With Control Of Reactor (e.g., Control Of Coolant Flow) Patents (Class 376/207)
  • Patent number: 10446282
    Abstract: Methods implemented by at least one electronic processor for generating pointwise fast neutron spectra may include receiving composition data; receiving source data or calculating the source data; receiving nuclear data; and calculating the pointwise fast neutron spectrum based on numerical integration using the composition, source, and nuclear data. Systems for generating pointwise fast neutron spectra may include a bus; at least one electronic processor connected to the bus; an input device connected to the bus; and a communication link connected to the bus. The at least one electronic processor may be configured to receive composition data from the input device via the bus, to receive source data from the input device via the bus or to calculate the source data, to receive nuclear data from the communication link via the bus, and to calculate the pointwise fast neutron spectrum based on numerical integration using the composition, source, and nuclear data.
    Type: Grant
    Filed: December 23, 2011
    Date of Patent: October 15, 2019
    Assignee: GE-HITACHI NUCLEAR ENERGY AMERICAS LLC
    Inventor: Brian S. Triplett
  • Patent number: 9436167
    Abstract: There is provided a device for monitoring an operation of a nuclear plant, including: a functional integration VDU having a regular-use-system VDU that monitors the operation of the plant under normal conditions, and a security-system VDU that leads to a safe state when the plant is in an abnormal state; and a security-system VDU that leads to a safe state when the plant is in an abnormal state. The functional integration VDU is mounted to a first operating console, the security-system VDU is mounted to a second operating console, and thereby an increase in the size of the operating consoles in the nuclear plant is suppressed, and increased ease of operation is enabled.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: September 6, 2016
    Assignee: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Satoshi Hanada, Koji Ito
  • Publication number: 20150103967
    Abstract: A steam generator for a nuclear reactor comprises plenums proximate with a first plane, wherein the first plane intersects a bottom portion of a riser column of a reactor vessel. The steam generator may further comprise plenums proximate with a second plane, approximately parallel with the first plane, wherein the second plane intersects a top portion of the riser column of the reactor vessel. The steam generator may further include a plurality of steam generator tubes that convey coolant from a plenum located proximate with the first plane to one of the plenums proximate with the second plane.
    Type: Application
    Filed: December 11, 2014
    Publication date: April 16, 2015
    Inventors: John T. Groome, Sooyun Joh, James Allan Nylander
  • Patent number: 8995601
    Abstract: An axial power distribution control device includes an axial offset calculation unit 52, a parameter calculation unit 53, and an axial offset determining unit 55. The axial offset determining unit 55 predicts whether a core axial offset of the power distribution is increased or decreased after a current time, based on a major axis of an ellipse drawn by the xenon parameter and the iodine parameter calculated by the parameter calculation unit 53 and the xenon parameter and the iodine parameter at the current time. This makes it possible to predict a change of the axial offset of the power distribution of a reactor for suppressing a xenon oscillation in the reactor.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: March 31, 2015
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Masayuki Kauchi, Masatoshi Nagai
  • Publication number: 20150036779
    Abstract: The present relates to the integration of the primary functional elements of graphite moderator and reactor vessel and/or primary heat exchangers and/or control rods into an integral molten salt nuclear reactor (IMSR). Once the design life of the IMSR is reached, for example, in the range of 3 to 10 years, it is disconnected, removed and replaced as a unit. The spent IMSR functions as the medium or long term storage of the radioactive graphite and/or heat exchangers and/or control rods and/or fuel salt contained in the vessel of the IMSR. The present also relates to a nuclear reactor that has a buffer salt surrounding the nuclear vessel. During normal operation of the nuclear reactor, the nuclear reactor operates at a temperature that is lower than the melting point of the buffer salt and the buffer salt acts as a thermal insulator.
    Type: Application
    Filed: August 5, 2014
    Publication date: February 5, 2015
    Inventor: David LEBLANC
  • Patent number: 8903032
    Abstract: An upper hole 37A and a lower hole 37B are provided at two positions, namely, upper and lower portions, of a side surface of a guide tube 27, and a thimble tube 22 is pressed against an inner circumferential surface of the guide tube 27, by a differential pressure between coolant inside and outside the upper hole 37A and the lower hole 37B.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: December 2, 2014
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Nobuki Uda, Shigeyuki Watanabe, Kazuo Hirota, Hideyuki Sakata, Hideyuki Morita, Makoto Nakajima, Chikara Kurimura, Toshio Ichikawa
  • Patent number: 8817941
    Abstract: According to an embodiment, a pressurized water reactor plant has a primary system which includes: a reactor vessel for housing a reactor core which is cooled by a primary coolant, a single steam generator, a hot leg pipe for connecting the reactor vessel and the steam generator, cold leg pipes, at least two primary coolant pumps, and a pressurizer for pressurizing the primary coolant pressure boundary in which the primary coolant flows. The plant also has: a passive cooling and depressurization system which is a primary depressurization means for equalizing the primary system pressure to the secondary system pressure at the time of a tube rupture accident of the steam generator, and a reactor containment vessel containing the primary system and cooling the primary system by air cooling. Thus, a compact pressurized water rector with high economic efficiency, safety, and reliability can be provided.
    Type: Grant
    Filed: March 10, 2011
    Date of Patent: August 26, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Sato, Kazunori Hashimoto, Hirohide Oikawa, Yasunobu Fujiki, Makoto Akinaga, Hisaki Sato
  • Patent number: 8811565
    Abstract: An integrated reactor missile shield and crane assembly (IRMSCA) is disclosed and claimed. The IRMSCA replaces the existing concrete missile shields and reactor services crane. The IRMSCA is moveable such that the missile shield can be moved away from the reactor head, allowing the integral crane to lift the control rod drive mechanism components and other routine loads at the refueling cavity.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: August 19, 2014
    Assignee: Areva Inc.
    Inventors: Harish Kamath, James R. Harris, Jr., Ravi Baliga
  • Patent number: 8798225
    Abstract: A radiation exposure reduction method includes the steps of: injecting iron into a coolant which flows from the reactor cooling system to the reactor core in a nuclear power plant; and ferritizing and fixing radionuclides or parent nuclides thereof, which are contained in the coolant, on the surface of a reactor core structure, wherein an iron citrate which is soluble organic iron, or iron oxalate or iron fumarate which has a particle diameter of 3 ?m or less, is used as the iron to be injected into the coolant.
    Type: Grant
    Filed: November 4, 2009
    Date of Patent: August 5, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yumi Yaita, Seiji Yamamoto, Hajime Hirasawa, Yutaka Uruma
  • Patent number: 8792604
    Abstract: To predict xenon oscillation at the present time and later. For this purpose, as an axial offset of a power distribution of a reactor is represented by AOp, an axial offset of a power distribution based on xenon distribution is represented by AOx, and an axial offset of a power distribution based on an iodine distribution is represented by AOi, a parameter DAOpx(=AOp?AOx) and a parameter DAOix(=AOi?AOx) are described by a relational expression of a trigonometric function and an exponential function using an angular frequency of xenon oscillation. Next, phases with respect to initial values of the parameters DAOpx and DAOix are obtained (Step S101). The parameter DAOpx and the parameter DAOix expressed by the obtained phase and a coefficient of the relational expression obtained from this phase are plotted on an X coordinate and a Y coordinate, respectively.
    Type: Grant
    Filed: April 30, 2008
    Date of Patent: July 29, 2014
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventor: Yoichiro Shimazu
  • Patent number: 8781056
    Abstract: Disclosed embodiments include electromagnetic flow regulators for regulating flow of an electrically conductive fluid, systems for regulating flow of an electrically conductive fluid, methods of regulating flow of an electrically conductive fluid, nuclear fission reactors, systems for regulating flow of an electrically conductive reactor coolant, and methods of regulating flow of an electrically conductive reactor coolant in a nuclear fission reactor.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: July 15, 2014
    Assignee: TerraPower, LLC.
    Inventors: Roderick A. Hyde, Muriel Y. Ishikawa, Jon D. McWhirter, Ashok Odedra, Joshua C. Walter, Kevan D. Weaver, Lowell L. Wood, Jr.
  • Patent number: 8767902
    Abstract: Nuclear reactor systems and methods are described having many unique features tailored to address the special conditions and needs of emerging markets. The fast neutron spectrum nuclear reactor system may include a reactor having a reactor tank. A reactor core may be located within the reactor tank. The reactor core may include a fuel column of metal or cermet fuel using liquid sodium as a heat transfer medium. A pump may circulate the liquid sodium through a heat exchanger. The system may include a balance of plant with no nuclear safety function. The reactor may be modular, and may produce approximately 100 MWe.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: July 1, 2014
    Assignee: Advanced Reactor Concepts LLC
    Inventor: Leon C. Walters
  • Publication number: 20140153685
    Abstract: Illustrative embodiments provide systems, methods, apparatuses, and applications related to annealing nuclear fission reactor materials.
    Type: Application
    Filed: June 13, 2013
    Publication date: June 5, 2014
    Inventors: Charles E. Ahlfeld, John Rogers Gilleland, Roderick A. Hyde, David G. McAlees, Jon David McWhirter, Ashok Odedra, Clarence T. Tegreene, Joshua C. Walter, Kevan D. Weaver, Charles Whitmer, Lowell L. Wood, JR., George B. Zimmerman
  • Publication number: 20140133618
    Abstract: A control room for a nuclear power plant including two or more nuclear reactor units includes a central workstation providing monitoring capability for both nuclear reactor units, a first operator at the controls (OATC) workstation in front of and to one side of the central workstation providing monitoring and control capabilities for the first nuclear reactor unit, a second OATC workstation in front of and to the other side of the central workstation providing monitoring and control capabilities for the second nuclear reactor unit, and a common control workstation directly in front of the central workstation providing monitoring and control capabilities for systems serving both the first nuclear reactor unit and the second nuclear reactor unit. The central and common control workstations do not provide control capabilities for either nuclear reactor unit. The common control workstation does not include any control capabilities that must be performed by a licensed operator.
    Type: Application
    Filed: April 11, 2013
    Publication date: May 15, 2014
    Inventor: Babcock & Wilcox mPower, Inc.
  • Patent number: 8711998
    Abstract: In a cooling structure and a cooling method for a control rod drive mechanism and in a nuclear reactor, a housing (59) in which magnetic jacks are housed is fixed to an upper portion of a reactor vessel (41), and an air intake unit (102) that takes cooling air into the housing (59), a first exhaust duct (104) that is arranged side by side with the air intake unit (102) in a circumferential direction of the housing (59), into which cooling air in the housing (59) is suctioned through a first inlet (109) at a lower portion thereof, and that guides the cooling air upward, a second exhaust duct (105) that is disposed below the air intake unit (102), into which cooling air in the housing (59) is suctioned through a second inlet (110), and that guides the cooling air to the first exhaust duct (104), and a discharging unit (111) that is formed at an upper portion of the housing (59) and discharges cooling air in the first exhaust duct (104) to the exterior are provided.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: April 29, 2014
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Nobuki Uda, Chikara Kurimura
  • Patent number: 8711997
    Abstract: A reactor core is immersed in a liquid metal coolant in a core barrel of a liquid metal cooled reactor. The reactor core includes a plurality of fuel assemblies contained in the core barrel, a neutron absorber that absorbs a neutron in the reactor core, and a neutron moderator that moderates a neutron therein so as to control a reactivity of the reactor core. The neutron absorber and the neutron moderator constitute a mixture contained in reactivity control assemblies of the reactor core in the liquid metal coolant prior to immersion of the reactor core. The neutron moderator is composed of zirconium hydride.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: April 29, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsugio Yokoyama, Hisato Matsumiya, Yasushi Tsuboi
  • Patent number: 8705682
    Abstract: A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) is disclosed. The system, in accordance with an example embodiment of the present invention, may include a controller configured to control a power output level of the NCBWR by controlling a heating subsystem to adjust a temperature of feedwater flowing into an annulus of the NCBWR. The heating subsystem may include a steam diversion line configured to receive steam generated by a core of the NCBWR and a steam bypass valve configured to receive commands from the controller to control a flow of the steam in the steam diversion line, wherein the steam received by the steam diversion line has not passed through a turbine. Additional embodiments of the invention may include a feedwater bypass valve for controlling an amount of flow of the feedwater through a heater bypass line to the annulus.
    Type: Grant
    Filed: July 13, 2007
    Date of Patent: April 22, 2014
    Assignee: GE-Hitachi Nuclear Energy Americas LLC
    Inventors: Stephan Craig Moen, Jack Patrick Noonan, Pradip Saha
  • Patent number: 8699653
    Abstract: A control strategy for a pressurized water nuclear reactor that employs separate, independent control rod banks for respectively controlling Tavg and axial offset within corresponding deadbands. The strategy does not permit the control banks controlling reactor core power and the control banks controlling axial offset to move together, but normally gives preference to the control banks controlling the Tavg except when a demand signal is received simultaneously by both independent control rod banks to move in a same direction, in which case, the control bank compensating for the axial offset is given preference.
    Type: Grant
    Filed: October 24, 2011
    Date of Patent: April 15, 2014
    Assignee: Westinghouse Electric Company, LLC
    Inventors: Keith J. Drudy, Norman P. Mueller, Elijah A. Richter
  • Patent number: 8699655
    Abstract: The present invention relates to tubular elements, such as fuel assembly tubes, which are designed to be used in high pressure and high temperature water in nuclear reactors, such as pressurized water nuclear reactors. In particular, the present invention relates to a method of improving wear resistance and corrosion resistance by depositing a protective coating having a depth of from about 5 to about 25 ?m on the surface of the tubular elements. The coating is provided by nitriding the tubular element at a temperature of from about 400° C. to about 440° C. The nitridation of the tubular element can be carried out for a duration of from about 12 hours to about 40 hours.
    Type: Grant
    Filed: March 10, 2011
    Date of Patent: April 15, 2014
    Assignee: Westinghouse Electric Company, LLC
    Inventor: Nagwa Mahmoud Elshaik
  • Patent number: 8670515
    Abstract: A digital rod control system that employs separate power modules to energize the respective coils of a magnetic jack control rod drive rod drive system so that two, independently powered grippers can simultaneously support the control rod drive rod when it is not in motion to avoid dropped rods. The basic building block of the system is two or more selecting cabinets which receive multiplex power from at least one moving cabinet and are under the control of a single logic cabinet. Each of the cabinets include monitoring features to confirm the reliability of the system.
    Type: Grant
    Filed: June 3, 2010
    Date of Patent: March 11, 2014
    Assignee: Westinghouse Electric Company LLC
    Inventors: Charles J. Roslund, Louis G. Ottobre, Christopher P. Meier, Jonathan E. Baisch, Jay B. Metha, Fred H. Bednar, Rololfo I. Pinal
  • Patent number: 8625733
    Abstract: A neutron source rodlet assembly having a separate source capsule assembly that is not encapsulated within the neutron source rodlet assembly. The neutron source rodlet assembly is made up, at least in part, of a neutron source positioning rodlet assembly and the source capsule assembly configured such that assembly together is feasible at a remote site and they can be shipped separately. The source capsule assembly has outer and inner capsules with the outer capsule having a threaded stud at one end that mates with a complimentary threaded recess on the neutron source positioning rodlet assembly. The inner capsule contains a neutron source. The neutron source positioning rodlet assembly and the source capsule assembly are locked together at their interface when the threaded joint is completely tightened. A secondary neutron source material may also be encapsulated within a hollow portion of the neutron source positioning rodlet assembly.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: January 7, 2014
    Assignee: Westinghouse Electric Company LLC
    Inventors: Ashutosh Chahande, Thanh Do
  • Patent number: 8599991
    Abstract: A boiling water reactor has a core disposed in the reactor pressure vessel and loaded with a plurality of fuel assemblies including transuranic nuclides. A ratio of Pu-239 in all of the transuranic nuclides included in the fuel assembly, which is loaded in the core, with a burnup of 0 is 3% or more but 45% or less. In the fuel assembly having a channel box and a plurality of fuel rods disposed in the channel box, a transverse cross section of a fuel pellet in the fuel rod occupies 30% or more but 55% or less of a transverse cross section of a unit fuel rod lattice in the channel box.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: December 3, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Renzo Takeda, Junichi Miwa, Kumiaki Moriya
  • Patent number: 8571162
    Abstract: A control rod drive mechanism according to the present invention includes a cylindrical guide tube having a latch hole, a hollow piston coupled to the control rod and freely moving up and down within the guide tube, a latch provided in the hollow piston so as to freely swing and freely engaging with and disengaging from the latch hole of the guide tube, and a spring locking the latch to the latch hole of the guide tube. Further, an elevating member having a latch guide which can come into contact with the latch is provided so as to freely move up and down within the guide tube. Further, the latch includes a guide surface coming into contact with the latch guide of the elevating member, and the latch guide includes a guide roller coming into contact with the guide surface of the latch.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: October 29, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daiki Maruyama, Tatsutoshi Tokuyama, Kazuhiro Kawagoe
  • Patent number: 8553829
    Abstract: The invention is principally directed to a reduced order model, XEDOR, facilitating the prediction of and the diagnostics of pellet-clad interaction stress-corrosion-cracking failure of nuclear fuel rods. The invention more particularly relates to assessment of susceptibility to PCI failure for guidance in the design of fuel loading in nuclear reactors. The invention additionally relates to the protection against PCI failure by providing operational information to operators of a nuclear reactor during power maneuvering, including predictive calculations prior to executing power maneuvers. Additionally, the invention relates to the diagnostics of an event suggesting a possible PCI cladding failure.
    Type: Grant
    Filed: September 26, 2007
    Date of Patent: October 8, 2013
    Assignee: Areva NP SAS
    Inventor: Yousef Farawila
  • Patent number: 8532245
    Abstract: A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: September 10, 2013
    Assignee: Westinghouse Electric Company LLC
    Inventors: Charles B. Gilmore, David R. Forsyth
  • Patent number: 8477899
    Abstract: A method of operating a nuclear reactor is disclosed. The reactor (1) encloses a core having a plurality of fuel rods (9). Each fuel rod (9) includes a cladding and fuel pellets of a nuclear fuel. The fuel pellets are arranged in an inner space of the cladding leaving a free volume comprising an upper plenum, a lower plenum and a pellet-cladding gap. The reactor is operated at a normal power and a normal inlet sub-cooling during a normal state. The reactor is monitored for detecting a defect on the cladding of any of the fuel rods. The operation of the reactor is changed to a particular state after detecting such a defect. The particular state permits an increase of the free volume in the defect fuel rod. The reactor is operated at the particular state during a limited time period, after which the reactor is operated at the normal state.
    Type: Grant
    Filed: April 7, 2008
    Date of Patent: July 2, 2013
    Assignee: Westinghouse Electric Sweden AB
    Inventors: Sture Lennart Helmersson, Nils Magnus Limback, Jonathan Michael Wright
  • Patent number: 8433029
    Abstract: In one embodiment, the method includes determining the safety limit minimum critical power ratio using the operating limit minimum critical power ratio, a change-in-critical-power-ratio distribution bias and a change-in-critical-power-ratio distribution standard deviation.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: April 30, 2013
    Assignee: Global Nuclear Fuel—Americas, LLC
    Inventor: James Edward Fawks, Jr.
  • Patent number: 8416908
    Abstract: A method for controlling a nuclear reactor is disclosed. The method includes providing a moderator zone in a core of the nuclear reactor, providing a fuel in the moderator zone, and providing one or more housings, each having a cavity, adjacent to the fuel. The method also includes allowing movement of a moderator between the moderator zone and the cavity of the one or more housings at a lower portion of the one or more housings. The method further includes confining moderator in the cavity of the one or more housings at an upper portion of the one or more housings.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: April 9, 2013
    Inventor: Neal Lawrence Mann
  • Patent number: 8318102
    Abstract: The present invention is directed to a cooling system for removing heat from a Fischer-Tropsch (F-T) slurry reactor. The cooling system including at least one downcomer having an upper portion, a lower portion, and a diameter; the at least one downcomer disposed within the F-T reactor to deliver a coolant downward through the F-T reactor at a predetermined velocity, the at least one downcomer extending a length within the F-T reactor wherein the coolant is introduced into the upper portion of the at least one downcomer in a substantially liquid phase; the diameter of the at least one downcomer and the pressure of the introduced coolant cooperate to increase the coolant velocity thereby generating backpressure in the at least one downcomer to maintain the coolant in the substantially liquid phase along the length of the at least one downcomer.
    Type: Grant
    Filed: December 15, 2008
    Date of Patent: November 27, 2012
    Assignee: Syntroleum Corporation
    Inventors: H. Lynn Tomlinson, William Manning, William Schaefer, Tsungani Record
  • Patent number: 8249840
    Abstract: A simulator system transfers parameters between an enhanced nuclear power plant simulator and a safety control system simulator. Problems concerning software common mode failure, interface interactions errors, software failure complexity, and other failure modes, are evaluated. Thus, diversity and defense-in-depth are analyzed and safety is improved.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: August 21, 2012
    Assignee: Atomic Energy Council—Institute of Nuclear Energy Research
    Inventors: Yuan-Chang Yu, Mao-Sheng Tseng, Hui-Wen Huang, Tsung-Chieh Cheng
  • Publication number: 20110293059
    Abstract: Disclosed embodiments include nuclear fission reactors, nuclear fission fuel pins, methods of operating a nuclear fission reactor, methods of fueling a nuclear fission reactor, and methods of fabricating a nuclear fission fuel pin.
    Type: Application
    Filed: May 25, 2010
    Publication date: December 1, 2011
    Inventors: Roderick A. Hyde, Jon D. McWhirter
  • Patent number: 8009788
    Abstract: A boiling water reactor includes a reactor pressure vessel; a steam pipe for transporting steam generated in the reactor pressure vessel out from a steam dome positioned at an upper part of the reactor pressure vessel; a high pressure turbine connected to the steam pipe and driven by the steam; a feedwater heater which heats feedwater supplied to the reactor pressure vessel using bleed steam flowing from the high pressure turbine to the feedwater heater; a bleeding valve which adjusts a flow rate of the bleed steam; and a pressure sensor provided in a main steam line including the steam dome and the steam pipe. The boiling water reactor further includes a monitor and control system which controls an opening degree of the bleeding valve based on a magnitude of fluctuating pressure in the main steam line that is detected by the pressure sensor.
    Type: Grant
    Filed: February 2, 2007
    Date of Patent: August 30, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Masaya Ohtsuka, Kiyoshi Fujimoto, Masaaki Tsubaki
  • Patent number: 7945011
    Abstract: The present invention relates to a method of controlling a nuclear reactor during a transient period. The method includes actuating the steam dump system in response to a temperature error signal and a power mismatch signal.
    Type: Grant
    Filed: May 4, 2010
    Date of Patent: May 17, 2011
    Assignee: Westinghouse Electric Company LLC
    Inventors: J. Seenu Srinivasan, Rachel R. Marangoni
  • Publication number: 20100266084
    Abstract: A nuclear fission reactor fuel assembly and system configured for controlled removal of a volatile fission product and heat released by a burn wave in a traveling wave nuclear fission reactor and method for same. The fuel assembly comprises an enclosure adapted to enclose a porous nuclear fuel body having the volatile fission product therein. A fluid control subassembly is coupled to the enclosure and adapted to control removal of at least a portion of the volatile fission product from the porous nuclear fuel body. In addition, the fluid control subassembly is capable of circulating a heat removal fluid through the porous nuclear fuel body in order to remove heat generated by the nuclear fuel body.
    Type: Application
    Filed: April 16, 2009
    Publication date: October 21, 2010
    Inventors: Charles E. Ahlfeld, John Rogers Gilleland, Roderick A. Hyde, Muriel Y. Ishikawa, David G. McAlees, Nathan P. Myhrvold, Clarence T. Tegreene, Thomas Allan Weaver, Charles Whitmer, Victoria Y.H. Wood, Lowell L. Wood, JR., George B. Zimmerman
  • Patent number: 7773716
    Abstract: A fast reactor having a reflector control system is provided which decreases the change in reactivity of the reactor core with time without controlling reflector lifting speed and a water flow rate. The reactor has a liquid metal coolant, a reactor core immersed therein, and a neutron reflector provided outside the core and is moved in a vertical direction for adjusting leakage of neutrons therefrom for controlling the reactivity of the core. The reflector described above is gradually moved in an upward direction with the change in reactivity caused by fuel burn-up, and at least a part of a lower region of the reflector is a high reflection region having a high neutron reflection ability as compared to that of the other region. The high reflection region is located between the bottom and one fourth and one half of the height of the neutron reflector.
    Type: Grant
    Filed: July 2, 2008
    Date of Patent: August 10, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsugio Yokoyama, Mitsuaki Yamaoka, Yasuyuki Moriki, Ryoma Kato, Yasushi Tsuboi, Atsuko Matsuda
  • Patent number: 7742555
    Abstract: The present invention relates to a method of controlling a nuclear reactor during a transient period. The method includes actuating the steam dump system in response to a temperature error signal and a power mismatch signal.
    Type: Grant
    Filed: July 14, 2008
    Date of Patent: June 22, 2010
    Assignee: Westinghouse Electric Company LLC
    Inventors: Seenu J. Srinivasan, Rachel R. Marangoni
  • Publication number: 20100150292
    Abstract: Exemplary embodiments provide automated nuclear fission reactors and methods for their operation. Exemplary embodiments and aspects include, without limitation, re-use of nuclear fission fuel, alternate fuels and fuel geometries, modular fuel cores, fast fluid cooling, variable burn-up, programmable nuclear thermostats, fast flux irradiation, temperature-driven surface area/volume ratio neutron absorption, low coolant temperature cores, refueling, and the like.
    Type: Application
    Filed: December 12, 2008
    Publication date: June 17, 2010
    Inventors: Roderick A. Hyde, Muriel Y. Ishikawa, Nathan P. Myhrvold, Lowell L. Wood, JR.
  • Patent number: 7627073
    Abstract: A method to design a nuclear fuel assembly having the following steps including establishing the falling speed of the control rod upon entry into the lower damping portion when the control cluster falls in the event of a shutdown of the nuclear reactor, establishing, based on the falling speed established in step a), the progression of the falling speed of the control rod in the lower damping portion, establishing, based on the progression of the speed established in step b), a maximum elevated pressure produced in the liquid contained in the lower damping portion, and establishing, based on the maximum elevated pressure established in step c), a maximum circumferential stress produced in the lower damping portion.
    Type: Grant
    Filed: February 25, 2003
    Date of Patent: December 1, 2009
    Assignee: Framatome ANP
    Inventors: Catherine Callens, Hélène Segura
  • Publication number: 20090141847
    Abstract: An method for operating a nuclear power generation plant, comprising the steps of: forming a plurality of control rod patterns by operating a plurality of control rods during a first period of one operation cycle of a reactor including said first period before a point of time when all control rods are completely withdrawn from a core of said reactor and a core flow rate reaches firstly a set core flow rate, and a second period after said point of time, controlling stepwise at least once a temperature of feed water supplied to said reactor based on a different set feed water temperature during a period included in said first period for operating said reactor with a formed same control rod pattern, and continuing feed water temperature control based on said set feed water temperature until said core flow rate reaches a set core flow rate set based on said set feed water temperature.
    Type: Application
    Filed: November 28, 2008
    Publication date: June 4, 2009
    Inventors: Tetsushi HINO, Masao CHAKI, Motoo AOYAMA, Takeshi MITSUYASU, Yoshihiko ISHII
  • Publication number: 20090086878
    Abstract: A nuclear power plant is provided including a BWR, a reactor cooling system cooling the BWR, an HWC hydrogen injection system connected to the reactor cooling system and an alcohol injection system connected to the reactor cooling system. Methods for providing methanol and hydrogen are also provided.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 2, 2009
    Applicant: AREVA NP INC.
    Inventors: Bernhard Stellwag, Mihai G.M. Pop
  • Patent number: 7447291
    Abstract: A nuclear reactor including: a vessel including at least two parts; a reactor core placed in the vessel and containing fuel rod assemblies; at least one internal structure located within the vessel and having a flange portion sandwiched between the two parts of the vessel; an insertion unit for inserting a neutron-absorbing liquid in the fuel rod assemblies, placed in the vessel; and external control devices placed outside the vessel and connected to the insertion unit through conduits placed inside the internal structure, including the flange portion, wherein the insertion unit comprises a transmission unit partly placed in the conduits.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: November 4, 2008
    Inventor: Michel Emin
  • Patent number: 7333584
    Abstract: A nuclear power plant and method of operation for augmenting a second reactor thermal power output in a second operation cycle to a level larger than a first reactor thermal power output in the previous operation cycle. The plant is equipped, for example, with a reactor; a steam loop comprising high and low pressure turbines; a condenser for condensing steam discharged therefrom the low pressure turbine; a feedwater heater for heating feedwater supplied from the condenser; and a feedwater loop for leading feedwater discharged from the feedwater heater to the reactor. The operation method includes decreasing a ratio of extraction steam which is led to the feedwater heater from a steam loop in the second operation cycle.
    Type: Grant
    Filed: January 13, 2005
    Date of Patent: February 19, 2008
    Assignee: Hitachi - GE Nuclear Energy, Ltd.
    Inventors: Kazuaki Kitou, Masao Chaki, Kouji Shina, Motoo Aoyama, Masaya Ohtsuka, Masayuki Nagasawa, Minoru Okura, Seiji Nemoto, Yasuhiro Takahashi
  • Patent number: 7257185
    Abstract: A fuel assembly includes a bottom nozzle set on a lower core plate of a nuclear reactor, a top nozzle with a hold down spring to urge the bottom nozzle against the lower core plate, guide thimbles which guide control rods, having passed through the top nozzle, toward the lower core plate, a dashpot formed on each of the guide thimbles to reduce the fall velocity of a corresponding one of the control rods, a thimble screw which connects each of the guide thimbles to the bottom nozzle, and a drain hole formed to extend through each of the thimble screw. The dashpot has a large-diameter portion with substantially the same diameter as that of each of the guide thimbles. The diameter d of the drain hole falls within a range of 0.04 D<d<0.08 D where D is an inner diameter of the large-diameter portion.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: August 14, 2007
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Masahiko Yamada, Koichi Nunokawa
  • Patent number: 7222061
    Abstract: In the method, a set of limits applicable to a test rod pattern design are defined, and a sequence strategy for positioning one or more subsets of the test rod pattern design is established. Reactor operation on a subset of the test rod pattern design, which may be a subset of fuel bundles in a reactor core for example, is simulated to produce a plurality of simulated results. The simulated results are compared against the limits, and data from the comparison is provided to indicate whether any of the limits were violated by the test rod pattern design during the simulation. A designer or engineer may use the data to determine which operator parameters need to be adjusted (e.g., control blade notch positions for example) in order to create a derivative rod pattern design for simulation, and eventually perfect a rod pattern design for a particular core.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: May 22, 2007
    Assignee: Global Nuclear Fuel - Americas, LLC
    Inventors: William Earl Russell, II, David Joseph Kropaczek, Steven Barry Sutton, Christian Carlos Oyarzun, William Charles Cline, Carey Reid Merritt
  • Patent number: 7002443
    Abstract: An apparatus and method for providing cooling to a magnetic circuit element having a magnetic core disposed around a centrally located core support member having at least one core support member wall is disclosed which may comprise a core support coolant inlet; a core support coolant outlet; a plurality of interconnected coolant flow passages contained within the core support member wall and interconnected and arranged to pass coolant from one coolant flow passage to the next within the core support member wall along a coolant flow path within at least a substantial portion of the core support member wall from the core support coolant inlet to the core support coolant outlet.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: February 21, 2006
    Assignee: Cymer, Inc.
    Inventors: Richard M. Ness, William N. Partlo, Paul C. Melcher, George X. Ferguson, Robert B. Saethre
  • Patent number: 6938584
    Abstract: A feedwater control system considering a pressure drop of feedwater control valve in a nuclear power plant and a control method therefor are provided. In the feedwater control system, a first detection unit includes: a flow error signal generator for generating a flow error signal corresponding to a difference between a steam flow signal and a feedwater flow signal; and a water level correction error signal generator for generating a water level correction error signal corresponding to a sum of a water level measurement signal and the flow error signal.
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: September 6, 2005
    Assignee: Korea Power Engineering Company, Inc.
    Inventors: Suk Whun Sohn, In Ho Song, Jong Joo Sohn, Jong Tae Seo
  • Patent number: 6925138
    Abstract: The present invention is to provide a reactor core that allows a nuclear plant to continuously operate for a long term period, for example 15 years or longer, without requiring any fuel exchange, reduces the duration and number of maintenance steps involved in regular plant inspections, markedly improves plant availability and economic efficiency, and is effective in terms of nuclear nonproliferation. A plurality of fuel assemblies 103, themselves obtained by arranging fuel rods 100 and water rods 107 in square lattices, are arranged in a square lattice at a certain pitch. The blades 102a of a cross-shaped (cruciform) control rod 102 in a cross section are inserted into four adjacent spaces formed by four fuel assemblies 100 facing each other. A value of 0.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: August 2, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mikihide Nakamaru, Hideaki Heki, Takehiko Saito, Kouji Hiraiwa, Tadashi Narabayashi, Satoru Oomizu, Tsuyoshi Shimoda, Kenji Arai, Shinichi Morooka, Seijiro Suzuki
  • Patent number: 6882696
    Abstract: A tie rod having a cruciform cross section is provided with steps for fixing sheaths at tips of cruciform arms of the tie rod; the tips of each of sheaths are fitted onto the steps of the tie rod, each of the sheaths having a U-shaped cross section; and each of the sheaths is fixed to the tie rod by performing a laser welding using a YAG laser beam or a CO2 laser beam with the sheath being fitted onto the tie rod to achieve a continuous weld of at least a part of the tie rod in a longitudinal direction thereof. An axial center position of the beam is shifted from an end face position of the step of the tie rod at least toward an axis center of the tie rod.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: April 19, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Michio Nakayama, Takehiro Seto, Noriaki Goto, Shouji Adachi
  • Patent number: 6873671
    Abstract: In a boiling water reactor controlling each control rod hydraulically by driving a solenoid valve, the control system comprises an operation control means 41 having a duplicated data processing unit for generating sequence patterns based on the timing of the driving sequence based on the control information provided manually, a transmission control means 42 for creating a command word corresponding to each control rod being controlled based on said sequence pattern, and mutually communicating each command word between duplicated data processing units and computing the AND logic of said data within a predetermined time difference, and when the computed result coincide, transmitting the selected command word serially; a transmission unit 32 for receiving said command word and performing protocol conversion thereto, and transmitting the same to a plurality of transmission branch units positioned downstream as the control command; and a solenoid valve drive circuit 31 for driving the control rod drive unit corres
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: March 29, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiko Ishii, Shigeru Udono, Koji Masui, Masahiro Matsuda
  • Patent number: 6862329
    Abstract: According to the method, a reactor core is shut down during the operation cycle. One or more fuel bundles of the reactor core are then moved to new positions within the reactor core to increase a total energy, output of the reactor core as compared to continuing operation of the reactor core without the shutting down and moving steps.
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: March 1, 2005
    Assignee: Global Nuclear Fuel-Americas LLC
    Inventors: David Joseph Kropaczek, William Earl Russell, II, Mehdi Asgari