A5024859767- Radioactive element chemistry and processing
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Nuclear Materials and Properties
- Radioactive contamination and transfer
- Nuclear and radioactivity studies
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Graphite, nuclear technology, radiation studies
- Chemical Synthesis and Characterization
- Crystallography and molecular interactions
- Fault Detection and Control Systems
- Spectroscopy and Chemometric Analyses
- Lanthanide and Transition Metal Complexes
- Radioactivity and Radon Measurements
- Nuclear materials and radiation effects
- Radiation Effects and Dosimetry
- Forensic and Genetic Research
- Astronomical and nuclear sciences
- Extraction and Separation Processes
- Metal-Organic Frameworks: Synthesis and Applications
- Analytical chemistry methods development
- Isotope Analysis in Ecology
Pacific Northwest National Laboratory
2014-2024
Pennsylvania State University
2012-2024
Battelle
2011-2022
Richland College
2018-2020
Los Alamos National Laboratory
2005-2013
United States Department of Commerce
2009-2013
National Technical Information Service
2009-2013
Office of Scientific and Technical Information
2009-2013
The University of Texas at Austin
2012
Charles University
2008
Effective collection of trace-level lanthanides and actinides is advantageous for recovery recycling valuable resources, environmental remediation, chemical separations, in situ monitoring. Using isotopic tracers, we have evaluated a number conventional nanoporous sorbent materials their ability to capture remove selected (Ce Eu) (Th, Pa, U, Np) from fresh salt water systems. In general, the nanostructured demonstrated higher level performance consistency. Nanoporous silica surface modified...
Researchers evaluated radionuclide measurements of environmental samples taken from the Fukushima Daiichi nuclear facility and reported on Tokyo Electric Power Co. Website following 2011 tsunami-initiated catastrophe. This effort identified Units 1 3 as major source radioactive contamination to surface soil near facility. Radionuclide trends in soils suggested that: (1) chemical volatility driven by temperature reduction potential within vented reactors' primary containment vessels dictated...
Assembly of a family 12 supramolecular compounds containing [AnO2Cl4]2– (An = U, Np, Pu), via hydrogen and halogen bonds donated by substituted 4-X-pyridinium cations (X H, Cl, Br, I), is reported. These materials were prepared from room-temperature synthesis wherein crystallization unhydrolyzed valence-pure [An(VI)O2Cl4]2– Pu) tectons the norm. We present hierarchy assembly criteria based on crystallographic observations subsequently quantify strengths non-covalent interactions using...
An attempt to confirm production of superheavy elements in the reaction $^{48}\mathrm{Ca}$ beams with actinide targets has been performed using $^{238}\mathrm{U}$($^{48}\mathrm{Ca}$,3$n){}^{283}$112 reaction. Two projectile energies were used that spanned energy range where largest cross sections have reported for this No spontaneous fission events observed. \ensuremath{\alpha} decay chains consistent either or theoretically predicted element 112 properties The cross-section limits reached...
Abstract We have made observations of noble metal phase fission-product agglomerates and gaseous xenon within the fuel-cladding interaction (FCI) zone a high-burnup UO 2 fuel. The FCI is boundary between pellet outer surface inner wall oxidized Zr-liner/cladding fuel rod. These are well known to occur spent matrix, although radionuclides been reported by others, we reveal aspects their speciation morphology. That they as discrete particles in Zr liner, suggests occurrence hitherto unknown...
Seven 271Ds decay chains were identified in the bombardment of 208Pb targets with 311.5 and 314.3 MeV 64Ni projectiles using Berkeley Gas-filled Separator. These data, combined previous results, provide an excitation function for this reaction. From these optimum energy 321 was estimated production (272)111 new reaction 208Pb(65Cu,n). One chain observed, resulting a cross section 1.7(+3.9)(-1.4) pb. This experiment confirms discovery element 111 by Darmstadt Group who used 209Bi(64Ni,n)(272)111
The $^{237}\mathrm{Np}$($n,\ensuremath{\gamma}$)$^{238}\mathrm{Np}$ cross section has been measured in the neutron energy range from 20 meV to 500 keV using DANCE array at Los Alamos National Laboratory. This new facility allows experiments with submilligram samples and is therefore well suited investigate isotopes half-lives as low a few hundred days. In this benchmark measurement, only 0.42 mg of $^{237}\mathrm{Np}$ was sufficient determine differential sections relative well-known...
During World War II, the Hanford Site in Washington became location for U.S. plutonium production. In 2004, a bottle containing sample of was recovered from waste trench. Here, state-of-the-art instrumental analyses, reactor model simulations, and investigative science techniques were used to provide insights as origin this unknown sample, process collectively termed nuclear archeology. Isotopic age dating conducted on 2007 indicated separated spent fuel 61.6 +/- 4.5 years earlier. The...
The DANCE detector is a segmented 4/spl pi/ gamma-ray calorimeter for measuring (n, /spl gamma/) and (n,fission) cross-sections of stable long-lived radioactive isotopes. uses waveform digitization to acquire the basic data, which maximizes information available event reconstruction, but has necessitated development several techniques handling resulting high data rates. This paper describes experimental requirements acquisition analysis how we have satisfied these primarily by extending...
The excitation function for production of $^{262}\mathrm{Bh}$ in the odd-Z-projectile reaction $^{208}\mathrm{Pb}$($^{55}\mathrm{Mn}$, $n)$ has been measured at three projectile energies using Berkeley Gas-filled Separator Lawrence National Laboratory 88-Inch Cyclotron. In total, 33 decay chains originating from and 2 $^{261}\mathrm{Bh}$ were observed. properties are good agreement with previous reports. maximum cross section ${540}_{\ensuremath{-}150}^{+180}$ pb is observed a lab-frame...
Herein, we report the synthesis and structural characterization of K8[(CO3)3Pu]2(μ-η2-η2-O2)2·12H2O. This is second Pu-containing addition to previously studied alkali-metal peroxocarbonate series M8[(CO3)3A]2(μ-η2-η2-O2)2·xH2O (M = alkali metal; A Ce or Pu; x 8, 10, 12, 18), for which only M Na analogue has been reported when Pu. The crystal structure Na8[(CO3)3Pu]2(μ-η2-η2-O2)2·12H2O not isomorphous with its known analogue. However, a new synthetic route these...
Abstract A new uranyl containing metal–organic framework, RPL‐1 : [(UO 2 ) (C 28 H 18 O 8 )] . (RPL for Radiochemical Processing Laboratory), was prepared, structurally characterized, and the solid‐state photoluminescence properties explored. Single crystal X‐ray diffraction data reveals structure of RPL ‐ 1 consists two crystallographically unique three dimensional, interpenetrating nets with a 4,3‐connected tbo topology. Each net contains large pores an average width 22.8 Å is formed from...
The crystal structures of americium species containing a common multifunctional phosphine oxide ligand, reported for its ability to extract f elements from acidic solutions, namely, 2,6-[Ph2P(O)CH2]2C5H3-NO, L, were finally determined after over three decades separations studies involving these and their surrogates. molecular compounds Am(L)(NO3)3, Am 1:1, [Am(L)2(NO3)][2(NO3)], 2:1, along with neodymium europium analogues, synthesized characterized using single-crystal X-ray...
Metallic particles formed in oxide fuels (e.g., UO2) during neutron irradiation have an adverse impact on fuel performance. A fundamental investigation of particle precipitation is needed to predict the performance and potentially improve designs operations. This study reports Mo-dominant β-phase polycrystalline CeO2 (surrogate for films doped with Mo, Pd, Rh, Ru, Re Tc). In situ heating scanning transmission electron microscopy indicates that starts at ∼1073 K a limited growth ∼10 nm. While...