Nuclear Engineering Commons^™

Cold Atmospheric Pressure Plasmas For Food Applications, Michael V. Lauria, Russell S. Brayfield Ii, Ronald G. Johnson, Allen L. Garner

The Summer Undergraduate Research Fellowship (SURF) Symposium

Successfully distributing shelf food requires treatment to eliminate microorganisms. Current chemical methods, such as chlorine wash, can alter food quality while only being effective for a limited time. Cold atmospheric pressure plasmas (CAPs) can eradicate the microorganisms responsible for food spoilage and foodborne illness. Optimizing CAP treatments requires understanding the reactive species generated and relating them to eradication efficiency. Recent studies have used optical emission spectroscopy (OES) to determine the species generated in a sealed package that would hold food. In this study,we supplement the OES results with optical absorption spectroscopy (OAS) using the same gases (helium, nitrogen, compressed air, …

Temperature Dependent Surface Modification Of Tungsten Exposed To High-Flux Low-Energy Helium Ion Irradiation, Antony Q. Damico, Jitendra K. Tripathi, Theodore J. Novakowski, Gennady Miloshevsky, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nuclear fusion is a great potential energy source that can provide a relatively safe and clean limitless supply of energy using hydrogen isotopes as fuel material. ITER (international thermonuclear experimental reactor) is the world first fusion reactor currently being built in France. Tungsten (W) is a prime candidate material as plasma facing component (PFC) due to its excellent mechanical properties, high melting point, and low erosion rate. However, W undergoes a severe surface morphology change when exposed to helium ion (He⁺) bombardment under fusion conditions. It forms nanoscopic fiber-form structures, i.e., fuzz on the surface. Fuzz is brittle …

Modeling Of Ion/Target Interactions In Plasma Facing Components Of Fusion Reactor, Nicole Neto Godry Farias, Tatyana Sizyuk, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nuclear fusion is a promising source of clean energy that can be one of the key future suppliers of the world’s increasing power demand. One of today’s main challenges faced by scientists and engineers regarding nuclear reactors is to design plasma-facing components (PFCs) that can withstand extreme conditions of temperature, pressure, and ions/particles irradiation. Material evolution and damage of PFCs are strongly related to the bombardment and diffusion processes of ions resulting from fusion fuel, i.e., deuterium and tritium and reaction products, i.e., helium. However, work is still needed in order to understand fuel diffusion in the presence of helium …

Radiation Tailored Polymers For Detectors, Adhesive-Coatings And Other Industrial Uses, Anna M. Earley, Alex Bakken, Rusi P. Taleyarkhan

The Summer Undergraduate Research Fellowship (SURF) Symposium

The ever growing importance of humans to depend on renewable resources has shifted the focus of consumers, producers, and even politicians to more sustainable answers. Furthermore, pressure on the oil and natural gas industry has elevated the status of biopolymers in this regard. Polylactic acid (PLA) is unique polymer that offers unique abilities for tailored property derivation; thereby, enabling one to replace many engineered polymers and provide a sustainable solution as a nontoxic renewable resource. As a bioplastic, the tailoring of PLA under various conditions is important to the application and integration into current industry uses. After irradiating high molecular …

Out From Darkness And Into The Light: The Role Of Transparency And Social Media In Government, Frances Nichols Bachstein

Doctoral Dissertations

Government agencies that protect secrecy often have a difficult time connecting to the public. Secretive, or perceived secretive government organizations often fall into the nebulous realm of uncertainty for the information consumer. This results in a great deal of misinformation and disinformation being thought of as correct. Since 2008, the US government is moving toward a more transparent, open, and easily accessed information base through social media. Agencies across the government are adopting types of social media communication. However, bureaus that primarily focus on security and safeguarding secrets struggle with how much disclose, which platforms of social media are the …

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 …

Characterizing Local Order And Physical Properties Of Rare Earth Complex Oxides, Thomas Jacob Shamblin

Doctoral Dissertations

With more than 500 compositions, materials possessing the pyrochlore structure have a myriad of technological applications and physical phenomena. Three of the most noteworthy properties are the structure’s ability to resist amorphization making it a possible host matrix for spent nuclear fuel, its exotic magnetic properties arising from geometric frustration, and fast ionic conductivity for solid-oxide fuel cell applications. This work focuses on these three aspects of the pyrochlore’s many potential uses. Structural characterization revealed that pyrochlore-type oxides have a tendency to disorder from a high symmetry cubic structure to a lower symmetry orthorhombic arrangement in response to a variety …

Actinium-225 Production Via Proton Irradiation Of Thorium-232, Justin Reed Griswold

Doctoral Dissertations

High energy proton spallation reactions on natural thorium metal targets have been utilized to produce multi mCi [milliCurie] quantities of Actinium-225. Theoretical cross sections for actinium and thorium isotopes as well as for a select number of the fission products produced in these reactions were generated by the Monte Carlo radiation transport code PHITS to simulate the experimental data obtained from sixteen irradiations of thorium metal targets with 25-210 µA [microampere] proton beams ranging in energies from 77 to 192 MeV. Irradiations were conducted at Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL), while target dissolution and processing …

X-Ray Fluorescence For Quantification Of Lead And Strontium In Vivo, Aaron James Specht

Open Access Dissertations

Lead (Pb) is a toxicant well known for its effects on almost every organ system in the body. Pb use in industry has declined since removal of Pb from gasoline, but many developing countries still have significant use of Pb. Exposure to Pb has been linked with diseases causing neurodegeneration and thus have lasting effects long after the initial exposure. Another metal, strontium (Sr), has been linked with bone disease in particular situations and shown to have uses in treating osteoporosis as a supplement. However, there are no studies of the effects of Sr using a meaningful biomarker. The most …

Bayesian Framework For High Confidence Signal Validation For Online Monitoring Systems In Nuclear Power Plants, Anjali Muraleedharan Nair

Masters Theses

Online Monitoring systems may offer an effective alternative to the current intrusive calibration assessment procedure used in the nuclear industry. Apart from optimizing the economic and human resource aspects of the currently utilized technique, OLM increases the opportunities for performance assessment and fault detection for nuclear instrumentation. This can lead to possibly extend or ultimately remove the current time based assessment process. Irrespective of its plausible benefits, OLM sees limited applicability in today’s US fleet. Regulatory constraints that limits the large scale implementation of OLM can be addressed by developing highly sensitive signal validation technique and thereby structurally quantify its …

Thermoelectric Half-Heuslers: Synthesis, Processing, And Performance, Joseph Robert Croteau

Boise State University Theses and Dissertations

Thermoelectric half-Heusler compounds have potential to convert the heat wasted from industrial and transportation processes to useful electricity. Among the highest performing half-Heusler compounds are nano-structured bulk materials which have been arc-melted, pulverized into a nano-powder, and sintered by DC-hot press. High performing n- and p-type half-Heusler compounds with nominal composition of Hf_0.25Zr_0.75NiSn_0.99Sb_0.01 and Nb_0.75Ti_0.25FeSb, respectively, have been provided to us in both dense and powder form by our collaborators at the University of Houston. We consolidate these powders by SPS, refine these powders to improve both particle size …

Development Of A National Human Reliability Program (Hrp) Model For An Emerging Nuclear Country: Nigerian Case Study, Stephen Olumuyiwa Ariyo Dahunsi

Masters Theses

The current demand for electricity and concern of the climate change in emerging countries has led to the rise in the number of nations adopting nuclear technology options. Besides this, the global rise in terrorism and the existence of credible threats in Nigeria and other emerging countries embarking on nuclear program for peaceful application may pose a critical challenge in implementation of this technology. Furthermore, the dual threat issue of providing electricity, while inadvertently producing weapon and radiological material that could similarly undermine international security must be mitigated. In order to achieve the mitigation target, it is highly important to …

The Impact Of The State-Level Concept On “Newcomers”: A Case Study Of The Kingdom Of Saudi Arabia, Thaqal Alhuzaymi, Ayodeji Babatunde Alajo

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The International Atomic Energy Agency’s (IAEA) latest reports indicate a growing number of states (newcomers) considering the deployment of nuclear energy programs. In developing nuclear infrastructure, newcomers have to employ the prevailing standards to deploy the nuclear program in a secure, safe, and sustainable manner. State-Level Concept (SLC) refers to a comprehensive approach that uses information about a state’s nuclear facilities and capabilities to implement safeguards within the scope of the state’s safeguards agreement. SLC focuses on strengthening the effectiveness and improving the efficiency of the safeguards system considering the State as whole. SLC has been implemented in 53 states, …

Thin Film Alsb Carrier Transport Properties And Room Temperature Radiation Response, Erin Vaughan

Nuclear Engineering ETDs

Theoretical predictions for AlSb material properties have not been realized using bulk growth methods. This research was motivated by advances in molecular beam epitaxial (MBE) growth technology to produce high-quality thin-film AlSb for the purpose of evaluating transport properties and suitability for radiation detection. Simulations using MCNP5 were performed to benchmark an existing silicon surface barrier detector and to predict ideal AlSb detector behavior, with the finding that AlSb should have improved detection efficiency due to the larger atomic number of Sb compared with Si. GaSb diodes were fabricated by both homoepitaxial MBE and ion implantation methods in order to …

Integrated Microsphere Whispering Gallery Mode Probe For Highly Sensitive Refractive Index Measurement, Hanzheng Wang, Lei Yuan, Cheol-Woon Kim, Jie Huang, Xinwei Lan, Hai Xiao

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

We report an integrated whispering gallery mode microresonator-based sensor probe for refractive index sensing. The probe was made by sealing a borosilicate glass microsphere into a thin-wall glass capillary pigtailed with a multimode optical fiber. The intensities of the resonant peaks were found decreasing exponentially (linearly in a log scale) with the increasing refractive index of the medium surrounding the capillary. The sensing capability of the integrated probe was tested using sucrose solutions of different concentrations and the resolution was estimated to be about 2.5 x 10^-5 in the index range of 1.3458 to 1.3847. The integrated sensor probe …

Particle Entrainment Studies From Dry And Wet Bed, Saber Ayatollahi

Electronic Thesis and Dissertation Repository

During the Fluid Coking Process™ bitumen is sprayed into a fluidized bed of hot coke particles. The bitumen undergoes thermal cracking and is converted into gasses, condensable vapors, and solid coke, which deposits on the coke particles. These vapors rise through the vessel and result in entrainment of coke particles. Wet fine coke particles from the freeboard region enter the cyclone and contribute to the fouling of the Coker cyclones which can lead to the premature shut-down of Fluid Cokers.

The primary objective of this research is to determine how bed wetness affects entrainment.

First, a new fluidized bed was …

Cyclotron Production And Biomedical Imaging Applications Of The Pet Isotope Manganese-52, Andrew Lake Wooten

McKelvey School of Engineering Theses & Dissertations

Manganese is an important element for biomedical research because of its roles as an essential micronutrient and as a neurotoxin from chronic elevated exposure, as well as the role of manganese(II) as a paramagnetic core for contrast agents in T1-weighted magnetic resonance imaging (MRI). Using a radiotracer of manganese provides excellent sensitivity for studying these phenomena, but only 52Mn met the criteria for our experiments: (1) a half-life (t1/2=5.6 days) that was long enough to examine timepoints over several days, (2) a half-life that was short enough to emit sufficient counts for a realistic scan time, and (3) emitted radiation …

Control System Requirements For A Nuclear Thermal Propulsion System, Adam Hasse, Michael Smith, Bradley Pershke, Andrew Adams, Stephen GilliAm

Chancellor’s Honors Program Projects

No abstract provided.

The Design Of A Fast Neutron Radiography System For Non-Destructive Analysis Of Thick, Dense Objects, Alicia Lauren Swift

Doctoral Dissertations

This dissertation describes the development of a novel time-of-flight (TOF) fast neutron radiography system, TiGReSSE ("Time Gating to Reject Scatter and Select Energy"), for non-destructive analysis of thick, dense objects, such as a spent nuclear fuel cask. Such objects create large scatter fields that mask interior flaws in an image, and are impenetrable with traditional x-ray or low-energy neutron radiography. By using a fast pulsed, high-energy monoenergetic neutron source with TiGReSSE, TOF methods may be employed to completely reject this problematic scatter. If using TOF methods with a fast pulsed, high-energy polyenergetic neutron source instead, partial scatter rejection is possible, …

Adopting 3d Time-Of-Flight Sensing Technology For Design Information Verification In International Safeguards, Matthew Stephen Duchene

Doctoral Dissertations

International safeguards inspectors periodically perform examinations at sensitive nuclear facilities to verify that the facilities’ designs, layouts, and functions are identical to information declared to the International Atomic Energy Agency (IAEA). Such design information verification (DIV) relies on tools and techniques—such as 3D laser range-finding (3DLR) with light detection and ranging (LIDAR) instruments—that are resource intensive. This research explores 3D Time-of-Flight (TOF) sensors as a possible alternative technology to LIDAR systems for performing spatial change-detection to enhance the DIV process.

This research uses the Microsoft Kinect Version 2 (Kinect v2) camera system, one of several commercial depth-sensing instruments that is …

Development And Application Of 3-D Fuel Performance Modeling To Assess Missing Pellet Surface Influence On Pellet Clad Interaction And Clad Failure, Nathan Allen Capps

Doctoral Dissertations

In the late 1970s PCI related failures caused the implementation of startup ramp restrictions. These ramp restrictions where intended to reduce the stresses caused by pellet cladding contact. These ramp restrictions had a significant impact on Westinghouse fueled PWRs, reducing PCI related failure until 2003. Through investigation into these fuel rod failures lead to the conclusion that missing pellet surfaces (MPS) were the root cause of the failures. MPS are local geometric defects in nuclear fuel pellets that result from pellet mishandling or the manufacturing process. The presence of MPS defects can cause stress concentrations in the clad of sufficient …

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 …

Development Of A Reactor Physics Analysis Procedure For The Plank-Based And Liquid Salt-Cooled Advanced High Temperature Reactor, Cole Andrew Gentry

Doctoral Dissertations

Presented in this dissertation is the investigation and development of an adapted lattice physics-to-core simulator two-step procedure based on the SERPENT 2 and NESTLE neutronics codes for the rapid analysis of the Advanced High Temperature Reactor (AHTR). AHTR specific characteristics, such as its longer neutron diffusion length and double heterogeneity of TRISO fuel particles, were taken into consideration when adapting the traditional Light Water Reactor (LWR) lattice to nodal diffusion procedure to AHTR applications. The coarse energy group structure was re-optimized from the traditional LWR 2-group structure to an alternative 4-group structures to address the AHTR specific flux spectrum and …

Machine Learning And Neutron Sensing In Mobile Nuclear Threat Detection, John Edward Sparger

Doctoral Dissertations

A proof of concept (PoC) neutron/gamma-ray mobile threat detection system was constructed at Oak Ridge National Laboratory. This device, the Dual Detection Localization and Identification (DDLI) system, was designed to detect threat sources at standoff distance using neutron and gamma ray coded aperture imaging. A major research goal of the project was to understand the benefit of neutron sensing in the mobile threat search scenario. To this end, a series of mobile measurements were conducted with the completed DDLI PoC. These measurements indicated that high detection rates would be possible using neutron counting alone in a fully instrumented system. For …

Bayesian-Based Methods For Transitioning Between Prognostic Estimates To Leverage Available Data, Alan Y. Nam

Doctoral Dissertations

The availability of failure data directly impacts the empirical prognostic models that can be built. In turn, these models impact the accuracy and uncertainty of remaining useful life (RUL) estimates of systems and components. While ideally a large amount of data of previous failure modes can be collected, the difficulty in obtaining such data can present a significant hurdle. To alleviate the constraints of limited data, Bayesian-based methods of transitioning between different prognostic models were developed. This updating scheme leverages existing data in order to create a unified estimate.

Two novel methods of transitioning are proposed to augment existing prognostic …

Characterization Of The Non-Uniqueness Of Used Nuclear Fuel Burnup Signatures Through A Mesh-Adaptive Direct Search, Steven Skutnik, David R. Davis

Faculty Publications and Other Works -- Nuclear Engineering

The use of passive gamma and neutron signatures from fission indicators is a common means of estimating used fuel burnup, enrichment, and cooling time. However, while characteristic fission product signatures such as ¹³⁴Cs, ¹³⁷Cs and ¹⁵⁴Eu, and others are generally reliable estimators for used fuel burnup within the context where the assembly initial enrichment and the discharge time are known, in the absence of initial enrichment and/or cooling time information (such as when applying NDA measurements in a safeguards/verification context), these fission product indicators no longer yield a unique solution for assembly enrichment, burnup, and cooling time …

Neutron-Gamma Discrimination In Elpasolite Scintillator Detector, Brittany Morgan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Existing nuclear stockpiles and weapons-making capabilities imperil the global community. Current nonproliferation efforts involve the research and development of newer, more efficient detection systems that can be deployed for the interdiction and monitoring of special nuclear materials (SNM). Spontaneous and induced fission events in SNM produce neutrons and gamma rays, which can be detected and analyzed, in particular, using scintillator detectors. Various electronic data acquisition systems and data analysis methods have been employed to record and characterize neutron and photon signatures. The goal of this thesis is to develop a new method of discrimination between neutrons and photons in the …

Cd Transport In Eutectic Licl-Kcl And Contamination Of Zr Metal And Thermal Dehydration Of Bulk Licl-Kcl, Nicholas Azoy Earle

Masters Theses

Researchers at Idaho National Labs have noted unexpectedly high Cd content in empty cladding hulls after processing in the Mark-IV ER. It has been theorized that Cd metal is transporting from the LCC pool through the eutectic LiCl-KCl salt bath to the anode baskets containing the empty hull where it is retained as a Zr-Cd intermetallic. This study sought to replicate the Cd contamination in a dry Ar glovebox using small-scale analogue of the Mark-IV ER salt-Cd metal system.

Anhydrous eutectic LiCl-KCl was an essential regent in this research and experiments were conducted to investigate the feasibility of dehydrating nominally …

Jet Flow Validation Of Positron Emission Particle Tracking Utilizing High Speed Video, Seth Thomas Langford

Masters Theses

Positron Emission Particle Tracking (PEPT) generates 4D Lagrangian particle trajectories and is used to evaluate flow in granular media and complex geometries where optical interrogation methods are not possible. A Multi-Particle PEPT (Multi-PEPT) approach was developed by the University of Tennessee Thermal Fluids Group capable of finding and tracking many particles simultaneously to extend the utility of the PEPT method. This thesis compares 4,014 trajectories generated using the Multi-PEPT method with 3,055 trajectories generated from High Speed Video (HSV) data. All trajectories are acquired in an acrylic test section with water flow using resin beads. The flow geometry includes a …

Advancement Of Computational Nuclear Fuel And Safeguard Tools, Nathan Shoman

Masters Theses

This thesis work was conducted in two separate but related areas: reactor physics and nuclear fuel safeguards. Reactor physics calculations at the assembly level are important to understand the buildup of fission products and major actinides. These calculations can be used to determine the content of a spent fuel assembly prior to reprocessing or disposal at a much cheaper price. This thesis presents an extension to the SCALE (A Nuclear Systems Modeling & Simulations Suite) by developing a lattice model and cross-section library for the CANada Deuterium Uranium (CANDU) 37 and 28 element assemblies. The previous cross-section library was based …