Kabushiki Kaisha Toshiba

Yoshikazu Matsubayashi

Hitoshi Nakamura

Kazuya Yamada

Reiko Fujita

Koji Mizuguchi

Atsushi Ohara

Yuya Takahashi

Shohei Kanamura

Takashi Oomori

Yoshie Akai

Naoki Kishimoto

Yasushi Yamaguchi

Yutaka Hasegawa

Yumiko Abe

Norihisa Saito

Hisao Oomura

According to an embodiment, a nuclear fuel material recovery method of recovering a nuclear fuel material containing thorium metal by reprocessing an oxide of a nuclear fuel material containing thorium oxide in a spent fuel is provided. The method has: a first electrolytic reduction step of electrolytically reducing thorium oxide in a first molten salt of alkaline-earth metal halide; a first reduction product washing step of washing a reduction product; and a main electrolytic separation step of separating the reduction product. The first molten salt further contains alkali metal halide, and contains at least one out of a group consisting of calcium chloride, magnesium chloride, calcium fluoride and magnesium fluoride. The method may further has a second electrolytic reduction step of electrolytically reducing uranium oxide, plutonium oxide, and minor actinoid oxide in a second molten salt of alkali metal halide.

Method of recovering nuclear fuel material

A high-pressure treatment apparatus comprises a first solid reservoir, a second solid reservoir connected to the first solid reservoir through a first connecting pipe, a high-pressure reactor connected to the second solid reservoir through a second connecting pipe, means for feeding reaction medium into the high-pressure reactor, a first sealing unit and a second sealing unit intervened respectively in the first connecting pipe and second connecting pipe, a first fluid feed unit for feeding a first fluid between the first sealing unit and the second sealing unit, a second fluid feed unit for feeding a second fluid between the second sealing unit and the high-pressure reactor, and means for opening the second sealing unit at the time of shut-off of the first sealing unit and controlling the first fluid and the second fluid to form a pressure-gradient so that pressure between the first sealing unit and the second sealing unit and pressure between the second sealing unit and the high-pressure reactor decrease gradually toward the high-pressure reactor.

High-pressure treatment apparatus, feeding method thereto and protection method thereof

A waste processing method decomposing an organic substance or an inorganic substance contained in organic wastes or inorganic wastes by holding a mixture of the organic wastes or the inorganic wastes and a medium, which is in its supercritical state, for a pre-determined time period, in which the hydrogen ion concentration of the medium is 10.sup.-4 mol or more to 1 kg of the medium. A waste processing method having a step of decomposing all or almost all of an organic substance included in organic wastes into lower-molecular-weight products by holding the organic wastes in a medium, which is in its supercritical state, for a pre-determined time and a step of oxidizing and decomposing the lower-molecular-weight products into carbon dioxide (CO.sub.2) and/or water (H.sub.2 O) by holding a mixture of an oxidant and the lower-molecular-weight products in the medium, which is in its subcritical state, for a pre-determined time period.

Waste processing method and waste processing apparatus

Growing community of inventors

Kanagawa, Japan

Yoshikazu Matsubayashi