A5052904160- Radioactive element chemistry and processing
- Nuclear Materials and Properties
- Radioactive contamination and transfer
- Nuclear materials and radiation effects
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Radioactivity and Radon Measurements
- Geological and Geochemical Analysis
- Geochemistry and Geologic Mapping
- Catalysis and Oxidation Reactions
- Chemical Synthesis and Characterization
- Graphite, nuclear technology, radiation studies
- Lanthanide and Transition Metal Complexes
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Nuclear and radioactivity studies
- Analytical chemistry methods development
- Spectroscopy and Chemometric Analyses
- Minerals Flotation and Separation Techniques
- Ion-surface interactions and analysis
- Forensic Fingerprint Detection Methods
- Polyoxometalates: Synthesis and Applications
- Inorganic Fluorides and Related Compounds
- Laser-induced spectroscopy and plasma
- Mercury impact and mitigation studies
Oak Ridge National Laboratory
2019-2025
ORCID
2024
Government of the United States of America
2022-2023
University of Notre Dame
2016-2022
Oak Ridge Associated Universities
2019
Uranyl fluoride (UO2F2) particles (<20 μm) were subjected to first-of-its-kind analysis via simultaneous laser-induced breakdown spectroscopy (LIBS) and laser ablation multi-collector inductively coupled plasma–mass spectrometry (LA–MC–ICP–MS). Briefly, a nanosecond pulsed high-energy was focused onto the sample (particle) surface. In single pulse, UO2F2 particle excited/ionized within microplasma volume, emission of light collected fiber optics such that could be employed for detection...
Amorphous calcium carbonate (ACC) occurs as a precursor to geological and biogenic (CaCO3), yet its transformation pathways reaction mechanisms remain inconsistent controversial. In this study, we investigated the of ACC calcite under both solution dry conditions, in presence absence impurity ions, utilizing operando time-resolved synchrotron X-ray diffraction (TRXRD) reactive transport modeling. Results demonstrate that TRXRD techniques allow us differentiate dissolution-reprecipitation...
Ammonium diuranate (ADU) is commonly encountered in the nuclear fuel cycle; however, previous investigations have shown that ADU a complex mixture of distinct compounds. Moreover, production parameters are known to heavily influence composition resulting ADU. Here, we examine four samples prepared at Oak Ridge National Laboratory (ORNL), and one sample made Pacific Northwest (PNNL), with goal further characterizing elucidating effect processing such as stir rate, strike direction,...
Abstract α-UO 3 is a common intermediate compound found in the nuclear fuel cycle, yet exact crystal structure of this material has long been debated. Inconsistent computational and experimental data previous works led to varying conclusions between authors. To ensure validity our results work, structural spectroscopic signatures pure phase α -UO are investigated using powder X-ray diffraction optical vibrational spectroscopy (infrared Raman). Rietveld refinement on collected work allows us...
Neptunium (Np) possesses a rich and unique chemistry that often diverges from other actinide elements yet remains relatively underexplored compared with the light actinides. A resurgence of interest in...
Abstract Identifying the provenance of uranium‐rich materials is a critical objective nuclear forensic analysis. Rare earth element ( REE ) distributions within uranium ores are well‐established indicators, but quantifying and correlating trace signatures for U to known deposits has thus far involved intricate statistical analyses. This study reports average chondrite normalized CN )‐ important deposit types worldwide, which then employed evaluate ore paragenesis using simple linear...
Abstract Identification of radioactive materials is a critical goal resource exploration, basic actinide science, and nuclear forensics, we provide here new insights toward rapid, nondestructive analysis uranium-containing minerals technogenic phases. Raman infrared spectroscopic data are powerful indicators solid-phase U(VI) coordination chemistry. In addition, exhibit high chemical structural diversity as artifacts geochemical processes leading to ore formation. Spectral signals axial...
By varying solvent systems, the solvothermal treatment of uranyl nitrate and methylenediphosphonic acid (H4PCP) afforded three new porous uranyl-organic frameworks (UOFs). All were structurally characterized by single-crystal X-ray diffraction formulated as (Et2NH2)2[(UO2)3(PCP)2](H2O)2.5 (1), (MeNH3)(H3O)[(UO2)3(PCP)2(H2O)3] (2), [Na(H2O)4](H3O)[(UO2)3(PCP)2(H2O)2](H2O)5 (3). These compounds crystallize with three-dimensional anionic containing U(VI) distinct cationic species due to in situ...
[(UO<sub>2</sub>F<sub>2</sub>)(H<sub>2</sub>O)]<sub>7</sub>·4H<sub>2</sub>O undergoes a transformation at high humidity to novel uranyl hydroxide hydrate with structural similarities schoepite and metaschoepite.
Understanding the crystal chemistry, materials properties, and thermodynamics of uranyl minerals their synthetic analogs is an essential step for predicting controlling long-term environmental behavior uranium. Uranyl vanadate are relatively insoluble widely disseminated within U ore deposits mine mill tailings. Pure mineral were synthesized investigation using high-temperature drop solution calorimetry. Calculated standard-state enthalpies formation found to be −4928.52 ± 13.90, −5748.81...
Voloxidation is a potential alternative reprocessing scheme for spent nuclear fuel that uses gas–solid reactions to minimize aqueous wastes and separate volatile fission products from the desired actinide phase. The process NO2(g) as an oxidant uranium dioxide (UO2) fuel, ideally producing soluble powders which can then be processed full recycle. To continue development of flowsheet voloxidation, ongoing examination chemistry associated materials required: discrepancies in proposed chemical...
Two novel hybrid uranyl peroxide phosphate cage clusters, designated U20P6 and U20P12, contain bridges between in an unusual μ–η1:η2 configuration, as well the common μ–η2:η2 configuration. These appear to be only high-nuclearity metal complexes containing bridges, they are unique among cages. Both clusters 20 polyhedra, U20P12 6 12 tetrahedra, respectively. The polyhedra both cages arranged on vertices of distorted topological dodecahedrons (20 vertex fullerenes). Each is completed by...