Nuclear Engineering Commons^™

An Assessment Of The Spatial Variation Of Isotopic Ratios In A Candu Reactor For Nuclear Treaty Monitoring, Aaron W. Burkhardt, James E. Bevins, Stephen H. Baxter

Faculty Publications

A 3-D Quarter-Core CANDU-6 is modeled using Serpent 2 for nuclear treaty monitoring. The spatial variation of flux spectra and isotopic concentrations is analyzed to determine the potential isotopic distribution of key radionuclides from standard reactor operations relevant to non-proliferation. The initial results of the model show a 46% difference in overall flux magnitude throughout the core as well as a 2-30% difference in discrete energy flux. The coupled production rate (magnitude) and spectral differences can contribute to significant spatial variations in isotope ratios throughout the core. Initial results indicate 239 Pu/ 240 Pu ratios vary by as much as …

Delayed Fast Neutron As An Indicator Of Burn-Up For Nuclear Fuel Elements, T. Akyurek, Shoaib Usman, S. B. Shoaib

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Feasibility study of burn-up analysis and monitoring using delayed fast neutrons was investigated at Missouri University of Science and Technology Reactor (MSTR). Burnt and fresh fuel elements were used to collect delayed fast neutron data for different power levels. Total reactivity varied depending on the burn-up rate of fuel elements for each core configuration. The regulating rod worth was 2.07E-04 Δk/k/in and 1.95E-04 Δk/k/in for T121 and T122 core configurations at 11 inch, respectively. Delayed fast neutron spectrum of F1 (burnt) and F16 (fresh) fuel elements were analyzed further, and a strong correlation was observed between delayed fast neutron emission …

Inverted Geometry Ceramic Insulators In High Voltage Dc Electron Guns For Accelerators, C. Hernandez-Garcia, G. Palacios-Serrano, P. Adderley, D. Bullard, J. Grames, Md. Abdullah Mamun, M. Poelker, M. Stutzman, R. Suleiman, Y. Wang, S.A.K. Wijethunga

Physics Faculty Publications

A direct current (dc) high voltage photo-emission electron gun operating at 130 kV is utilized at the Jefferson Lab (JLab) Continuous Electron Beam Accelerator Facility to generate spin-polarized electrons for nuclear physics experiments. Over the past decade, JLab has tested and implemented inverted-geometry ceramic insulators in photoguns, connecting the cathode electrode in vacuum to the high voltage power supply using commercial high voltage cables. The results of those tests showed that breakdown voltage was increased using triple-point shielding electrodes and bulk-doped insulators that allow charge drainage. This contribution describes ongoing work to develop a robust insulatorcable connector for reliably applying …

Impact Of Neutron Energy On Asteroid Deflection Performance, Lansing S. Horan Iv, Darren E. Holland, Megan Bruck Syal, James E. Bevins, Joseph W. Wasem

Faculty Publications

In the future, a hazardous asteroid will find itself on a collision course with Earth. For asteroids of moderate size or larger, a nuclear device is one of humanity's only technologies capable of mitigating this threat via deflection on a timescale of less than a decade. This work examined how the output neutron energy from a nuclear device standoff detonation affects the deflection of a notional asteroid that is 300 meters in diameter and composed of silicon dioxide at a bulk density of 1.855 g/cm³. 14.1 MeV and 1 MeV neutron energy sources were modeled in MCNP to …

Experimental Evaluation Of The Deadtime Phenomenon For Gm Detector: Deadtime Dependence On Operating Voltages, Bader Almutairi, Syed B. Alam, Tayfun Akyurek, Cameron S. Goodwin, Shoaib Usman

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A detailed analysis of Geiger Mueller counter deadtime dependence on operating voltage is presented in the manuscript using four pairs of radiation sources. Based on two-source method, detector deadtime is calculated for a wide range of operating voltages which revealed a peculiar relationship between the operating voltage and the detector deadtime. In the low voltage range, a distinct drop in deadtime was observed where deadtime reached a value as low as a few microseconds (22 µs for ²⁰⁴Tl, 26 µs for ¹³⁷Cs, 9 µs for ²²Na). This sharp drop in the deadtime is possibly due to reduced …

Corrigendum: “A Correlation For Interfacial Area Concentration In High Void Fraction Flows In Large Diameter Channels” ([Chem. Eng. Sci.131 (2015) 172–186] (2015) 131 (172–186), (S0009250915002547), (10.1016/J.Ces.2015.04.004)), Joshua P. Schlegel, T. Hibiki

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

There is a Typographical Mistake in Eq. (21), Used in the Derivation of the Final Model, Which Should Read [Fourmula Presented] This Typographical Mistake is Also Present in Eq. (22b), Which is Necessary for Implementation of the Final Model, Which Should Read

High Heat Flux Testing Facilities And An Electrothermal-Arc Plasma Source For Plasma-Material Interaction Studies And Diagnostic Development, Elizabeth G. Lindquist

Faculty Publications and Other Works -- Nuclear Engineering

Tokamak plasma-facing components experience significant stresses from plasma-material interactions (PMI) due to cyclic high thermal loads, plasma exposure, and neutron irradiation. As the field progresses to reactor-level power fluxes, the harsh fusion environment demands much of plasma-facing materials.

Chapter 1 introduces plasma-material interactions and the condition plasma-facing components are expected to endure. While plasma exposure and neutron radiation damage are introduced, the synergistic effects of cyclic high thermal loads under plasma exposure are focused on. This motivates the need for plasma-facing materials studies.

Chapter 2 gives a brief overview of many high heat flux test facilities worldwide. Three prominent high …

Applications Of Portable Libs For Actinide Analysis, Ashwin P. Rao, John D. Auxier Ii, Dung Vu, Michael B. Shattan

Faculty Publications

A portable LIBS device was used for rapid elemental impurity analysis of plutonium alloys. This device demonstrates the potential for fast, accurate in-situ chemical analysis and could significantly reduce the fabrication time of plutonium alloys.

A Physics-Based Machine Learning Study Of The Behavior Of Interstitial Helium In Single Crystal W–Mo Binary Alloys, Adib J. Samin

Faculty Publications

In this work, the behavior of dilute interstitial helium in W–Mo binary alloys was explored through the application of a first principles-informed neural network (NN) in order to study the early stages of helium-induced damage and inform the design of next generation materials for fusion reactors. The neural network (NN) was trained using a database of 120 density functional theory (DFT) calculations on the alloy. The DFT database of computed solution energies showed a linear dependence on the composition of the first nearest neighbor metallic shell. This NN was then employed in a kinetic Monte Carlo simulation, which took into …

Neutronic Investigation Of Alternative & Composite Burnable Poisons For The Soluble-Boron-Free And Long Life Civil Marine Small Modular Reactor Cores, Syed B. Alam, Bader Almutairi, Tuhfatur Ridwan, Dinesh Kumar, Cameron S. Goodwin, For Full List Of Authors, See Publisher's Website.

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Concerns about the effects of global warming provide a strong case to consider how best nuclear power could be applied to marine propulsion. Currently, there are persistent efforts worldwide to combat global warming, and that also includes the commercial freight shipping sector. In an effort to decarbonize the marine sector, there are growing interests in replacing the contemporary, traditional propulsion systems with nuclear propulsion systems. The latter system allows freight ships to have longer intervals before refueling; subsequently, lower fuel costs, and minimal carbon emissions. Nonetheless, nuclear propulsion systems have remained largely confined to military vessels. It is highly desirable …

Monte Carlo And Experimental Analysis Of A Novel Directional Rotating Scatter Mask Gamma Detection System, Julie V. Logan, Darren E. Holland, Larry W. Burggraf, Justin A. Clinton, Buckley E. O'Day Iii

Faculty Publications

Excerpt: This work demonstrates successful experimental operation of a prototype system to identify source direction which was modeled using a library of signals simulated using GEANT and a novel algorithm....

Possible Detection Of Low Energy Solar Neutrons Using Boron Based Materials, Nicole Benker, Elena Echeverria, Robert Olesen, Brant E. Kananen, John W. Mcclory, Yaroslav V. Burak, Volodymyr T. Adamiv, Ihor M. Teslyuk, George Glenn Peterson, Ben Bradley, Ethiyal R. Wilson, James C. Petrosky, Bin Dong, Jeffry Kelber, Jennifer Hamblin, Jaques Doumani, Peter A. Dowben, Alex Enders

Faculty Publications

Solar neutrons have been detected aboard the International Space Station (ISS), using lithium tetraborate and boron carbide detector elements. We find that evidence of a solar neutron flux, as detected in a neutron calorimeter following subtraction of the proton background, with an energy of about 2 to 4 MeV. This solar neutron flux is likely no more than 250 to 375 neutrons cm⁻²sec⁻¹, with a lower bound of 50–75 neutrons cm⁻²sec⁻¹ at one au.

Quantitative Analysis Of Cerium-Gallium Alloys Using A Hand-Held Laser Induced Breakdown Spectroscopy Device, Ashwin P. Rao, Matthew Cook, Howard L. Hall, Michael B. Shattan

Faculty Publications

A hand-held laser-induced breakdown spectroscopy device was used to acquire spectral emission data from laser-induced plasmas created on the surface of cerium-gallium alloy samples with Ga concentrations ranging from 0–3 weight percent. Ionic and neutral emission lines of the two constituent elements were then extracted and used to generate calibration curves relating the emission line intensity ratios to the gallium concentration of the alloy. The Ga I 287.4-nm emission line was determined to be superior for the purposes of Ga detection and concentration determination. A limit of detection below 0.25%was achieved using a multivariate regression model of the Ga I …

Methods Of Use And Manufacture Of Silver-Doped, Nano-Porous Hydroxyapatite, Cheol-Woon Kim, Richard K. Brow

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A silver-doped, nano-porous hydroxyapatite material is provided that can be utilized to capture radioactive iodine, ¹²⁹I. Methods of using the silver-doped, nano-porous hydroxyapatite material to remove radioactive iodine, and methods of manufacturing the material are also provided.

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 …

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, …

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 …

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 …

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 …

Experimental Investigation On Heat Transfer In A Prismatic Modular Reactor Under Cosine Heat Flux, S. M. Alshehri, I. A. Said, Muthanna H. Al-Dahhan, Shoaib Usman

Chemical and Biochemical Engineering Faculty Research & Creative Works

The current study has investigated natural convection heat during pressurized conduction cooldown (PCC) accident scenario to understand the passive safety features of prismatic modular reactors (PMR) under different intensities of nonuniform center peaking step heat flux distributions (approximating cosine shape) using an advanced fast-response heat transfer technique. A scaled-down PMR module was designed and developed at Missouri S&T by the research team of the Multiphase Reactors Engineering and Applications Laboratory (mReal). The module consists of upper and lower plena connected by heated and cooled channels. Nonuniform heat flux distribution was applied to the heated channel under nonuniform heating center peaking …

Evaluation Of Eu:Licaf For Neutron Detection Utilizing Sipms And Portable Electronics, Michael A. Ford, Buckley E. O'Day Iii, John W. Mcclory, Manish K. Sharma, Areg Danagoulian

Faculty Publications

With the increasing cost and decreasing availability of ³He, there have been many efforts to find alternative neutron detection materials. Lithium calcium aluminum fluoride (LiCAF) enriched to 95% ⁶Li doped with europium was evaluated here as a replacement material for ³He. Wafers 0.5 cm thick, consisting of LiCAF crystals in a rubberized matrix, were embedded with wavelength shifting fibers (WSF) and mated to silicon photo-multipliers (SiPMs) to measure the photon response in a flux of neutrons from a DD neutron generator. Excellent discrimination was realized between neutrons and gammas, and both pulse-height discrimination and pulse-shape analysis were …

Radiation Detector Deadtime And Pile Up: A Review Of The Status Of Science, Shoaib Usman, Amol Patil

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Since the early forties, researchers from around the world have been studying the phenomenon of deadtime in radiation detectors. Many have attempted to develop models to represent this phenomenon. Two highly idealized models; paralyzable and non-paralyzable are commonly used by most individuals involved in radiation measurements. Most put little thought about the operating conditions and applicability of these ideal models for their experimental conditions. So far, there is no general agreement on the applicability of any given model for a specific detector under specific operating conditions, let alone a universal model for all detectors and all operating conditions. Further the …

Direct Synthesis Of Radioactive Nanoparticles Involving Neutrons, Carlos Henry Castano Giraldo, Maria Camila Garcia Toro, Brian Michael Mills

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A method to synthesize radioactive nanoparticles includes the production of metallic and multimetallic nanoparticles in a single step by providing an aqueous solution of the metal precursor, and irradiating the aqueous solution thereby producing nanoparticles. The obtained nanoparticles include one or more radioactive isotopes of gold, such as 198Au and 199Au as well as radioisotopes of silver when the obtained nanoparticles are bimetallic. The aqueous solution is irradiated in a radiation field that includes neutrons and gamma rays. The radiation field may be provided by a nuclear reactor. The aqueous solution may include silver, and bimetallic nanoparticles may be produced. …

Pnnl Dark Matter Bubble Chamber, Ryan Robinson

STAR Program Research Presentations

The Pacific Northwest National Laboratory (PNNL) prototype bubble chamber is intended to address issues encountered with the current PICO dark matter search detectors and improve the functionality of future experimental designs. The PNNL bubble chamber accomplishes this with a simplified interface between the hydraulic pressure controls and the target vessel and altering the standard chamber design such that it can be easily exchanged and replaced with vessels of various sizes and materials for testing purposes. The chamber itself is a glass vessel which houses perfluorobutane and holds the target fluid above room temperature and atmospheric pressure. The target fluid becomes …

Actinium-225 Production Via Different Irradiation Beams Of Thorium-232, Naser Burahmah

Nuclear Engineering Reports

No abstract provided.

The Effects Of Frequent Atmospheric Events And Hydrologic Infrastructure On Flow Characterization In Tims Branch And Its Major Tributary, Sc, Mohammed Albassam

FIU Electronic Theses and Dissertations

Hydrological models are powerful tools used to predict water systems behavior such as flow and water level characteristics for rivers and streams. In this research, a fully dynamic 1-D model was developed using the MIKE 11 model for a specific stream called A-014, this stream is in the Savannah River Site (SRS), SC.

A field study was conducted in order to collect data needed as inputs for the model development. Data like water velocity and cross-section measurement played a major role in understanding the behavior of the A-014 and the validation of our model.

Results showed a correlation capable to …

The Rhetoric Of Science Education And Technology, Iwasan D. Kejawa

School of Computing: Faculty Publications

Nearly thousands of science experiments are performed both on humans and animals every year in the United States (Gregory, 1999). Does Science enormously play a role in the well-beings of individual in the society? Research has found that science education is through motivation and satisfying the needs of humans. The scientific world is part of an elongated human development. This can be substantiated with the use and evolution of TECHNOLOGY and SCIENCE (Minton, 2004). Education of the entities that comprise the need to achieve the goal of TECHNOLOGY and SCIENCE which are important issues of today. Research has shown that …

The U.S. Nuclear Waste Impasse: Transportation Implications, Robin M. Rotman, Michael F. Mcbride

Faculty Publications

For several years there has been an impasse, in the political branches, over how to make progress on dealing with the intractable problem of nuclear waste disposal in the United States. Currently, over 120 sites, spread across 39 states, host commercial spent fuel—many of these sites are former reactors that have become de facto interim nuclear waste storage sites, pending a permanent solution. Transportation considerations are central in this discussion. With the potential for Congress to make progress on this issue following the 2018 midterm elections, this article reviews the potential paths forward and considers possible implications for the transportation …

Sensitivity Analysis For Best-Estimate Thermal Models Of Vertical Dry Cask Storage Systems, Remy R. Devoe, Kevin R. Robb, Steven Skutnik

Faculty Publications and Other Works -- Nuclear Engineering

Loading requirements for dry cask storage of spent nuclear fuel are driven primarily by decay heat capacity limitations, which themselves are determined through recommended limits on peak cladding temperature within the cask. This study examines the relative sensitivity of peak material temperatures within the cask to parameters that influence both the stored fuel residual decay heat as well as heat removal mechanisms. These parameters include the detailed reactor operating history parameters (e.g., soluble boron concentrations and the presence of burnable poisons) as well as factors that influence heat removal, including non-dominant processes (such as conduction from the fuel basket to …

Electrical Characterization Of Irradiated Semiconducting Amorphous Hydrogenated Boron Carbide, George Glen Peterson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Semiconducting amorphous partially dehydrogenated boron carbide has been explored as a neutron voltaic for operation in radiation harsh environments, such as on deep space satellites/probes. A neutron voltaic device could also be used as a solid state neutron radiation detector to provide immediate alerts for radiation workers/students, as opposed to the passive dosimetry badges utilized today. Understanding how the irradiation environment effects the electrical properties of semiconducting amorphous partially dehydrogenated boron carbide is important to predicting the stability of these devices in operation. p-n heterojunction diodes were formed from the synthesis of semiconducting amorphous partially dehydrogenated boron carbide on silicon …