Development of highly selective compounds for solvent extraction processes: partitioning and transmutation of long-lived radionuclides from spent nuclear fuels

Highly Efficient Europium(III) Uptake with an Extraction Chromatographic Resin Containing a Unique Multiple Diglycolamide Ligand with a Tetraaza-12-crown-4 Scaffold

“…Despite the existence of many efficient methods for the separation of radionuclides from acidic feeds, literature on the separation of trivalent actinides and lanthanides is still evolving. Out of the various separation methods, extraction chromatography appears to be highly promising due to the use of a very small amount of organic solvents, generation of low amounts of secondary waste, and ease of technical operation when separations are carried out in a column. − Use of selective organic extractants for trivalent lanthanides and actinides such as CMPO (carbamoylmethyl phosphine oxide), malonamide ( N,N’ -dimethyl- N,N’ -dibutyl tetradecyl malonamide), and DGA (diglycolamide) − in extraction chromatographic resins has shown good results for the separation of trivalent lanthanides and actinides. Out of these extractants, the DGA extractants such as TODGA ( N,N,N′,N′ -tetraoctyl diglycolamide, Figure a) have given very impressive results in the separation of trivalent actinides from a variety of acidic feed solutions …”

Sigma Team for Advanced Actinide Recycle FY2015 Accomplishments and Directions

“…Relatively minor, though not negligible, benefit in energy utilization is expected from MA recycle. Rather, the international research community has anticipated the benefit of MA recycle as mainly being felt in the back end of a fuel cycle, particularly in reducing the effects of heating on repository performance and in minimizing radiotoxicity [Salvatores and Palmiotti, 2011;Tachimori and Morita, 2010;Hill, 2010Hill, , 2011Boullis, 2008;Arm et al, 2008;Todd and Wigeland, 2006;Nash et al, 2006;Romary and Grygiel, 2015;Poinssot et al, 2015]. The importance of these factors and the extent to which their associated benefits 3 can be realized depends on the design and siting of a repository.…”

“…On the other hand, An/Ln or Am/Cm separations have been especially difficult because the chemistry of their common trivalent oxidation states is very similar. Although we can point to significant progress, a fully satisfactory solution has not yet been found [Hill, 2010[Hill, , 2011].…”

“…The most straightforward scenario for MA separation from lanthanides in STAAR strategy follows a codecontamination flowsheet such as UREX+ [Regalbuto, 2010] or co-decontamination [Herbst, 2011; flowsheet in which MA separation must be performed on a highly acidic raffinate stream from which U, Pu, and Np have already been removed. A major advance by itself would be a one-step An/Ln separation [Hill, 2010[Hill, , 2011Lumetta et al, 2010a,b]. Two of the most selective solvent-extraction methods were incorporated into the framework of the UREX+ suite in the form of the TRUEX-TALSPEAK (Transuranic Extraction-Trivalent Actinide-Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) tandem processes or the TRUEX-SANEX (Selective Actinide Extraction) tandem processes using Cyanex ® 301 as the SANEX extractant [Regalbuto, 2011].…”

Development of a New Flowsheet for Co-Separating the Transuranic Actinides: The “EURO-GANEX” Process

“…For this purpose we developed an aqueous soluble version of the bis-triazinyl pyridine (BTP) ligands [23]. BTP, when dissolved in an organic diluent, are well known for their selectivity for An(III) over Ln(III) [24][25]. The aqueous phase BTP ligand is also capable of stripping plutonium(IV) ions [26].…”