Nuclear Engineering Commons^™

Characterization Of The Acquisition Parameters Of A Submersible Gamma-Ray Computed Tomography System, Zhongmin Jin

Doctoral Dissertations

"The purpose of this work is to study a component of a submersible gamma-ray computed tomography (CT) system used in the non-destructive testing of irradiated nuclear fuels. The first section of this study proposes two acceleration approaches for rapidly modeling a transmission-type gamma-ray tomography system. The first relies on Monte Carlo simulations with a monodirectionally biased source sampled from a sub-volume of the whole source volume. This method estimates the real count rate using analytical correction factors. The second way of acceleration is based on deterministic calculations that use the Beer-Lambert law and detector response characteristics. It shows that both …

Integrated Study Of Heat Transfer And Local Gas Dynamics In A Pebble Bed Very High Temperature Nuclear Reactor Using Advance Measurement Techniques, Muhna N. Alshammari

Doctoral Dissertations

"The aim of this study, pebbles of diameter of 5 cm and a pebble-to-diameter ratio (aspect ratio) of 6 were used. In part I, the local gas velocities were studied at different radial and axial locations in the pebble bed using a sophisticated hot wire anemometry (HWA) technique, which was supported with a novel probe-protector case to protect the fragile probe, allowing the measurements to be taken between the pebbles for the first time. The local gas velocities were found to be significantly higher in the near wall region due to the higher void fractions in the near-wall region, compared …

Validation Of Athlet With Purdue University Multi-Dimensional Integral Test Assembly (Puma) Test, Emin Fatih Ozdem

Masters Theses

"Following the Three Mile Island Unit 2 (TMI-2) disaster, the development of a diagnostic system for emergency situations in a nuclear power plant was identified as an essential research area to strengthen the safety of nuclear power plants. A real-time estimation system of vital safety parameters on the main side of a PWR (Pressurized Water Reactor) facility was investigated since precise post-event scenario estimations are thought to be a crucial component of the diagnostic system. The alarm system of the plant can detect an SB-LOCA (Small Break Loss-Of-Coolant-Accident), but there were a couple of potential long-term transient occurrences. The accident …

Investigating Accident-Tolerant Cladding In A Molten Salt-Cooled Micro-Reactor Using Multi-Physics Analysis And Uncertainty Quantification, Alexander Niles Foutch

Masters Theses

"Renewed interest in nuclear safety has resulted in development of accident-tolerant materials, such as cladding. Although developed for light water reactors, their use in more advanced reactors would save time and development costs for other new materials. This paper performed a Multiphysics investigation into the power profile, thermodynamics, heat transfer, and tensor mechanics of four candidate materials (Haynes 230, Zircaloy-4, FeCrAl, and SiC-SiC), using the highly benchmarked Kilo power design as an example of a high-temperature, highly enriched, sodium-cooled microreactor environment.

From neutronic code MCNP, no significant difference in power profile was found among the four. Using finite element software …

Computational Fluid Dynamics Analysis Of Thermal-Hydraulic Phenomena In Nuclear Reactor Systems, Mehedi Hasan Tusar

Masters Theses

"A computational analysis of thermal-hydraulic processes in nuclear reactor systems is performed, leveraging Computational Fluid Dynamics (CFD) to advance the design and ensure the safety of nuclear reactors. Divided into two primary sections, the initial part examines thermal-hydraulic behavior in the Replacement Research Reactor (RRR) operating at 20 megawatts and evaluates potential enhancements for the Missouri University of Science and Technology Reactor (MSTR) to operate at an increased capacity of 2 megawatts from the existing 0.2 megawatts. Detailed simulations reveal insights into flow characteristics, temperature distributions, and pressure drops, highlighting the effective use of realistic and porous media modeling techniques …

Two-Group Drift-Flux Model For Dispersed Gas-Liquid Flow In Large-Diameter Pipes, Hossein Barati, Takashi Hibiki, Joshua P. Schlegel, Naofumi Tsukamoto

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Interfacial Heat and Mass Transfer Are Prevalent in Industrial Processes. the Interfacial Transfer Rate Can Be Obtained by the Product of their Fluxes and Interfacial Area Concentration (IAC) Calculated by the Interfacial Area Transport Equation (IATE). Bubbles Show Different Behavior According to their Sizes. Hence, Bubbles Are Classified into Two Groups. Consequently, Two-Group IATE is Required Causing to Use of Two Gas Momentum Equations Leading to More Complexity. the Present Study Suggests a New Reliable Two-Group Drift-Flux Modeling to Reduce the Two Gas Momentum Equations to One Gas Mixture Momentum Equation for Gas-Liquid Flow in Large-Diameter Pipes. the Model is …

Cement-Based Materials With Solid-Gel Phase Change Materials For Improving Energy Efficiency Of Building Envelope, Zhuo Liu, Jiang Du, Ryan Steere, Joshua P. Schlegel, Kamal Khayat, Weina Meng

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

This paper evaluated the cement-based materials incorporated with novel solid-gel phase change materials (PCMs) for improving the energy efficiency of building envelopes. This novel PCM is form-stable, which will not leak as solid-liquid PCMs do and not need encapsulation, and it features high energy-storage capacity. Experimental results showed that the thermal properties of cement-based materials were improved as the increase of PCM content. A 30% replacement of sand by volume with PCM can increase the latent heat of the mixture from around 0 to 7 J/g and decrease the thermal conductivity of PCM mortar based on the generalized self-consistent (GSC) …

3d Cfd Simulation Of A Bubble Column With Internals: Validation Of Interfacial Forces And Internal Effects For Local Gas Holdup Predictions, Hayder Al-Naseri, J. P. Schlegel, Muthanna H. Al-Dahhan

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

CFD models (turbulent models and interfacial forces) incorporated with the population balance model (PBM) have been validated, azimuthally, with the gamma-ray-computed tomography (CT) results to address the effect of the presence of internals with different arrangements and diameters. the superficial gas velocity applied was varied from 0.05 to 0.45 m/s. the results exhibit the capability to predict the hydrodynamics of the bubble column, further incorporating the population balance model and promoting the prediction of simulation in high superficial gas velocity. the effect of internals revealed that the gas holdup was significantly enhanced in the bubble column's wall region, while the …

Defect Generation Mechanisms In Silica Under Intense Electronic Excitation By Ion Beams Below 100 K: Interplay Between Radiative Emissions, M. L. Crespillo, Joseph T. Graham, W. J. Weber, F. Agulló-López

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Ion-beam effects on bulk silica at low temperature have been studied with the aim of understanding the routes and mechanisms leading from the initial generation of free carriers and self-trapped excitons (STEs) to the production of two stable defect structures in irradiated silica, non-bridging oxygen hole centers (NBOHCs) and oxygen deficient centers (ODCs). Ion beam induced luminescence (ionoluminescence, IL) spectra were obtained using 3 MeV H, 3.5 MeV He, 19 MeV Si, and 19 MeV Cl ions and a range of cryogenic irradiation temperatures from 30 to 100 K. The kinetic behavior of three emission bands centered at 1.9 eV …

Numerical Study Of Turbulent Flow And Heat Transfer In A Novel Design Of Serpentine Channel Coupled With D-Shaped Jaggedness Using Hybrid Nanofluid, Raditun E. Ratul, Farid Ahmed, Syed B. Alam, Md Rezwanul Karim, Arafat A. Bhuiyan

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

This Study Aimed to Examine Numerically the Effects of a Dimpled Surface over a Mini-Channel Heat Exchanger on the Flow Characteristics and Heat Transfer Across a Serpentine Channel with a Uniform Rectangular Cross-Section. the Dimples Were Arranged in Parallel with a Spanwise (Y/d) Distance of 3.125 and Streamwise (X/d) Distance of 11.25 Along Just One Side of the Serpentine Channel's Surface. Turbulent Flow Regime with Reynolds Number Ranging from 5 X 103 to 20 X 103 in the Channel with the Surface Modification Was Studied using Water and Various Volume Concentrations (Φ = 0.1%, 0.33%, 0.75%, 1%) of Al2O3-Cu/water Hybrid …

Studies On The Enrichment Feasibility Of Rare Earth-Bearing Minerals In Mine Tailings, Jose L. Corchado-Albelo, Lana Z. Alagha

Mining Engineering Faculty Research & Creative Works

This Study Aimed to Investigate the Potential of Enrichment of Rare-Earth-Bearing Minerals in Historic Mine Tailing using the Froth Flotation Process. Characterization Studies Indicated that Tailings Contained 11,000 Ppm of Rare Earth Elements (REEs). the Major Mineral in the Tailings Was Apatite at ~84%, Which Was Associated with Iron Oxides (~16%). TESCAN's Integrated Mineral Analysis (TIMA) Showed that Monazite Was the Main REE Mineral, and 69% of Monazite Was Locked in Apatite Grains. Characterization Studies Suggested that the Separation of REEs-Bearing Apatite from Iron Oxides is Possible using Froth Flotation, Wherein Apatite Was Floated and Iron Oxides Were Depressed. Zeta …

Thermal Analysis Of Si-Igbt Based Power Electronic Modules In 50kw Traction Inverter Application, Mohammad Shahjalal, Tamanna Shams, Sadat Bin Hossain, Md Rishad Ahmed, Mominul Ahsan, Julfikar Haider, Rajib Goswami, Syed B. Alam, Atif Iqbal

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Estimation of Accurate IGBT Junction Temperature is Crucial for Reliability Assessment. the Well-Known RC Lumped Approach Can Help Predict Junction Temperature. However, This Method Suffers from Inaccuracy While Characterizing the Thermal Behavior of Several IGBT Modules Mounted to the Liquid-Cooled Heatsink. Specifically, the Thermal Challenge Originates from the Thermal Cross-Coupling and Module-To-Module Heat Spreading and the Converter Cooling Condition. This Article Demonstrates a Methodology to Study the Impact of Heat Spreading, Thermal Interface Material, and Massive Size Liquid Cold-Plate on the overall Thermal Behavior. a Case Study of 50 KW Traction Inverter is Chosen to Demonstrate the Benefit of Early …

Cfd Analysis For Beyond Bubbly Gas-Liquid Two-Phase Flows In A Large Diameter Pipe, Sungje Hong

Doctoral Dissertations

"Due to the complexity of multiphase flow phenomena, numerical analysis for multiphase turbulent flow is not as reliable as single-phase computational fluid dynamics (CFD). A literature review has revealed that the current efforts on multiphase flow simulation have focused on small diameter channels under very restricted flow conditions and have been conducted without identifying some important procedures. To expand CFD applications to a wide range of two-phase flow conditions in large diameter channels, this study aims to validate the current CFD models for vertical concurrent air-water two-phase flow simulations beyond bubbly flows. First, a numerical model developed to describe dynamical …

3d Cfd Simulation Of A Bubble Column With Internals: Validation Of Interfacial Forces And Internal Effects For Local Gas Holdup Predictions, Hayder Al-Naseri, Joshua P. Schlegel, Muthanna H. Al-Dahhan

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

CFD Models (Turbulent Models and Interfacial Forces) Incorporated with the Population Balance Model (PBM) Have Been Validated, Azimuthally, with the Gamma-Ray-Computed Tomography (CT) Results to Address the Effect of the Presence of Internals with Different Arrangements and Diameters. the Superficial Gas Velocity Applied Was Varied from 0.05 to 0.45 M/s. the Results Exhibit the Capability to Predict the Hydrodynamics of the Bubble Column, Further Incorporating the Population Balance Model and Promoting the Prediction of Simulation in High Superficial Gas Velocity. the Effect of Internals Revealed that the Gas Holdup Was Significantly Enhanced in the Bubble Column's Wall Region, While the …

Small Modular Reactors, Joshua P. Schlegel, P. K. Bhowmik

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Small Modular Reactors (SMRs) have been a very promising development in nuclear power over the last two decades. SMRs are defined as nuclear reactors with a power output of less than 300MWe. This is in comparison to gigawatt-size reactors, which can have electrical output of 1000–1500MWe or more. This chapter will consist of two major sections. the first will be a detailed summary of the small modular reactor designs being proposed around the world. This section will focus on those that are the furthest along in their development but will also include some information about the wide variety of proposed …

Reinforcement Of The Plasmon–Phonon Coupling In Α-Quartz Via Deposition Of Gold Nanoparticles In Etched Ion Tracks, Maria C. Garcia Toro, Miguel L. Crespillo, Jose Olivares, Joseph T. Graham

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

This study reports a large reinforcement of the plasmon–phonon coupling in alpha quartz achieved through the controlled deposition of gold nanoparticles into nano templates produced through chemical etching of ion tracks. Preferential agglomeration of nanoparticles within the etched ion tracks (nano wells) was observed in Scanning Electron Microscopy and Atomic Force Microscopy images. Raman characterization of quartz substrates with different nanoparticle concentrations revealed a relationship between the plasmon–phonon coupling intensity and nanoparticle concentration. Reinforcement of the plasmon–phonon coupling was observed as an increase in the Raman intensity with increasing concentration of deposited nanoparticles. The intensity initially increased linearly with nanoparticle …

A Numerical Thermal Analysis Of A Battery Pack In An Electric Motorbike Application, Mohammad Shahjalal, Tamanna Shams, Sadat Bin Hossain, Probir Kumar Roy, Arafat Alam Jion, Mominul Ahsan, Jahedul Islam Chowdhury, Md Rishad Ahmed, Syed B. Alam, Julfikar Haider

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Today, electric driven motorbikes (e-motorbikes) are facing multiple safety, functionality and operating challenges, particularly in hot climatic conditions. One of them is the increasing demand for efficient battery cooling to avoid the potential thermal stability concerns due to extreme temperatures and the conventional plastic enclosure of the battery pack. A reliable and efficient thermal design can be formulated by accommodating the battery within an appropriate battery housing supported by a cooling configuration. The proposed design includes a battery pack housing made of high conductive materials, such as copper (Cu) and aluminum (Al), with an adequate liquid cooling system. This study …

Modeling The Reactor Time-Dependent Delayed Particle Tail With Monte Carlo N-Particle (Mcnp) Version 6.2, Eli James Boland

Masters Theses

"Energy is deposited into experiment packages due to post-shutdown decay heat created from delayed particles. Modeling these delayed particles in a reactor assists researchers in quantifying the expected energy deposition sources to an experiment package before irradiation. This paper focuses on modeling the delayed particles in a reactor in MCNP6.2 by capturing a reactor as a source, converting this source capture to a source definition, applying appropriate physics such as activation and photonuclear interactions, and finally using proper tallies to create the expected delayed particle tail of a reactor.

To capture the source distribution, the FMESH capability within MCNP was …

First-Principles Study Of The Thermal Properties Of Zr2c And Zr2co, Yue Zhou, William Fahrenholtz, Joseph T. Graham, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

First-principles calculations of lattice thermal conductivities and thermodynamic properties of Zr2C and Zr2CO were performed using the quasi-harmonic approximation. Oxygen in the lattice gives Zr2CO higher bonding strength than Zr2C. Thus, the mechanical properties of Zr2C are enhanced when the vacancies in its crystal structure are filled with oxygen. Among the critical parameters that determine the lattice thermal conductivity, Zr2C has significantly higher Grüneisen parameters, thus Zr2C has lower lattice thermal conductivity than Zr2CO. In addition, Zr2CO has a higher heat capacity and thermal expansion coefficient than Zr2C at most temperatures. These results indicate that the addition of oxygen has …

Light Emission Of Self-Trapped Excitons From Ion Tracks In Silica Glass: Interplay Between Auger Recombination, Exciton Formation, Thermal Dissociation, And Hopping, Joseph T. Graham, Miguel L. Crespillo, Fernando Agulló-López, William J. Weber

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The initial luminescence yield of amorphous silica under ion irradiation has been studied at temperatures between 30 and 100 K, using swift ions of different masses and energies (3 MeV H, 3.5 MeV He, 19 MeV Si and 19 MeV Cl). The intensity of the 2.1 eV emission band, ascribed to the intrinsic recombination of self-trapped excitons (STEs), has been found to vary systematically with ion mass, energy and irradiation temperature. A detailed model has been developed to quantitatively describe those variations in terms of the competition between non-radiative Auger recombination, STE formation, STE thermal dissociation, and subsequent STE hopping …

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 top …

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 …

Particle Swarm Optimization For Critical Experiment Design, Cole Michael Kostelac

Masters Theses

“Critical experiments are used by nuclear data evaluators and criticality safety engineers to validate nuclear data and computational methods. Many of these experiments are designed to maximize the sensitivity to a certain nuclide-reaction pair in an energy range of interest. Traditionally, a parameter sweep is conducted over a set of experimental variables to find a configuration that is critical and maximally sensitive. As additional variables are added, the total number of configurations increases exponentially and quickly becomes prohibitively computationally expensive to calculate, especially using Monte Carlo methods.

This work presents the development of a particle swarm optimization algorithm to design …

Feasibility Of A Critical Experiment Utilizing Uranium Dioxide-Beryllium Oxide With Neutron Spectrum Shifting Capabilities, Ashley Rachel Raster

Masters Theses

“The goal of this project is to determine the feasibility of utilizing Annular Core Research Reactor (ACRR) fuel in core design with Sandia Pulse Reactor Facility’s (SPRF) Seven Percent Critical Experiment (7uPCX) fuel rods as driver fuel for a critical experiment facility to support future critical and benchmark experiments for the International Criticality Safety Benchmark Evaluation Project (ICSBEP) handbook. This is part of the Critical Experiment Design (CED) process for future criticality experiments. These criticality experiment designs have the main goal of being performed in the same facility at different neutron energy ranges. To test the feasibility of this experiment …

Effects Of Vacancies And Electron Temperature On The Electron Phonon Coupling In Cubic Silicon Carbide And Their Connection To The Inelastic Thermal Spike, Salah Al-Smairat

Doctoral Dissertations

“The electron-phonon interaction is an important interaction in many solids as it influences transport phenomena and related quantities such as the electrical and thermal conductivities, especially in nuclear and space applications. The importance of the electron-phonon interaction in primary damage production in 3C-SiC is the subject of this research.

The electron-phonon coupling factor was calculated using a hybrid Density Functional Perturbation Theory - Classical Electron Gas model. The coupling factor was calculated as a function of electron temperature in pristine and defective 3C-SiC, and relaxed defective cells. The electron-phonon coupling is found to depend strongly on the electronic temperature and …

Using Computational Methods To Optimize High Heat Flux Component Thermal Performance In Magnetic Confinement Fusion Reactor Research, Monica Gehrig

Doctoral Dissertations

"Heat transfer enhancement by means of internally modified geometries in tubes and channels is an important mechanism to improve the survivability of components in extreme high-heat flux environments. Various features such as ribs and fins are studied using computational fluid dynamics in both uniform and one-sided heating in tubes and rectangular channels respectively to determine the most effective geometries across a variety of different flow and heating conditions. This work examines heat transfer enhancement and rib geometry optimization to support experimental research for nuclear fusion applications. The project begins by designing and analyzing test sections supporting a helium flow loop …

Sensitivity Of The Two-Fluid Model To Constitutive Correlations For Large Diameter Pipes, Alexander Lee Swearingen

Doctoral Dissertations

"Multiphase flows are a significant factor in nuclear reactor operations. In order to understand this behavior in reactor systems, system analysis codes are used to simulate reactor conditions. Due to the nature of the nuclear industry, simulations predicting the void development in the core are required to be highly accurate. This work evaluated the sensitivity of the void fraction and interfacial area concentration predictions to changes in correlations used to calculate three parameters that are used to complete the interfacial drag calculation. The three parameters evaluated were drift-flux, void fraction covariance, and interfacial area concentration. The change in drift-flux correlation …

Characterization Of Cermet Fuel For Nuclear Thermal Propulsion (Ntp), James Floyd Mudd

Masters Theses

“A manned flight to Mars is met with many technical challenges, not the least of which is the development of propulsion technology capable of moving a transit vehicle from Earth orbit to Mars orbit. NASA is investigating Nuclear Thermal Propulsion (NTP) as a way of reducing flight time and providing the option for a mid-mission abort. NTP, which uses a high temperature nuclear reactor to heat a propellant, requires advanced fuel materials capable of withstanding temperatures well in excess of 2000 K. Among the fuel options are ceramic metal (cermet) composites composed of refractory metals and Ultra-High Temperature Ceramics (UHTCs). …

Validation Of Athlet-Cd With Cora-28 Test, Murat Tuter

Masters Theses

“Following the incidents at Chernobyl and Fukushima, severe accidents at nuclear power plants (NPP) have become a global concern. These accidents generally occur because of a failure in the reactor cooling system (RCS) and result in the melting of the reactor core and fission product release. This event is mostly caused by a LOCA, loss of flow accident, station blackout or loss of heat sink. During a severe accident, generation of hydrogen as a result of steam-zircaloy fuel cladding is a significant safety concern. To better understand and prevent the hydrogen generation issue, safety related experiments and safety related codes …

A New Dead-Time Determination Method For Gamma-Ray Detectors Using Attenuation Law, T. Akyurek

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

This study presents a new dead-time measurement method using the gamma attenuation law and generalized dead-time models for nuclear gamma-ray detectors. The dead-time of the NaI(Tl) detection system was obtained to validate the new dead-time determination method using very thin lead and polyethylene absorbers. Non-paralyzing dead-time was found to be 8.39 μs, and paralyzing dead-time was found to be 8.35 μs using lead absorber for NaI(Tl) scintillator detection system. These dead-time values are consistent with the previously reported dead-time values for scintillator detection systems. The gamma build-up factor's contribution to the dead-time was neglected because a very thin material was …