Nuclear Engineering Commons^™

Experimental Investigation Of Steady-State And Transient Flow Boiling Critical Heat Flux, Soon Kyu Lee

Nuclear Engineering ETDs

The Critical Heat Flux (CHF) causes a rapid reduction of heat transfer coefficient with a rapid increase of cladding temperature, which may induce physical failure of the heated material. Understanding CHF phenomena and reliable prediction of the boiling behavior are needed to design a heat transfer system including nuclear reactors. Due to the complex nature of CHF, it is still an active research topic of interest. With an increasing interest in Accident Tolerant Fuel (ATF), CHF of ATF is essential topic of study for the detailed design of the fuel – cladding element and for the reactor safety analysis.

In …

The Blue Emission At 2.8 Ev In Strontium Titanate: Evidence For A Radiative Transition Of Self-Trapped Excitons From Unbound States, Miguel L. Crespillo, Joseph T. Graham, Fernando Agullo-Lopez, Y. Zhang, William J. Weber

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The origin of the blue emission in SrTiO₃ has been investigated as a function of irradiation fluence, electronic excitation density, and temperature using a range of ion energies and masses. The emission clearly does not show correlation with the concentration of vacancies generated by irradiation but is greatly enhanced under heavy-ion irradiation. The intensity ratio of the 2.8 and 2.5 eV bands is independent of fluence at all temperatures, but it increases with excitation rate. The 2.8 eV emission is proposed to correspond to a transition from conduction band states to the ground state level of the self-trapped exciton …

Implementation Of View Factor Model And Radiative Heat Transfer Model In Moose, Abdurrahman Ozturk

Theses and Dissertations

View factors are functions that represent the geometric relationship between surfaces. They are important parameters for radiative heat transfer calculations. View factor catalogues are available for simple geometries in the current literature. However, in the case of complicated geometry, analytical or numerical methods are needed to evaluate view factors. The Monte Carlo (MC) method is the most flexible one among numerical methods, which are used to calculate view factors, since it can be applied to any geometry.

When experimental studies are not affordable to conduct, modeling of engineering problems gains more importance. Idaho National Laboratory (INL)’s finite element framework Multiphysics …

Nuclear Engineering At The Air Force Institute Of Technology: A Unique Graduate School Experience For A Unique Set Of Students, Michael B. Shattan

Faculty Publications

In August 2018, the Air University Commander formed a task force to review the Air Force’s Science, Technology, Engineering, and Mathematics (STEM) graduate education programs that are delivered and administered through the Air Force Institute of Technology (AFIT). The study was rooted in strategies to support the 2018 National Defense Strategy, and provided the necessary technologically equipped personnel for the 21st century. The study was commonly referred to as “reimagining AFIT”. Several themes emerged from the study, which include reaching a broader community of Airmen through alternate educational modes (e.g. distance learning, short course etc.), forming strategic educational and research …

Low-Power Core Reconfiguration For Missouri S&T Reactor (Mstr), Thaqal Alhuzaymi, Ayodeji Babatunde Alajo

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The Missouri University of Sciences and Technology Reactor (MSTR) is pool-type research reactor which operates up to 200 kilowatt (kW). MSTR used for training and educating nuclear engineering students at Missouri S&T. A several of nuclear researches and irradiation experiments have been conducted in MSTR for example, neutron activation analysis (NAA), neutron radiography, radiolysis, image processing, etc. MSTR initial criticality took place on December 9, 1961. The first power level that MSTR operates at, was 10 kW. The power level alongside the core configuration was upgraded to the current ones, see Fig. 1. MSTR used light-water for moderation and natural …

Achieving High-Power Configuration In Missouri S&T Reactor (Mstr) For Potential Uprate, Thaqal Alhuzaymi, Ayodeji Babatunde Alajo

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Research reactor is a powerful tool because of its wide contribution, almost to each field of science. It’s considered to be an essential element for advancing research, development and improvement in nuclear industry. The main goal of research reactor is to produce neutrons which are beneficially used for a wide range of applications such as industrial, agricultural, medical, etc. Neutron spectrum impact it uses. Commonly, neutrons with low energy level, up to 0.5 eV, called thermal neutrons where neutrons with intermediate energy level, ranging from 0.5 eV to 0.10 MeV, called epithermal "resonance" neutrons and neutron with high energy level, …

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons

Mechanical Engineering

Lawrence Livermore National Laboratories (LLNL) has several steps in the production process for ceramic nanofiber tubes that they would like to improve - electrospinning, cutting, rolling, sealing and heat treating. We undertook the challenge to deliver LLNL with a semi-automated process that efficiently integrates the steps of cutting, rolling, and sealing to save time and improve control over end dimensions. In this document, we discuss the technical background of the manufacturing steps currently followed to create nanofiber tubes, identify which steps are incorporated in our prototype and explain how they will interface with one another, define the design requirements, present …

Neutronic And Cfd-Thermal Hydraulic Analyses Of Very-Small, Long-Life, Modular (Vsllim) Reactor, Luis M. Palomino

Nuclear Engineering ETDs

Neutronic and CFD-thermal hydraulic analyses are performed of the Very-Small, Long-LIfe, and Modular (VSLLIM) nuclear reactor. This reactor was developed at the University of New Mexico’s Institute for Space and Nuclear Power Studies (UNM-ISNPS) to generate 1.0 – 10 MW_th for extended periods without refueling. It offers passive operation and safety features and redundant control and would be fabricated, assembled and sealed in the factory. During nominal operation and after shutdown, the VSLLIM is cooled by natural circulation of in-vessel liquid sodium, with the aid of an in-vessel chimney and annular helically-coiled …

Calculation And Tabulation Of Efficiencies For Tungsten Foil Positron Moderators, R. Alsulami, M. Albarqi, S. Jaradat, Shoaib Usman, Joseph T. Graham

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Monte Carlo radiation transport simulations were used to calculate the positron stopping profiles in tungsten positron moderator foils. Stopping profiles were numerically integrated with efficiency kernels derived from Green's function solutions of the 3D diffusion equation to determine the moderation efficiency in both the backscattering and transmission geometries. Stopping profiles and efficiencies were calculated for positron energies from 10 keV to 10 MeV and incident angles from 0° to 75°. The resulting efficiencies agreed with other calculated and measured values in the literature, especially when similar values of the positron diffusion length and surface emission branching ratio were used. Large …

Numerical Study Of Spacer Grid Geometry In A 5 X 5 Nuclear Fuel Rod Bundle, Wan Chuan Fan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Reactor fuel rod bundles serve as the primary heat source in light water reactors (LWRs), commonly found in the aforementioned PWR plants. The fuel rod bundles’ structure consists of a collection of fuel rods put into a parallel grid configuration. The bundles also include fuel rod spacers, which hold the fuel rods in place, in accordance with the grid. Repeating structures of the fuel bundles create the meta-structure in the reactor. In other words, the grid configuration repeats until it fills the entire space of the reactor. This results in reactor fuel rods suspended in the working fluid domain, oriented …

Interrogation Of Spent Nuclear Fuel Casks Using Cosmic-Ray Muon Computed Tomography, Daniel C. Poulson

Nuclear Engineering ETDs

Properly accounting and safeguarding spent nuclear fuel are key components in the International Atomic Energy Agency’s mission of non-proliferation. Currently, no instruments are deployed that are able to verify the spent nuclear fuel contents of dry storage casks. Cosmic-ray muons provide an ideal probe for the heavily shielded casks due to their ability to penetrate thick, dense materials. Coulombic scattering of the muons, to first order, is proportional to the Z2/A of the material; this makes it especially sensitive to actinides, such as uranium and plutonium. The combination of these traits allows muons to be used to image and verify …

Modeling Complex Oxides: Thermochemical Behavior Of Nepheline-Forming Na-Al-Si-B-K-Li-Ca-Mg-Fe-O And Hollandite-Forming Ba-Cs-Ti-Cr-Al-Fe- Ga-O Systems, Stephen A. Utlak

Theses and Dissertations

High concentrations of Na2O and Al2O3 in the liquid high-level radioactive waste (HLW) stored at the Hanford Site can cause nepheline (NaAlSiO4) to precipitate in a vitrified monolithic waste form upon cooling. Nepheline phase formation removes glass- former SiO2 and -modifier Al2O3 from the immobilization matrix in greater proportion to alkalis, which can reduce glass durability and consequently increase the leach rate of radionuclides into the surrounding environment.

Current uncertainty in defining the HLW glass composition region prone to precipitating nepheline necessitates targeting a conservative waste loading, which raises operational costs by extending the liquid radioactive waste disposal mission and …

Modeling Complex Oxides: Thermochemical Behavior Of Nepheline-Forming Na-Al-Si-B-K-Li-Ca-Mg-Fe-O And Hollandite-Forming Ba-Cs-Ti-Cr-Al-Fe- Ga-O Systems, Stephen A. Utlak

Theses and Dissertations

High concentrations of Na2O and Al2O3 in the liquid high-level radioactive waste (HLW) stored at the Hanford Site can cause nepheline (NaAlSiO4) to precipitate in a vitrified monolithic waste form upon cooling. Nepheline phase formation removes glass- former SiO2 and -modifier Al2O3 from the immobilization matrix in greater proportion to alkalis, which can reduce glass durability and consequently increase the leach rate of radionuclides into the surrounding environment.

Current uncertainty in defining the HLW glass composition region prone to precipitating nepheline necessitates targeting a conservative waste loading, which raises operational costs by extending the liquid radioactive waste disposal mission and …

Investigation Of The Coupled Nuclear, Thermal-Hydraulic, And Thermomechanical Response Of A Natural Circulation Research Reactor Under Severe Reactivity-Initiated Accident Transients, Darren G. Talley

Mechanical Engineering ETDs

Research reactors play an important role in higher education, scientific research, and medical radioisotope production around the world. It is thus important to ensure the safety of facility workers and the public. This work presents a new reactor transient analysis code, referred to as Razorback, which computes the coupled reactor kinetics, fuel element heat transfer, fuel element thermal expansion and thermal stress, and thermal-hydraulic response of a natural circulation research reactor. The code was developed for the evaluation of large rapid reactivity addition in research reactors, with an initial focus on the Annular Core Research Reactor (ACRR) at Sandia National …

Developing A Simulation Tool For Evaluating In-Motion Detector Systems (La-Ur-18-29139), Brian Jennings

Nuclear Engineering ETDs

Available simulation software lacks the ability to produce in-motion detector responses for detector systems that may be used to detect the illicit trafficking of nuclear materials. In this thesis, a simulation tool is developed that uses static measured data as a basis set for producing in-motion detector responses with the ability to vary many parameters in each simulated trial. Once the basis set is measured and loaded into the simulation tool, the user interface allows the user to enter variations to speed, source height, source-to-detector distance, background exposure rate, which source(s) are present, their relative strength and shielding configuration, and …

Uranium Dioxide Actinide Detection Device Support Design For Space Applications, Jennifer N. Ramos

Theses and Dissertations

Attention concerning the proliferation of nuclear weapons and materials has generated many research initiatives to detect, identify, and locate radiation emitted by actinides. In support of this effort, the `Fission Induced Neutron Detection of Nuclear Materials' (FIND'NM) program was established to comprise a joint effort to explore this issue. The objective also co-extends the Air Force Research Laboratory uranium dioxide (UO2) detection sample growth, characterization, and electrical interface research. AFIT's study accomplishes the design and fabrication of a space-tolerant PCB to support a UO2-based neutron detector. Further design considerations are made with the expectation of the platform to be inside …

Development Of A Mixed-Radiation Directional Rotating Scatter Mask Detection System, Bryan V. Egner

Theses and Dissertations

Previous work demonstrated gamma-ray directional detection through the integration of a radiation detection system and an additively manufactured rotating scatter mask (RSM). This work advances the RSM directional detection system through improvements in the system's design, validation of a new scatter mask, and the novel ability to directionally detect both neutrons and gamma rays, a desirable feature for many nuclear safeguard and counterproliferation applications. The mixed-radiation RSM system developed for this research utilized the Spartan I mask design coupled with a 1" EJ-309 liquid scintillator. A GEome-try ANd Tracking (Geant4) model is developed and quantitatively compared to experimental measurements for …

Regulatory Design For Transport Security Regulations Of Nuclear And Other Radioactive Material, Marc R. Fialkoff

Purdue Workshop on Nonproliferation: Technology and Approaches

A cornerstone within a nuclear security regime of a country is a legislative and regulatory framework that both regulates the individuals using radioactive and nuclear materials, but also regulates the regulators for their commitments under International Law. When drafting nuclear law and regulations, both technical and legal expertise is needed to ensure the regulation meets the technical requirements for security, but also is legally enforceable within a country’s jurisdiction. While the Primary Nuclear Law, or Enabling Act provides establishes the Competent Authority and responsibilities for nuclear security, regulatory development is where the proverbial, rubber meets the road for requirements. The …

Analysis Of Proliferation Resistance Of Small Modular Reactors (Smr) For The Expansion Of Civilian Nuclear Power Systems, Abdus Sattar Mollah, Abdus Sattar Mollah Prof.

Purdue Workshop on Nonproliferation: Technology and Approaches

Analysis of Proliferation Resistance of Small Modular Reactors (SMR) for the Expansion of Civilian Nuclear Power Systems A. S. Mollah Department of Nuclear Science and Engineering Military Institute of Science and Technology Mirpur Cantonment, Dhaka-1216, Bangladesh Abstract Nuclear energy has the potential benefit to make an important contribution for mitigating greenhouse gas (GHG) emissions that cause climate change. Expanding nuclear energy capacity worldwide based on large centralized facilities poses many challenges and risks due to the large capital costs, important safety issues, obstructive public attitude, and persistent concerns about proliferation-that is, the intentional misuse of nuclear technology and material. SMRs, …

Initial Active Interrogation Experiments At The University Of Michigan Linear Accelerator Laboratory, Christopher Meert, Cameron A. Miller, Shaun D. Clarke, Sara A. Pozzi

Purdue Workshop on Nonproliferation: Technology and Approaches

To support the mission of the Countering Weapons of Mass Destruction Office of the Department of Homeland Security, the Detection for Nuclear Nonproliferation group is researching active interrogation techniques and the development of new detection algorithms for fast neutron spectroscopy. The Countering Weapons of Mass Destruction Officehas loaned us a Varian M9 linear accelerator (linac), helium-3 detectors, boron-coated straw detectors, and perfluorocarbondetectors as part of this research, providing a variety of tools to conduct our experiments.In the summer of 2018, a thorough licensing process concluded, and preliminary experiments commenced. Later in the year, the facility was approved to possess and …

The Effects Of The Urban Environment On Background Neutron Flux, Eric Reddick, John Burkhardt, Marshall Millett

Purdue Workshop on Nonproliferation: Technology and Approaches

This project will measure the neutron background inan urban environment using United States Naval Academy’s(USNAs)high sensitivity neutron detection system, called the Large Neutron Sensor (LNS).The background neutron flux represents noise and affects our ability to identify a signal from illicit source material, including plutonium.As the neutron background essentially rains down from high energy cosmic ray events in our upper atmosphere, the shielding effect of skyscrapers in an urban environment on the ground level background is of interest.Witha characterization of the neutron background in this environment, end users will be able to optimize the effectiveness of survey protocols and alarm algorithms.

A Characterization Of Undersea Neutron And Capture Gamma Signatures Resulting From Special Nuclear Material On A Maritime Vessel, Elizabeth Troy

Purdue Workshop on Nonproliferation: Technology and Approaches

Special Nuclear Materials (SNM) located aboard ships emit radiation that may be detectable in the undersea environment. An Unmanned Underwater Vehicle (UUV) could be equipped with detection capabilities to determine whether commercial or private vessels are carrying SNM prior to reaching port. Additional research is needed improve such a UUV’s ability to detect and discriminate between types of SNM and reduce false- positive detections. This research builds on past work by C. T. McKay to provide a higher fidelity characterization of detectable radiation signatures from SNM in the undersea environment with a focus on plutonium-bearing SNM. 252Cf will be used …

Overview Of The United States Withdrawal From The Intermediate-Range Nuclear Forces Treaty, William Steinberger

Purdue Workshop on Nonproliferation: Technology and Approaches

The Intermediate-Range Nuclear Forces (INF) Treaty symbolized the end of the Cold War and the likely termination of thistreaty marks the beginning of a new era. On February 1, 2019, Secretary of State Pompeo announced that the United States(U.S.) would withdrawal from the INF Treaty citing repeated violations by the Russian Federation as cause for withdrawal. Asearly as 2008, U.S. intelligence agencies reported missile testing by the Russian Federation of a cruise missile system that couldhave a range between the limits outlined by the INF Treaty. The Russian Federation has repeatedly denied the allegations andhas suggested that the U.S. is …

Purdue Conference On Active Nonproliferation, Daniel Hartman, Sean Alcorn, Tyler Naughton, Chris Duff, Gavin Webb

Purdue Workshop on Nonproliferation: Technology and Approaches

Conference for the discussion of nuclear nonproliferation

Exploring Laser Induced Breakdown Spectroscopy (Libs) For Post-Detonation Nuclear Forensics Debris Analysis, Justin Knoll, Chad Schools, David Fobar

Purdue Workshop on Nonproliferation: Technology and Approaches

In the unlikely but catastrophic event of a nuclear terrorist attack our government leadership will need reliable information to rapidly inform critical decisions. This research explores the use of Laser Induced Breakdown Spectroscopy (LIBS) as a potential analysis tool in the National Technical Nuclear Forensics process. The current state of post detonation nuclear forensics requires ground and air samples be collected and shipped to state-of-the-art laboratories for radiochemical analysis. The samples undergo many measurements and useable data is produced as these measurements are completed. This data flows back into the process to guide additional measurements and inform the process of …

Radiation Detection, Measurement, And Visualization Assisted By Virtual And Augmented Reality, Erik Medhurst, Rizwan Uddin

Purdue Workshop on Nonproliferation: Technology and Approaches

Localizing a radiation source in an urban environment is a challenge in nuclear nonproliferation and radiation detection. Mobile radiation sensor networks can be sent into an area of interest to collect count rate measurements at many locations in an attempt to find the radiation source. However, there are numerous factors that cause fluctuations in background count rate such as time and location, and these factors make it challengingto analyze thecollected data. Displaying these measurements in a virtual model has contextualized them and made it easier to determine if environmental factors are introducing false positives. A virtual model has been shown …

Purdue Conference On Active Nonproliferation, Angela Di Fulvio, Yoann Altma, Marc G. Paff, Al Hero, Sara A. Pozzi

Purdue Workshop on Nonproliferation: Technology and Approaches

One major problem with nuclear security measurements involves source identification inthe presence of low signal-to-background ratio. This scenario iscommon to several applications, ranging from radiation identification atportal monitors to radiation source search with unmanned vehicles. In this context of identification of a large variety of sources, including natural and medical sources, sensitive sources of particular interest, but also potentially new/unknown sources for which no reference measurement is available, statistical methods are particularly appealing for their ability to capture the random nature of the measurements. Among them, Bayesian methods form a generic framework allowing for uncertainty quantification and propagation, which is …

Purdue Conference On Active Nonproliferation, Trent Baker, Ray Benitez, Jack Mcmahan, Josh Monge, Kayla Robinson

Purdue Workshop on Nonproliferation: Technology and Approaches

Design a small modular reactor that is easily transportable for use in disaster relief as well as remote military outposts. A rail shippable reactor gives quick and easy transportation from one part of a country to another. The reactor must have a three MWe production capacity to ensure the reactor has the performance to power larger government facilities, such as hospitals and water treatment plants. The reactor must have enough fuel for a six-month minimum fuel cycle. Atmospheric cooling only provides the ability to reject heat to the atmosphere, minimizing the weight requirements. Uranium fuel will have a maximum of …

Nuclear Data Covariance Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments, Nicholas J. Quartemont

Theses and Dissertations

An energy tuning assembly was characterized to spectrally shape the National Ignition Facility neutron source to a notional thermonuclear and prompt fission neutron spectrum to approximate a boosted nuclear device. This research performed nuclear data covariance analysis to predict the performance of the energy tuning assembly to create the objective spectrum, assessed anticipated experimental outcomes, and determine the fission products produced in a highly enriched uranium foil in the sample cavity. Nuclear data covariance impacted the neutron fluence energy distribution by a few percent for a large energy range of the neutron fluence. Neutron flux unfolding techniques provided broad spectral …

Recent Advances On Carrier And Exciton Self-Trapping In Strontium Titanate: Understanding The Luminescence Emissions, Miguel L. Crespillo, Joseph T. Graham, Fernando Agullo-Lopez, Yanwen Zhang, William J. Weber

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

An up-to-date review on recent results for self-trapping of free electrons and holes, as well as excitons, in strontium titanate (STO), which gives rise to small polarons and self-trapped excitons (STEs) is presented. Special attention is paid to the role of carrier and exciton self-trapping on the luminescence emissions under a variety of excitation sources with special emphasis on experiments with laser pulses and energetic ion-beams. In spite of the extensive research effort, a definitive identification of such localized states, as well as a suitable understanding of their operative light emission mechanisms, has remained lacking or controversial. However, promising advances …