N,N,N′,N′-Tetraoctyl diglycolamide (TODGA):: a promising extractant for actinide-partitioning from high-level waste (HLW)

N,N,N',N'-Tetraoctyl diglycolamide (TODGA) has been evaluated as an extractant for the partitioning of minor actinides from simulated high level nuclear waste solutions. Acid uptake studies suggested that TODGA is more basic (K-H: 4.1) as compared to TRUEX and DIAMEX solvents viz. CMPO (K-H: 2.0) and DMDBTDMA (K-H: 0.32), respectively. TODGA molecules display a tendency toward aggregation in n-dodecane at lower acidities. Effect of diluent on the distribution behavior of Am(III) was studied employing diluents of different dielectric constants. N,N-dialkyl amides with different alkyl groups viz. dibutyl decanamide (DBDA), di(2-ethylhexyl) acetamide (D2EHAA), di(2-ethylhexyl) propionamide (D2EHPRA), di(2-ethylhexyl) isobutyramide (D2EHIBA), dihexyl octanamide (DHOA) and dihexyl decanamide (DHDA) were evaluated as phase modifiers. Distribution behavior of various metal ions viz. Am(III), Pu(IV), U(VI), Eu(III), Fe(III), Sr(II) and Cs(I) was studied from pure nitric acid solution as well as from simulated high level waste solution.