Hitachi-Ge Nuclear Energy, Ltd.

Motomasa Fuse

Kazushige Ishida

Motohiro Aizawa

Naoshi Usui

Makoto Nagase

Yoichi Wada

Hideyuki Hosokawa

Masahiko Tachibana

Masao Endo

Nobuyuki Ota

Youichi Wada

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 capdisposed to cover an outer surface of the electrode fixing body. The ECP sensor with such a construction can lengthen the lifetime.

Electrochemical corrosion potential sensor

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.

Suppression method of radionuclide deposition on reactor component of nuclear power plant

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.

Method of stress corrosion cracking mitigation for nuclear power plant structural materials

Suppression method of radionuclide deposition on reactor component of nuclear power plant and ferrite film formation apparatus

Method of stress corrosion cracking mitigating for nuclear power plant structural materials

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.

Growing community of inventors

Hitachinaka, Japan

Motomasa Fuse