Nuclear Engineering Commons^™

Viscous Sealing Glass Compositions For Solid Oxide Fuel Cells, Cheol-Woon Kim, Richard K. Brow

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A sealant for forming a seal between at least two solid oxide fuel cell components wherein the sealant comprises a glass material comprising B₂O₃ as a principal glass former, BaO, and other components and wherein the glass material is substantially alkali-free and contains less than 30% crystalline material.

Deterministic Neutron Transport And Multiphysics Experimental Safety Analyses At The High Flux Isotope Reactor, Christopher James Hurt

Doctoral Dissertations

The computational ability to accurately predict the conditions in an experiment under irradiation is a valuable tool in the operation of a research reactor whose scientific mission includes isotope production, materials irradiation, and neutron activation analysis. Understanding of different governing physics is required to ascertain satisfactory conditions within the experiment: the neutron transport behavior throughout the reactor and the coupled behavior of heat transfer, structural mechanics and fluid flow. Computational methods and tools were developed for robust numerical analysis of experiment behavior at the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR), including fully-coupled thermo-mechanics in three plutonium-238 …

Reconfigurable Liquid Attenuated Collimator, Larry W. Burggraf, Benjamin R. Kowash, Jack G. M. Fitzgerald

AFIT Patents

A reconfigurable radiographic aperture mask collimator apparatus includes a body portion configured to receive an attenuating liquid having a first attenuation value per unit volume. The apparatus further includes a grid portion mated to a face of the body portion and a plurality of passageways each having a cross sectional area and a length. The plurality of passageways is disposed within the grid portion. A plurality of plugs is slidably disposed within the plurality of passageways, and each of the plurality of plugs has a second attenuation value per unit volume less than the first attenuation value. One of the …

Radiation Tailored Polymers For Detectors, Adhesive-Coatings And Other Industrial Uses, Anna M. Earley, Alex Bakken, Rusi P. Taleyarkhan

The Summer Undergraduate Research Fellowship (SURF) Symposium

The ever growing importance of humans to depend on renewable resources has shifted the focus of consumers, producers, and even politicians to more sustainable answers. Furthermore, pressure on the oil and natural gas industry has elevated the status of biopolymers in this regard. Polylactic acid (PLA) is unique polymer that offers unique abilities for tailored property derivation; thereby, enabling one to replace many engineered polymers and provide a sustainable solution as a nontoxic renewable resource. As a bioplastic, the tailoring of PLA under various conditions is important to the application and integration into current industry uses. After irradiating high molecular …

Characterizing Local Order And Physical Properties Of Rare Earth Complex Oxides, Thomas Jacob Shamblin

Doctoral Dissertations

With more than 500 compositions, materials possessing the pyrochlore structure have a myriad of technological applications and physical phenomena. Three of the most noteworthy properties are the structure’s ability to resist amorphization making it a possible host matrix for spent nuclear fuel, its exotic magnetic properties arising from geometric frustration, and fast ionic conductivity for solid-oxide fuel cell applications. This work focuses on these three aspects of the pyrochlore’s many potential uses. Structural characterization revealed that pyrochlore-type oxides have a tendency to disorder from a high symmetry cubic structure to a lower symmetry orthorhombic arrangement in response to a variety …

Thermoelectric Half-Heuslers: Synthesis, Processing, And Performance, Joseph Robert Croteau

Boise State University Theses and Dissertations

Thermoelectric half-Heusler compounds have potential to convert the heat wasted from industrial and transportation processes to useful electricity. Among the highest performing half-Heusler compounds are nano-structured bulk materials which have been arc-melted, pulverized into a nano-powder, and sintered by DC-hot press. High performing n- and p-type half-Heusler compounds with nominal composition of Hf_0.25Zr_0.75NiSn_0.99Sb_0.01 and Nb_0.75Ti_0.25FeSb, respectively, have been provided to us in both dense and powder form by our collaborators at the University of Houston. We consolidate these powders by SPS, refine these powders to improve both particle size …

Thermal Characteristics Of Lithium Indium Diselenide And Lithium Indium Gallium Diselenide Neutron Detection Crystals, Dustin Carroll Giltnane

Masters Theses

Tracking special nuclear materials (SNM) has never been more important than in the 21^st century where information is transferred rapidly around the globe. Tracking SNM is important to nuclear power, weapons, medicine, and science. Neutron and gamma ray detection are the primary methods of detecting SNM. Increased movement and availability of SNM have increased the demand for radiation detection systems beyond the capacity of traditional neutron detection technologies (³He) [Helium three]. Many alternative neutron detection materials are being considered, including ⁶LiInSe₂ [Lithium Indium Diselenide grown with lithium enriched in lithium six] and its derivative ^{6 …}

Modeling And Experimental Investigation On The Influence Of Radiation Defects On Helium Behavior In Bcc Iron, Zuya Huang

Masters Theses

Fe-based alloys are important structural materials for both fission and fusion energy. For fusion applications, the challenges of radiation-induced changes in microstructure, properties and performance is further challenged by the concomitant production of helium from (n, alpha) nuclear reactions and fusion reactions. Due to the lack of a volumetric, high flux 14-MeV neutron source, studying these phenomena require the use of computational materials modeling and novel experimental methods. In this thesis, molecular dynamics (MD) simulations was used to investigate the synergistic interactions of helium with prismatic dislocation loops characteristic of those observed in neutron irradiated iron to determine how the …

Magnetron Sputtering And Corrosion Of Ti-Al-C And Cr-Al-C Coatings For Zr-Alloy Nuclear Fuel Cladding, Devin Alan Roberts

Masters Theses

The disaster at the Fukushima Daiichi Nuclear Power Plant in March 2011 bought renewed focus to the issue of corrosion in nuclear fuel cladding applications. This thesis reports on the background behind these issues, the investigation strategy, and the analysis of experiments focused on mitigating oxidation of Zr-alloy fuel cladding. This thesis seeks to develop magnetron sputtered Ti-Al-C and Cr-Al-C coatings for Zr-alloy substrates and characterize the as-deposited and corroded samples.

Ti-Al-C and Cr-Al-C coatings were deposited onto ZIRLO, Si, and Al₂O₃ [Aluminum Oxide] substrates under various sputtering conditions. A combinatorial sputtering method was employed to refine …

Nanoscale Phonon Thermal Conductivity Via Molecular Dynamics, Jonathan M. Dunn

Open Access Theses

Molecular dynamics (MD) simulations provide a useful and simple means of calculating the nanoscale thermal properties of materials, which requires special analysis since the thermal properties of materials change when their dimensions reach the nanoscale. In this research, MD is used to investigate the nanoscale phonon thermal transport of materials that are attracting much interest in the areas of materials science and nuclear physics. In order to evaluate two distinct methods of calculating the thermal conductivity of materials using MD, the simulation methods are first applied to Si. Once an understanding of each simulation method is established, they are then …

Thermal Characterization Of Phase Change Materials For Thermal Energy Storage, Rami Mohammad Reda Saeed

Masters Theses

"The study provides a valuable and useful database for Phase Change Materials (PCMs) for Thermal Energy Storage (TES) applications. Only a few existing studies have provided an overall investigation of thermophysical properties of PCMs in this detailed manner. Several organic PCMs, namely Myristic acid, Capric Acid, Lauryl Alcohol, Palmitic acid and Lauric acid, have been characterized after being carefully selected to cover wide range of TES applications. Insights and information gained from this work will be applied toward the design and modelling of many low temperature thermal energy storage applications. The study experimentally investigated uncertainty of thermal characterization of PCMs …

Synthesis Of Radioactive Nanostructures In A Research Nuclear Reactor, Maria Camila Garcia Toro

Masters Theses

In this work, the synthesis of radioactive nanostructures by water radiolysis was studied. The irradiation processes were done in the Missouri University of Science and Technology research nuclear reactor (MSTR).

Radioactive gold nanoparticles (AuNPs) were synthesized from aqueous solutions containing the metal salt precursors by radiolysis of water. Seven different samples were irradiated at 200kW of thermal power for 0.5, 1, 3, 5, 10, 30, and 60 minutes. The average sizes of the obtained nanoparticles ranged from 3 nm to 400 nm, it was found that the particle size decreased with the irradiation time. Some agglomerations of particles were found …