Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “UO3”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

15 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on UO3 by Materials Project

UO3 is Cementite structured and crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. U6+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of U–O bond distances ranging from 1.87–2.50 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two equivalent U6+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three equivalent U6+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent U6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UO3 by Materials Project

UO3 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. U6+ is bonded to eight O2- atoms to form a mixture of corner and edge-sharing UO8 hexagonal bipyramids. There are a spread of U–O bond distances ranging from 2.07–2.36 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three equivalent U6+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UO3 by Materials Project

UO3 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. there are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing UO6 octahedra. There are two shorter (1.91 Å) and four longer (2.23 Å) U–O bond lengths. In the second U6+ site, U6+ is bonded to six O2- atoms to form distorted corner-sharing UO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 26–52°. There are a spread of U–O bond distances ranging from 1.81–2.36 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three U6+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one U6+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two U6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UO3 by Materials Project

UO3 is alpha Rhenium trioxide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. U6+ is bonded to six equivalent O2- atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All U–O bond lengths are 2.08 Å. O2- is bonded in a linear geometry to two equivalent U6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UO3 by Materials Project

UO3 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. U6+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are two shorter (2.08 Å) and six longer (2.25 Å) U–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three equivalent U6+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UO3 by Materials Project

UO3 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are five inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share a cornercorner with one UO8 hexagonal bipyramid and corners with five UO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of U–O bond distances ranging from 2.06–2.10 Å. In the second U6+ site, U6+ is bonded to eight O2- atoms to form UO8 hexagonal bipyramids that share corners with two equivalent UO8 hexagonal bipyramids, a cornercorner with one UO6 octahedra, and edges with two equivalent UO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 1°. There are a spread of U–O bond distances ranging from 2.10–2.39 Å. In the third U6+ site, U6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of U–O bond distances ranging from 1.94–2.72 Å. In the fourth U6+ site, U6+ is bonded to five O2- atoms to form distorted UO5 trigonal bipyramids that share a cornercorner with one UO6 octahedra and corners with four equivalent UO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of U–O bond distances ranging from 2.06–2.21 Å. In the fifth U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with five UO6 octahedra and a cornercorner with one UO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of U–O bond distances ranging from 2.06–2.11 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two U6+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two U6+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two U6+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two U6+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent U6+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms. In the eighth O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms. In the ninth O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms. In the tenth O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms. In the eleventh O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent U6+ and one O2- atom. The O–O bond length is 1.48 Å. In the thirteenth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent U6+ and one O2- atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three U6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiUO3 by Materials Project

LiUO3 is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional and consists of one lithium molecule and one UO3 framework. In the UO3 framework, U5+ is bonded to six equivalent O2- atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All U–O bond lengths are 2.14 Å. O2- is bonded in a linear geometry to two equivalent U5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UBCO5 by Materials Project

UO3CBO2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four metaboric acid molecules, four methane molecules, and four UO3 clusters. In each UO3 cluster, U3+ is bonded in a 3-coordinate geometry to three O2- atoms. There is two shorter (1.83 Å) and one longer (1.90 Å) U–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one U3+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one U3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

ASMS 2024 Investigation of Uranyl Perchlorate Anion Complexes in the Gas Phase via Infrared Multiphoton Dissociation and Collision Induced Dissociation

Investigation of Uranyl Perchlorate Anion Complexes in the Gas Phase via Infrared Multiphoton Dissociation and Collision Induced Dissociation Brittany D. M. Hodges, Christopher A. Zarzana, JungSoo Kim, Jonathan Martens, and W. C. M. Berden Introduction (120 words max) Effects of electronic structure on chemical bonding and reactivity play critical roles shaping the chemical bonding and reactivity behaviors of heavy elements. Understanding the role of f electrons in bond formation between the actinide-series elements like uranium with other ligands is critical for solving technical challenges associated with these heavy elements, important to nuclear fuel cycles, efficient separations of rare earth metals, and understanding the chemistry of stored nuclear fuels and related environmental management sites. In this study, we further examine the interactions between uranyl and the perchlorate ion in order to understand the structures of these ions through the use of IRMPD. Here we report the IRMPD spectra of [UO2(ClO4)3]-, [UO3(ClO4)2]-, and a proposed transition state. Methods (120 word max) IRMPD spectra and CID spectra were acquired using a Bruker amaZon QIT/MS instrument at the Free-Electron Lasers for Infrared eXperiments (FELIX) laboratory at Radboud University. The FELIX QIT/MS is modified to allow for the high-intensity tunable IR beam from FELIX to be directed into the ion packet, resulting in multiphoton dissociation that is measured only when the IR frequency is in resonance with an adequately high absorption vibrational mode of the mass-selected complex. DFT geometry optimizations and frequency calculations using the Gaussian suite of programs were performed using B3LYP, TPSSh, and PBE0 level of theory with 6-31+G(d) basis for the O, C, H, and N atoms and the SDD basis set for U. The SDD basis set employs the Stuttgart/Dresden effective core potential. Preliminary Data or Plenary Speakers Abstract (300 words max) Metal ion clusters of uranyl perchlorate were formed via direct electrospray ionization. For each metal ligand complex of interest, the parent ion was isolated and collision induced dissociation fragmentation and Infrared Multiphoton Dissociation (IRMPD) fragmentation spectra were acquired. Results presented here are the first look at the IRMPD spectra of [UO3(ClO4)2]-, [UO2(ClO4)3]-. Structures were examined using Gaussian at different levels of theory B3LYP level of theory, TPPSh and PBE0 levels, to reflect the behaviors of uranium metal ligand complexes most accurately. In these structures, we identified an overlap between each of these uranyl stretches resulting in their largely being obscured by a perchlorate mode. The CID product spectra agree with similar structures reported by Groenewold for uranyl nitrate in 2006 (10.1021/ja058106n).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Optical vibrational spectra and proposed crystal structure of ε-UO 3

ε-UO 3 is an exotic polymorph in the uranium trioxide system with an undetermined crystal structure and limited optical vibrational spectroscopic data. To improve understanding of this compound, we synthesize and investigate the crystal structure and optical vibrational spectra of ε-UO 3 . Infrared spectra collected for ε-UO 3 are in good agreement with previously published results, and our studies extend the available data into the low-energy (600–100 cm –1 ) regime. For the first time, Raman spectra are presented for ε-UO 3 using both 785 and 532 nm excitation wavelengths. Previous reports suggest an impurity phase may be present in ε-UO 3 produced by calcination of U 3 O 8 ; however, spectral center-of-mass calculations, principal component analyses, and Raman spectroscopic mapping employed to investigate this possibility indicate that the product of U 3 O 8 calcined in O 3 (g) in this work is likely phase-pure. A possible novel structure solution for ε-UO 3 is determined via Rietveld refinement of powder X-ray diffraction data and is triclinic, P-1, with a = 4.01 Å, b = 3.85 Å, c = 4.18 Å, and α = 98.26°, β = 90.41°, γ = 120.46° (R wp = 8.30%). The asymmetric unit of ε-UO 3 consists of U(VI) in hexagonal bipyramidal coordination with displaced equatorial oxygen. Further analysis reveals that the structure of ε-UO3 is best described by a 2 × 1 × 2 supercell structure in P-1 with a = 8.03 Å, b = 3.86 Å, c = 8.37 Å with α = 98.26°, β = 90.41°, and γ = 120.46°, although a higher-symmetry structure is possible. Optical vibrational spectroscopic and structural measurements of ε-UO 3 presented here furthers our understanding of this complex uranium oxide and clarifies the origin of reported structural similarity to U 3 O 8 .

-UO3↗
DOE OSTI2026

Analytical workflow dependence of experimental observables for uranium chemistries

In this work, we investigated how the sequencing of laboratory analytical methods used for chemical and morphological characterization influences analytical findings for particulate materials relevant to the nuclear fuel cycle, including UO2, U3O8, studtite (UO2O2·4H2O), and β-UO3, in the context of nuclear forensic analysis. Particles of each chemistry obtained from consistent production batches were exposed to Raman spectroscopy and scanning electron microscopy in varying orders to elucidate how the order in which the techniques are applied influences morphological and chemical observations as a function of particle size. The results indicate that particles from all four chemistries exposed to high-resolution electron imaging before Raman spectral analysis demonstrate optical vibrational spectral changes that reduce accurate interpretation of the underlying chemistry via Raman spectral analysis. We hypothesize that these changes are due to the thermal load of the electron beam imparted to the sample being unable to be dissipated by materials with poor thermal conduction properties. Results from this study will aid in determining best practices for forensic analysis procedures to reduce uncertainty in chemical determination of unknown particulate samples.

Manns, Rebecca [University of Nevada, Las Vegas]↗
DOE OSTI2023

Advanced Fuel Cycle Cost Basis Report: Supporting Document 7 Presentation: Du and RU Disposal Costs [Slides]

Worldwide DU and RU in various chemical forms are some of the largest legacy products of the nuclear industry (defense & power) in both mass and volume. Chemical forms include U metal or alloy, UF6, UO2, UO3, U3O8, and UF4. Most of this material is now in above ground storage. Due to chemical stability and low water solubility oxides are the preferred form for safe storage and ultimate disposal. Long term U disposal in large amounts presents more of a potential radioactivity problem than its conversion and temporary storage. Now a near term problem with freshly-mined uranium ore, radon emanation will eventually be a long-term problem for both DU and RU dispositioned in large quantities at a specific location.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Conceptual Design of a Scaled Voloxidation Apparatus for Testing with Used Nuclear Fuel

This report details the conceptual design overview for Department of Energy (DOE) Level 2 milestone M2FT-25IN030101021 titled “Complete conceptual design of a scaled voloxidation apparatus for testing with used nuclear fuel.” Advanced voloxidation uses high temperature nitrogen dioxide (NO2) gas to oxidize uranium dioxide (UO2) material to triuanium octoxide (U3O8) and ultimately to uranium trioxide (UO3). After consideration of multiple available options and inputs, a rotating advanced voloxidation design was determined to be the best fit for the needs of a full-scale apparatus. The system, which will be deployed in hot cell 4 of the Analytical Research Laboratory (ARL), has been designed to meet the space constraints of the facility while still accommodating at least 100g of used nuclear fuel (UNF). The apparatus consists of three main unit operations, including the gas panel, the custom furnace with reaction vessel, and the liquid scrubber.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Overview of Algorithms for Using Particle Morphology in Pre-Detonation Nuclear Forensics

A major goal in pre-detonation nuclear forensics is to infer the processing conditions and/or facility type that produced radiological material. This review paper focuses on analyses of particle size, shape, texture (“morphology”) signatures that could provide information on the provenance of interdicted materials. For example, uranium ore concentrates (UOC or yellowcake) include ammonium diuranate (ADU), ammonium uranyl carbonate (AUC), sodium diuranate (SDU), magnesium diuranate (MDU), and others, each prepared using different salts to precipitate U from solution. Once precipitated, UOCs are often dried and calcined to remove adsorbed water. The products can be allowed to react further, forming uranium oxides UO3, U3O8, or UO2 powders, whose surface morphology can be indicative of precipitation and/or calcination conditions used in their production. This review paper describes statistical issues and approaches in using quantitative analyses of measurements such as particle size and shape to infer production conditions. Statistical topics include multivariate t tests (Hotelling’s T 2 ), design of experiments, and several machine learning (ML) options including decision trees, learning vector quantization neural networks, mixture discriminant analysis, and approximate Bayesian computation (ABC). ABC is emphasized as an attractive option to include the effects of model uncertainty in the selected and fitted forward model used for inferring processing conditions.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2022

Unexpected features in the optical vibrational spectra of δ-UO 3

Uranium trioxide displays a complex chemical phase space, with at least six structurally distinct polymorphs accessible via different synthetic routes. Remarkably, despite its technological importance, full structural and electronic characterization of these polymorphs remains an open area of study. δ-UO 3 in particular has attracted significant theoretical attention due to its high point group and space group symmetries, having U (VI) in octahedral coordination with polyhedra interconnected through corner-sharing to build a 3-D cubic lattice with space group symmetry Pm-3m and Z = 1. Critical experimental information, such as its optical vibrational spectra, are not known. Here, we study the Raman and infrared (IR) spectra of δ-UO 3 together with the support of density functional theory (DFT) calculations for spectral interpretation. A symmetry analysis of the DFT-predicted phonon eigenmodes indicates that δ-UO 3 should have two IR active modes and no Raman active modes. Experimental results, however, indicate significant Raman scattering from δ-UO 3 . We therefore propose four potential explanations for this apparent contradiction: a possible tetragonal distortion to the cubic cell, the existence of a surface impurity layer, vacancy scattering, and structural activation of Raman signal. We use powder X-ray diffraction and confocal Raman spectroscopy with depth profiling to investigate these possibilities and suggest future experiments to explore this phenomenon in more detail. Understanding the lattice dynamics of δ-UO 3 is important for identification of technogenic U phases via Raman and infrared spectroscopy and our results indicate that the simple understanding of δ-UO 3 as a high-symmetry cubic structure should be reconsidered.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗