Patents by Inventor John C. Griffith

John C. Griffith has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9721680
    Abstract: A method of operating a nuclear reactor is provided. The method includes defining a layer increment of a deposit layer modeling a deposit on a heat transfer surface of the nuclear reactor; periodically updating a thickness of the deposit layer by adding the layer increment to the deposit layer; recalculating properties of the deposit layer after each layer increment is added to the deposit layer; determining a temperature related variable of the heat transfer surface as a function of the recalculated properties of the deposit layer; and altering operation of the nuclear reactor when the temperature related variable of the heat transfer surface reaches a predetermined value. A method of modeling a deposit on a heat transfer surface of a nuclear reactor is also provided.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: August 1, 2017
    Assignee: AREVA Inc.
    Inventors: Mihai G. M. Pop, Joseph R. Wyatt, John C. Griffith
  • Publication number: 20150092901
    Abstract: A method of operating a nuclear reactor is provided. The method includes defining a layer increment of a deposit layer modeling a deposit on a heat transfer surface of the nuclear reactor; periodically updating a thickness of the deposit layer by adding the layer increment to the deposit layer; recalculating properties of the deposit layer after each layer increment is added to the deposit layer; determining a temperature related variable of the heat transfer surface as a function of the recalculated properties of the deposit layer; and altering operation of the nuclear reactor when the temperature related variable of the heat transfer surface reaches a predetermined value. A method of modeling a deposit on a heat transfer surface of a nuclear reactor is also provided.
    Type: Application
    Filed: September 30, 2013
    Publication date: April 2, 2015
    Applicant: AREVA NP Inc.
    Inventors: Mihai G. M. Pop, Joseph R. Wyatt, John C. Griffith
  • Publication number: 20140257718
    Abstract: A method for determining tube support plate blockage of a steam generator includes the following steps: measuring at least five different eddy current values per tube support intersection; calculating a nominal clean fit radius of flow hole; determining a center signal response; converting the center signal response to a deposit thickness; determine an edge reduction; converting the edge reduction to an edge thickness; calculating the resulting flow hole radius; verifying the reasonableness of the resulting flow hole radius; and determining a virtual calibration range.
    Type: Application
    Filed: May 22, 2014
    Publication date: September 11, 2014
    Applicant: AREVA Inc.
    Inventors: John C. Griffith, Joseph R. Wyatt, Mihai G.M. Pop, Jeffrey M. Fleck
  • Patent number: 8744781
    Abstract: A method for determining tube support plate blockage of a steam generator includes the following steps: measuring at least five different eddy current values per tube support intersection; calculating a nominal clean fit radius of flow hole; determining a center signal response; converting the center signal response to a deposit thickness; determine an edge reduction; converting the edge reduction to an edge thickness; calculating the resulting flow hole radius; verifying the reasonableness of the resulting flow hole radius; and determining a virtual calibration range.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: June 3, 2014
    Assignee: AREVA Inc.
    Inventors: John C. Griffith, Joseph R. Wyatt, Mihai G. M. Pop, Jeffrey M. Fleck
  • Publication number: 20130338940
    Abstract: A method for determining tube support plate blockage of a steam generator includes the following steps: measuring at least five different eddy current values per tube support intersection; calculating a nominal clean fit radius of flow hole; determining a center signal response; converting the center signal response to a deposit thickness; determine an edge reduction; converting the edge reduction to an edge thickness; calculating the resulting flow hole radius; verifying the reasonableness of the resulting flow hole radius; and determining a virtual calibration range.
    Type: Application
    Filed: August 20, 2013
    Publication date: December 19, 2013
    Applicant: AREVA NP Inc.
    Inventors: John C. Griffith, Joseph R. Wyatt, Mihai G. M. Pop, Jeffrey M. Fleck
  • Patent number: 8527216
    Abstract: A method for determining tube support plate blockage of a steam generator includes the following steps: measuring at least five different eddy current values per tube support intersection; calculating a nominal clean fit radius of flow hole; determining a center signal response; converting the center signal response to a deposit thickness; determine an edge reduction; converting the edge reduction to an edge thickness; calculating the resulting flow hole radius; verifying the reasonableness of the resulting flow hole radius; and determining a virtual calibration range.
    Type: Grant
    Filed: February 8, 2010
    Date of Patent: September 3, 2013
    Assignee: Areva NP Inc
    Inventors: John C. Griffith, Joseph R. Wyatt, Mihai G. M. Pop, Jeffrey M. Fleck
  • Publication number: 20110022333
    Abstract: A method for determining tube support plate blockage of a steam generator includes the following steps: measuring at least five different eddy current values per tube support intersection; calculating a nominal clean fit radius of flow hole; determining a center signal response; converting the center signal response to a deposit thickness; determine an edge reduction; converting the edge reduction to an edge thickness; calculating the resulting flow hole radius; verifying the reasonableness of the resulting flow hole radius; and determining a virtual calibration range.
    Type: Application
    Filed: February 8, 2010
    Publication date: January 27, 2011
    Applicant: AREVA NP INC
    Inventors: John C. Griffith, Joseph R. Wyatt, Mihai G.M. Pop, Jeffrey M. Fleck
  • Patent number: 5793205
    Abstract: An eddy current testing apparatus for nondestructive examination of pipe. The apparatus includes an eddy current coil adapted to removably circumferentially surround the pipe, the coil including a cable having a plurality of conductors adapted to form a continuous conductor coil when the cable is circumferentially wrapped around the pipe. A guide system extends along the length and adjacent to the surface of the pipe and a coil form is adapted to removably circumferentially surround the pipe and engage the guide system to provide for travel of the coil along the pipe.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: August 11, 1998
    Assignee: Framatome Technologies, Inc.
    Inventors: John C. Griffith, Barry L. Everett, Randall G. Krotke, William S. Cooper
  • Patent number: 5134367
    Abstract: A rotating cross wound eddy current head for inspecting tubing. A main body portion has a coil mounting arm pivotally mounted in a bore on the main body portion that allows for radial movement of the arm. A cross wound eddy current coil is mounted adjacent the opposite end of the arm from the pivotal mounting point. Opposing magnets mounted in the main body portion and coil mounting arm bias the arm and coil radially outward so that the coil tracks the surface of the tube being inspected and only reads one point on the tube. A helical inspection path is provided by moving the head axially through the tube while simultaneously rotating the head.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: July 28, 1992
    Assignee: The Babcock & Wilcox Company
    Inventors: John C. Griffith, Ivan G. Masters
  • Patent number: 5117548
    Abstract: An apparatus and method for loosening a mechanical plug in a tube. A cartridge having a nose portion, central portion formed from a material that produces an exothermic reaction when ignited, and a base is inserted into the plug to be loosened and removed. An insulated wire extends through the base into the central portion and is connected to a resistive noninsulated wire positioned in the central portion. Sending an electrical current through the wiring causes the noninsulated wire to heat up rapidly. The rapid heat buildup initiates an exothermic reaction in the central portion. The heat generated causes stress conditions in the plug that exceed plug yield and results in a stress relief condition in the plug where the diameter of the plug is reduced. This loosens the plug in the tube and reduces pulling forces needed to remove the plug from the tube.
    Type: Grant
    Filed: May 20, 1991
    Date of Patent: June 2, 1992
    Assignee: The Babcock & Wilcox Company
    Inventors: John C. Griffith, James E. Gutzwiller
  • Patent number: 4937524
    Abstract: A rotating eddy current roller head for inspecting tubing. A main body portion has a set of whisker wheels rotatably attached thereto which center the main body portion in the tube. A roller housing slidably mounted on the main body portion for radial movement relative thereto is caused to track the surface of the tube by opposing magnets mounted in the main body portion and roller housing. An eddy current coil is mounted in a coil holder which is pivotally mounted in an offset manner at the exterior end of the roller housing. A spring mounted in the roller housing biases the trailing edge of the coil holder against the surface of the tube to maintain the eddy current coil at a constant distance from the surface of the tube during inspection procedures.
    Type: Grant
    Filed: April 24, 1989
    Date of Patent: June 26, 1990
    Assignee: The Babcock & Wilcox Company
    Inventors: Floyd A. Fasnacht, John C. Griffith, Francis C. Klahn
  • Patent number: 4766374
    Abstract: A fuel channel flatness measuring system. A stationary measuring unit which allows measuring of two sides of fuel channels without detaching the fuel channel from the crane send warp and axial position electronic signals to conditioning electronics which amplify and digitize the signals for computer use. A computer analysis unit receives the signals and processes and corrolates them to generate a contour profile of the entire length of the measured fuel channel. Fixed and spring loaded rollers mounted on the measuring unit and in rolling contact with the fuel channel guide the fuel channel and allow the movement caused by warp which results in the generated signals.
    Type: Grant
    Filed: November 14, 1986
    Date of Patent: August 23, 1988
    Assignee: The Babcock & Wilcox Company
    Inventors: Samuel W. Glass, III, John C. Griffith, John D. Brew, Charles C. England, Jr., John M. Phillips