Japan Nuclear Cycle Development Institute

Doryokuro Kakunenryo Kaihatsu Jigyodan

Mitsui Engineering and Shipbuilding Company Limited

Chlorine Engineers Corp., Ltd.

Japan Cycle Nuclear Development Institute

Masaki Ozawa

Takamichi Kishi

Yukio Wada

Nobuyuki Sasao

Masayuki Watanabe

Hidechiyo Kashihara

Chisako Kawakami

Hiroyuki Tanuma

Vasily Alexandrovich Babain

Yoshihiro Hoshino

Kaoru Sugawara

Andey Yurievich Shadrin

Yasuhiko Fujii

Tatsuya Suzuki

Yoshiaki Kobuke

Tetsuo Ikegami

Valery Nikolaevich Romanovsky

Yoshihiko Shinoda

Akio Togashi

Yuichi Sano

Yasumasa Tanaka

Igor Valentinovich Smirnov

Yury Stepanovich Fedorov

Boris Yakovlevich Zilberman

Kazumasa Kosugi

A nitric acid solution containing ions of any one element selected from the group consisting of rare element FP of Ru, Rh and Pd and a rare element of Re is electrolytically reduced by electrolyzing at a constant current to thereby deposit the ions of the element on an electrode. Alternatively, a nitric acid solution containing ions of two or more elements selected from the group consisting of rare element FP of Ru, Rh and Pd and a rare element of Re is electrolytically reduced by electrolyzing at a constant current to thereby collectively deposit the ions of the elements on an electrode. Alkaline water is electrolyzed by using the thus obtained electrodeposit electrode directly as it is as a catalytic electrode to efficiently generate hydrogen. Thus, a clean and sustaining energy system integrating the nuclear energy with the fuel cell power generation is provided.

Method of producing electrolytic hydrogen using rare element-deposit electrode

Extraction mixture capable of recovering actinide elements such as U, Pu and transplutonium elements from radioactive liquid waste in reprocessing of spent nuclear fuel. One embodiment of the extraction mixture includes a solution of bidentate organophosphorus extractant, dihexyl-N, N-diethylcarbamoyl phosphonate in a polar diluent, wherein bis-tetrafluoropropyl ether of diethylene glycol is used as the polar diluent at the following ratio of components: 0.1-1.2 M/L of bidentate extractant and the rest of diluent. Another embodiment of the extraction mixture includes a solution of bidentate organophosphorus extractant, phenyloctyl-N,N-diisobutylcarbamoylphosphine oxide in a polar diluent, wherein a mixture of metanitrobenzotrifluoride with trialkylphosphate is used as the polar diluent at the following ratio of components: 0.1-1.2 M/L of bidentate extractant, 0.3-1.1 M/L of TBP, and the rest of MNBTF.

Extraction mixture for recovery of actinide elements from acidic solutions

A method for separation of actinide elements comprising feeding a solution containing actinide elements such as americium, curium, californium and the like, into a resin column in which a weakly basic primary, secondary or tertiary anion exchange resin obtained by resinifying pyridine, imidazole or alkylamine has been packed, and then feeding an eluent of a mixed solution of nitric acid and alkyl alcohol such as methanol, ethanol, propanol and the like into the resin column to chromatographically separate the actinide elements from each other. This method makes it possible to efficiently separate the actinide elements from each other by a unit operation at ordinary temperature and ordinary pressure while avoiding oxidation operation, and hence makes it possible to avoid generation of secondary wastes and operations difficult in terms of engineering, such as precipitation.

Method for separation of actinide elements

A method of separating and recovering useful rare FP contained in spent nuclear fuels (platinum group element (Ru, Rh, Pd), Ag, Tc, Se, Te) selectively and at high recovery percentage is provided. Nitric acid solution to be processed containing useful rare FP in spent nuclear fuels is electrolytically reduced by using Pd or Fe as a catalyst and rare FP are collectively deposited on an electrode and then deposits on the electrode are collectively dissolved by electrolytic oxidation. Then, the deposit-dissolved solution is electrolytically reduced at low current density, medium current density and high current density, successively, whereby Ag.Pd group, Se.Te group and Ru.Rh.Tc group are separately deposited and recovered, group by group. A cooperation system for nuclear power generation and fuel cell power generation can be provided by utilizing the recovered rare FP as electrode materials and production and purification catalysts for hydrogen fuel in fuel cell.

Method of separating and recovering rare FP in spent nuclear fuels and cooperation system for nuclear power generation and fuel cell power generation utilizing the same

A method for easily decomposing viscous, solidified spilled fuel oil or crude oil containing sea water and other disposal inhibiting substances. Titanium dioxide particles are added to viscous spilled fuel oil recovered in drums in a weight ratio of at least 0.2 to 1 times. Fuel oil is specifically adsorbed by the adsorbent and the mixture can be suspended in water. The suspension is filtered by a coarse filter to remove substances interfering with disposal by the oil. This filtrate is passed through a high performance filter (of sufficiently fine mesh to retain the adsorbent) so that the adsorbent is recovered, and sea water and other substances are discarded.

Disposal method for fuel oil and crude oil spills

CMPO is safely, reliably and rapidly decomposed under mild conditions. A CMPO-containing substance is emulsified in an electrolyte comprising an oxidation promoter (silver ion) by an emulsifier in an emulsifying tank, this electrolyte comprising the CMPO-containing substance is supplied to an anode chamber, and an electrolytic oxidation reaction is performed by passing an electric current. By emulsifying the CMPO-containing substance, the surface area of CMPO in contact with electrolyte is increased, and electrolytic decomposition is thereby promoted. As sufficient CMPO decomposition is not obtained by passing the emulsion only once through an electrolysis tank 1, a batch oxidation method is employed wherein an anolyte is recirculated by a recirculating pump 3a through the anode chamber, a constant temperature bath 7a and an emulsifying tank 6, so that electrolysis is performed with the CMPO-containing substance permanently emulsified in the electrolyte. To maintain a catholyte in a cathode chamber at the same temperature as the anolyte, the catholyte is recirculated by a recirculating pump 3b between the cathode chamber and a constant temperature bath 7b. The current supplied to an anode 4 and cathode 5 in the electrolysis tank 1 is controlled by a rectifier 8.

Method of decomposing CMPO

An extractant for selectively extracting strontium from an aqueous solution containing the same, which comprises a 1,2-benzenebis(1,4-dioxanonyl-6,8-dionato)metal complex of the following structural formula: ##STR1## wherein M represents a metal ion of Cu (II), Zn (II) or Ni (II).

Extractant for selectively extracting strontium from aqueous solution

Growing community of inventors

Higashiibaraki-gun, Japan

Masaki Ozawa