Abstract: To provide a corrosion mitigation method for carbon steel pipe that can further reduce corrosion of the carbon steel pipe. In a BWR plant, oxygen is injected from an oxygen injection device 30 into a clean up system pipe 18 which is constituted by a Cr-containing carbon steel pipe containing Cr in a range of larger than 0.052 wt % and less than 0.4 wt % and being in communication with a RPV 3, and reactor water of 150° C. having a dissolved oxygen concentration of 30 ?g/L is generated. The reactor water is brought into contact with an inner surface of the clean up system pipe 18 to perform an oxidizing treatment on the inner surface, and an oxide film containing Cr is formed on the inner surface.

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.

Abstract: An aqueous solution of alkali hexahydroxo platinate is produced. As a alkali hexahydroxo platinate, sodium hexahydroxoplatinate or potassium hexahydroxoplatinate is used. The aqueous solution of alkali hexahydroxo platinate is passed through a hydrogen form cation exchange resin layer in a cation exchange resin tower. The aqueous solution of alkali hexahydroxo platinate makes contact with the hydrogen form cation exchange resin of the hydrogen form cation exchange resin layer, thus a suspension of hexahydroxo platinic is generated. If gamma rays are irradiated to the suspension, a platinum oxide colloidal solution in which colloidal particles including a platinum dioxide, a platinum monoxide, and a platinum hydroxide exist is generated. In a platinum oxide colloidal solution, the content of impurities is little and a noble metal compound is dispersed stably in water.

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.

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.

Abstract: An aqueous solution of alkali hexahydroxo platinate is produced. As a alkali hexahydroxo platinate, sodium hexahydroxoplatinate or potassium hexahydroxoplatinate is used. The aqueous solution of alkali hexahydroxo platinate is passed through a hydrogen form cation exchange resin layer in a cation exchange resin tower. The aqueous solution of alkali hexahydroxo platinate makes contact with the hydrogen form cation exchange resin of the hydrogen form cation exchange resin layer, thus a suspension of hexahydroxo platinic is generated. If gamma rays are irradiated to the suspension, a platinum oxide colloidal solution in which colloidal particles including a platinum dioxide, a platinum monoxide, and a platinum hydroxide exist is generated. In a platinum oxide colloidal solution, the content of impurities is little and a noble metal compound is dispersed stably in water.

Abstract: An aqueous solution of alkali hexahydroxo platinate is produced. As a alkali hexahydroxo platinate, sodium hexahydroxoplatinate or potassium hexahydroxoplatinate is used. The aqueous solution of alkali hexahydroxo platinate is passed through a hydrogen form cation exchange resin layer in a cation exchange resin tower. The aqueous solution of alkali hexahydroxo platinate makes contact with the hydrogen form cation exchange resin of the hydrogen form cation exchange resin layer, thus a suspension of hexahydroxo platinic is generated. If gamma rays are irradiated to the suspension, a platinum oxide colloidal solution in which colloidal particles including a platinum dioxide, a platinum monoxide, and a platinum hydroxide exist is generated. In a platinum oxide colloidal solution, the content of impurities is little and a noble metal compound is dispersed stably in water.

Abstract: An electrochemical corrosion potential sensor has a sensor unit, a lead wire and a quasi-reference electrode. A sensor unit includes a tube-shaped insulator, a tube-shaped metal casing joined to an end portion of the insulator, and a Pt electrode joined to another end portion of the insulator. A lead wire connected to the Pt electrode passes through the insulator and the metal casing. The quasi-reference electrode disposed in the metal casing is made of a less noble metal and electrically connected with the lead wire. Since an electrochemical corrosion potential sensor has the quasi-reference electrode, the measurement of the corrosion potential of a structural member of a nuclear power plant and an abnormality occurrence (water intrusion) can be accurately detected during the operation of a nuclear power plant.

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.

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.

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.

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.

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.

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.

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.

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.

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.