Kolesar Filip, Van Hecke Karen, Verguts Ken, Marie Cécile, Berthon Laurence, Binnemans Koen, Cardinaels Thomas
Institute for Nuclear Energy Technology, Belgian Nuclear Research Center (SCK CEN), Boeretang 200, 2400 Mol, Belgium.
Department of Chemistry, KU Leuven, Celestijnenlaan 200F, P.O. Box 2404, 3001 Leuven, Belgium.
ACS Omega. 2024 Nov 26;9(49):48336-48349. doi: 10.1021/acsomega.4c06426. eCollection 2024 Dec 10.
Partitioning and transmutation are important strategies for closing the nuclear fuel cycle. The diglycolamide extractant TODGA has played a major role in the development of solvent extraction processes for nuclear fuel reprocessing due to its good extraction performance, its hydrolytic and radiolytic stability, and its compliance with the CHON principle. However, due to drawbacks such as the tendency to form a third phase during extraction if no phase modifiers are used, continued research on diglycolamide-type extractants has led to the development of diglycolamides with decreased symmetry. In this study, it is shown that the recently developed diglycolamide, ,-diisopropyl-','-didodecyldiglycolamide (iPDdDGA), is a potential alternative to TODGA with improved separation between Am and Cm or the Ln. Using the AmSel system as a reference, the extraction kinetics, influence of the acid concentration, influence of the iPDdDGA concentration, and influence of temperature were evaluated. Slope analysis indicates similar average stoichiometries for iPDdDGA and TODGA complexes, but the extraction efficiency of iPDdDGA is orders of magnitude higher. The feasibility of selective americium stripping in combination with the hydrophilic sulfonated bis-triazinyl bipyridine SO-Ph-BTBP complexant was demonstrated. Selective stripping of americium was found to be possible, and the use of iPDdDGA gave an unexpected improvement in Am/Cm separation, with SF values of up to 3.0. This represents a small but significant improvement compared to the 2.5 value typically found for TODGA, and it demonstrates the potential of this solvent extraction system to improve existing processes based on diglycolamide-type extractants.
分离和嬗变是闭合核燃料循环的重要策略。二甘醇酰胺萃取剂TODGA因其良好的萃取性能、水解和辐解稳定性以及符合CHON原则，在核燃料后处理溶剂萃取工艺的发展中发挥了重要作用。然而，由于存在如不使用相调节剂在萃取过程中易形成第三相的缺点，对二甘醇酰胺类萃取剂的持续研究导致了对称性降低的二甘醇酰胺的开发。本研究表明，最近开发的二甘醇酰胺，α，α'-二异丙基-α''，α''-二正十二烷基二甘醇酰胺（iPDdDGA），是TODGA的一种潜在替代品，在镅与锔或镧系元素之间具有更好的分离效果。以AmSel体系为参考，评估了萃取动力学、酸浓度的影响、iPDdDGA浓度的影响和温度的影响。斜率分析表明iPDdDGA和TODGA配合物具有相似的平均化学计量比，但iPDdDGA的萃取效率要高几个数量级。证明了与亲水性磺化双三嗪基联吡啶SO-Ph-BTBP络合剂结合进行选择性镅反萃的可行性。发现可以选择性地反萃镅，使用iPDdDGA意外地改善了镅/锔的分离，分离因子值高达3.0。与TODGA通常的2.5值相比，这是一个虽小但显著的改进，并且证明了这种溶剂萃取体系改善基于二甘醇酰胺类萃取剂的现有工艺的潜力。
