Lectures (13h) : Definition of the fuel cycle. Situation in France.
Front-end fuel cycle:
Uranium ressources (ores, earth crust, types of rocks...), uranium ore deposit typology, ore mining techniques and mine types
On-site ore purification to yellow cake, additional purification techniques and conversion to UF4 and UF6
Fuel enrichment: definitions of SWU, different available enrichment techniques
Fuel reprocessing and actinide recycling
Composition and relevant properties of spent fuel for subsequent processing
Front-end processes: from fuel assembly to nitric solution, the dissolution steps
Core processes: extraction of major actinides U,Pu from the dissolution solution, processes and chemical engineering
Production of recycling fluxes: uranium and plutonium conversion
Specificity of Pu recycling: from PuO2 to MOX fuels
Nuclear wastes conditioning and long term management
Designing of specific matrices for waste confinement (glasses, concrete, compacted waste) and conditioning steps; focus on the vitrification technology.
Classification of nuclear wastes: origin, volumes, flux, specific long term management options for shorter lived waste (TFA, FMA)
Radioactive waste repository: from the 1991 Law towards the selection of the Meuse/Haute-Marne repository to be decided in 2015 through the help of the Underground Research labs.
From the current towards the future fuel cycles
Background: meeting the future energy needs by increasing the sustainability of nuclear energy in the societal, economic and environmental fields.
Significant input of Pu mono-recycling for the sustainability of nuclear energy: resources economy, waste toxicity decrease. Necessity to prevent any divertion of fissile material: development of COEX process (separation, conversion)...
From the Pu mono-recycling towards the Pu multi-recycling and U-recycling: limitations of mono-recycling, requirement for fast neutrons reactors, towards a fuel cycle without any front-end anymore.
From the Pu/U-recycling towards the MA recycling: limiting the waste toxicity and inventory for the long term, increasing the public acceptance, optimising the repository resources, specific processes under development, various options considered (GANEX, SANEX-TODGA, EXAm).
Fuel cycle scenarios and perspectives
Tutorials and practicals:
Simplified design of a fuel processing unit by liquid/liquid extraction (determination of mass flows, evaluation of performances). Use of SIMULEX simulation code.
Scenarios studies (calculation of mass fluxes).
Simplified modelling of representative radionuclides migration within the environment considering the relevant processes (speciation, retention, diffusion).
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