Open Access. Powered by Scholars. Published by Universities.®

Nuclear Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Masters Theses

Discipline
Institution
Keyword
Publication Year

Articles 1 - 30 of 165

Full-Text Articles in Nuclear Engineering

Customized Multi-Group Cross Section Generation With Njoy For Discrete Ordinates Computed Tomography And Radiography Simulation, Steven Michael Wagstaff Jan 2018

Customized Multi-Group Cross Section Generation With Njoy For Discrete Ordinates Computed Tomography And Radiography Simulation, Steven Michael Wagstaff

Masters Theses

"The purpose of this work was to explore the creation of photoatomic multi-group cross section libraries to be used with a software package DOCTORS (Discrete Ordinates Computed TOmography and Radiography Simulator). This software solves the linear Boltzmann equation using the discrete ordinates method [1]. To create these libraries, NJOY2016 was used, creating both fine and broad energy multi-group cross section files. The cross section's accuracy was tested against an equivalent Monte Carlo simulation using MCNP6.

Two simulation geometries were used. The first, a cylindrical water phantom with a single source projection placed in front, simulating an X-ray radiography. The ...


Fuel Burnup Simulation And Analysis Of The Missouri S&T Reactor, Joshua Hinkle Rhodes Jan 2018

Fuel Burnup Simulation And Analysis Of The Missouri S&T Reactor, Joshua Hinkle Rhodes

Masters Theses

"The purpose of this work is to simulate the fuel burnup of the Missouri S&T Reactor. This work was accomplished using the Monte Carlo software MCNP. The primary core configurations of MSTR were modeled and the power history was used to determine the input parameters for the burnup simulation. These simulations were run to determine the burnup for each fuel element used in the core of MSTR.

With these simulations, the new predicted isotopic compositions were added into the model. New core configurations were determined, and the burnup corrected model was used to predict the excess reactivity and control ...


Modulated Photothermal Radiometry: Detector Sensitivity Study And Experimental Setup, Jessica Nicole Seals Jan 2018

Modulated Photothermal Radiometry: Detector Sensitivity Study And Experimental Setup, Jessica Nicole Seals

Masters Theses

"This thesis outlines the development of a system used for determining the surface thermal diffusivity of both non-irradiated and irradiated materials. The motivation for this work is to establish a modulated photothermal radiometry (PTR) system on the campus of Missouri University of Science and Technology. One of the main efforts described in this thesis is the design and construction of the physical apparatus. Along the way, it was necessary to perform a detailed sensitivity analysis of the system to determine whether the expected signal emitted from the sample falls within the bounds of detectivity for the HgCdTe (MCT) detector used ...


An Investigation Into The Effects Of Ion Tracks On Α-Quartz, Bryant Alan Kanies Jan 2018

An Investigation Into The Effects Of Ion Tracks On Α-Quartz, Bryant Alan Kanies

Masters Theses

"The passage of a swift heavy ion through a material can cause columnar, amorphous nano-structures known as ion tracks. Swift heavy ions are present in a number of applications ranging from nuclear reactors to nuclear waste storage and onboard spacecraft. The study of ion tracks has been ongoing since the late 1950s and has led to several technological advancements. In fact, ion beams have been used to enhance material properties and aid in the production of electrical components. Ion beams, and their resultant ion tracks, can therefore be seen as a method to purposefully alter material properties such as thermal ...


Development And Monte Carlo Validation Of A Finite Element Reactor Analysis Framework, Wayne J. Brewster Jan 2018

Development And Monte Carlo Validation Of A Finite Element Reactor Analysis Framework, Wayne J. Brewster

Masters Theses

"This study presents the development and Monte Carlo validation of a continuous Galerkin finite element reactor analysis framework. In its current state, the framework acts as an interface between the mesh preparation software GMSH and the sparse linear solvers in MATLAB, for the discretization and approximation of 1-D, 2-D, and 3-D linear partial differential equations. Validity of the framework is assessed from the following two benchmarking activities: the 2-D IAEA PWR benchmark; and the 2-D Missouri Science and Technology Reactor benchmark proposed within this study. The 2-D IAEA PWR multi-group diffusion benchmark is conducted with the following discretization schemes: linear ...


The Development Of Cesium Calcium Bromo-Iodide Scintillator For X-Ray And Gamma Ray Detection, Matthew Starr Loyd Dec 2017

The Development Of Cesium Calcium Bromo-Iodide Scintillator For X-Ray And Gamma Ray Detection, Matthew Starr Loyd

Masters Theses

CsCaI3:Eu [cesium calcium iodide doped with europium] is a promising scintillator material that can be grown from the melt, but undergoes a tetragonal to orthorhombic phase transition upon cooling at 255 °C [degrees Celsius], causing twinning and cloudiness. The purpose of this work is to suppress this solid to solid phase transition in the CsCaI3:Eu scintillator, which has a light yield of ~40000 ph/Mev and energy resolution at 662keV of ~4%, by halide replacement to form the compound CsCaBrxI3-x:Eu [cesium calcium bromo-iodide doped with europium]. Crystals 8 cm3 [cubic centimeters ...


Positron Emission Particle Tracking Software Maturation Project, Eric Michael Moore Dec 2017

Positron Emission Particle Tracking Software Maturation Project, Eric Michael Moore

Masters Theses

Positron Emission Particle Tracking (PEPT) software at the University of Tennessee (MultiPEPT) has demonstrated promising performance in multiple measurement domains. In order to contribute to its further development, a full codebase audit and three focused performance assessments were undertaken. Several improvements were made to the codebase as a result of the audit. The assessments demonstrated a linear axial detector- MultiPEPT response, the effect of mesh size variation, and the effect of temporal overlap variation. A number of best practices are compiled for effective use of MultiPEPT.


Modeling Of Dislocation Channel Formation And Evolution In Irradiated Metals, Peter James Doyle Dec 2017

Modeling Of Dislocation Channel Formation And Evolution In Irradiated Metals, Peter James Doyle

Masters Theses

Defect-free dislocation channel formation has been reported to promote plastic instability during tensile testing via localized plastic flow, leading to a distinct loss of ductility and strain hardening in many low-temperature irradiated materials. In order to study the underlying mechanisms governing dislocation channel width and formation, the channel formation process is modeled via a simple stochastic dislocation-jog process dependent upon grain size, defect cluster density, and defect size. Dislocations traverse a field of defect clusters and jog stochastically upon defect interaction, forming channels of low defect-density. Based upon prior molecular dynamics (MD) simulations and in-situ experimental transmission electron microscopy (TEM ...


Improvements To Nestle: Cross Section Interpolation And N-Group Extension, William Matthews Kirkland Dec 2017

Improvements To Nestle: Cross Section Interpolation And N-Group Extension, William Matthews Kirkland

Masters Theses

The NESTLE program is a few-group neutron diffusion reactor core simulator code utilizing the nodal expansion method (NEM). This thesis presents two improvements made to NESTLE regarding cross-section interpolation and multigroup capability.

To quickly and accurately obtain cross sections from lattice physics input data, a new cross section interpolation routine was developed utilizing multidimensional radial basis function interpolation, also known as thin plate spline interpolation. Testing showed that, for existing NESTLE lattice physics input, accuracy was retained but not improved and processing time was longer. However, the new interpolation routine was shown allow much greater exibility in the case matrix ...


Hot Filament Chemical Vapor Deposition Of Semiconducting Boron Carbide Thin Films, Michael Dylan Richardson May 2017

Hot Filament Chemical Vapor Deposition Of Semiconducting Boron Carbide Thin Films, Michael Dylan Richardson

Masters Theses

A highly efficient, low-power, compact thermal neutron detection system with excellent gamma-ray discrimination is desired for a number of applications. 10B [boron- 10] has a large cross section for thermal values and a Q-value of 2.78 MeV. For this reason, investigations into boron carbide, boron nitride, and boron phosphide semiconductor neutron detectors are underway. Because boron carbide has the highest fraction of boron of the three, it holds the highest potential. With this in mind, a hot filament chemical vapor deposition (HFCVD) system was designed and built in order to grow thin films of boron carbide onto n-type ...


Development Of Nuclear Underground Engineered Test Surrogates For Technical Nuclear Forensics Exploitation, Robert Boone Gilbreath May 2017

Development Of Nuclear Underground Engineered Test Surrogates For Technical Nuclear Forensics Exploitation, Robert Boone Gilbreath

Masters Theses

A method for formulation and production of Nuclear UnderGround Engineered Test Surrogates (NUGETS) based on notional improvised nuclear device (IND) detonations in an underground environment analogous to the Nevada National Security Site (NNSS) is presented. Extensive statistical analyses of precursory geochemical and geophysical characteristics are combined with an augmented surrogate debris cooling technique and predictive IND contributions from the ORIGEN Fallout Analysis Tool. Precursory and resultant elemental compositions, cooling curve calculations, and visual comparison of NUGETS to genuine underground debris are reported. Application of NUGETS methodology to future studies in urban, underground post-detonation technical nuclear forensic (TNF) analysis is suggested.


Practical Methods For Optimizing Equipment Maintenance Strategies Using An Analytic Hierarchy Process And Prognostic Algorithms, Gregory Michael Bosco May 2017

Practical Methods For Optimizing Equipment Maintenance Strategies Using An Analytic Hierarchy Process And Prognostic Algorithms, Gregory Michael Bosco

Masters Theses

Many large organizations report limited success using Condition Based Maintenance (CbM). This work explains some of the causes for limited success, and recommends practical methods that enable the benefits of CbM. The backbone of CbM is a Prognostics and Health Management (PHM) system. Use of PHM alone does not ensure success; it needs to be integrated into enterprise level processes and culture, and aligned with customer expectations. To integrate PHM, this work recommends a novel life cycle framework, expanding the concept of maintenance into several levels beginning with an overarching maintenance strategy and subordinate policies, tactics, and PHM analytical methods ...


Analysis Of Highly-Enriched Uranium Spectra Obtained With Lanthanum Bromide Scintillation Detection Systems, Danielle Lynn Mcfall May 2017

Analysis Of Highly-Enriched Uranium Spectra Obtained With Lanthanum Bromide Scintillation Detection Systems, Danielle Lynn Mcfall

Masters Theses

Cerium-doped lanthanum bromide scintillation detection systems have recently been examined as an alternative to conventional detection systems, namely high-purity germanium, cadmium zinc telluride, and thallium-doped sodium iodide systems for various reasons including portability, sizing, and efficacy. As a non-destructive assay technique, these detectors quantify gamma rays from various samples to measure and identify specific radioisotopes. In nuclear facilities specializing in uranium, these detectors are mainly utilized to detect characteristic low-energy gamma rays of uranium-235, specifically, 143 keV, 163 keV, 186 keV, 202 keV and 205 keV gamma rays. Accurately distinguishing closely-spaced gamma rays in spectral data is a common challenge ...


Effects Of Grain Size And Dopants On The Irradiation Response Of Actinide Oxides, Jeffrey Morgan Walters May 2017

Effects Of Grain Size And Dopants On The Irradiation Response Of Actinide Oxides, Jeffrey Morgan Walters

Masters Theses

High energy irradiation can induce physical and chemical changes in nuclear materials, impacting their properties and performance in reactor systems. Of particular interest is the radiation response of actinide oxides, such as UO2 [Uranium Dioxide] and ThO2 [Thorium Dioxide], as well as analogue materials such as CeO2 [Cerium Dioxide]. During the course of reactor operations, these nuclear materials are exposed to high energy ionizing radiation in the form of nuclear fission fragments. This study simulates the extreme conditions found in a nuclear reactor by utilizing accelerated heavy ions with mass and kinetic energy comparable to fission fragments ...


Analysis And Implementation Of Accident Tolerant Nuclear Fuels, Benjamin Joseph Prewitt Jan 2017

Analysis And Implementation Of Accident Tolerant Nuclear Fuels, Benjamin Joseph Prewitt

Masters Theses

"To improve the reliability and robustness of LWR, accident tolerant nuclear fuels and cladding materials are being developed to possibly replace the current UO2/zirconium system. This research highlights UN and U3Si2, two of the most favorable accident tolerant fuels being developed. To evaluate the commercial feasiblilty of these fuels, two areas of research were conducted. Chemical fabrication routes for both fuels were investigated in detail, considering UO2 and UF6 as potential starting materials. Potential pathways for industrial scale fabrication using these methods were discussed.

Neutronic performance of 70%UN-30%U3Si2 ...


Comparison Of ²⁵²Cf Time Correlated Induced Fission With Amli Induced Fission On Fresh Mtr Research Reactor Fuel, Jay Prakash Joshi Jan 2017

Comparison Of ²⁵²Cf Time Correlated Induced Fission With Amli Induced Fission On Fresh Mtr Research Reactor Fuel, Jay Prakash Joshi

Masters Theses

"The effective application of international safeguards to research reactors requires verification of spent fuel as well as fresh fuel. To accomplish this goal various nondestructive and destructive assay techniques have been developed in the US and around the world. The Advanced Experimental Fuel Counter (AEFC) is a nondestructive assay (NDA) system developed at Los Alamos National Laboratory (LANL) combining both neutron and gamma measurement capabilities. Since spent fuel assemblies are stored in water, the system was designed to be watertight to facilitate underwater measurements by inspectors. The AEFC is comprised of six 3He detectors as well as a shielded ...


The Viability Of Advantg Deterministic Method For Synthetic Radiography Generation, Andrew Albert Bingham Jan 2017

The Viability Of Advantg Deterministic Method For Synthetic Radiography Generation, Andrew Albert Bingham

Masters Theses

"Time sensitive and high resolution image simulations are needed for synthetic radiography generation. The standard stochastic approach requires lengthy run times with poor statistics at higher resolutions. The investigation of the viability of a deterministic approach to synthetic radiography image generation was explored. The aim was to analyze a computational time decrease over the stochastic method. ADVANTG was compared to MCNP in multiple scenarios including a Benchtop CT prototype, to simulate high resolution radiography images. By using ADVANTG deterministic code to simulate radiography images the computational time was found to decrease over 10 times compared to the MCNP stochastic approach ...


Design And Analysis Of A Passive Heat Removal System For A Small Modular Reactor Using Star Ccm+, Raymond Michael Fanning Jan 2017

Design And Analysis Of A Passive Heat Removal System For A Small Modular Reactor Using Star Ccm+, Raymond Michael Fanning

Masters Theses

"Next generation nuclear power plants, specifically small modular reactor designs, are the best alternative to fossil fuels for power generation due to their power density and low carbon emissions and constant awareness of safety concerns. A promising safety feature of new designs is the removal of heat by passive systems in accident scenarios. The passive systems require no moving parts and no intervention by personnel. These systems must be accurately simulated for better understanding of the heat transport phenomena: natural convection cooling. Due to the fact that most work developing these passive heat removal systems are proprietary information, a passive ...


Cfd Validation And Scaling Of Condensation Heat Transfer, Varun Kalra Jan 2017

Cfd Validation And Scaling Of Condensation Heat Transfer, Varun Kalra

Masters Theses

"A CFD study was performed using STAR-CCM+ to validate the software for its competence in the prediction and scaling of condensation heat transfer in the presence of air acting as a non-condensable gas. Three vertical concentric tube heat exchanger geometries with different diameters were studied in the CFD analysis. It was seen that the steam bulk temperatures predicted by STAR-CCM+ closely matched the experimental data. However, the temperatures of outer wall of the steel condenser tubes showed a deviation of 2% to 11% from the experimental values. The error in adiabatic water wall temperatures were found to range from 18 ...


Preliminary Investigation For The Development Of Surrogate Debris From Nuclear Detonations In Marine-Urban Environments, Adam G. Seybert Dec 2016

Preliminary Investigation For The Development Of Surrogate Debris From Nuclear Detonations In Marine-Urban Environments, Adam G. Seybert

Masters Theses

No nuclear weapon has ever been detonated in a United States city. However, this also means the nuclear forensic community has no actual debris from which to develop analytical methods for source attribution, making the development of surrogate nuclear debris a vital undertaking. Moreover, the development of marine-urban debris presents an unusual challenge because unlike soil and urban structures, which remain compositionally consistent, the elemental composition of harbor and port waters fluctuates considerably due to natural phenomenon and human activity. Additionally, marine vessel composition and cargo can vary dramatically. While early US nuclear tests were carried out in shallow-water coastal ...


A Bayesian Approach To Aerial Localization Of Radioactive Sources, Robert Blake Wilkerson Dec 2016

A Bayesian Approach To Aerial Localization Of Radioactive Sources, Robert Blake Wilkerson

Masters Theses

Securing nuclear material has become an important area for the safety of the U.S. and other countries. Within nuclear security, there is a potential to use orphaned or stolen radioactive sources to cause harm. As the amount of radioisotopes used by government and commercial businesses increases, the need to secure these sources becomes exponentially more difficult. It is well known that there have been several cases of lost, orphaned or stolen nuclear sources across the globe. There is a need for state-of-the-art radiation search methods to search for these potentially dangerous radioactive sources that could be misplaced. While there ...


Bayesian Framework For High Confidence Signal Validation For Online Monitoring Systems In Nuclear Power Plants, Anjali Muraleedharan Nair Aug 2016

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 ...


Development Of A National Human Reliability Program (Hrp) Model For An Emerging Nuclear Country: Nigerian Case Study, Stephen Olumuyiwa Ariyo Dahunsi Aug 2016

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 ...


Magnetron Sputtering And Corrosion Of Ti-Al-C And Cr-Al-C Coatings For Zr-Alloy Nuclear Fuel Cladding, Devin Alan Roberts May 2016

Magnetron Sputtering And Corrosion Of Ti-Al-C And Cr-Al-C Coatings For Zr-Alloy Nuclear Fuel Cladding, Devin Alan Roberts

Masters Theses

The disaster at the Fukushima Daiichi Nuclear Power Plant in March 2011 bought renewed focus to the issue of corrosion in nuclear fuel cladding applications. This thesis reports on the background behind these issues, the investigation strategy, and the analysis of experiments focused on mitigating oxidation of Zr-alloy fuel cladding. This thesis seeks to develop magnetron sputtered Ti-Al-C and Cr-Al-C coatings for Zr-alloy substrates and characterize the as-deposited and corroded samples.

Ti-Al-C and Cr-Al-C coatings were deposited onto ZIRLO, Si, and Al2O3 [Aluminum Oxide] substrates under various sputtering conditions. A combinatorial sputtering method was employed to refine ...


Advancement Of Computational Nuclear Fuel And Safeguard Tools, Nathan Shoman May 2016

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 on ...


Cd Transport In Eutectic Licl-Kcl And Contamination Of Zr Metal And Thermal Dehydration Of Bulk Licl-Kcl, Nicholas Azoy Earle May 2016

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 ...


Thermal Characteristics Of Lithium Indium Diselenide And Lithium Indium Gallium Diselenide Neutron Detection Crystals, Dustin Carroll Giltnane May 2016

Thermal Characteristics Of Lithium Indium Diselenide And Lithium Indium Gallium Diselenide Neutron Detection Crystals, Dustin Carroll Giltnane

Masters Theses

Tracking special nuclear materials (SNM) has never been more important than in the 21st century where information is transferred rapidly around the globe. Tracking SNM is important to nuclear power, weapons, medicine, and science. Neutron and gamma ray detection are the primary methods of detecting SNM. Increased movement and availability of SNM have increased the demand for radiation detection systems beyond the capacity of traditional neutron detection technologies (3He) [Helium three]. Many alternative neutron detection materials are being considered, including 6LiInSe2 [Lithium Indium Diselenide grown with lithium enriched in lithium six] and its derivative 6LiIn ...


Modeling And Experimental Investigation On The Influence Of Radiation Defects On Helium Behavior In Bcc Iron, Zuya Huang May 2016

Modeling And Experimental Investigation On The Influence Of Radiation Defects On Helium Behavior In Bcc Iron, Zuya Huang

Masters Theses

Fe-based alloys are important structural materials for both fission and fusion energy. For fusion applications, the challenges of radiation-induced changes in microstructure, properties and performance is further challenged by the concomitant production of helium from (n, alpha) nuclear reactions and fusion reactions. Due to the lack of a volumetric, high flux 14-MeV neutron source, studying these phenomena require the use of computational materials modeling and novel experimental methods. In this thesis, molecular dynamics (MD) simulations was used to investigate the synergistic interactions of helium with prismatic dislocation loops characteristic of those observed in neutron irradiated iron to determine how the ...


Jet Flow Validation Of Positron Emission Particle Tracking Utilizing High Speed Video, Seth Thomas Langford May 2016

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 ...


Multi-Signal Accelerated Degradation Testing Of Rolling Ball Bearings Through Radial Overload, Anna Marie Mazzolini May 2016

Multi-Signal Accelerated Degradation Testing Of Rolling Ball Bearings Through Radial Overload, Anna Marie Mazzolini

Masters Theses

Bearings are essential components in rotating machinery found in abundance in nuclear power plants. Bearing failure in nuclear power plants can lead to increased operations and maintenance costs and even plant trips. When developing maintenance procedures, it is ideal to minimize costs and equipment downtime while maximizing safety. Reactive, or run-to-failure, maintenance minimizes maintenance costs at the expense of operation costs and safety. Preventative, or time-based, maintenance maximizes safety and minimizes operation costs at the expense of equipment downtime and maintenance costs. Predictive, or condition-based, maintenance attempts to optimize overall costs while maintaining system safety and reducing downtown.

Predictive maintenance ...