Closing the nuclear fuel cycle is a key objective in the development of Generation IV nuclear systems,enabling the recycling of actinides and reducing the long-term radiotoxicity of nuclear waste.Americium is a prime ...Closing the nuclear fuel cycle is a key objective in the development of Generation IV nuclear systems,enabling the recycling of actinides and reducing the long-term radiotoxicity of nuclear waste.Americium is a prime candidate for transmutation,but its effective use requires high-purity separation from chemically similar curium and lanthanides.In this work,we report the design,synthesis,and evaluation of a novel extractant,4,7-dicyano-N,N’-diethyl-N,N’-diphenyl-1,10-phenanthroline-2,9-dicarboxamide(DAPhenCN),for selective separation of Am(Ⅲ)from Cm(Ⅲ).This extractant was selected for synthesis based on the DFT modeling results of the complexes of 4-and 7-disubstituted 1,10-phenanthroline-2,9-dicarboxamides with Am(Ⅲ),Cm(Ⅲ)and lanthanides(Ⅲ).Solvent extraction experiments revealed Am/Cm separation factors(SFAm/Cm)of 5–6,with favorable distribution ratios for counter-current processing.Crucially,DAPhenCN demonstrated excellent resistance to hydrolysis and radiolysis underα-,γ-,and electron-beam irradiation.Counter-current tests using real raffinates from VVER-1000 spent nuclear fuel reprocessing confirmed the robustness and efficiency of the extraction system,achieving>99%americium recovery and>99.9%curium purity.Light lanthanides partially co-extracted with Am(Ⅲ),while heavier ones had no significant impact.The developed process enables the production of curium-free americium suitable for transmutation fuel fabrication,advancing the implementation of closed nuclear fuel cycles.展开更多
基金support from the State Atomic Energy Corporation Rosatom.
文摘Closing the nuclear fuel cycle is a key objective in the development of Generation IV nuclear systems,enabling the recycling of actinides and reducing the long-term radiotoxicity of nuclear waste.Americium is a prime candidate for transmutation,but its effective use requires high-purity separation from chemically similar curium and lanthanides.In this work,we report the design,synthesis,and evaluation of a novel extractant,4,7-dicyano-N,N’-diethyl-N,N’-diphenyl-1,10-phenanthroline-2,9-dicarboxamide(DAPhenCN),for selective separation of Am(Ⅲ)from Cm(Ⅲ).This extractant was selected for synthesis based on the DFT modeling results of the complexes of 4-and 7-disubstituted 1,10-phenanthroline-2,9-dicarboxamides with Am(Ⅲ),Cm(Ⅲ)and lanthanides(Ⅲ).Solvent extraction experiments revealed Am/Cm separation factors(SFAm/Cm)of 5–6,with favorable distribution ratios for counter-current processing.Crucially,DAPhenCN demonstrated excellent resistance to hydrolysis and radiolysis underα-,γ-,and electron-beam irradiation.Counter-current tests using real raffinates from VVER-1000 spent nuclear fuel reprocessing confirmed the robustness and efficiency of the extraction system,achieving>99%americium recovery and>99.9%curium purity.Light lanthanides partially co-extracted with Am(Ⅲ),while heavier ones had no significant impact.The developed process enables the production of curium-free americium suitable for transmutation fuel fabrication,advancing the implementation of closed nuclear fuel cycles.
