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 …

Mechanisms For The Incorporation And Distribution Of Radionuclides In Near-Surface Fallout, Marc Alan Fitzgerald

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fallout is the radioactive glass formed from a mixture of vaporized anthropogenic materials with proximate environmental material. These glassy byproducts constitute a compositional record of environmental materials such as soil and vapor precursors that are responsible for chemical heterogeneity in the glasses. The work of this dissertation is to untangle these different sources of compositional heterogeneity, distinguishing low-abundance vaporized anthropogenic-rich material from natural compositions, in order examine soil behavior and chemical evolution during fallout formation. Unfortunately, mixing convolutes the multivariate elemental relationships in these melts due to overlapping element abundances that might distinguish different source materials and chemical behaviors, making …

Development Of Chemical Separation Methods Using Transition Metals For Nuclear Forensic And Medicinal Applications, Lucas Peter Boron-Brenner

UNLV Theses, Dissertations, Professional Papers, and Capstones

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 …