Category Archives: Advanced separation techniques for nuclear fuel reprocessing and radioactive waste treatment

Voloxidizer

A voloxidizer and electroreduction cell are pieces of equipment specific to spent oxide fuels treatment. Voloxidation is a well-known technique; however, most experiments have been carried out at the laboratory scale. KAERI is developing engineering-scale voloxidizers for decladding and pulverization of oxide fuel. A voloxidizer of 20 kg HM/batch was designed to oxidize fuels on a vibrating mesh where powdered […]

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Solid-phase extraction technology for actinide and lanthanide separations in nuclear fuel reprocessing

T. J. TRANTER, Idaho National Laboratory, USA Abstract: Solid-phase extraction has become a subject of increased interest for separation applications specific to radioisotopes of the nuclear fuel cycle. The objective of this chapter is to discuss recent advances in the technology with a focus on the separations of minor actinides and lanthanides from streams associated with nuclear fuel reprocessing. The […]

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Behavior in molten salts/molten metals/ionic liquids/alternative media

In advanced fuel cycles, it is likely that fast spectrum, high temperature reactors will be utilized to transmute actinide isotopes that are inefficiently transmuted in light water moderated reactors. Many such reactors will utilize metallic fuels and electrometallurgical processing might become a practical alternative to aqueous processing methods like solvent extraction and ion exchange. The solution chemistry of actinides and […]

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Equipment materials considerations

3.4.1 Materials selection The selection of a material for any chemical process plant is a complicated decision involving many parameters such as corrosion resistance, mechani­cal properties, availability and cost. What makes nuclear plant more demand­ing is the presence of radiation, particularly gamma, and of radioactive contamination of surfaces, usually alpha radiation emitting particles, which need to be decontaminated either on […]

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Partitioning with U(IV) and hydrazine

Thermodynamically, U(IV) is a stronger reducing agent for Pu(IV) than either HAN or Fe(II) and has the additional advantage that it does not introduce any additional metal into the system. However, it is imperative to understand that Pu(III) is an unstable species at the conditions of Pu partitioning, and rapidly reoxidizes to Pu(IV) in the presence of nitrous acid. The […]

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Advantages and disadvantages of techniques

The UREX+ separations strategy provides the advantage of a focused optimization approach for the recovery of products that meet pre­determined key objectives for a fuel cycle or a waste disposal strategy. The concept has been successfully tested for the recycle of LWR SNF for a number of different product and waste form configurations. The complexity

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Handling of spent UNEX-extractant

To regenerate the spent UNEX-extractant, a technique for the distillation of the diluent (phenyltrifluoromethylsulfone — FS-13) water steam in the presence of sodium carbonate was elaborated. In this way it is possible to distill more than 90% of practically pure diluent (with purification coeffi­cients from the radionuclides — above 1000). During this process, over 40% CCD transfers into the sodium […]

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Which long-lived radionuclides to partition and why?

The transformation of uranium or mixed uranium/plutonium (U/Pu) oxides through fission and/or neutron capture reactions in pressurized (PWR) or boiling (BWR) water nuclear reactors generates more than 400 radionu­clides (representing 40 elements of the periodic table) with differing physi­cal and chemical properties and making spent nuclear fuels extremely radioactive. The fissile and/or fertile properties of the major actinides, U and […]

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Emerging separation techniques: supercritical fluid and ionic liquid extraction techniques for nuclear fuel reprocessing and radioactive waste treatment

C. M. WAI, University of Idaho, USA Abstract: Minimizing liquid waste generation in the nuclear fuel cycle is of great importance to the future of nuclear energy. Separation techniques utilizing green solvents, supercritical fluid carbon dioxide and ionic liquids, for dissolution and extraction of uranium dioxide and fission products relevant to nuclear waste management are described in this chapter. An […]

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