Nuclear Engineering Commons^™

A Bayesian Approach To Broad-Area Nuclear And Radiological Search Operations, Samuel James Willmon

Doctoral Dissertations

This dissertation describes the development, implementation, and initial performance testing of the Broad-Area Search Bayesian Processor (BASBP). The BASBP is a novel FORTAN code designed to combine the data from aerial radiation detection platforms with available geo-spatial data using Bayesian techniques to provide updated parameter estimates of the problem space. By employing empirical fits to the Monte Carlo photon flux estimates generated using MCNP6, the core BASBP model accounts for the increasing significance of photon scattering and absorption events with source-detector range. The BASBP employs Bayesian signal processing methods to estimate both the spatially varying background and the most likely …

Particle Modeling Of Fuel Plate Melting During Coolant Flow Blockage In Hfir, Hiraku Nakamura

Doctoral Dissertations

Cooling channel inlet flow blockage has damaged fuel in plate fueled reactors and contributes significantly to the probability of fuel damage based on Probabilistic Risk Assessment. A Smoothed Particle Hydrodynamics (SPH) model for fuel melt from inlet flow blockage for the High Flux Isotope Reactor is created. The model is coded for high throughput graphics processing unit (GPU) calculations. This modeling approach allows movement toward quantification of the uncertainty in fuel coolant flow blockage consequence assessment. The SPH modeling approach is convenient for following movement of fuel and coolant during melt progression and provides a tool for capturing the interactions …

Development Of A Method For Incorporating Fault Codes In Prognostic Analysis, Eric Allen Strong

Doctoral Dissertations

Information from fault codes associated with a component may be used as an indicator of its health. A fault code is defined as a timestamp at which a component is not operating according to recommended guidelines. The type of fault codes which are relevant for this analysis represent mild or moderate deviations from normal behavior, rather than those requiring immediate repair. Potentially, fault codes may be used to determine the Remaining Useful Life (RUL) of a component by predicting its failure time, which will improve safety and reduce maintenance costs associated with the component. In this dissertation, methods have been …

Development Of A Fluka-Based Lookup Tool For Rapid Analysis Of Radiation Exposures In Space Environments, John Macdougall Brittingham

Doctoral Dissertations

Monte Carlo transport codes such as FLUKA provide an accurate and effective method to model the transport of space radiation. However, their use in time-sensitive applications is limited because they do not generate results as quickly as other methods, such as deterministic transport codes. The development of a pre-calculated lookup tool for use in complex space radiation environments allows the calculation of space radiation quantities such as dose, dose equivalent, and fluence using Monte Carlo results with minimal loss of accuracy. In this work, a lookup tool suitable for rapidly estimating radiation exposures is developed using the FLUKA Monte Carlo …

Multi-Cycle Boiling Water Reactor Fuel Cycle Optimization, Keith Everette Ottinger

Doctoral Dissertations

A multi-cycle nuclear fuel cycle optimization code, BWROPT (Boiling Water Reactor OPTimization), has been developed. BWROPT uses the Parallel Simulated Annealing (PSA) algorithm to solve the coupled out-of-core and in-core optimization problems. There are two depletion methods used for the in-core optimization: the Haling depletion and a Control Rod Pattern (CRP) search. The result of this optimization is the optimum new fuel inventory and the core loading pattern for the first cycle considered in the optimization. Several changes were made to the optimization algorithm with respect to other nuclear fuel cycle optimization codes that use PSA. Instead of using constant …

Solute Additives And Neutron Absorber Alloys For The Improvement Of Spent Fuel Pool Safety And Increased Storage Space, Seth H. Jobe, John R. Chalmers, Zach Hensley, Austin O'Connor, Nathan Shoman, Matthew Weeks

Chancellor’s Honors Program Projects

No abstract provided.

Improvement Of Spent Fuel Storage With Advanced Mechanical Shielding Placement, Gordon M. Petersen, Nicole Galante, Hannah Hale, Dylan Richardson, Robert Vance

Chancellor’s Honors Program Projects

No abstract provided.

Cd Dipping To Reduce Reactivity Of Fuel Assemblies In Spent Fuel Pools, John Clark Stooksbury

Chancellor’s Honors Program Projects

No abstract provided.

Methods To Enhance Spent Fuel Pool And Dry Cask Storage, Dustin Giltnane, David Gotthold, Seth Langford, Michael Ratliff, Jessica Dawn Shewmaker, Cody Wiggins

Chancellor’s Honors Program Projects

No abstract provided.

The Effects Of Shielding On Non-Destructive Analysis (Nda) And The Use Of Small-Angle Compton Scattering To Overcome Those Effects, Cory Jake Hudson

Masters Theses

The use of passive Non-Destructive Analysis (NDA) equipment and techniques are very beneficial tools in the nuclear industry that have a plethora of applications and advantages over destructive or more invasive measurement methods. Of course, NDA techniques also have many limitations including dealing with many unknown parameters, overcoming the effects of gamma ray shielding, and the reliance on making many gross assumptions in the analysis of non-destructively acquired data. These limitations can lead to biased results or extremely difficult analysis which often introduces inaccurate conclusions and/or high levels of uncertainty.

This thesis paper will focus on specific NDA equipment and …

A Benchmark Comparison Of Epa Computer Models For Demonstrating Compliance To The Regulatory Effluent Dose Constraint At A Radioactive Waste Processing Facility, Debra Ann Mccroskey

Masters Theses

The U.S. Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC), or NRC agreement states, establish radiation dose limits to members of the public from airborne radionuclide emissions released from facilities licensed to use and/or handle radioactive material. These regulations specify that the licensee ensure that the individual member of the public likely to receive the highest dose shall not be expected to receive a total effective dose equivalent (EDE) in excess of 10 mrem (0.1 mSv) per year. Doses to members of the public from airborne effluents are evaluated using EPA-approved computer programs, such as COMPLY or CAP88. …

Low Pressure Chemical Vapor Deposition Of Semiconducting Boron Carbide Thin Films On Silicon, Thomas Gregory Wulz

Masters Theses

Boron carbide thin films were grown on the (100) plane of n-type silicon in a low pressure chemical vapor deposition (CVD) system from the thermal decomposition of boron trichloride and methane reactant gases with hydrogen as a carrier gas. Boron trichloride to methane molar ratio was 5, while the boron trichloride to hydrogen molar ratio was 3.5. Thin film deposition was carried out at 900 degrees Celsius at 25 Torr. The thin films were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDS), Laser Induced Breakdown Spectroscopy (LIBS), and current-voltage characteristics. The crystallography of …

Production Of Nuclear Debris Surrogates For Forensic Methods Development, Joshua James Molgaard

Masters Theses

A novel method for producing synthetic debris similar to the melt glass produced by nuclear surface testing is demonstrated. Melt glass from the first nuclear weapon test (commonly referred to as trinitite) is used as the benchmark for this study. These surrogates can be used to simulate a variety of scenarios and will serve as a tool for developing and validating forensic analysis methods.

The ultimate goal is to provide the nuclear forensics community with a robust method to supply realistic yet non-sensitive surrogate materials simulating a variety of detonation scenarios. This work will also allow for the development of …

Verification Of The Shift Monte Carlo Code Using The C5g7 And Casl Benchmark Problems, Nicholas Cameron Sly

Masters Theses

While Monte Carlo simulation has been recognized as a powerful numerical method for use in radiation transport, it has required a mixture of methods development and hardware advancement to meet these expectations in practical applications. In an effort to continue this advancement for uses of Monte Carlo simulation in ever larger capacities, Oak Ridge National Laboratory is developing the Shift hybrid deterministic/Monte Carlo code to be massively-parallel for use on parallel computing systems of all sizes. As part of this development, verification of the Monte Carlo parts of the code is needed to confirm that the current version of the …

Multidimensional Cfd Modeling Of A Liquid Salt Pebble Bed Heat Transfer Loop, Richard B. Cunningham

Masters Theses

The Pebble Bed Advanced High Temperature Reactor (PB-AHTR) is a next generation reactor design proposed by the University of California at Berkeley. Oak Ridge National Laboratory’s Liquid Salt Test Loop (LSTL) is designed to simulate AHTR operating conditions for component testing. In this study, COMSOL Multiphysics is used to model the LSTL. Full 3D modeling of the LSTL is computationally expensive. However, COMSOL allows users to combine 1D, 2D, and 3D fluid flow physics in order to design models that are both representative and efficient. 1D pipe flow calculations are used for the piping sections. COMSOL’s porous media module is …

A Nuclear Solution For The Energy Security Vulnerabilities Of The Department Of Defense: Using A Small Modular Reactor To Power Military Installations, Margaret Alva Kurtts

Masters Theses

Due to its reliance on the civil electrical grid, the Department of Defense has significant energy security vulnerabilities. DoD does not have energy production capabilities within its organization necessary to sustain the operations of a military installation. Its current installation energy strategy is a combination of energy reduction measures and renewable production efforts. Therefore, increased threats from cyber attacks combined with an aging electrical infrastructure threaten DoD’s energy supply to its installations. The electrical grid provides aggressors an opportune target for weakening military response capabilities in the event of a natural or man-made disaster. While DoD is successfully using energy …

Metal Chronometry For Pre-Detonation Nuclear Forensics Applications, Edward Thomas Peskie

Masters Theses

The ability to determine the time since forming of seized nuclear material would provide crucial data to be used in its investigation. This paper examines the time dependent processes of diffusion; to include grain boundary diffusion, and discontinuous precipitation, and assess the utility of examination of impurity and alloying element concentration profiles, for use as a pre-detonation nuclear forensics tool for determining the age of a metal sample. Several examples provided illustrate the effects of time on both binary alloys and multi-component systems. This study draws parallels from studies of diffusion in mineral samples under geologic time and proposes modifications …

Particle Image Velocimetry (Piv) For Positron Emission Particle Tracking (Pept) And Turbulence Modeling Validation, Sarah Ridley Rupert

Masters Theses

A Particle Image Velocimetry (PIV) experiment is designed and data collected with intention to validate Positron Emission Particle Tracking (PEPT) methods. The PIV data are collected in a narrow rectangular channel for flow Reynolds number near 20,000. The narrow channel and attendant pump, header tanks and flow instrumentation are portable and designed to allow identical tests in a Concord Microsystems MicroPET P4 pre-clinical PET scanner at the pre-clinical Imaging Suite at the UT Hospital. The PIV data are instantaneous velocity field data, allowing statistics on the flow turbulence to be collected in the Eulerian frame. The PEPT method measures activated …

Time Correlated Measurements Using Plastic Scintillators With Neutron-Photon Pulse Shape Discrimination, Norman Edison Richardson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the beginning of the nuclear age, there has been a strong demand for the development of efficient technologies for the detection of ionizing radiation. According to the United States' Department of Energy, the accurate assessment of fissile materials is essential in achieving the nonproliferation goals of enhancing safety and security of nuclear fuel cycle and nuclear energy facilities [1]. Nuclear materials can be characterized by the measurement of prompt and delayed neutrons and gamma rays emitted in spontaneous or induced fission reactions [2] and neutrons emitted in fission reactions are the distinctive signatures of nuclear materials. Today, the most …

Drift-Flux Correlation Development For Two-Phase Flow In Rod Bundles, Collin M. Clark

Open Access Theses

A rod bundle drift-flux correlation is developed with intended application across a wide range of two-phase flow conditions. Special consideration is made for fluid flow mechanisms at low liquid velocity and low pressure conditions. In these instances, gravitational forces from the density difference of the associated fluid phases are more significant. Secondary flow patterns may develop as a result and a drift-flux correlation would need to make appropriate adjustments. Earlier correlations may have increased error at these conditions if they have been formulated with respect to relatively higher pressures or flow rates. In the present work, area-average void fraction data …

Understanding The Global Energy Crisis, Eugene D. Coyle, Richard A. Simmons

Purdue University Press Books

We are facing a global energy crisis caused by world population growth, an escalating increase in demand, and continued dependence on fossil-based fuels for generation. It is widely accepted that increases in greenhouse gas concentration levels, if not reversed, will result in major changes to world climate with consequential effects on our society and economy. This is just the kind of intractable problem that Purdue University’s Global Policy Research Institute seeks to address in the Purdue Studies in Public Policy series by promoting the engagement between policy makers and experts in fields such as engineering and technology.

Major steps forward …

Characterization Of Two Ods Alloys: 18cr Ods And 9cr Ods, Julianne Goddard

Julianne Goddard

ODS alloys, or oxide dispersion strengthened alloys, are made from elemental or pre-alloyed metal powders mechanically alloyed with oxide powders in a high-energy attributor mill, and then consolidated by either hot isostatic pressing or hot extrusion causing the production of nanometer scale oxide and carbide particles within the alloy matrix; crystalline properties such as creep strength, ductility, corrosion resistance, tensile strength, swelling resistance, and resistance to embrittlement are all observed to be improved by the presence of nanoparticles in the matrix. The presented research uses various methods to observe and characterize the microstructural and microchemical properties of two experimental ODS …

Radium-228 As A Target For Production Of Thorium-229 In A Nuclear Reactor, Chelsea Burnham

Nuclear Engineering Reports

No abstract provided.

Hybrid Tio2 Solar Cells Produced From Aerosolized Nanoparticles Of Water-Soluble Polythiophene Electron Donor Layer, Marshall L. Sweet, Joshua G. Clarke, Dmitry Pestov, Gary C. Tepper, James T. Mcleskey Jr.

Mechanical and Nuclear Engineering Publications

Hybrid solar cells (HSCs) with water soluble polythiophene sodium poly[2-(3-thienyl)-ethyloxy-4-butylsulfonate] (PTEBS) thin films produced using electrospray deposition (ESD) were fabricated, tested, and modeled and compared to devices produced using conventional spin coating. A single device structure of FTO/TiO2/PTEBS/Au was used to study the effects of ESD of the PTEBS layer on device performance. ESD was found to increase the short circuit current density (J_sc) by a factor of 2 while decreasing the open circuit voltage (V_oc) by half compared to spin coated PTEBS films. Comparable efficiencies of 0.009% were achieved from both device construction types. Current-voltage …

Termodynamika Procesowa I Techniczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Tematyka Prac Dyplomowych Dla Studentów Wydziału Mechaniczno-Energetycznego Pwr., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Tematyka Prac Dyplomowych Dla Studentów Wydziału Chemicznego Pwr., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Mechanika Płynów Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Dynamic Testing Procedures For Performance Assessment Of Nuclear Fuel Rods, Travis M. Adams

Honors Theses and Capstones

Existing transportation probabilistic risk assessment for spent nuclear fuel in the United States is based on short-term (decades) on-site storage at power plants before transport. Updated risk assessment estimates will be required as extended on-site storage (centuries) and higher burnup levels in fuel become standard. Nuclear fuel rods under these two conditions are more brittle than rods from short-term storage and intermediate burnup due to several mechanisms, including hydrogen embrittlement. Development of risk assessment requires characterizations of dynamic behavior of these degraded rods under transportation scenarios. This Honors thesis provides an initial literature review for a larger project that will …

Development Of A Flat-Panel X-Ray Source, Edwin Joseph Grant

Doctoral Dissertations

"A novel flat-panel transmission type X-ray source was developed for both medical and industrial use. Depending on the geometry of the given situation, the flat-panel X-ray source could be used in tomography, radiography or tomosynthesis. Furthermore, the unit could be used as a portable X-ray scanner or an integral part of an existing detection system. The design incorporates a field emission cathode made of ultra-nanocrystalline diamonds (UNCD) doped with nitrogen. These field emitters show good electron output at low power and can be deposited over large areas as is the case with carbon nanotube "forest" (CNT) cathodes. This work presents …