1-Cycle Actinide Partitioning Strategy for Direct Recovery of High-Purity Americium from High-Level Waste Using T2EHDGA Extraction and SO₃-Ph-BTP Assisted Stripping

Abstract

Abstract

The present study was focused on direct separation of pure americium (Am) over lanthanides directly from Simulated High Level Waste (SHLW) in 1-cycle of extraction and stripping. Experiments were performed in a six-stage mixer–settler unit with 2 L of SHLW spiked with 241Am and 152,154Eu tracers (chosen as a representative of lanthanides). In the extraction cycle, 0.2 M T2EHDGA (N,N,N′,N′-tetra-2-ethylhexyl diglycolamide) was employed to extract Am and lanthanides together. The extraction cycle results confirmed >99.9% extraction of Am and Eu into the organic phase within five extraction stages. The raffinate leaving from the mixer-settler unit was free from 241Am and 152,154Eu activity. Subsequently, the selective stripping of Am over Eu from the loaded T2EHDGA phase was done with water soluble SO3-Ph-BTP solution (20 mM in 2 M HNO3). In the stripping cycle, >99% Am was successfully stripped. However, the product was found to be contaminated with about 10% Eu. Subsequently, the aqueous product was washed with a washing solvent (0.02 M T2EHDGA + 0.02 M TODGA (N,N,N′,N′-tetraoctyl diglycolamide)). This treatment effectively removed the residual Eu, yielding a high purity Am product. The overall recovery of Am was estimated to be 93±2%. The results demonstrated the feasibility of Am recovery from HLW in 1-cycle actinide partitioning strategy. The developed approach offers a promising route for an advance actinide partitioning strategies for the sustainable management of HLW.