This thesis focuses on the selective removal of the trivalent higher actinides from the acidic liquid waste stream originating from the reprocessing step (partitioning) and to obtain these elements sufficiently pure (free of lanthanides) to use them for transmutation. In Chapter 2 an overview of the reprocessing processes and the extractants is given, and the research outline is defined. In order to achieve selective extraction, new extractants with one to four preorganized functionalities on a macrocyclic template have been developed. The synthesis of the template is described in Chapter 3, followed by the ligand synthesis and the extraction properties in Chapters 4 and 5. The synthesis and extraction properties of other types of extractants are discussed in Chapter 6. In Chapter 7 a model for the extraction mechanism is discussed. The application of the ligands in membrane separations and the derivation of a model is described in Chapter 8. Chapter 9 concludes the thesis with the description of a continuous separation technique and an outlook for further research.
|Award date||19 Nov 1998|
|Place of Publication||Enschede|
|Publication status||Published - 19 Nov 1998|