Fluid Actinides Extraction
Study of Supercritical Fluid Extraction of Uranium and Transuranium Complexes with B-Diketones and Other Complexones as Applied to Decontamination
Tech Area / Field
- ENV-RED/Remediation and Decontamination/Environment
- ENV-RWT/Radioactive Waste Treatment/Environment
8 Project completed
Senior Project Manager
Svetlova A V
Khlopin Radium Institute, Russia, St Petersburg
- British Nuclear Fuels Ltd (BNFL) / Waste Disposal Research Group Sellafield R&D, UK, Cumbria, Seascale\nCEA / DCC / CEN Valrho, France, Pierrelatte\nUniversité Louis Pasteur / Institut de Chimie, France, Strasbourg
Project summarySupercritical fluid extraction is one of promising methods for decontamination of solid surfaces.
The preliminary studies have revealed a principal possibility for removing cobalt, uranium and transuranium elements from surfaces of stainless steel, rubber, asbestos, cloths, and some other solids. Laboratory tests of supercritical fluid decontamination of a real contaminated stainless steel sample have been performed.
However, the most efficient complexone (hexafluoroacetylacetone) is rather expensive and should be recycled or replaced by a cheaper complexing agent. In this connection, it is necessary to conduct studies on solubility of uranium and transuranium complexes in supercritical carbon dioxide, to investigate complex-formation mechanism in supercritical fluids and, on the basis of obtained data, to search for new complexones and modifiers for the process of supercritical fluid decontamination.
In the framework of the proposed Project the following studies are to carried out: (i) determining the solubility of uranium, thorium and europium complexes with different P-diketones in supercritical carbon dioxide; (ii) studying the supercritical fluid extraction of uranium and transuranium complexes with P-diketones and other ligands; (iii) determining the conditions for formation of uranium and transuranium complexes with P-diketones immediately in medium of supercritical carbon dioxide; (iv) determining the correlation between complex formation and liquid-liquid extraction of resulting complexes, on the one hand, and complex formation in medium of supercritical carbon dioxide and supercritical fluid extraction of complexes, on the other.
The obtained information is to be used for developing the decontamination technology for solid surfaces by means of supercritical fluid extraction. Results of studies may be of interest to countries where the nuclear facilities are in operation.
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