Award Date
5-15-2026
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry and Biochemistry
First Committee Member
Artem Gelis
Second Committee Member
Frederic Poineau
Third Committee Member
Kenneth Czerwinski
Fourth Committee Member
Alexander Barzilov
Number of Pages
184
Abstract
This thesis investigates the extraction of Th(IV), U(VI), Np(IV, VI), and Pu(IV, VI) from nitric acid using T2EHDGA and HEH[EHP] in n-dodecane. Using primarily slope analysis, extraction models were developed and/or speciation predictions were made for both single-ligand and synergistic mixed-ligand systems. T2EHDGA extractions of An(IV) and An(VI) involve multiple species with co-extracted nitric acid. HEH[EHP] extraction of An(IV) appears to involve multiple species, while HEH[EHP] extraction of An(VI) appears to involve only a single complex. In the mixed-ligand solvent (HEH[EHP] + T2EHDGA), evidence suggests the formation of synergistic complexes containing a single DGA unit for all investigated actinides. These fundamental studies partially informed the development of the Group Actinide Separation Process (GrASP), a novel flowsheet for nuclear reprocessing. GrASP utilizes a single organic solvent to partition actinides into three distinct groups: high-valent U/Np/Pu, bulk U, and trivalent Am/Cm. Batch testing with simulated fuel demonstrated excellent recovery and decontamination of all actinides and efficient back-extraction.
Keywords
f-elements; liquid-liquid extraction; nuclear; solvent extraction
Disciplines
Chemistry | Physical Sciences and Mathematics | Radiochemistry
File Format
File Size
2700 KB
Degree Grantor
University of Nevada, Las Vegas
Language
English
Repository Citation
Smith, Logan A., "Extraction of Tetra-and Hexavalent Actinides From Nitric Acid by HEH[EHP] and T2EHDGA With Applications" (2026). UNLV Theses, Dissertations, Professional Papers, and Capstones. 5630.
https://oasis.library.unlv.edu/thesesdissertations/5630
Rights
IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/