Abstract: A formic acid aqueous solution that contains Fe (II) ions is produced by dissolving metal iron in a formic acid aqueous solution. Nitrogen is supplied from a nitrogen supply device to a chemical liquid tank and then discharged from a discharge line to reduce the dissolved oxygen concentration in the aqueous solution. The chemical liquid tank is filled with the formic acid aqueous solution sealed with nitrogen, and is transferred from a factory to a nuclear reactor building designated as radiation-controlled areas. Inside the nuclear reactor building, the chemical liquid tank is installed in a film deposition apparatus connected to a reactor water recirculation pipeline. The formic acid aqueous is supplied from the chemical liquid tank to the inside of the reactor water recirculation pipeline, and then a ferrite film is formed on the inner surface of the reactor water recirculation pipeline.

Abstract: A formic acid aqueous solution that contains Fe (II) ions is produced by dissolving metal iron in a formic acid aqueous solution. Nitrogen is supplied from a nitrogen supply device to a chemical liquid tank and then discharged from a discharge line to reduce the dissolved oxygen concentration in the aqueous solution. The chemical liquid tank is filled with the formic acid aqueous solution sealed with nitrogen, and transferred from a factory to a nuclear reactor building designated as radiation-controlled areas. Inside the nuclear reactor building, the chemical liquid tank is installed in a film deposition apparatus connected to a reactor water recirculation pipeline. The formic acid aqueous is supplied from the chemical liquid tank to the inside of the reactor water recirculation pipeline, and then a ferrite film is formed on the inner surface of the reactor water recirculation pipeline.

Abstract: A method for suppressing deposit of radionuclide onto structure member composing a nuclear power plant, comprising the steps of: bringing film formation liquid including iron (II) ions and either of zinc (II) ions and nickel (II) ions into contact with a surface of the structure member; and forming either of a ferrite film including the zinc and a ferrite film including the nickel on the surface of the structure member.

Abstract: The present invention is a method for suppressing corrosion of carbon steel members composing a nuclear power plant. That is, the processing solution contains a chemical including iron (II) ions, an oxidizing agent for oxidizing at least one part of the iron (II) ions into iron (III) ion, and a pH adjustment agent for adjusting pH. The pH of the processing solution is adjusted in the range of 5.5 to 9.0 by the pH adjustment agent. The processing solution is introduced into a purifying system pipe having the carbon steel members. The iron (II) ions are adsorbed on an inner surface of the purifying system pipe, namely, a surface of the carbon steel members. The ferrite film is formed on the surface of the carbon steel members by oxidizing the absorbed iron (II) ions. Therefore, corrosion of the carbon steel members is suppressed by the ferrite film.

Abstract: A formic acid aqueous solution that contains Fe (II) ions is produced by dissolving metal iron in a formic acid aqueous solution. Nitrogen is supplied from a nitrogen supply device to a chemical liquid tank and then discharged from a discharge line to reduce the dissolved oxygen concentration in the aqueous solution. The chemical liquid tank is filled with the formic acid aqueous solution sealed with nitrogen, and is transferred from a factory to a nuclear reactor building designated as radiation-controlled areas. Inside the nuclear reactor building, the chemical liquid tank is installed in a film deposition apparatus connected to a reactor water recirculation pipeline. The formic acid aqueous is supplied from the chemical liquid tank to the inside of the reactor water recirculation pipeline, and then a ferrite film is formed on the inner surface of the reactor water recirculation pipeline.

Abstract: The present invention is a method for suppressing corrosion of carbon steel members composing a nuclear power plant. That is, the processing solution contains a chemical including iron (II) ions, an oxidizing agent for oxidizing at least one part of the iron (II) ions into iron (III) ion, and a pH adjustment agent for adjusting pH. The pH of the processing solution is adjusted in the range of 5.5 to 9.0 by the pH adjustment agent. The processing solution is introduced into a purifying system pipe having the carbon steel members. The iron (II) ions are adsorbed on an inner surface of the purifying system pipe, namely, a surface of the carbon steel members. The ferrite film is formed on the surface of the carbon steel members by oxidizing the absorbed iron (II) ions. Therefore, corrosion of the carbon steel members is suppressed by the ferrite film.

Abstract: A formic acid aqueous solution that contains Fe (II) ions is produced by dissolving metal iron in a formic acid aqueous solution. Nitrogen is supplied from a nitrogen supply device to a chemical liquid tank and then discharged from a discharge line to reduce the dissolved oxygen concentration in the aqueous solution. The chemical liquid tank is filled with the formic acid aqueous solution sealed with nitrogen, and transferred from a factory to a nuclear reactor building designated as radiation-controlled areas. Inside the nuclear reactor building the chemical liquid tank is installed in a film deposition apparatus connected to a reactor water recirculation pipeline. The formic acid aqueous is supplied from the chemical liquid tank to the inside of the reactor water recirculation pipeline, and then a ferrite film is formed on the inner surface of the reactor water recirculation pipeline.

Abstract: An object of the present invention is to provide a chemical decontamination liquid decomposing system having a catalyst tower which has a mesh filter capable of certainly preventing catalyst from flowing out and a mechanism of pushing-down the catalyst capable of preventing convection of the catalyst caused by decomposition gas. The catalyst tower in accordance with the present invention used for decomposing a chemical decontamination liquid comprises an inlet pipe, a catalyst for decomposing the chemical decontamination liquid, an outlet mesh filter for preventing the catalyst from flowing out, an outlet pipe, a catalyst charging port for charging the catalyst, a catalyst pushing-down mechanism for preventing occurrence of convection of the catalyst caused by a decomposed gas and so on. The outlet mesh filter is arranged so as to closely attached to the inner surface of the catalyst tower and to the inner surface of the catalyst charging port.

Abstract: An object of the present invention is to provide a chemical decontamination liquid decomposing system having a catalyst tower which has a mesh filter capable of certainly preventing catalyst from flowing out and a mechanism of pushing-down the catalyst capable of preventing convection of the catalyst caused by decomposition gas.

Abstract: An object of the present invention is to provide a chemical decontamination liquid decomposing system having a catalyst tower which has a mesh filter capable of certainly preventing catalyst from flowing out and a mechanism of pushing-down the catalyst capable of preventing convection of the catalyst caused by decomposition gas. The catalyst tower in accordance with the present invention used for decomposing a chemical decontamination liquid comprises an inlet pipe, a catalyst for decomposing the chemical decontamination liquid, an outlet mesh filter for preventing the catalyst from flowing out, an outlet pipe, a catalyst charging port for charging the catalyst, a catalyst pushing-down mechanism for preventing occurrence of convection of the catalyst caused by a decomposed gas and so on. The outlet mesh filter is arranged so as to closely attached to the inner surface of the catalyst tower and to the inner surface of the catalyst charging port.

Abstract: An object of the present invention is to provide a chemical decontamination liquid decomposing system having a catalyst tower which has a mesh filter capable of certainly preventing catalyst from flowing out and a mechanism of pushing-down the catalyst capable of preventing convection of the catalyst caused by decomposition gas.