Engineering Commons^™

Analyses For The Production And Dosimetry Of Adding Uranium-232 As A Tracer To The Uranium Fuel Cycle, Joshua H. Rhodes

Doctoral Dissertations

This dissertation is an examination of the use of uranium-232 as a tracer in nuclear fuel. Decay daughters from ²³²U, particularly thallium-208, produce high energy gamma rays that, when added to uranium, may increase detectability in case of theft or diversion, but are also hazardous in high quantities. Previous studies of the ²³²U decay chain are examined. This work will go in to a dosimetry study to determine how hazardous varying levels of ²³²U are, and how to efficiently produce ²³²U in sufficient quantities.

A dosimetry study was performed to determine the dose hazards due to …

Nestle To Origami Coupling: A Nuclear Non-Proliferation Tool For Lwr Fuel Assembly Isotope Analysis, Margaret Alva Kurtts

Doctoral Dissertations

NESTLE to ORIGAMI coupling is a versatile nuclear modeling tool that allows researchers to directly observe the impact of operator induced changes on LWR assembly isotope production. The paper presents an experimental method by which to test the ability of an operator to manipulate the core neutron spectrum in order to produce higher quality plutonium for weapons use. The paper presents two plutonium production scenarios and evaluates their feasibility based on potential for detection and production capacity. Reactor modeling of a VVER-1000 uses NESTLE core simulation software. NESTLE outputs burnup and relative power information for all nodes in the core. …

A Generalized Method For Fissile Material Characterization Using Short-Lived Fission Product Gamma Spectroscopy, Justin Richard Knowles

Doctoral Dissertations

Characterizing the fissile content of nuclear materials is of particular interest to the safeguards and nuclear forensics communities. Short-lived fission product gamma spectroscopy offers a significant reduction in analysis time and detection limits when compared to traditional non-destructive assay measurements. Through this work, a fully generalizable method that can be applied to variations in fissile compositions and neutron spectra was developed for the modeling and measurement of short-lived fission product gamma-rays. This method uses a 238-group neutron flux that was characterized for two pneumatic tube positions in the High Flux Isotope Reactor using flux monitor irradiations. This flux spectrum was …

Process Attribute Monitoring Approach To Gaseous Centrifuge Enrichment Plant Safeguards, Adam Michael Shephard

Doctoral Dissertations

Unattended and remote monitoring systems for the early detection of gas centrifuge enrichment plant (GCEP) misuse have long been sought by the International Atomic Energy Agency (IAEA) safeguards inspectorate, but have yet to be realized for most GCEPs. The primary misuse of concern is high enriched uranium (HEU) production but additionally include excess low enriched uranium (LEU) production and material diversion.

The current research is a feasibility study that investigates a process monitoring approach combined with passive gamma spectroscopy techniques to monitor GCEPs. In the current research, a simulated reference cascade and monitoring system is used to demonstrate several techniques …