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).
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Publication number: 20210296019Abstract: Provided are a chemical decontamination method and a chemical decontamination apparatus capable of preventing deterioration of a metal ion exchange resin and performing decontamination at a low cost in a short time. The chemical decontamination method of the invention includes: a reduction decontamination step of supplying a reduction decontamination solution to a decontamination target portion and performing reduction decontamination on a surface of a member constituting the decontamination target portion; a hydrogen peroxide decomposition step of decomposing hydrogen peroxide contained in the reduction decontamination solution after the reduction decontamination step; and a metal ion removing step of removing a metal ion contained in the reduction decontamination solution after the hydrogen peroxide decomposition step.Type: ApplicationFiled: March 10, 2021Publication date: September 23, 2021Inventors: Takashi OOHIRA, Satoshi OOUCHI, Motohiro AIZAWA, Nobuyuki OTA, Hideyuki HOSOKAWA, Ryo HAMADA, Hiroo YOSHIKAWA, Naobumi TSUBOKAWA, Masahiko KAZAMA
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Patent number: 10083769Abstract: 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: GrantFiled: October 20, 2014Date of Patent: September 25, 2018Assignees: KURITA WATER INDUSTRIES LTD., HITACHI-GE NUCLEAR ENERGY, LTD.Inventors: Shingo Miyamoto, Mamoru Iwasaki, Mami Hirose, Motohiro Aizawa, Nobuyuki Ota, Takako Sumiya, Kazushige Ishida
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Publication number: 20180079663Abstract: 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: ApplicationFiled: March 30, 2016Publication date: March 22, 2018Inventors: Shingo MIYAMOTO, Mami HIROSE, Mamoru IWASAKI, Hideyuki KOMORI, Motohiro AIZAWA, Nobuyuki OTA, Takako SUMIYA, Kazushige ISHIDA
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Publication number: 20160247589Abstract: 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: ApplicationFiled: October 20, 2014Publication date: August 25, 2016Inventors: Shingo MIYAMOTO, Mamoru IWASAKI, Mami HIROSE, Motohiro AIZAWA, Nobuyuki OTA, Takako SUMIYA, Kazushige ISHIDA
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Patent number: 9299463Abstract: 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: GrantFiled: November 16, 2012Date of Patent: March 29, 2016Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Tsuyoshi Ito, Hideyuki Hosokawa, Makoto Nagase, Yoichi Wada, Kazushige Ishida, Motohiro Aizawa
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Patent number: 9230699Abstract: 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: GrantFiled: August 4, 2014Date of Patent: January 5, 2016Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Kazushige Ishida, Hideyuki Hosokawa, Motohiro Aizawa
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Publication number: 20150073198Abstract: 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: ApplicationFiled: August 4, 2014Publication date: March 12, 2015Inventors: Kazushige ISHIDA, Hideyuki HOSOKAWA, Motohiro AIZAWA
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Publication number: 20140037037Abstract: 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: ApplicationFiled: November 16, 2012Publication date: February 6, 2014Applicant: HITACHI-GE NUCLEAR ENERGY, LTD.Inventors: Tsuyoshi ITO, Hideyuki HOSOKAWA, Makoto NAGASE, Yoichi WADA, Kazushige ISHIDA, Motohiro AIZAWA
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Patent number: 8524056Abstract: 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: GrantFiled: January 29, 2010Date of Patent: September 3, 2013Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Kazushige Ishida, Yoichi Wada, Masahiko Tachibana, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa, Nobuyuki Ota
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Patent number: 8457270Abstract: 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: GrantFiled: January 4, 2011Date of Patent: June 4, 2013Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
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Patent number: 8175211Abstract: 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: GrantFiled: June 18, 2008Date of Patent: May 8, 2012Assignee: Hitachi-Ge Nuclear Energy, Ltd.Inventors: Kazushige Ishida, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa
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Publication number: 20110268242Abstract: 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: ApplicationFiled: April 27, 2011Publication date: November 3, 2011Applicants: 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
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Publication number: 20110176649Abstract: 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: ApplicationFiled: January 4, 2011Publication date: July 21, 2011Applicant: Hitachi-GE Nuclear Energy, Ltd.Inventors: Hideyuki HOSOKAWA, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
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Patent number: 7889828Abstract: 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: GrantFiled: March 25, 2009Date of Patent: February 15, 2011Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
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Patent number: 7869557Abstract: 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: GrantFiled: January 16, 2009Date of Patent: January 11, 2011Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Kazushige Ishida, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa
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Patent number: 7864914Abstract: 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: GrantFiled: February 2, 2009Date of Patent: January 4, 2011Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Kazushige Ishida, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa
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Patent number: 7844024Abstract: 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: GrantFiled: February 3, 2009Date of Patent: November 30, 2010Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Yoichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
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Patent number: 7811392Abstract: 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: GrantFiled: July 14, 2006Date of Patent: October 12, 2010Assignee: Hitachi-GE Nuclear Energy, Ltd.Inventors: Hideyuki Hosokawa, Makoto Nagase, Kazushige Ishida, Youichi Wada, Naoshi Usui, Motohiro Aizawa, Motomasa Fuse
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Publication number: 20100206729Abstract: 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: ApplicationFiled: January 29, 2010Publication date: August 19, 2010Applicant: HITACHI-GE NUCLEAR ENERGY, LTD.Inventors: Kazushige ISHIDA, Yoichi WADA, Masahiko TACHIBANA, Motomasa FUSE, Naoshi USUI, Motohiro AIZAWA, Nobuyuki OTA
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Publication number: 20090225928Abstract: 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: ApplicationFiled: January 16, 2009Publication date: September 10, 2009Inventors: Kazushige ISHIDA, Yoichi Wada, Makoto Nagase, Masahiko Tachibana, Masao Endo, Motomasa Fuse, Naoshi Usui, Motohiro Aizawa