Japan Nuclear Cycle Development Institute

Tadahiro Washiya

Kenji Koizumi

Tsutomu Koizumi

Hideki Ogino

Hiroshi Hayashi

Hideki Yamai

Kazunari Uchida

Tomozo Koyama

Shinichi Aose

Kazuhiko Fujisaku

Nobuo Okamura

Masato Ooura

An electrolytic apparatus for an oxide electrolytic method includes an interior of an electrolytic vessel, a common cathode and two types of anodes different in shape and arrangement, a first electrolysis controller is connected between the cathode and the first anode, and a second electrolysis controller is connected between the cathode and the second anode. The electrolytic processing of the substance in the electrolytic vessel is carried out such that a pair of the cathode and one of the anodes is used for main electrolysis and a pair of the cathode and the other anode is used for auxiliary electrolysis. By this apparatus, prevention of the ununiform distribution of the electrodeposit, improvement of the processing speed and improvement of the durability of the crucible are achieved, whereby the recycling of spent nuclear fuels based on the nonaqueous reprocessing method is made feasible in a commercial scale.

Electrolytic apparatus for use in oxide electrowinning method

This invention is provided for improvement of corrosion-resistant property of a crucible and for promotion of safety in a pyrochemical reprocessing method for the spent nuclear fuel. The spent nuclear fuel is dissolved in a molten salt placed in the crucible. In a pyrochemical reprocessing method, the nuclear fuel is deposited, and the crucible () is heated by induction heating. Cooling media () are supplied to cool down, and a molten salt layer () is maintained by keeping balance between the heating and the cooling, and a solidified salt layer () is formed on inner wall surface of the crucible.

Pyrochemical reprocessing method for spent nuclear fuel

An agitation type powder dissolving apparatus comprises a dissolving tank into which powder of spent nuclear fuel is to be supplied, an agitating member rotatably disposed in the dissolving tank, and rise inhibiting structure, disposed in the dissolving tank above the agitating member, for inhibiting the powder from swirling and rising due to rotation of the agitating member. The rise inhibiting structure is composed of a plurality of fixed blades for causing powder, which would otherwise swirl and rise due to rotation of the agitating member, to move downward. Each fixed blade has a descending slope with respect to a swirling direction during swirling and rising. This dissolving apparatus prevents non-dissolved particles from overflowing.

Agitation type powder dissolving apparatus for reprocessing spent nuclear fuel

A centrifugal extractor of non-contact journaled construction is provided in which, even under the environments of corrosive gase and mist-like liquid such as nitric acid mist generated in the reprocessing of a spent nuclear fuel, no problem in corrosion or deterioration of parts occurs and high reliability is obtained, and operation is enabled for a long period of time free from maintenance. A rotorhoused in a rotor housingis journaled by a main shaftand rotated and driven by a motor. The main shaft is surrounded by a drive-portion housing, and has a thrust magnetic diskon the upper end and radial magnetic disksand a motor-rotor portionin the circumference thereof. Thrust bearing electromagnets, radial bearing electromagnetsand a motor stator portionare incorporated into the drive-portion housing, and covered by non-magnetic anticorrosive protective plates, and a protective pipe, the motor-rotor portion being also covered by a protective can. Slide bearingsfor touch down made of fluorocarbon resin are disposed on the upper end of the main shaft and on the inner wall of the drive-portion housing in the vicinity of the upper end of the rotor.

Centrifugal extractor of non-contact journaled construction

This invention is provided for improvement of corrosion-resistant property of a crucible and for promotion of safety in a pyrochemical reprocessing method for the spent nuclear fuel. The spent nuclear fuel is dissolved in a molten salt placed in the crucible. In a pyrochemical reprocessing method, the nuclear fuel is deposited, and the crucible ( ) is heated by induction heating. Cooling media ( ) are supplied to cool down, and a molten salt layer ( ) is maintained by keeping balance between the heating and the cooling, and a solidified salt layer ( ) is formed on inner wall surface of the crucible.

Pyrochemical reprocessing method for spent nuclear fuel and induction heating system to be used in pyrochemical reprocessing method

A centrifugal extractor has a rotor supported rotatably in a housing and an aqueous phase liquid and an organic phase liquid are supplied to the outer circumference of the rotor and mixed between the housing and the rotor. A mixed phrase liquid is sucked into the rotor and is separated into two phases in a centrifugal force field generated in the inside of the rotor, and the separated aqueous phase liquid and organic phase liquid are discharged to an aqueous phase collector and an organic phase collector respectively. A cavity portion is provided in the center of the rotor, and a neutron absorption body is disposed in the cavity portion. Preferably, the rotor has a lower rotating and supporting mechanism (such as a sliding bearing ), and a neutron absorption material is sealed into the lower rotating and supporting mechanism. By such a centrifugal extractor, criticality safety and durability can be enhanced, even when the extractor is designed to be larger-size and larger-capacity.

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Naka-gun, Japan

Tadahiro Washiya