Nuclear Engineering Commons^™

Radiolabeled Nanohydroxyapatite As A Platform For The Development Of New Pet Imaging Agents, Stacy Lee Queern

Arts & Sciences Electronic Theses and Dissertations

Positron emission tomography (PET) imaging utilizes drugs labeled with positron emitters to target and evaluate different biological processes occurring in the body. Tailoring medicine to the individual allows for higher quality of care with better diagnosis and treatment and is a key purpose for advancing research into developing new platforms for PET imaging agents. A PET nuclide of high interest for the development of these agents is 89Zr. This can be attributed to the long half-life of 3.27 days and low positron energy of 89Zr.

In this work, we developed a production method for 89Zr using Y sputtered coins that …

Development Of The University Of New Mexico Spectrometer For High-Resolution Fission Product Yield Data, Richard Emery Blakeley

Nuclear Engineering ETDs

Well-defined fission product yield data has been of increasing interest in various applications within the nuclear industry. With this need in mind, a fission fragment mass spectroscopy system was designed and developed at the University of New Mexico in collaboration with the Los Alamos National Laboratories with a stated goal of attaining a mass resolution of ≤ 1 % (FWHM/centroid) for light fragments and near 1 % for heavy fragments. The mass spectrometer utilized in this work consists of a transmission time-of-flight detection system to measure fission product velocity and an axial ionization chamber to measure the fission product energy, …

Corrosion Dynamics Of Carbon Steel In Used Fuel Container Environments, Dan Guo

Electronic Thesis and Dissertation Repository

The current Canadian used nuclear fuel container (UFC) design uses a pressure‑grade carbon steel (CS) vessel with its outer surface coated with a thin layer of copper. One concern regarding the structural integrity of the UFC design is the potential internal corrosion of the CS vessel. Moisture trapped inside a UFC could condense within the gap between the hemispherical head and the cylindrical body of the vessel. The internal UFC environment will be exposed to a continuous flux of ionizing radiation arising from the decay of radionuclides trapped in the used UO₂ fuel matrix.

This thesis research project investigates …

Investigating The Electrodeposition Of Plutonium And Curium For Safeguarding The Electrorefiner, Chantell L. Murphy

Nuclear Engineering ETDs

This research investigated the electrochemical deposition behavior of plutonium (Pu) and curium (Cm) for safeguarding the electrorefiner (ER) in a pyroprocessing facility. The main goal of this investigation was to evaluate the feasibility of using a safeguards concept called the neutron balance method to account for Pu in the ER. The neutron balance method relies on a known Pu/Cm ratio and measures neutrons from Cm-244 coming into and leaving a unit operation to track Pu. The application of the neutron balance approach for pyroprocessing facilities requires that Pu and Cm remain together in all extraction, product recovery, and waste streams. …

Exploration Of Radiation Damage Mechanism In Mems Devices., Pranoy Deb Shuvra

Electronic Theses and Dissertations

We explored UV, X-ray and proton radiation damage mechanisms in MEMS resonators. T-shaped MEMS resonators of different dimensions were used to investigate the effect of radiation. Radiation damage is observed in the form of resistance and resonance frequency shift of the device. The resistance change indicates a change in free carrier concentration and mobility, while the resonance frequency change indicates a change in mass and/or elastic constant. For 255nm UV radiation, we observed a persistent photoconductivity that lasts for about 60 hours after radiation is turned off. The resonance frequency also decreases 40-90 ppm during irradiation and slowly recovers at …

Investigation Of The Formation Of Γꞌꞌ Precipitates Under Ion Irradiation And Elevated Temperature Environments, James R. Pike

Nuclear Engineering ETDs

During a preventative maintenance at the Los Alamos Neutron Science Center (LANSCE) Isotope Production Facility (IPF), a beam window made of solution annealed Alloy 718 was replaced and the old beam window was analyzed. The old beam window underwent mechanical testing and microstructure analysis. During the microstructure analysis, the formation of γꞌꞌ precipitates was observed in Transmission Electron Microscopy (TEM) electron diffraction pattern. The formation of γꞌꞌ precipitates was not expected since they are not stable under irradiation. Furthermore, the formation of γꞌꞌ precipitates was observed only at a temperature of 33ºC, and a dose of 0.7 displacement per atom …

Radiation Effects In Metal Oxides And Carbides, Benjamin Jackson Cowen

Nuclear Engineering ETDs

MD simulations of SiO₂, TiO₂, Cr₂O₃, Al₂O₃, MgO, and SiC, are performed to: (a) calculate TDE probability distributions and dependence on crystallographic direction, and (b) determine the number and types of defects formed with low- and high-energy PKAs and projectiles. In addition, a qualitative comparison of the MD simulation results of radiation damage in TiO₂, MgO, and crystalline and amorphous SiC thin films are compared with those of in situ TEM ion beam irradiation experiments at the Sandia National Laboratories’ I³TEM facility.

The TDE …

Neutron Spectroscopy Using Rubberized Eu:Licaf Wafers, Michael A. Ford

Theses and Dissertations

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, based on the absorption of thermalized neutrons by the ⁶Li and subsequent energy release of the ⁶Li(n,t)⁴He reaction. 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 …

Spin Alignment Generated In Inelastic Nuclear Reactions, Daniel Hoff

Arts & Sciences Electronic Theses and Dissertations

The spin alignment of inelastically excited 7Li projectiles, when the target remains in its ground state, was determined through angular-correlation measurements between the breakup fragments of 7Li_ (_ + t). It was found that 7Li_ is largely aligned along the beam axis (longitudinal) in this type of inelastic reaction, regardless of the target. This longitudinal alignment is well described by DWBA calculations, which can be explained by an angular-momentum-excitation-energy mismatch condition. These calculations also explain the longitudinal spin alignment of excited nuclei in several other systems, showing the phenomenon is more general. The experiment involving 7Li was performed at the …

Sonomechanical Enhanced Sparging Techniques For Advanced Reactor Applications, Floren V. Rubio

Nuclear Engineering ETDs

The fluoride salt cooled high temperature reactor (FHR) is a Generation IV advanced reactor design that has potential to produce efficient, low carbon, and safe energy. But, there are significant engineering challenges that need to be addressed before the deployment of this reactor. One of the key challenges is tritium release mitigation and sequestration. Because the FHR utilizes a eutectic LiF-BeF2 (flibe) salt as a coolant, the coolant is a significant source of tritium.

High-power ultrasonics have been used in many industrial process streams such as food processing, metal production, chemical production, and pharmaceutical manufacturing. Techniques and concepts from these …

Radiation Effects In Apatite And High Entropy Alloy Under Energetic Ions And Electrons, Jianren Zhou

LSU Doctoral Dissertations

Radiation effects in apatite and high entropy alloy under energetic ions and electrons are studied in this doctoral dissertation to develop advanced crystalline ceramic waste forms and nuclear structural materials. Apatite is proposed as a ceramic waste form for the immobilization of radionuclides, but its performance is strongly affected by the irradiation of the incorporated radionuclides. It is thus important to understand the radiation effects in apatite structure and the underlying physics. Effects of chemical composition, grain size, interfacial structure, as well as radiation conditions on the microstructural evolution, phase transformation and damage mechanisms of apatite under alpha-decay and beta-decay …

Detector Arrays For Nuclear Security And Safeguards Applications, Jessica Hartman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Over the last two decades it has become increasingly apparent that there is a need for new technologies capable of reliable and efficient fast neutron detection. As national and international stockpiles of 3He continue to dwindle, the need to find a new gold standard of neutron detection becomes more critical. Moreover, neutrons are generated typically in the MeV energy range. The use of 3He detectors for fast neutron measurements requires the use of moderators. Detector arrays capable of fast neutron detection are one solution to this problem. To this end, the focus of this work was the study of detector …

Analysis Of Double-Wall And Twisted-Tube Heat Exchanger Concepts For Use In Fluoride Salt-Cooled High-Temperature Reactors, Bryan M. Wallace

Nuclear Engineering ETDs

Fluoride Salt-cooled High-temperature Reactors (FHRs) are an attractive fourth generation reactor concept. Like other fourth generation concept designs, FHRs offer characteristics such as a high-temperature low-pressure molten salt coolant allowing the reactor to be combined with a high-temperature high-efficiency power generation cycle such as an air-Brayton or supercritical carbon dioxide (SCO2). \par

Like most Gen IV reactor concepts, there are a few problems which need to be addressed with the design before it can be licensed. One particular design is the Mark 1 pebble bed FHR, a design put out by the University of California Berkeley. Two problems that need …

Scintillator-Based Uav, Austin Mullen, Chris Haseler, Sarah Davis, Brooke Mcmurrer, Tanner Jefferies, Peyton Lara

Chancellor’s Honors Program Projects

No abstract provided.

Design And Characterization Of Systems For Direct Spatial Imaging Of Low-Energy Gamma-Radiation Sources, Phoenix Baldez

Nuclear Engineering ETDs

This work describes the development of radiation detection systems to identify and image special nuclear material (SNM) using low energy gamma rays. The imaging of these materials is crucial for timely, in the field responses to potential threats to national security. Using a spectroscopy system, the sources can be identified while images can be produced concurrently for the sources which are present. Two systems were designed and characterized in this study, a collimated imager which used collimation in front of a small CdTe detector, and a pixelated pinhole imager, using a pinhole mask in front of a pixelated CZT detector. …

An Exploration Of The Optical Detection Of Ionizing Radiation Utilizing Modern Optics Technology, Sean D. Fournier, Adam Hecht, Cassiano De Oliveira, Jeffrey B. Martin, Richard K. Harrison, Charles Potter

Nuclear Engineering ETDs

Modern ultraviolet (UV) cameras, when combined with UV-transmitting lenses/filter arrangements, can be used to detect radiation dose in air. Ionizing radiation excites nitrogen molecules in ambient air, the resulting decay includes weak emission of ultraviolet photons. Previous work has proven this phenomenon is detectable using highly-sensitive electronically cooled cameras traditionally used in astronomy for low-background imaging. While the ability to detect the presence of radiation (i.e. qualitative measurement) has been demonstrated at Sandia National Laboratories, there are several challenges in correlating images to known dose-fields (quantitative measurement). These challenges include: a low signal to background ratio, interferences due to electronic …

Patient Specific Radiation Doses From Projection Radiography Images: Improving The Accuracy Of Low Dose Radiation Calculations, Daniel J. Sandoval

Nuclear Engineering ETDs

Due to an increase in regulatory scrutiny and medical facility accreditation requirements to monitor patient radiation dose from diagnostic imaging procedures, there is a growing necessity to determine and record accurate patient radiation dose from diagnostic medical imaging procedures. Current methods of patient dosimetry in diagnostic imaging are both extremely difficult and time consuming, require large computing resources (such as Monte Carlo computations), or lack accuracy due to using data based on homogeneous materials and “standard-man sized” anthropomorphic models.

This dissertation provides an algorithm that calculates a more accurate dose using patient-specific projection radiographic images. The algorithm includes measurements acquired …

Case Study On The Development Of Engineering Design Modification Projects For U.S. Nuclear Power Plants: A Knowledge Retention Tool In Support Of The Longevity And Resilience Of The Nuclear Power Industry, Pamela M. Torres-Jiménez

Engineering Management & Systems Engineering Theses & Dissertations

The nuclear power industry in the United States (U.S.) has gone through various changes throughout its history. Most recently, plans to grow the industry through the construction of new power plants have ceased. Because of this, the industry is at a period where the longevity and resilience of existing nuclear power plants are vital to its subsistence.

One of the ways existing nuclear power plants can assure longevity and resilience is by performing engineering design modifications efficiently and at a lower cost. Strategic plans, such as the Delivering the Nuclear Promise, can support nuclear utilities to achieve this. Another strategy …

Development Of A Novel Framework For The Application Of Signature Based Safeguards (Sbs) To Pyroprocessing, Philip Leo Lafreniere

Nuclear Engineering ETDs

Traditional nuclear material accountancy (NMA) faces several challenges when applied to pyroprocessing facilities. To address these challenges, alternative methods of safeguarding nuclear material are being developed. One method is process monitoring (PM). PM involves taking operational process data and applying it to safeguards using an advanced framework. Signature Based Safeguards (SBS), a proposed PM framework, involves the identification of anomalous scenarios and the subsequent identification and detection of their respective PM signatures from a system of measurements. SBS has previously focused on failure modes that result in transfer of mass to unexpected places in the mass flowsheet. This work developed …

A Cfd Assisted Closed-Loop Control System Design For The 37-Element Canadian Scwr Under Full Load Condition, Huirui Han

Electronic Thesis and Dissertation Repository

A method to design the closed-loop control system for the 37-element vertical Canadian supercritical water-cooled reactor (SCWR) fuel bundle has been proposed in this study. The dynamic models used in the controller design are obtained based on the computational fluid dynamics (CFD) simulations of the fluid flow and heat transfer of the supercritical water in the SCWR fuel bundle. The Reynolds Stress Model is used in the CFD simulations. Comparisons of the supercritical water flow behaviors and heat transfer phenomenon in the single- rod channel and multi-rod channel are also carried out. The results show that there are secondary flows …

Innovative Fuel Design To Improve Proliferation Management, Taylor C. Britt

Theses and Dissertations

This research uses an existing innovative fuel design (IFD) that has intrinsic safety features and enhanced economics over the current uranium dioxide (UO₂) light water fuel design and evaluates promising methods to improve the waste management and proliferation resistance of the IFD by doping the fresh fuel with select actinides.The most robust approach for proliferation resistance is to denature these materials by adding a uranium or plutonium isotope that hampers the usability of the materials in weapons. The proposed modifications to the IFD use this approach through elevated fractions of ²³⁸Pu. ²³⁸Pu generates large quantities of …

Computational Design And Numerical Analyses Of Thermal-Hydraulics In A Pwr-Type Small Modular Nuclear Reactor, Vivek Murlidhar Rao

Doctoral Dissertations

"This dissertation focuses on computational design of a PWR-type small modular nuclear reactor (SMR), and analysis of coolant thermal-hydraulics during steady-state operation. Physical design of the SMR is based on the existing AP-1000 and Small Modular Reactor designs by Westinghouse Nuclear.

The first paper discusses a two-stage simulation of turbulent flow in the lower plenum of the RPV. In the first stage, four time-dependent Reynolds-Averaged Navier-Stokes (RANS) based turbulence models were used to simulate turbulent flow, compare predictions and identify an appropriate turbulence model. In the second stage, the selected turbulence model was once again used to simulate flow on …

Modulated Photothermal Radiometry: Detector Sensitivity Study And Experimental Setup, Jessica Nicole Seals

Masters Theses

"This thesis outlines the development of a system used for determining the surface thermal diffusivity of both non-irradiated and irradiated materials. The motivation for this work is to establish a modulated photothermal radiometry (PTR) system on the campus of Missouri University of Science and Technology. One of the main efforts described in this thesis is the design and construction of the physical apparatus. Along the way, it was necessary to perform a detailed sensitivity analysis of the system to determine whether the expected signal emitted from the sample falls within the bounds of detectivity for the HgCdTe (MCT) detector used …

Customized Multi-Group Cross Section Generation With Njoy For Discrete Ordinates Computed Tomography And Radiography Simulation, Steven Michael Wagstaff

Masters Theses

"The purpose of this work was to explore the creation of photoatomic multi-group cross section libraries to be used with a software package DOCTORS (Discrete Ordinates Computed TOmography and Radiography Simulator). This software solves the linear Boltzmann equation using the discrete ordinates method [1]. To create these libraries, NJOY2016 was used, creating both fine and broad energy multi-group cross section files. The cross section's accuracy was tested against an equivalent Monte Carlo simulation using MCNP6.

Two simulation geometries were used. The first, a cylindrical water phantom with a single source projection placed in front, simulating an X-ray radiography. The second …

An Investigation Into The Effects Of Ion Tracks On Α-Quartz, Bryant Alan Kanies

Masters Theses

"The passage of a swift heavy ion through a material can cause columnar, amorphous nano-structures known as ion tracks. Swift heavy ions are present in a number of applications ranging from nuclear reactors to nuclear waste storage and onboard spacecraft. The study of ion tracks has been ongoing since the late 1950s and has led to several technological advancements. In fact, ion beams have been used to enhance material properties and aid in the production of electrical components. Ion beams, and their resultant ion tracks, can therefore be seen as a method to purposefully alter material properties such as thermal …

Development And Monte Carlo Validation Of A Finite Element Reactor Analysis Framework, Wayne J. Brewster

Masters Theses

"This study presents the development and Monte Carlo validation of a continuous Galerkin finite element reactor analysis framework. In its current state, the framework acts as an interface between the mesh preparation software GMSH and the sparse linear solvers in MATLAB, for the discretization and approximation of 1-D, 2-D, and 3-D linear partial differential equations. Validity of the framework is assessed from the following two benchmarking activities: the 2-D IAEA PWR benchmark; and the 2-D Missouri Science and Technology Reactor benchmark proposed within this study. The 2-D IAEA PWR multi-group diffusion benchmark is conducted with the following discretization schemes: linear, …

Investigation Of The Hydrodynamics And Scale-Up Of Advanced Triso Nuclear Fuel Manufacturing Using Sophisticated Measurement Techniques, Thaar M. Aljuwaya

Doctoral Dissertations

"The successful performance and safety of the Very-High-Temperature Nuclear Reactors (VHTR) extremely depend on the quality of the TRISO nuclear fuel coated particles. However, the coating of the TRISO particles is delicate process and impacted by the hydrodynamics of spouted beds. Therefore, in this work, we applied advanced non-invasive measurement techniques which are gamma-ray computed tomography (CT) and radioactive particle tracking (RPT), to investigate foremost the local parameters to advance the fundamental understanding of the hydrodynamics and scale-up of gas-solid spouted beds. The CT technique has been applied to study the effects of particle density, particle size, bed size, and …

Advancement In Thermal Energy Storage Using Phase Change Materials, Rami Mohammad Reda Saeed

Doctoral Dissertations

"The dissertation is intended to study the fundamental physical behavior of phase change materials (PCMs) and provide a comprehensive overview of the state of the art in their design and applications for thermal energy storage. Standard, predictive and thermodynamic models were presented to develop new PCM eutectic mixtures in a more scientific design approach. As new eutectic PCMs were developed, further research efforts were initiated to develop functionalized PCMs with enhanced thermal and physical properties to create the next generation of PCMs. Further efforts have been expanded to review several high-temperature PCM candidates with phase transition temperatures in the range …

Synthesis Of High Efficiency Amidoxime Polymer Adsorbents For Uranium Extraction From Seawater By Radiation-Induced Polymerization, Wijittra Wongjaikham

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study synthesized amidoxime polymer gel for uranium extraction from seawater through a polymerization process with gamma ray or UV-C radiation. The synthesis started with a mixture of acrylonitrile (AN) and methacrylic acid (MAA) monomers together with methylene bisacrylamide as a crosslinker and hydrogen peroxide in the case of UV radiation. The mixture was irradiated with gamma ray at various doses or UV-C for various durations. The resulting polymer gel was ground into fine particles and immersed in a hydroxylamine hydrochloride solution for 90 minutes in order to convert the chemical functional group from the cyano group into the amidoxime …

การพัฒนาเทคนิคเอกซเรย์คอมพิวเตดโทโมกราฟีโดยการบันทึกภาพบนฉากเรืองรังสีด้วยกล้องดิจิตอล, พณพณ สาวิโรจน์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีจุดประสงค์ในการพัฒนาระบบถ่ายภาพด้วยรังสีเอกซ์โดยใช้ฉากเรืองรังสีและพัฒนาเทคนิคการสร้างภาพโทโมกราฟีของชิ้นงาน ระบบบันทึกภาพประกอบด้วยฉากเรืองรังสี กล้องถ่ายภาพดิจิตอล และแท่นวางชิ้นงานที่หมุนได้ การหมุนของแท่นวางชิ้นงานถูกควบคุมโดยสเตปปิงมอเตอร์และซอฟต์แวร์ที่เขียนด้วย Visual basic 6.0 ในขณะที่การตั้งค่าและการถ่ายภาพของกล้องถ่ายภาพดิจิตอลถูกควบคุมด้วยคอมพิวเตอร์ผ่านทางสายยูเอสบี ได้ทำการศึกษาผลของการตั้งค่าต่างๆ ของกล้องถ่ายภาพและของเครื่องกำเนิดรังสีเอกซ์ที่มีต่อคุณภาพของภาพที่ได้ จากนั้นได้ทดสอบชิ้นงาน 6 ชิ้นที่มีองค์ประกอบและลักษณะต่างกัน โดยทำการถ่ายภาพแต่ละชิ้นงานทุกๆ 1.8 องศา รวมทั้งหมด 100 ภาพ เมื่อนำไปสร้างภาพซีทีแล้วพบว่ามีคุณภาพน่าพอใจมาก เวลาที่ใช้ในการถ่ายภาพ และสร้างภาพแต่ละตัวอย่างรวมทั้งสิ้นประมาณ 7 นาที อย่างไรก็ตามสำหรับตัวอย่างที่มีความหนามากและมีความหนาแน่นสูงอาจต้องปรับเปลี่ยนไปขึ้นอยู่กับการตั้งค่าของกล้องถ่ายภาพและของเครื่องกำเนิดรังสีเอกซ์ รวมทั้งชนิดของฉากเรืองรังสี งานวิจัยนี้ชี้ให้เห็นการนำระบบและเทคนิคที่พัฒนาขึ้นไปใช้งานในการตรวจสอบชิ้นงานในอนาคต