Kabushiki Kaisha Toshiba

Kouki Fuse

Hitoshi Nakamura

Reiko Fujita

Koji Mizuguchi

Nobuhiko Tanaka

Kazuhiro Utsunomiya

Mitsuru Kawamoto

Masaru Ito

A spent nuclear fuel is reprocessed by dissolving a spent nuclear fuel in an aqueous nitric acid solution and separating and recovering nuclides contained in the resulting fuel solution by solvent extraction. A spent nuclear fuel reprocessing method includes: an electrolytic valence adjustment step in which nuclides contained in the fuel solution is electrolytically reduced without removing fission products or minor actinides until valence of plutonium is at a level at which solvent extraction efficiency is low by using the valence of plutonium contained in the fuel solution as a parameter; and a nuclide separation step in which, by using an extraction solvent which extracts uranium contained in the fuel solution, uranium is distributed from the fuel solution subjected to the electrolytic valence adjustment step to the extraction solvent.

Method for reprocessing spent nuclear fuel and centrifugal extractor therefor

An object of the present invention is to provide a method of producing metal zirconium, the method having a fewer steps and a smaller amount of secondary wastes generated, wherein the metal zirconium is obtained from a zirconium compound containing hafnium. A method of producing metal zirconium according to the present invention includes: a separation step of separating a hafnium oxychloride from a first substance containing a zirconium oxychloride and a hafnium oxychloride to obtain a second substance having a higher content of the zirconium oxychloride; a calcination step of calcining the second substance to obtain a third substance containing at least any of a zirconium oxychloride and a zirconium oxide; and a direct reduction step of holding the third substance in a molten salt with the third substance brought into contact with a cathode and applying a voltage between the cathode and an anode to directly reduce the third substance to obtain metal zirconium.

Method for manufacturing zirconium metal and hafnium metal

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Ota-ku, Japan

Kouki Fuse