Physical Sciences and Mathematics Commons^™

Revisiting The Chemistry Of Uranium And Rhenium Fluorides: Implication To Fuel Cycle And Nuclear Forensics Science, James Amos-Aimé Louis-Jean

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fluorine plays a major role in the nuclear industry where F2(g) and HF(g) are critical to the preparation of UF6 and UF4. These materials are prepared for uranium enrichment to increase the isotopic concentration of 235U. During separation efforts, the isotope 99Tc (a high yield fission product, 6.1% from 235U) is extracted along with uranium and can be converted to binary technetium fluorides (i.e., TcF4, TcF6) during re-enrichment of used uranium material. This provides a route for 99Tc to reenter the reactor environment and affect the nuclear properties of fuel pellets made with reprocessed uranium. The objective of this work …

Synthesis, Characterization And Biological Studies Of Technetium-99m And Rhenium-188 Peptides, Vanessa Anne Sanders

UNLV Theses, Dissertations, Professional Papers, and Capstones

Radiopharmaceuticals are very powerful diagnostic tools for evaluation of a host of medical conditions. These drugs are labeled with radioactive isotopes, which are utilized to create pictures of areas of interest through absorption of the drug. They are currently in high demand due to their ability to image areas that traditional imaging devices cannot. The radioisotope 99mTc, with a half-life of 6.01 hours and a 140 keV gamma emission, is central to many radiopharmaceutical compounds. This isotope is easily obtained from a 99Mo-99mTc generator, through beta decay and column chromatography separations. Very little technetium, less than 6 ng, is needed …

Volatile Technetium Oxides: Implications For Nuclear Waste Vitrification, Bradley Covington Childs

UNLV Theses, Dissertations, Professional Papers, and Capstones

From 1943 to 1987, the Hanford site was the primary location for the production of Pu for military applications in the United States. Decades of Pu production have been accompanied by generation of large amounts of liquid and solid radioactive waste. One of radioelements present in the Hanford wastes is Tc, principally the isotope 99Tc (1500 kg). In the waste, it is primarily present in the heptavalent state as TcO4 - . One option for the management of Tc at the Hanford site is its vitrification into a borosilicate glass. The behavior of Tc during vitrification is problematic, as it …

Technetium Sulfide: Fundamental Chemistry For Waste Storage Form's Application, Maryline Ghislaine Ferrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

Technetium is the lightest radioelement. The isotope ⁹⁹Tc has around a 6% yield from ²³⁵U with a half-life of 2.13 x 10⁵ years. The high mobility of TcO₄^-, the common chemical form of technetium in the environment makes ⁹⁹Tc an isotope of concern in nuclear waste management. Despite its important role in radiopharmaceuticals and in the nuclear fuel cycle, the fundamental chemistry of technetium is not as well developed as that of the neighboring transition metals; one of the most striking examples being its sulfide chemistry.

Only two technetium binary sulfide compounds had …

Speciation Of Pentavalent Technetium Complexes With Aniline And Thiobenzene Derivatives, Kyle E. Childs

UNLV Theses, Dissertations, Professional Papers, and Capstones

The reaction of bidentate aniline oligomers with pentavalent technetium has been investigated previously through the reaction of (n-Bu4N)TcOCl4 with o-phenylenediamine (PDA). The initial studies found that PDA reacted in a 1 to 2 molar ratio with pentavalent technetium in in ethanol. This study was expanded by the examination of a second aniline derivatives, 2-aminophenol (AMP)) and two thiobenzene derivatives (2-mercaptophenol (MP) and thiosalicylic acid (TSA)) to evaluate the kinetic formation of these complexes with pentavalent technetium. The pentavalent technetium complexes all showed reactivity with technetium having a coordination numbers of 5 with all ligands reacting in a 1 to 2 …

Novel Production Techniques Of Radioisotopes Using Electron Accelerators, Daniel Robert Lowe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Non-traditional radioisotope production techniques using a compact, high power linear electron accelerator have been demonstrated and characterized for the production of 18F, 47Sc, 147Pm, and 99mTc from a variety of target candidates. These isotopes are used extensively in the medical field as diagnostic and therapy radioisotopes, as well as the space industry as RTG's. Primary focus was placed on 99mTc as it constitutes approximately 80% of all diagnostic procedures in the medical community that use radioactive tracers. It was also the prime focus due to recent events at the Chalk River nuclear reactor, which caused global shortages of this isotope …

Electrochemistry Of Technetium Analogues Rhenium And Molybdenum In Room Temperature Ionic Liquid, Pauline Nancy Serrano

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rhenium was used as an analog for Technetium to study the electrochemical redox properties because the two elements share the same stable oxidation states in aqueous solutions. However, Tc-99 is radioactive and is not readily available for experimentation purposes. Molybdenum is also of interest because when Mo-99 is irradiated, the decay products are Tc-99m and Tc-99. Approximately 30% Tc-99m is eluted from the Mo columns for radiopharmaceutical use with the remaining Mo-99 source decaying to Tc-99 which is discarded as radioactive hospital waste. Currently there are no viable procedures for the reclamation of the radioactive Tc-99 from either fission streams …