limiter for the control rod, since there is no need to assume that the linkage might be released, thus reducing the building costs.A stop piston 112 is disposed so as to cover a buffer piston 110 and a buffer spring 111 from above, rollers 113 are disposed above this stop piston 112, and the lower end of a piston tube 107 is fixed to a flange 103a in such a manner that the piston tube 107 does not move in the axial and peripheral directions. A collet piston 115, collet fingers 116, and a return spring 117 are disposed between an outer tube 104 and a cylinder tube 105. A guide cap 120 is disposed at the upper end of the outer tube 104. Guide grooves 106c that engage with the rollers 113 are provided in the index tube 106.
    Type: Grant
    Filed: December 24, 1996
    Date of Patent: July 7, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Zenshin Tani