N,N,N',N'-Tetraoctyl Diglycolamide (TODGA):A Promising Extractant for Actinide-Partitioning from High-Level Waste(HLW)

摘要

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.