Patents by Inventor Youichi Wada

Youichi Wada 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).

  • Publication number: 20200055758
    Abstract: The present disclosure provides a method for relieving a corrosive environment of a boiling water reactor, the method including a step of injecting hydrogen and a noble metal compound into water to be replenished into the reactor pressure vessel during a period of a generating operation of a boiling water nuclear power plant including the reactor pressure vessel. In the method, the hydrogen is injected into water to be supplied into the reactor pressure vessel, and the noble metal compound is injected into water in a line of the boiling water nuclear power plant in which a concentration of oxygen or hydrogen peroxide is stoichiometrically higher than the concentration of hydrogen at which hydrogen undergoes a chemical reaction to turn to water.
    Type: Application
    Filed: September 20, 2019
    Publication date: February 20, 2020
    Inventors: Kazushige ISHIDA, Youichi WADA, Masahiko TACHIBANA, Nobuyuki OOTA, Ryosuke SHIMIZU, Mayu SASAKI
  • Patent number: 10457583
    Abstract: The present disclosure provides a method for relieving a corrosive environment of a boiling water reactor, the method including a step of injecting hydrogen and a noble metal compound into water to be replenished into the reactor pressure vessel during a period of a generating operation of a boiling water nuclear power plant including the reactor pressure vessel. In the method, the hydrogen is injected into water to be supplied into the reactor pressure vessel, and the noble metal compound is injected into water in a line of the boiling water nuclear power plant in which a concentration of oxygen or hydrogen peroxide is stoichiometrically higher than the concentration of hydrogen at which hydrogen undergoes a chemical reaction to turn to water.
    Type: Grant
    Filed: January 30, 2017
    Date of Patent: October 29, 2019
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Kazushige Ishida, Youichi Wada, Masahiko Tachibana, Nobuyuki Oota, Ryosuke Shimizu, Mayu Sasaki
  • Publication number: 20170287573
    Abstract: The present disclosure provides a method for relieving a corrosive environment of a boiling water reactor, the method including a step of injecting hydrogen and a noble metal compound into water to be replenished into the reactor pressure vessel during a period of a generating operation of a boiling water nuclear power plant including the reactor pressure vessel. In the method, the hydrogen is injected into water to be supplied into the reactor pressure vessel, and the noble metal compound is injected into water in a line of the boiling water nuclear power plant in which a concentration of oxygen or hydrogen peroxide is stoichiometrically higher than the concentration of hydrogen at which hydrogen undergoes a chemical reaction to turn to water.
    Type: Application
    Filed: January 30, 2017
    Publication date: October 5, 2017
    Inventors: Kazushige ISHIDA, Youichi WADA, Masahiko TACHIBANA, Nobuyuki OOTA, Ryosuke SHIMIZU, Mayu SASAKI
  • Patent number: 7811392
    Abstract: It is an object of the present invention to efficiently suppress radionuclide deposition on a reactor component of nuclear power plant. Radionuclide deposition on the surface of a metallic reactor component of nuclear power plant is suppressed by forming a ferrite film on the component, wherein the film is formed, after decontamination for removing radionuclides contaminants from the component surface is completed and before the plant is started up, by contacting a treatment solution which mixes a first agent containing the iron (II) ions, a second agent for oxidizing the iron (II) ions into the iron (III) ions and a third agent for adjusting pH level of a solution to 5.5 to 9.0 in this order with the reactor component surface.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: October 12, 2010
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Youichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
  • Publication number: 20070127619
    Abstract: It is an object of the present invention to efficiently suppress radionuclide deposition on a reactor component of nuclear power plant. Radionuclide deposition on the surface of a metallic reactor component of nuclear power plant is suppressed by forming a ferrite film on the component, wherein the film is formed, after decontamination for removing radionuclides contaminants from the component surface is completed and before the plant is started up, by contacting a treatment solution which mixes a first agent containing the iron (II) ions, a second agent for oxidizing the iron (II) ions into the iron (III) ions and a third agent for adjusting pH level of a solution to 5.5 to 9.0 in this order with the reactor component surface.
    Type: Application
    Filed: July 14, 2006
    Publication date: June 7, 2007
    Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Youichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
  • Patent number: 6126907
    Abstract: A thermal decomposition apparatus for decomposing polymer waste is provided which is simple in structure, small in size and inexpensive, and also the operating cost thereof is low.A feed pipe 18 and an inclined pipe 23 are connected in the form of the letter V at a large angle therebetween, and a feed screw 19 and an feed-up screw 25 are arranged inside the respective pipes. Polymer waste introduced into a hopper 17 is melted in the interior of the feed pipe 18 by heat from a first hot air furnace 10 and accumulated in the V-shaped portion. The polymer melt is then conveyed upward by the feed-up screw 25. In the process of conveyance, the polymer melt undergoes primary decomposition by means of heat from a second hot air furnace 11 and the cracked gas thus generated undergoes secondary decomposition by the heat from a third hot air furnace 12, the resultant gas being guided to a condenser 7. Sludge drops down through a chute pipe 35 into a water tank 36.
    Type: Grant
    Filed: June 19, 1998
    Date of Patent: October 3, 2000
    Inventor: Youichi Wada