Nuclear Engineering Commons^™

Steam Reheat In Nuclear Power Plants, Paul John Marotta

Doctoral Dissertations

In this work, reheating steam from a commercial nuclear power plant is explored in order to increase efficiency and power output. A thermal source in the form of a High Temperature Gas Reactor (HTGR) is considered. Engineering challenges include proof-of-principle, reactor sizing, evaluation, and feasibility.

The proposed thermodynamic process modifications have been evaluated for a range of inlet steam quality conditions. The evaluation of the steam tube dimensions and number of optimal tubes have been calculated utilizing the so-called Log Mean Temperature Difference method. Subsequently, the performance of the steam tubes was further analyzed within a water vapor and liquid …

Optimization Of Transcurium Isotope Production In The High Flux Isotope Reactor, Susan Hogle

Doctoral Dissertations

The Radiochemical Engineering Development Center at Oak Ridge National Laboratory is the world's leader in production of californium-252. This and other heavy actinides are produced by irradiation of mixed curium/americium targets in the High Flux Isotope Reactor. Due to the strong dependence of isotopic cross sections upon incoming neutron energy, the efficiency with which an isotope is transmuted is highly dependent upon the neutron flux energy spectrum and intensities. There are certain energy ranges in which the rate of fissions in feedstock materials can be minimized relative to the rate of (n,γ) absorptions. This work shows that by perturbing the …

Development Of Patient Specific Predictive Treatment Margins To Account For Prostate Motion During Treatment Using Real-Time Intra Fraction Tracking, Michael Edward Howard

Doctoral Dissertations

Radiation therapy for prostate cancer has evolved over time. Intra-fractional motion of the prostate has been a clinical limitation in dose delivery. Reduced margins can lead to less toxicity to critical structures and an overall reduction in the risk of secondary cancers. Three models have been developed to predict prostate margins based on the first five fractions of treatment.

An 8^th order polynomial model is utilized with the 95% and 99% predictive lines indicating margins. This approach is applied to 24 patients. The maximum values as indicated by the predictive lines are used as the margins for the patient. …

Development Of A Novel Technique For Predicting Tumor Response In Adaptive Radiation Therapy, Rebecca Marie Seibert

Doctoral Dissertations

This dissertation concentrates on the introduction of Predictive Adaptive Radiation Therapy (PART) as a potential method to improve cancer treatment. PART is a novel technique that utilizes volumetric image-guided radiation therapy treatment (IGRT) data to actively predict the tumor response to therapy and estimate clinical outcomes during the course of treatment. To implement PART, a patient database containing IGRT image data for 40 lesions obtained from patients who were imaged and treated with helical tomotherapy was constructed. The data was then modeled using locally weighted regression. This model predicts future tumor volumes and masses and the associated confidence intervals based …

Novel Production Techniques Of Radioisotopes Using Electron Accelerators, Daniel Robert Lowe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Non-traditional radioisotope production techniques using a compact, high power linear electron accelerator have been demonstrated and characterized for the production of 18F, 47Sc, 147Pm, and 99mTc from a variety of target candidates. These isotopes are used extensively in the medical field as diagnostic and therapy radioisotopes, as well as the space industry as RTG's. Primary focus was placed on 99mTc as it constitutes approximately 80% of all diagnostic procedures in the medical community that use radioactive tracers. It was also the prime focus due to recent events at the Chalk River nuclear reactor, which caused global shortages of this isotope …

Evaluation Of Tagging Techniques Gamma-Decay Probabilities Using The Surrogate Method, Timothy Lee Reed

Masters Theses

A detailed analysis of the statistical and discrete [gamma]-decay tagging techniques was conducted using the absolute surrogate and surrogate ratio method (SRM) to obtain the 92Mo(n,[gamma]) cross section in an equivalent neutron energy range of 80 to 880 keV. Excited 93Mo and 95Mo nuclei were populated using (d,p) reactions on 92Mo and 94Mo targets, respectively. The absolute surrogate 92Mo(n,[gamma]) cross sections disagreed with evaluated neutron capture cross section data by as much as a factor of 4 using the statistical tagging approach, whereas the discrete [gamma]-decay tag absolute surrogate cross section disagreed with the evaluated neutron capture cross section by …

Design Of A Neutron Detector Capable Of Replacing He-3 Detectors Utilizing Thin Polymeric Films, Matthew J. Urffer

Masters Theses

There exists a significant need to develop a new neutron detection system which would reduce the dependency on the current He-3 based detectors for Domestic Nuclear Detection Office (DNDO) applications. One of the technologies being developed is the use of Li-6 (thermal cross section of 940 barns) in scintillating polymeric thin films. The purpose of this research is to provide a framework for the characterization of thin polymeric films in terms of meeting the detection requirements set forth by the governing bodies, most notability a detector count rate of 2.5 cps/ng with and only misclassifying a neutron as a gamma …

The Use Of A Fluidized Bed In A Spent Fuel Pool, Charles R. Menke, Natalie B. Camilli, Nathan A. Capps, Claire Fage, Timothy R. Hillard, Matthew B. Nash, Matthew L. Thornbury

Chancellor’s Honors Program Projects

No abstract provided.

Prognostic Approaches Using Transient Monitoring Methods, Michael Eric Sharp

Doctoral Dissertations

The utilization of steady state monitoring techniques has become an established means of providing diagnostic and prognostic information regarding both systems and equipment. However, steady state data is not the only, or in some cases, even the best source of information regarding the health and state of a system. Transient data has largely been overlooked as a source of system information due to the additional complexity in analyzing these types of signals. The development for algorithms and techniques to quickly, and intuitively develop generic quantification of deviations a transient signal towards the goal of prognostic predictions has until now, largely …

Secondary Light Particle Data Base Development Using A Thermodynamic Coalescence Model, Mahmoud Pourarsalan

Doctoral Dissertations

ABSTRACT

As heavy ions are transported through shielding and interact with shielding materials accurate values of total, elastic scattering, reactions cross sections and angular distributions of the emitted nucleons, light high energy particles such as deuteron, triton, helion, alpha particles and other heavy ions are required in order to design appropriate and adequate shielding to protect the human crews and instruments from ionizing radiations during long duration space missions. Double-differential (energy and angle) light energetic particle production cross sections must be known for ion energies from tens of MeV/nucleon to tens of GeV/nucleon for all emitted light energetic particles for …

A Validation Study Of The Amp Nuclear Fuel Performance Code, Aaron Martin Phillippe

Masters Theses

The Advanced Multi-Physics (AMP) Fuel Performance Code is a fully coupled, 3-dimensional (3D) code currently in development at the Oak Ridge National Laboratory (ORNL) for the purposes of advanced fuel performance evaluation and simulation. The purpose of this study was to investigate and examine the capabilities of AMP, as developed so far, in thermo-mechanical evaluations of experimental benchmark data. The IFA-432 and IFA-597 datasets from the Nuclear Energy Agency’s (NEA) International Fuel Performance Experiments (IFPE) database were examined, and a code-to-code comparison made against FRAPCON-3.4, a one dimensional (1D) code used by the Nuclear Regulatory Commission (NRC) for fuel licensing. …

The Leading Contributor Of The Fukushima Daiichi Nuclear Power Plant Accident, Christopher Torres

Liberal Arts and Engineering Studies

No abstract provided.

Anti-Nuclear Activism And The Past, Present And Future Of United States Nuclear Energy Policy, Isabel C. Zellweger

Honors Theses

Nuclear power has had a long and controversial history leading people to have many different views on the topic. Even though nuclear power does provide the nation with a significant portion of its electricity, many still fear its risks, especially after the events at Fukushima last spring. This thesis explores how public opinion, current events, and anti-nuclear activism have shaped nuclear power in America today. After reviewing the literature on nuclear energy in the United States, I discuss the past and current state of United States nuclear energy policy, and then describe changing American attitudes toward nuclear power over time. …

Turbulent Gas Breakup Modeling And Acoustic Void-Fraction Determination Studies In Support Of Cavitation Damage Mitigation Of The Spallation Neutron Source Target Vessel, Stuart Alexander Walker

Doctoral Dissertations

Pressure pulses induced by proton beam deposition lead to cavitation and pitting erosion of the SNS target vessel; this damage limits the lifetime of the vessel. Dampening the pressure pulse by adding compressibility to the bulk mercury in the form of microbubbles is a promising technique for damage mitigation. The physics governing gas bubble breakup in turbulent flows is examined leading to mechanistic based scaling models for the gas breakup in a swirling jet type microbubble generator. These models are verified experimentally in an air/water system and compared to a legacy empirical model. Verifying the performance of a microbubble generator …

Derivation Of Correction Terms To The Eikonal Approximations In The Formulation Of Analytical Abrasion-Ablation Model, Santosh Bhatt

Doctoral Dissertations

Analytical models for the quantitative predictions of spectra from the neutrons and light ions produced from the high energy, heavy ion (HZE) reactions are extremely important in assessment of the radiation damage during long duration deep space missions, and for various accelerator applications. The fundamental physics of the secondary particle production and transport from these HZE reactions is described using the abrasion-ablation model. The abrasion part of the model is based on the Glauber multiple scattering theory while the ablation process is based on statistical decay based on an evaporation model. The current formulations for the abrasion process are based …

Analyses Of Measurements From The Crater Instrument On The Lro Spacecraft Using Space Radiation Transport Codes, Jamie Alicia Anderson

Doctoral Dissertations

In June 2009, the Lunar Reconnaissance Orbital (LRO) Spacecraft was launched to orbit Earth’s Moon. Objectives of this mission are to find potential safe landing sites, locate potential resources, test new technologies, and characterize the lunar radiation environment. Located on the LRO is the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument which is designed to characterize the lunar radiation environment, its biological impact on humans, and impact on equipment. CRaTER will provide a better and more accurate understanding of the lunar radiation environment by measuring linear energy transfer (LET). This lunar environment includes solar particle events (SPEs) …

Leksell Gamma Knife Treatment Planning Via Kernel Regression Data Mining Initialization And Genetic Algorithm Optimization, Joseph Michael Bowling

Doctoral Dissertations

Gamma Knife is a medical procedure that is used to treat several types of intracranial disease. The system utilizes gamma rays from Cobalt-60 radiation sources focused at an isocenter and a stereotactic frame system that serves as an immobilization device coordinate system. Treatment is performed by localizing the patient’s disease with a medical imaging study and positioning the diseased area at the focused intersection of the beams. Patient treatment may require multiple treatment positions and varying beam sizes. The treatment position, time, and beam size is determined through a treatment planning process. Traditionally Gamma Knife treatment planning is performed manually …

Liquid Jet Experiments And Simulations For A Verification And Validation Study, Lee Paul Tschaepe

Doctoral Dissertations

The velocity field for two vertical parallel water jets impinging into a large stationary volume of water is mapped using ultrasonic interrogation. Thermal mapping of the vertical parallel water jets at high Reynolds numbers has been performed. The velocity data and associated statistics are related to the measurement volume and the ultrasonic Doppler measurement technique. The data are also compared to the literature for twin jets. The interaction of parallel jets is of interest to liquid metal reactor design. Liquid metal fast reactor (LMFR) coolant enters the bottom of the fuel bundles and exits through the top of the bundles. …

An Investigation Of The Use Of Ceramic Microencapsulated Fuel For Transuranic Waste Recycling In Pressurized Water Reactors, Cole Andrew Gentry

Masters Theses

Presented is an investigation of the utilization of Tristructural-Isotropic (TRISO) particle-based fuel designs for the recycling of Plutonium/Neptunium (Pu/Np) Transuranic (TRU) isotopes in typical Westinghouse four-loop pressurized water reactors. Though numerous studies have evaluated the recycling of TRU isotopes in light water reactors (LWRs), this work differentiates itself by employing Pu/Np loaded TRISO particles embedded within a SiC matrix and formed into pellets that can be loaded into standard 17x17 fuel element cladding. This approach provides the capability of Pu/Np recycling, and by virtue of the TRISO particle design, will allow for greater burnup of Pu/Np material and improved fuel …

A High-Energy Neutron Flux Spectra Measurement Method For The Spallation Neutron Source, Nicholas Patrick Luciano

Masters Theses

The goal of this work was to develop a foil activation method to measure high-energy (∼1-100 MeV) neutron flux spectra at the Spallation Neutron Source by researching the scientific literature, assembling an experimental apparatus, performing experiments, analyzing the results, and refining the technique based on experience. The primary motivation for this work is to provide a benchmark for the neutron source term used in target station and shielding simulations Two sets of foil irradiations were performed, one at the ARCS beamline and one at the POWGEN beamline. The gamma radiation of the foil activation products was measured with a high …

Materials And Configuration From Nmis Type Neutron Imaging And Gamma Spectroscopy, Alicia Lauren Swift

Masters Theses

The Nuclear Material Identification System (NMIS) was first developed at Oak Ridge National Laboratory (ORNL) by the US Department of Energy (DOE) in 1984 for nuclear material control and accountability, and for possible future treaty verification applications by the Office of Nuclear Verification since the mid-1990s. NMIS is being developed into a fieldable form (designated FNMIS) and will incorporate gamma spectroscopy and an information barrier. This project, supported by the US DOE at ORNL, tested a previously developed procedure to determine the configuration of an object with unknown geometry and composition from neutron imaging, induced fission radiation detection, and passive …

Active Neutron Interrogation Of Non-Radiological Materials With The Nuclear Materials Identification System, Mark Edwin Walker, John T. Mihalczo

Chancellor’s Honors Program Projects

No abstract provided.

A System For Cooling Nuclear Spent Fuel Using Fluidized Bed Technology, Ian J. Miller

Chancellor’s Honors Program Projects

No abstract provided.

Theoretical Study Of The Effects Of Di-Muonic Molecules On Muon-Catalyzed Fusion, Eugene V. Sheely

Theses and Dissertations

This document presents a theoretical study di-muonic hydrogen and helium molecules that have the potential of enhancing the muon-catalyzed fusion reaction rate. In order to study these di-muonic molecules a method of non-adiabatic quantum mechanics referred to as a General Particle Orbital (GPO) method was developed. Three mechanisms that have the possibility of enhancing the muon-catalyzed fusion rate were discovered. Two involve the formation of di-muonic hydrogen molecules, and the other uses di-muonic molecules to liberate muons stuck to ³He nuclei. The effects of muon spin on dimuonic hydrogen molecules was studied. The nuclear separation in di-muonic hydrogen molecules …

Investigation On The Benefits Of Safety Margin Improvement In Candu Nuclear Power Plant Using An Fpga-Based Shutdown System, Jingke She

Electronic Thesis and Dissertation Repository

The relationship between response time and safety margin of CANadian Deuterium Uranium (CANDU) nuclear power plant (NPP) is investigated in this thesis. Implementation of safety shutdown system using Field Programmable Gate Array (FPGA) is explored. The fast data processing capability of FPGAs shortens the response time of CANDU shutdown systems (SDS) such that the impact of accident transient can be reduced. The safety margin, which is closely related to the reactor behavior in the event of an accident, is improved as a result of such a faster shutdown process.

Theoretical analysis based on neutron dynamic theory is carried out to …

A Programmable Liquid Collimator For Both Coded Aperture Adaptive Imaging And Multiplexed Compton Scatter Tomography, Jack G. M. Fitzgerald

Theses and Dissertations

A novel, fully reconfigurable collimator device for gamma-ray and X-ray imaging was built and tested as a coded aperture. The device consisted of 10x10, 5x5x5 mm³ chambers. Each chamber either was filled with an attenuating liquid, stopping photons, or evacuated of the attenuating liquid, allowing the photons to pass through. As the pattern of on and off chambers was manipulated, different, semi-independent views of the gamma-ray source were found. Noise in reconstructed images decreased in all tests. Image reconstruction was performed with correlation methods and Maximum Likelihood Expectation Maximization (ML-EM). Using 10 mask patterns, the signal-to-noise ratio (SNR) in …

Verification Of A Monte Carlo Model Of The Missouri S&T Reactor, Brad Paul Richardson

Masters Theses

The purpose of this research is to ensure that an MCNP model of the Missouri S&T reactor produces accurate results so that it may be used to predict the effects of some desired upgrades to the reactor. The desired upgrades are an increase in licensed power from 200 kW to 400kW, and the installation of a secondary cooling system to prevent heating of the pool. This was performed by comparing simulations performed using the model with experiments performed using the reactor. The experiments performed were, the approach to criticality method of predicting the critical control rod height, measurement of the …

Hot Channel Determination And Burnup Analysis Of Missouri University Of Science And Technology Research Nuclear Reactor, Kelly Christopher Rogers O'Bryant

Masters Theses

"A burnup analysis has been performed on the Missouri University of Science and Technology (Missouri S&T) Research Nuclear Reactor (MSTR). With use of the Monte Carlo neutronics depletion code MCNPX, burned material was input into a neutronics model (burned model) in order better simulate MSTR core characteristics. Simulated burnup values of ²³⁵U for the past twenty years of MSTR operations totaled 14.266 grams, slightly less than the 14.527 grams reported by the reactor staff. A distribution of ²³⁵U was simulated and a burnup map was developed.

Using the updated fuel material, the hot channel of the current configuration of the …

Wavelet Based Contrast Limited Histogram Equalization For Contrast Enhancement Of Digital Mammography, Ashish Vighnahar Avachat

Masters Theses

"Mammography has been the most efficient tool for screening of microcalcification and cancer tissues; however, the raw images produced by mammography systems are usually of poor contrast. In order to use these raw images for early diagnosis; their contrast, sharpness and noise need to be enhanced. Among these important enhancement parameters contrast enhancement is critical. A novel algorithm is introduced which blends wavelet transforms with Contrast Limited Adaptive Histogram Equalization (CLAHE) for contrast enhancement. In this algorithm, the input image is decomposed to its low frequency and high frequency components in wavelet domain. Decomposed coefficients from different bands are then …

Determination Of Linear Attenuation Coefficients Of Chemically Bonded Phosphate Ceramics, Jason Joseph Pleitt

Masters Theses

"Chemically Bonded Phosphate Ceramics (CBPCs) is a composite based material formed in a manner similar to cements. CBPCs have shown to be a good structural material with excellent thermal resistance properties. They have also been shown to have potential as a radiation shield. By incorporating various powders into the ceramic the improvement in its radiation shielding properties are examined. The method for obtaining the linear attenuation coefficients for CBPCs as well as MCNP simulated results for gamma and neutrons are presented"--Abstract, page iv.