Award Date

May 2018

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry and Biochemistry

First Committee Member

Ralf Sudowe

Second Committee Member

Ken Czerwinski

Third Committee Member

Evelyn Bond

Fourth Committee Member

Alexander Barzilov

Number of Pages

178

Abstract

Insufficient data exists on the effects of prompt fast neutron activation on metals found commonly in nuclear devices and the urban environment. Different metals such as Ti, Au, Fe, and Cu were activated using the Flattop Criticality Benchmark at the Device Assembly Facility on the Nevada Test Site using a known neutron spectrum and flux to determine a baseline cross section value. Cross section information gathered from these neutron activation measurements could provide information that helps government and law enforcement agencies to correctly trace the origin of a nuclear device’s fuel or component features.

Based on activation products produced in the Flattop benchmark irradiations, chemical separation methods were developed to isolate higher specific activity samples for doping simulated urban melt glass debris. Extraction chromatography batch contact studies using resins from Eichrom Technologies were performed to determine the retention of stable scandium and titanium. Column studies adapted from these contact studies were optimized using higher mass loading for later use to purify 46Sc, 47Sc, and 48Sc produced from natural titanium through the n-p nuclear reaction.

This method shown above could also be applied to the field of nuclear medicine for use in extracting 44Sc (a positron emitter) from 44Ti. Positron emitting radionuclides such as 44Sc, or more commonly 13C, 14N, and 18F can be utilized in Positron Emission Tomography (PET), which is a form of nuclear diagnostic medicine used to model metabolic processes. All of these isotopes have half-lives of a few minutes to a few hours, which requires localized medical cyclotrons and chemistry laboratories for production followed by separation.

In recent years, interest has been shown in using longer-lived radioisotopes such as 52Mn for positron emission tomography, which has a significantly longer half-life of 5.591 days and similar positron decay energy. The isotope 52Mn could easily be produced at a cyclotron,

chemically separated, and shipped further distances allowing for a wider use of PET while minimizing the need to purchase cyclotrons and chemistry laboratories. In this research, chemical separation methods solvent extraction and extraction chromatography were employed to separate stable Mn from Cr using trioctylamine (TOA) ligand. Once developed, this method will be used to separation medically produced quantities of 52Mn from 52Cr.

Keywords

Analytical; Extraction Chromatography; Nuclear Forensics; Nuclear Medicine; Radiochemistry; Separations

Disciplines

Radiochemistry

Language

English


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