Abstract: 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.

Abstract: 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 (2) is heated by induction heating. Cooling media (5, 6) are supplied to cool down, and a molten salt layer (7) is maintained by keeping balance between the heating and the cooling, and a solidified salt layer (8) is formed on inner wall surface of the crucible.

Abstract: 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.

Abstract: 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 (2) is heated by induction heating. Cooling media (5, 6) are supplied to cool down, and a molten salt layer (7) is maintained by keeping balance between the heating and the cooling, and a solidified salt layer (8) is formed on inner wall surface of the crucible.

Abstract: An electrolytic apparatus for an oxide electrolytic method having a constitution such that in the interior of an electrolytic vessel 10, a common cathode 12 and two types of anodes different in shape and arrangement (here, a first anode 14 arranged beneath the cathode, and a second anode 16 arranged in parallel to the cathode) are provided; a first electrolysis controller 18 is connected between the cathode and the first anode, and a second electrolysis controller 20 is connected between the cathode and the second anode. The electrolytic processing of the substance 22 to be processed in the electrolytic vessel is carried out in such a way 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.

Abstract: 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 rotor 12 housed in a rotor housing 10 is journaled by a main shaft 14 and rotated and driven by a motor 16. The main shaft is surrounded by a drive-portion housing 30, and has a thrust magnetic disk 36 on the upper end and radial magnetic disks 46, 48 and a motor-rotor portion 54 in the circumference thereof.

Abstract: 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 (2) is heated by induction heating. Cooling media (5, 6) are supplied to cool down, and a molten salt layer (7) is maintained by keeping balance between the heating and the cooling, and a solidified salt layer (8) is formed on inner wall surface of the crucible.

Abstract: An agitation type powder dissolving apparatus for reprocessing spent nuclear fuel is provided. The apparatus comprises a dissolving tank (1) to which powder of spent nuclear fuel is supplied, an agitating member (3) rotatably disposed in the dissolving tank; and rise inhibiting means, disposed in the dissolving tank above the agitating member, for inhibiting the powder from swirling and rising due to the rotation of the agitating member. The rise inhibiting means is composed of a plurality of fixed blades (11) for causing the powder which would otherwise swirl and rise due to the rotation of the agitating member to move downward. The fixed blade has a descending slope with respect to a swirling direction in swirling and rising. This dissolving apparatus effectively prevents the non-dissolved particles from overflowing, thereby providing improvement in the speed with which spent nuclear fuel is reprocessed and in the ability to carry out the nuclear fuel cycle process.

Abstract: 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 rotor 12 housed in a rotor housing 10 is journaled by a main shaft 14 and rotated and driven by a motor 16. The main shaft is surrounded by a drive-portion housing 30, and has a thrust magnetic disk 36 on the upper end and radial magnetic disks 46, 48 and a motor-rotor portion 54 in the circumference thereof.

Abstract: A centrifugal extractor has a rotor supported rotatably in a housing 10, 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 50 and an organic phase collector 44, respectively. A cavity portion is provided in the center of the rotor, and a neutron absorption body 60 is disposed in the cavity portion. Preferably, the rotor has a lower rotating and supporting mechanism (such as a sliding bearing 66), 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.

Abstract: A centrifugal extractor wherein a rotor is supported rotatably in a housing 10, an aqueous phase and an organic phase are supplied to the outer circumference of the rotor and mixed between the housing and the rotor, a mixed phase 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 and organic pahse are discharged to an aqueous phase collector 50 and an organic phase collector 44, respectively. A cavity portion is provided in the center of the rotor, and a neutron absorption body 60 is disposed making use of the cavity portion. Preferably, a lower rotating and supporting mechanism (such as a sliding bearing 66) of the rotor is disposed, 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 it is designed to be larger-size and larger-capacity.

Abstract: 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 (2) is heated by induction heating. Cooling media (5, 6) are supplied to cool down, and a molten salt layer (7) is maintained by keeping balance between the heating and the cooling, and a solidified salt layer (8) is formed on inner wall surface of the crucible.