Patents by Inventor Motohiro Aizawa

Motohiro Aizawa 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: 10083769
    Abstract: In an electrodeposition treatment of an iron-group metal ion-containing liquid, without being influenced by the properties of the iron-group metal ion-containing liquid, iron-group metal ions are efficiently removed from the liquid by precipitation. An anode chamber 2A provided with an anode 2 and a cathode chamber 3A provided with a cathode 3 are separated from each other by a cation exchange membrane 5, an iron-group metal ion-containing liquid is charged into the anode chamber 2A, a cathode liquid is charged into the cathode chamber 3A, and by applying the voltage between the anode 2 and the cathode 3, iron-group metal ions in the liquid in the anode chamber 2A are moved into the liquid in the cathode chamber 3A through the cation exchange membrane 5, so that an iron-group metal is precipitated on the cathode 3.
    Type: Grant
    Filed: October 20, 2014
    Date of Patent: September 25, 2018
    Assignees: KURITA WATER INDUSTRIES LTD., HITACHI-GE NUCLEAR ENERGY, LTD.
    Inventors: Shingo Miyamoto, Mamoru Iwasaki, Mami Hirose, Motohiro Aizawa, Nobuyuki Ota, Takako Sumiya, Kazushige Ishida
  • Publication number: 20180079663
    Abstract: A method in which an anode chamber and a cathode chamber are separated by a cation exchange membrane, an acid solution containing metal ions is introduced into the anode chamber, a cathode solution is introduced into the cathode chamber, and a current is applied across the anode and the cathode, whereby the metal ions in the solution in the anode chamber pass through the cation exchange membrane, move into the cathode solution, and precipitate as metal onto the cathode, wherein there are minimal instances where electrodeposition is impossible or the electrodeposition rate decreases. Pre-adding a salt of the acid contained in the acid solution makes it possible to suppress concentration-diffusion of the acid from the acid solution. Adding a salt of the acid into the cathode chamber makes it possible to reduce the impressed voltage, reduce the amount of hydrogen generated on the cathode, and reduce the amount of power.
    Type: Application
    Filed: March 30, 2016
    Publication date: March 22, 2018
    Inventors: Shingo MIYAMOTO, Mami HIROSE, Mamoru IWASAKI, Hideyuki KOMORI, Motohiro AIZAWA, Nobuyuki OTA, Takako SUMIYA, Kazushige ISHIDA
  • Publication number: 20160247589
    Abstract: In an electrodeposition treatment of an iron-group metal ion-containing liquid, without being influenced by the properties of the iron-group metal ion-containing liquid, iron-group metal ions are efficiently removed from the liquid by precipitation. An anode chamber 2A provided with an anode 2 and a cathode chamber 3A provided with a cathode 3 are separated from each other by a cation exchange membrane 5, an iron-group metal ion-containing liquid is charged into the anode chamber 2A, a cathode liquid is charged into the cathode chamber 3A, and by applying the voltage between the anode 2 and the cathode 3, iron-group metal ions in the liquid in the anode chamber 2A are moved into the liquid in the cathode chamber 3A through the cation exchange membrane 5, so that an iron-group metal is precipitated on the cathode 3.
    Type: Application
    Filed: October 20, 2014
    Publication date: August 25, 2016
    Inventors: Shingo MIYAMOTO, Mamoru IWASAKI, Mami HIROSE, Motohiro AIZAWA, Nobuyuki OTA, Takako SUMIYA, Kazushige ISHIDA
  • Patent number: 9299463
    Abstract: A noble metal injection apparatus is connected to a piping of a nuclear plant at the time of stop of the nuclear plant before start of the nuclear plant. In chemical decontamination, oxidation decontamination agent decomposition, and reduction decontamination on an inner surface of the pipe system are executed. After reduction decontamination, a part of an oxalic acid included in a reduction decontamination solution is decomposed and platinum is injected into the reduction decontamination solution of pH 3.5 or higher. When the platinum concentration becomes a preset concentration, a reduction agent is injected and the reduction decontamination solution including the platinum and reduction agent is brought into contact with the inner surface of the piping. The platinum is deposited on the inner surface of the piping. The injection of the platinum and reduction agent is stopped and the platinum and reduction agent are decomposed.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: March 29, 2016
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Tsuyoshi Ito, Hideyuki Hosokawa, Makoto Nagase, Yoichi Wada, Kazushige Ishida, Motohiro Aizawa
  • Patent number: 9230699
    Abstract: A circulation pipe of a chemical decontamination apparatus including a malonic acid injection apparatus and an oxalic acid injection apparatus is connected to a purification system pipe, which is made of carbon steel, of a boiling water nuclear power plant. A malonic acid aqueous solution is injected from the malonic acid injection apparatus into the circulation pipe. An oxalic acid aqueous solution is injected from the oxalic acid injection apparatus into the circulation pipe. A reduction decontaminating solution including a malonic acid of 5200 ppm and an oxalic acid within a range of 50 to 400 ppm is supplied into the purification system pipe through the circulation pipe. Reduction decontamination for an inner surface of the purification system pipe is executed. After the reduction decontamination for the purification system pipe finishes, the malonic acid and oxalic acid included in the solution are decomposed and furthermore, the solution is purified.
    Type: Grant
    Filed: August 4, 2014
    Date of Patent: January 5, 2016
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Kazushige Ishida, Hideyuki Hosokawa, Motohiro Aizawa
  • Publication number: 20150073198
    Abstract: A circulation pipe of a chemical decontamination apparatus including a malonic acid injection apparatus and an oxalic acid injection apparatus is connected to a purification system pipe, which is made of carbon steel, of a boiling water nuclear power plant. A malonic acid aqueous solution is injected from the malonic acid injection apparatus into the circulation pipe. An oxalic acid aqueous solution is injected from the oxalic acid injection apparatus into the circulation pipe. A reduction decontaminating solution including a malonic acid of 5200 ppm and an oxalic acid within a range of 50 to 400 ppm is supplied into the purification system pipe through the circulation pipe. Reduction decontamination for an inner surface of the purification system pipe is executed. After the reduction decontamination for the purification system pipe finishes, the malonic acid and oxalic acid included in the solution are decomposed and furthermore, the solution is purified.
    Type: Application
    Filed: August 4, 2014
    Publication date: March 12, 2015
    Inventors: Kazushige ISHIDA, Hideyuki HOSOKAWA, Motohiro AIZAWA
  • Publication number: 20140037037
    Abstract: A noble metal injection apparatus is connected to a piping of a nuclear plant at the time of stop of the nuclear plant before start of the nuclear plant. In chemical decontamination, oxidation decontamination agent decomposition, and reduction decontamination on an inner surface of the pipe system are executed. After reduction decontamination, a part of an oxalic acid included in a reduction decontamination solution is decomposed and platinum is injected into the reduction decontamination solution of pH 3.5 or higher. When the platinum concentration becomes a preset concentration, a reduction agent is injected and the reduction decontamination solution including the platinum and reduction agent is brought into contact with the inner surface of the piping. The platinum is deposited on the inner surface of the piping. The injection of the platinum and reduction agent is stopped and the platinum and reduction agent are decomposed.
    Type: Application
    Filed: November 16, 2012
    Publication date: February 6, 2014
    Applicant: HITACHI-GE NUCLEAR ENERGY, LTD.
    Inventors: Tsuyoshi ITO, Hideyuki HOSOKAWA, Makoto NAGASE, Yoichi WADA, Kazushige ISHIDA, Motohiro AIZAWA
  • Patent number: 8524056
    Abstract: An electrochemical corrosion potential sensor (ECP sensor) has an electrode cap, an electrode fixing body, a tubular insulator, a tubular metallic housing, and a conductive wire. Both ends of the tubular insulator are connected to the electrode fixing body and the tubular metallic housing respectively. A conductive wire passes through the tubular insulator and the tubular metallic housing, and is connected to an inner surface of the electrode fixing body. The electrode cap 11 disposed to cover an outer surface of the electrode fixing body. The ECP sensor with such a construction can lengthen the lifetime.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: September 3, 2013
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Kazushige Ishida, Yoichi Wada, Masahiko Tachibana, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa, Nobuyuki Ota
  • Patent number: 8457270
    Abstract: A method of suppressing deposition of radionuclides on components of a nuclear power plant comprises forming a ferrite film by contacting a first chemical including iron (II) ions, a second chemical for oxidizing the iron (II) ions to iron (III) ions, and a third chemical for adjusting the pH of a processing solution containing a mixture of the first and second chemicals to be 5.5 to 9.0 with the metal member surface in a time period from a finishing stage in decontamination step of removing contaminants formed on the surface of metal member composing the nuclear power plant, and suppressing deposition of radionuclides on the metal member by the ferrite film.
    Type: Grant
    Filed: January 4, 2011
    Date of Patent: June 4, 2013
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
  • Patent number: 8175211
    Abstract: The object of this invention is to provide a method for mitigating a stress corrosion cracking of reactor structural material which makes it possible to suppress the rise in the main steam line dose rate without secondary effects such as a rise in the concentration of radioactive cobalt-60, etc. in the reactor water. Hydrogen and a reductive nitrogen compound containing nitrogen having a negative oxidation number (for example, hydrazine) are injected into the core water of boiling water nuclear power plant. By injecting the reductive nitrogen compound containing nitrogen having a negative oxidation number into the core water, the stress corrosion cracking of structural material of reactor can be mitigated without side reactions such as a rise in the concentration of cobalt-60, etc.
    Type: Grant
    Filed: June 18, 2008
    Date of Patent: May 8, 2012
    Assignee: Hitachi-Ge Nuclear Energy, Ltd.
    Inventors: Kazushige Ishida, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa
  • Publication number: 20110268242
    Abstract: A recombination apparatus is provided to an off-gas system of a boiling water nuclear plant. An off-gas system pipe connected to a condenser is connected to the recombination apparatus. A catalyst layer filled with a catalyst for recombining hydrogen and oxygen is disposed in the recombination apparatus. The recombination catalyst has a percentage of the number of Pt particles whose diameters are in a range from more than 1 nm to not more than 3 nm to the numbers of Pt particles whose diameters are in a range from more than 0 nm to not more than 20 nm, falling within a range from 20 to 100%. The condenser discharges gas containing an organosilicon compound (ex. D5), hydrogen, and oxygen, which is introduced to the recombination apparatus. Use of the above recombination catalyst can improve the performance of recombining hydrogen and oxygen more than conventional catalysts and the initial performance of the catalyst can be maintained for a longer period of time.
    Type: Application
    Filed: April 27, 2011
    Publication date: November 3, 2011
    Applicants: Nikki-Universal Co., Ltd., Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Hidehiro IIZUKA, Motohiro AIZAWA, Toru KAWASAKI, Hirofumi MATSUBARA, Takashi NISHI, Shuichi KANNO, Yasuo YOSHII, Yoshinori EBINA, Takanobu SAKURAI, Tsukasa TAMAI, Michihito ARIOKA
  • Publication number: 20110176649
    Abstract: A method of suppressing deposition of radionuclides on components of a nuclear power plant comprises forming a ferrite film by contacting a first chemical including iron (II) ions, a second chemical for oxidizing the iron (II) ions to iron (III) ions, and a third chemical for adjusting the pH of a processing solution containing a mixture of the first and second chemicals to be 5.5 to 9.0 with the metal member surface in a time period from a finishing stage in decontamination step of removing contaminants formed on the surface of metal member composing the nuclear power plant, and suppressing deposition of radionuclides on the metal member by the ferrite film.
    Type: Application
    Filed: January 4, 2011
    Publication date: July 21, 2011
    Applicant: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Hideyuki HOSOKAWA, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
  • Patent number: 7889828
    Abstract: A method of suppressing deposition of radionuclides on components of a nuclear power plant comprises forming a ferrite film by contacting a first chemical including iron (II) ions, a second chemical for oxidizing the iron (II) ions to iron (III) ions, and a third chemical for adjusting the pH of a processing solution containing a mixture of the first and second chemicals to be 5.5 to 9.0 with the metal member surface in a time period from a finishing stage in decontamination step of removing contaminants formed on the surface of metal member composing the nuclear power plant, and suppressing deposition of radionuclides on the metal member by the ferrite film.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: February 15, 2011
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
  • Patent number: 7869557
    Abstract: The object of this invention is to provide a method for mitigating a stress corrosion cracking of reactor structural material which makes it possible to suppress the rise in the main steam line dose rate without secondary effects such as a rise in the concentration of radioactive cobalt-60, etc. in the reactor water. Hydrogen and a reductive nitrogen compound containing nitrogen having a negative oxidation number (for example, hydrazine) are injected into the core water of boiling water nuclear power plant. By injecting the reductive nitrogen compound containing nitrogen having a negative oxidation number into the core water, the stress corrosion cracking of structural material of reactor can be mitigated without side reactions such as a rise in the concentration of cobalt-60, etc.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: January 11, 2011
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Kazushige Ishida, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa
  • Patent number: 7864914
    Abstract: The object of this invention is to provide a method for mitigating a stress corrosion cracking of reactor structural material which makes it possible to suppress the rise in the main steam line dose rate without secondary effects such as a rise in the concentration of radioactive cobalt-60, etc. in the reactor water. Hydrogen and a reductive nitrogen compound containing nitrogen having a negative oxidation number (for example, hydrazine) are injected into the core water of boiling water nuclear power plant. By injecting the reductive nitrogen compound containing nitrogen having a negative oxidation number into the core water, the stress corrosion cracking of structural material of reactor can be mitigated without side reactions such as a rise in the concentration of cobalt-60, etc.
    Type: Grant
    Filed: February 2, 2009
    Date of Patent: January 4, 2011
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Kazushige Ishida, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa
  • Patent number: 7844024
    Abstract: A method of suppressing deposition of radionuclides on components of a nuclear power plant comprises forming a ferrite film by contacting a first chemical including iron (II) ions, a second chemical for oxidizing the iron (II) ions to iron (III) ions, and a third chemical for adjusting the pH of a processing solution containing a mixture of the first and second chemicals to be 5.5 to 9.0 with the metal member surface in a time period from a finishing stage in decontamination step of removing contaminants formed on the surface of metal member composing the nuclear power plant, and suppressing deposition of radionuclides on the metal member by the ferrite film.
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: November 30, 2010
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
  • 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: 20100206729
    Abstract: An electrochemical corrosion potential sensor (ECP sensor) has an electrode cap, an electrode fixing body, a tubular insulator, a tubular metallic housing, and a conductive wire. Both ends of the tubular insulator are connected to the electrode fixing body and the tubular metallic housing respectively. A conductive wire passes through the tubular insulator and the tubular metallic housing, and is connected to an inner surface of the electrode fixing body. The electrode cap 11 disposed to cover an outer surface of the electrode fixing body. The ECP sensor with such a construction can lengthen the lifetime.
    Type: Application
    Filed: January 29, 2010
    Publication date: August 19, 2010
    Applicant: HITACHI-GE NUCLEAR ENERGY, LTD.
    Inventors: Kazushige ISHIDA, Yoichi WADA, Masahiko TACHIBANA, Motomasa FUSE, Naoshi USUI, Motohiro AIZAWA, Nobuyuki OTA
  • Publication number: 20090225928
    Abstract: The object of this invention is to provide a method for mitigating a stress corrosion cracking of reactor structural material which makes it possible to suppress the rise in the main steam line dose rate without secondary effects such as a rise in the concentration of radioactive cobalt-60, etc. in the reactor water. Hydrogen and a reductive nitrogen compound containing nitrogen having a negative oxidation number (for example, hydrazine) are injected into the core water of boiling water nuclear power plant. By injecting the reductive nitrogen compound containing nitrogen having a negative oxidation number into the core water, the stress corrosion cracking of structural material of reactor can be mitigated without side reactions such as a rise in the concentration of cobalt-60, etc.
    Type: Application
    Filed: January 16, 2009
    Publication date: September 10, 2009
    Inventors: Kazushige ISHIDA, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa
  • Publication number: 20090190712
    Abstract: The object of this invention is to provide a method for mitigating a stress corrosion cracking of reactor structural material which makes it possible to suppress the rise in the main steam line dose rate without secondary effects such as a rise in the concentration of radioactive cobalt-60, etc. in the reactor water. Hydrogen and a reductive nitrogen compound containing nitrogen having a negative oxidation number (for example, hydrazine) are injected into the core water of boiling water nuclear power plant. By injecting the reductive nitrogen compound containing nitrogen having a negative oxidation number into the core water, the stress corrosion cracking of structural material of reactor can be mitigated without side reactions such as a rise in the concentration of cobalt-60, etc.
    Type: Application
    Filed: February 2, 2009
    Publication date: July 30, 2009
    Inventors: Kazushige ISHIDA, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa