Hitachi-ge Nuclear Energy, Ltd.

Other

Hitachi, Ltd.

Kurita Water Industries Ltd.

Kurita Engineering Co., Ltd.

Kazushige Ishida

Makoto Nagase

Yoichi Wada

Motohiro Aizawa

Naoshi Usui

Hideyuki Hosokawa

Motomasa Fuse

Masahiko Tachibana

Hiroo Yoshikawa

Naohito Uetake

Kazumi Anazawa

Tadashi Tamagawa

Nobuyuki Ota

Masao Endo

Fumito Nakamura

Masaaki Tsubaki

Shiro Takahashi

Fumihito Hirokawa

Takako Sumiya

Tsuyoshi Ito

Yoshiyuki Takamori

Atsushi Yukita

Kenji Noshita

Mamoru Kamoshida

Sohei Fukui

Satoshi Oouchi

Atsushi Watanabe

Youichi Wada

Mayu Sasaki

Mamoru Iwasaki

Yuko Hino

Tomoharu Hashimoto

Shingo Miyamoto

Kazuo Tominaga

Motoi Tanaka

Masahiko Kazama

Naobumi Tsubokawa

Nozomu Nagayama

Satoshi Ouchi

Junji Iwasa

Nobuyuki Oota

Ryosuke Shimizu

Hideyuki Komori

Mami Hirose

Mizuho Tsuyuki

Toru Kawasaki

Shintarou Yanagisawa

There is provided an organic iodine trapping apparatus that can efficiently trap an organic iodine without using complicated or large equipment. An organic iodine trapping apparatusis an apparatus that traps an organic iodine, including: a trapping vesselthrough which gas containing an organic iodine is passed; an organic iodine remover(Example: trihexyl (tetradecyl) phosphonium chloride, or the like) that is disposed in or injected into the trapping vesseland decomposes the organic iodine; and a trapping materialthat is disposed in or injected into the trapping vesseland traps iodine ions generated by decomposition of the organic iodine, in which the trapping materialis a metal (Example: silver or the like) or a metal compound (Example: silver chloride, silver oxide, or the like).

Organic iodine trapping apparatus

A chemical decontamination method includes a dissolution step in which a radioactive insoluble substance containing a metal oxide, the radioactive insoluble substance being adhered to a decontamination object including carbon steel, is dissolved in a decontamination solution and a metal-ion removal step in which the decontamination solution containing the metal ion, the decontamination solution being produced in the dissolution step, is brought into contact with a cation-exchange resin in order to remove the metal ion, the dissolution step including a reductive dissolution step conducted using a decontamination solution containing formic acid, ascorbic acid and/or erythorbic acid, and a corrosion inhibitor.

Chemical decontamination method

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.

Platinum oxide colloidal solution, manufacturing method therefor, manufacture apparatus thereof, and method of injection noble metal of boiling water nuclear power plant

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. Thus, when a noble metal is injected into a boiling water reactor, the noble metal can be restrained from adhering onto a pipe for an injection and other pipes, and thereby can increase the amount of the noble metal to be injected into a cooling water in a reactor pressure vessel.

Method for relieving corrosive environment of boiling water reactor, nuclear power plant, and method for injecting noble metal which is carried out in nuclear power plant

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 chamberA provided with an anodeand a cathode chamberA provided with a cathodeare separated from each other by a cation exchange membrane, an iron-group metal ion-containing liquid is charged into the anode chamberA, a cathode liquid is charged into the cathode chamberA, and by applying the voltage between the anodeand the cathode, iron-group metal ions in the liquid in the anode chamberA are moved into the liquid in the cathode chamberA through the cation exchange membrane, so that an iron-group metal is precipitated on the cathode

Treatment method and treatment apparatus of iron-group metal ion-containing liquid, method and apparatus for electrodepositing Co and Fe, and decontamination method and decontamination apparatus of radioactive waste ion exchange resin

Disclosed is a method for treating a radioactive organic waste, the radioactive organic waste including a cation exchange resin adsorbing radionuclide ions, the method including the step of bringing the radioactive organic waste into contact with an organic acid salt aqueous solution containing an organic acid salt and whereby desorbing the radionuclide ions from the cation exchange resin, in which the organic acid salt contained in the organic acid salt aqueous solution includes a cation that is more readily adsorbable by the cation exchange resin than hydrogen ion is. This enables reduction in concentration of a radioactive substance in the radioactive organic waste and reduction in amount of a high-dose radioactive waste.

Radioactive organic waste treatment method

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.

Method of depositing noble metal on structure member of nuclear plant

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.

Method of chemical decontamination for carbon steel member of nuclear power plant

In the boiling water nuclear plant of the present invention, a steam dryer is disposed in a reactor pressure vessel. Materials that have capability of capturing nitrogen compounds containing N-16 are supported on porous member. The porous members are placed in a region where steam goes through in the steam dryer. For example, both or either of perforated plates installed in the steam dryer is constituted of the porous member on which N-16 capture material is supported. When steam containing N-16 goes through the perforated plates, the N-16 is captured by the porous member, whereby the N-16 transfer amount into the turbine system is reduced.

Boiling water nuclear plant and steam dryer

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

A natural circulation boiling water reactor provides to a chimney with a plurality of tubes. That is to say, each of the plurality of tubes partitions the coolant flow path above a core. Thus, unlike the conventional natural circulation boiling water reactor providing the flow path partition wall grid in which the plate members are made integral by welding and coolant flow paths are partitioned, the chimney of the natural circulation boiling water reactor can reduce the number of welded portions because the edges of the four corners of each flow path do not need to be welded. The natural circulation boiling water reactor can avoid removal as a single unit, as in the case of the flow path partition wall grid in the conventional natural circulation boiling water reactor, by detaching each tube. The chimney can be easily detached from the reactor pressure vessel.

Natural circulation boiling water reactor and handling method thereof

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

Growing community of inventors

Hitachi, Japan

Kazushige Ishida