Nuclear Energy As A Reliable And Safe Source Of Power Generation, 2022 University of Mississippi
Nuclear Energy As A Reliable And Safe Source Of Power Generation, Sarup Dhungana
There is a high demand of energy for generating civil applicable power in the world and in the USA, correspondingly. The world has been consuming various sources to extract the power to meet its demands. Most of the power sources include renewable and non-renewable sources like fossil fuels, natural gas, coal, water, solar, wind, and nuclear power. Although most of these sources have many advantages in terms of their capacity and cost of production, nuclear power can be categorized as the emerging driving force in the United States and in the world for power generation, because of its reliability and ...
Wetland Uranium Transport Via Iron-Organic Matter Flocs And Hyporheic Exchange, 2022 Clemson University
Wetland Uranium Transport Via Iron-Organic Matter Flocs And Hyporheic Exchange, Connor J. Parker
Uranium (U) released from the M-Area at the Department of Energy Savannah River Site into Tims Branch, a seasonal wetland and braided stream system, is estimated to be 43,500 kg between 1965 and 1984. The motivation for this work is the uranium’s persistence in the wetland for decades, where it is estimated that 80% of the U currently remains in the Tims Branch wetland. U has begun to incorporate into wetland iron (Fe) and carbon cycles, associating with local Fe mineralogy and deposits of rich wetland organic matter (OM). The objective of this work is to characterize the ...
Effects Of Plastic Deformation From Ultrasonic Additive Manufacturing, 2022 University of Tennessee, Knoxville
Effects Of Plastic Deformation From Ultrasonic Additive Manufacturing, Michael Pagan
Nuclear energy technology can be exponentially advanced using advanced manufacturing, which can drastically transform how materials, structures, and designs can be built. Ultrasonic Additive Manufacturing (UAM) represents one of the four main additive manufacturing methods, although it is also the newest. As UAM technology and applications develop, a fundamental understanding of the bonding mechanism is crucial to fully realize its potential. Currently UAM bonding is considered to occur through breaking down surface asperities and removing surface oxides. Plastic deformation occurs although its role is currently unclear. This research analyzes material configurations in a variety of geometries, with similar and dissimilar ...
A High Rate Pixelated Neutron Detector For Neutron Reflectometry At The Spallation Neutron Source, 2022 University of Tennessee, Knoxville
A High Rate Pixelated Neutron Detector For Neutron Reflectometry At The Spallation Neutron Source, Su-Ann Chong
This work presents the development of a high-rate 6Li-based pixelated neutron detector for neutron reflectometry instruments at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory. The current detector technology falls short on the instrument requirements, particularly on the counting rate capability. This detector was designed specifically to overcome the limitation in counting rate by having a fully pixelated design from neutron conversion layer to photodetector and readout system. For the neutron converting layer, a 6Li-based neutron scintillator was used. Each scintillator element was coupled to a photodetector, in this case, a silicon photomultiplier (SiPM). The output of each SiPM ...
Nuclear Thermal Rocket Engine Control Autonomy Via Embedded Decision, 2022 University of Tennessee, Knoxville
Nuclear Thermal Rocket Engine Control Autonomy Via Embedded Decision, David Sikorski
This doctoral dissertation presents an investigation of embedded decision capabilities as a means for developing nuclear reactor autonomous control. Nuclear thermal propulsion (NTP) is identified as a high priority technology for development, and is the focus of this research. First, a background investigation is presented on the state of the art in nuclear thermal rocket (NTR) engine control and modeling practices, resulting in the development of a low order NTR engine dynamic model based on the literature. The engine model was used to perform the following investigation, and is intended to serve as a research platform for the future development ...
Tokamak 3d Heat Load Investigations Using An Integrated Simulation Framework, 2022 University of Tennessee, Knoxville
Tokamak 3d Heat Load Investigations Using An Integrated Simulation Framework, Thomas Looby
Reactor class nuclear fusion tokamaks will be inherently complex. Thousands of interconnected systems that span orders of magnitude in physical scale must operate cohesively for the machine to function. Because these reactor class tokamaks are all in an early design stage, it is difficult to quantify exactly how each subsystem will act within the context of the greater systems. Therefore, to predict the engineering parameters necessary to design the machine, simulation frameworks that can model individual systems as well as the interfaced systems are necessary. This dissertation outlines a novel framework developed to couple otherwise disparate computational domains together into ...
Corrosion And Microstructural Characterization Of Molybdenum-Ysz Cermets Following Hydrogen Exposure Up To 2630 K, 2022 University of Tennessee, Knoxville
Corrosion And Microstructural Characterization Of Molybdenum-Ysz Cermets Following Hydrogen Exposure Up To 2630 K, Taylor G. Duffin
Ceramic-metallic (cermet) fuels are a promising fuel type for outer space nuclear thermal propulsion (NTP). A key feasibility issue is the hydrogen chemical compatibility of candidate fuels in the proposed extreme operating temperatures for NTP systems (> 2500 K). In this study, molybdenum matrix cermets containing 40–70 vol% yttria stabilized zirconia (YSZ) particles (as a surrogate for ceramic fuel particles) were produced via spark plasma sintering (SPS) and exposed to flowing hydrogen at high temperature (2000–2630 K). Both steady state and thermally cycled (4 cycles with intermediate cooling to room temperature) conditions were examined for a constant total hot ...
Reactive Thin Film Polymers And Thin Film Composite Membranes For The Rapid Screening Of Uranium Isotopes, Abenazer W. Darge
Traditional radiochemistry approaches for the detection of trace-level alpha-emitting radioisotopes in water require lengthy offsite sample preparations and do not lend themselves to rapid quantification. Therefore, a novel platform is needed that combines onsite purification, concentration, and isotopic screening with a fieldable detection system. My dissertation research objective was to develop novel reactive thin polymer films and thin film composite membranes for the selective separation of uranium from environmental water followed by direct isotopic analysis by alpha spectroscopy. Chapter 1 reviews progress made on uranium separation from aqueous matrices and discusses methods used for the determination of isotopic composition.
Validation Of Relap5-3d For Transient Simulation Of Lead-Lithium Systems For Fusion Applications, 2022 University of Tennessee, Knoxville
Validation Of Relap5-3d For Transient Simulation Of Lead-Lithium Systems For Fusion Applications, Nicholas Akira Meehan
With increasing development in fusion technology including the construction and subsequently planned experimental campaign of the International Thermonuclear Experimental Reactor (ITER), validation must be performed for simulation tools used in the design, development, and licensing of future commercial fusion systems. This thesis contains several validation studies for transient simulation of lead-lithium eutectic (PbLi) systems using the RELAP5-3D code. This validation analysis is performed initially using models of systems without the influence of a magnetic field to inspect heat transfer and pressure drop phenomena. The validation study then uses models of systems under the influence of a magnetic field to inspect ...
Meta-Heuristic Optimization Techniques For The Production Of Medical Isotopes Through Special Target Design, 2022 University of Tennessee, Knoxville
Meta-Heuristic Optimization Techniques For The Production Of Medical Isotopes Through Special Target Design, Cameron Ian Salyer
Medical isotopes are used for a variety of diﬀerent diagnostic and therapeutic purposes Ruth (2008). Due to recent newly discovered applications, their production has become rapidly more scarce than ever before Charlton (2019). Therefore, more eﬃcient and less time consuming methods are of interest for not only the industry’s demand, but for the individuals who require radio-isotope procedures. Currently, the primary source of most medical isotopes used today are provided by reactor and cyclotron irradiation techniques, followed by supplemental radio-chemical separations Ruth (2008). Up until this point, target designs have been optimized by experience, back of the envelope calculations ...
Design And Evaluation Of A Unique Weighted-Sum-Based Anger Camera, 2022 University of Tennessee, Knoxville
Design And Evaluation Of A Unique Weighted-Sum-Based Anger Camera, Matthew W. Seals
Anger camera imaging technology has become widely popular for neutron diffraction imaging due to recent shortages in Helium-3 (He-3). Research into neutron diffraction optimized Anger camera by the Oak Ridge National Laboratory (ORNL) detectors group has provided an alternative to He-3 Tube-based detectors with a high-resolution Anger camera. However, the cost of these high-resolution Anger camera technology can make it less attractive than He-3 tubes when a large Field of View (FOV) is desired. Currently, there is a need for a lower-cost alternative to this high-resolution anger camera. Further applications for Anger camera have become of interest with the advent ...
Enigma - Ongoing Development Towards Novel Beta-Decay Spectroscopy Station At Isolde, 2022 University of Tennessee, Knoxville
Enigma - Ongoing Development Towards Novel Beta-Decay Spectroscopy Station At Isolde, Philipp Wagenknecht
Beta decay and collinear laser spectroscopy are proven efficient tools to study nuclear structure far from stability. Two areas of significance are investigations into nuclear deformation and shape coexistence, as well as delayed neutron emissions used in nuclear energy applications. This contribution presents the ongoing development towards a novel beta-decay spectroscopy station for the VITO experiment at CERN’s radioactive ion beam facility ISOLDE. The setup will utilize both collinear laser spectroscopy and beta-decay spectroscopy to measure the energy and spin-parities of the ground and excited states of radioactive beams. Initial designs of the support structure, magnetic field, and detector ...
Development Of Codoped Cesium Iodide Scintillators For Medical Imaging Applications, 2022 University of Tennessee, Knoxville
Development Of Codoped Cesium Iodide Scintillators For Medical Imaging Applications, Everett M. Cavanaugh
Cesium iodide has a rich history of use as a scintillating material. CsI finds use in a variety of fields, but it is primarily used in radiography, tomography, and geological exploration. Of the three common variants of CsI, thallium doped CsI is by far the most widely used among these applications. It possesses favorable physical characteristics like a high density and high effective Z and exhibits high light output at room temperature. Despite how great CsI scintillators may be on paper, they have an Achilles heel: afterglow. CsI:Tl has significant afterglow which leads to imaging artifacts that can be ...
A Dislocation-Based Crystal Plasticity Model For Hexagonal Close-Packed Polycrystals, 2022 The University of Western Ontario
A Dislocation-Based Crystal Plasticity Model For Hexagonal Close-Packed Polycrystals, Omid Sedaghat
Electronic Thesis and Dissertation Repository
Due to their low neutron absorption cross-section and good corrosion properties, zirconium and its alloys have been widely used as the structural material in the core of nuclear reactors. These alloys are exposed to an intensive neutron flux which may lead to dimensional instabilities and the degradation of the mechanical properties of the alloy over the service time of the reactor. The changes in deformation behavior and mechanical properties can be traced back to the formation, evolution, and interaction of the irradiation-induced microstructural defects, e.g., point defect clusters, dislocation loops, and complex dislocation line networks. However, the materials constitutive ...
Addressing Underground, Unmanned Threats: A Case Study Of Gpr Detecting Illegal Objects At Nuclear Facilities And Enhancing Subterranean Physical Protection Systems, Md. Shamsul Huda Sohel, Mohammad Khan, Dr. Debashis Datta
International Journal of Nuclear Security
In nuclear installations, any unmanned threat is unacceptable. Such threats are a major issue for the nuclear physical protection system (PPS). Although the PPS of a nuclear power plant (NPP) is well prepared to deal with threats above ground level, until now, a special PPS had never been developed for detecting and tackling underground threats. One example of such a threat is a weapon-carrying, unmanned object operated by remote. Using this technology, a terrorist could launch an attack and overcome security barriers. While a normal PPS would not detect the underground activities of a mobile object, a PPS using a ...
A Detailed Hydrodynamic Study Of The Split-Plate Airlift Reactor By Using Non-Invasive Gamma-Ray Techniques, 2022 Missouri University of Science and Technology
A Detailed Hydrodynamic Study Of The Split-Plate Airlift Reactor By Using Non-Invasive Gamma-Ray Techniques, Laith S. Sabri, Abbas J. Sultan, Hasan Shakir Majdi, Shadha K. Jebur, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
This study focused on detailed investigations of selected local hydrodynamics in split airlift reactor by using an unconventional measurements facility: computed tomography (CT) and radioactive particle tracking (RPT). The local distribution in a cross-sectional manner with its radial's profiles for gas holdup, liquid velocity flow field, shear stresses, and turbulent kinetic energy were studied under various gas velocity 1, 2 and 3 cm/s with various six axial level z = 12, 20, 40, 60, 90 and 112 cm. The distribution in gas-liquid phases in the whole split reactor column, the riser and downcomer sides, including their behavior at the ...
Geant4 Simulation For Radioactive Particle Tracking (Rpt) Technique, 2022 Missouri University of Science and Technology
Geant4 Simulation For Radioactive Particle Tracking (Rpt) Technique, Ahmed A. Alghamdi, Thaar M. Aljuwaya, Abdullah S. Alomari, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
In the past two decades, the radioactive particle tracking (RPT) measurement technique has been proven to visualize flow fields of most multiphase flow systems of industrial interest. The accuracy of RPT, and hence the data obtained, depend largely on the calibration process, which stands here as a basis for two subsequent processes: tracking and reconstruction. However, limitations in the RPT calibration process can be found in different experimental constrains and in assumptions made in the classical Monte Carlo approach used to simulate number of counts received by the detectors. Therefore, in this work, we applied a GEANT4-based Monte Carlo code ...
Uranium 233: The Nuclear Superfuel No One Is Using, 2022 Seattle University School of Law
Uranium 233: The Nuclear Superfuel No One Is Using, Maris Hanson
Seattle Journal of Technology, Environmental & Innovation Law
Nuclear power offers more energy in less physical space than solar and wind and yields more energy per pound than fossil fuels. However different nuclear fuels yield different waste profiles and create different beneficial products. Uranium 233 (U233) resists use in nuclear weapons, yields beneficial daughter products, and produces dramatically less of the most problematic waste products than Uranium 235 (U235). U233 results from reactions with Thorium, a plentiful, ubiquitous element currently considered waste from rare earth mines. Additionally, U233 functions well in a liquid fuel reactor resulting in safer, more efficient reactors than current solid fuel U235 or Plutonium ...
Design Of An Accelerator-Based Shielding Experiment At The Nasa Space Radiation Laboratory Relevant To Enclosed, Shielded Environments In Space, 2022 Brookhaven National Laboratory
Design Of An Accelerator-Based Shielding Experiment At The Nasa Space Radiation Laboratory Relevant To Enclosed, Shielded Environments In Space, Lawrence H Heilbronn, Michael Sivertz, Adam Rusek, Charlie Pearson, Martha Clowdsley, Luis Castellanos, Natalie Mcgirl, Ashwin Srikrishna, Cary Zeitlin
Faculty Publications and Other Works -- Nuclear Engineering
Recent calculations indicate that the dose equivalent in an enclosed, shielded environment in a galactic cosmic ray field will increase or remain unchanged when shielding thickness increases beyond 20 to 30 g/cm2. This trend is seen out to 100 g/cm2, beyond which calculations were not run since depths greater than this are not envisioned for human missions in deep space. If these calculations are accurate, then an optimal shielding thickness (or narrow range of thicknesses) exists, with important implications for spacecraft and habitat design. Crucially, the calculation reveals a minimum dose equivalent value that cannot be reduced with ...
Performance Degradation Based On Importance Change And Application In Dissimilar Redundancy Actuation System, 2022 Old Dominion University
Performance Degradation Based On Importance Change And Application In Dissimilar Redundancy Actuation System, Yadong Zhang, Chao Zhang, Shaoping Wang, Rentong Chen, Mileta M. Tomovic
Engineering Technology Faculty Publications
The importance measure is a crucial method to identify and evaluate the system weak link. It is widely used in the optimization design and maintenance decision of aviation, aerospace, nuclear energy and other systems. The dissimilar redundancy actuation system (DRAS) is a key aircraft control subsystem which performs aircraft attitude and flight trajectory control. Its performance and reliability directly affect the aircraft flight quality and flight safety. This paper considers the influence of the Birnbaum importance measure (BIM) and integrated importance measure (IIM) on the reliability changes of key components in DRAS. The differences of physical fault characteristics of different ...