Article
Chemistry, Analytical
R. Boone Gilbreath, John D. Auxier, Jerrad P. Auxier, Justin M. Alexander
Summary: A method for formulating and producing a new variety of surrogate nuclear explosive melt debris, NUGETS, is presented based on detonation of an improvised nuclear device in an underground environment similar to the Nevada National Security Site. Extensive statistical analyses of precursory geochemical and geophysical characteristics are combined with an augmented surrogate debris cooling technique. The comparison of NUGETS formulation with other NEMD surrogates is reported, suggesting its application to future studies in urban, underground, post-detonation technical nuclear forensic analysis.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2021)
Article
Chemistry, Analytical
Robert Lusk, Jess Meiers, Brian Bucher, Nathalie Wall, Saige Forbush, Kevin Carney, David L. Chichester, Mathew Snow
Summary: Sol-gel vitrification is a rapid method for producing solid, vitreous materials for nuclear forensics research. This study compares the ability of three sol-gel synthetic approaches to retain fission products within the glass at different drying temperatures. Results show that using an acidic catalyst, eight out of ten fission products were quantitatively retained up to 600 degrees C, while using a basic catalyst, retention was observed up to 300 degrees C. However, ruthenium and iodine showed partial and complete losses, respectively, at temperatures above 300 and 100 degrees C.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2023)
Article
Chemistry, Analytical
Mark A. Boggs, Andrew A. Reinhard, Jeremy Inglis, James Tutt, Gabrielle Lee, Cheriece Margiotta
Summary: Cs-135/Cs-137 measurements were conducted on debris samples from the Trinity nuclear test, revealing variations in condensation times and Cs-135/Cs-137 ratios. The measurements also showed heterogeneities in Cs-135/Cs-137 ratios within different trinitite lithologies in a single sample.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2023)
Article
Environmental Sciences
Mathew P. Johansen, David P. Child, Richard Collins, Megan Cook, Joel Davis, Michael A. C. Hotchkis, Daryl L. Howard, Nicholas Howell, Atsushi Ikeda-Ohno, Emma Young
Summary: Radioactive particles from anthropogenic sources are widespread in global environments and have the potential to cause radiological harm to living organisms. This study compares a diverse set of particles from past nuclear fission and non-fission sources in Australia, revealing that many radioactive particles persist in soils even decades after their release events. The particles can be distinguished by their elemental ratios and their compositions affect their persistence and potential to leach radionuclides into the environment or organisms.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Chemistry, Inorganic & Nuclear
Jacqueline L. Mann, John L. Molloy, JoAnn Buscaglia, Kevin P. Pfeuffer, Barbara L. Fallon, Mark A. Tyra
Summary: Nondestructive microbeam X-ray fluorescence (mu XRF) spectrometry was used to investigate elemental microheterogeneity in a nuclear forensics reference material, showing most elements are homogeneous except for zinc. To minimize measurement uncertainty from elemental microheterogeneity, a minimum sample mass of 24 mg is recommended for analysis.
APPLIED RADIATION AND ISOTOPES
(2021)
Article
Thermodynamics
Yan Xiang, Disen Liang, Andrei Komlev, Di Fang, Yucheng Deng, Lu Zhao, Weimin Ma
Summary: During severe accidents in a light water reactor (LWR), the core melt (corium) can relocate to the lower head and cause the reactor pressure vessel (RPV) to fail. Fuel coolant interactions (FCI) occur when the reactor cavity is flooded with water, and the energetics of FCI and the coolability of resulting debris bed are crucial for reactor safety. This study aims to quantify the characteristics of a debris bed resulting from FCI using various materials, and high-speed photography was used to visualize the process. The comparative results provide insights into debris bed characteristics under different melt materials and compositions.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Yan Xiang, Yucheng Deng, Di Fang, Disen Liang, Weimin Ma
Summary: A series of experiments was conducted to investigate the characteristics of metallic melt-water interactions. The results showed that water pool depth significantly influenced steam explosion and debris bed formation characteristics, and jet breakup length was sensitive to jet diameter and free fall height. Additionally, the features of metallic debris beds were compared with those of oxidic ones in terms of configuration, porosity, and particle morphology and size distribution.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
D. R. Rounce, R. Hock, R. W. McNabb, R. Millan, C. Sommer, M. H. Braun, P. Malz, F. Maussion, J. Mouginot, T. C. Seehaus, D. E. Shean
Summary: Supraglacial debris affects glacier mass balance by either enhancing or reducing surface melting. Accounting for debris can reduce sub-debris melt by up to 37%, impacting regional mass balance by 0.40 m water equivalent per year. Recent observations suggest differences in ice dynamics are the primary reason for thinning rates over debris-covered and clean ice glaciers.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Nuclear Science & Technology
Yan Xiang, Sachin Thakre, Weimin Ma, Sevostian Bechta
Summary: This study focuses on the formation and characteristics of debris during a severe accident in a light water reactor, analyzing the debris bed formed by a metal-rich corium jet falling into a water pool. Experimental results show the influence of parameters like superheat and subcooling on the characteristics of the debris bed, including configuration, porosity, particle morphology, and size distribution. Preliminary comparison between metallic and oxidic debris beds was also provided.
NUCLEAR ENGINEERING AND DESIGN
(2021)
Article
Chemistry, Analytical
Joseph V. Goodwin, Benjamin T. Manard, Brian W. Ticknor, Paula Cable-Dunlap, R. Kenneth Marcus
Summary: The liquid sampling-atmospheric pressure glow discharge (LS-APGD) is a versatile ionization source that can be used to analyze different chemical substances. By employing moving average methods, the precision of the measurements can be improved while reducing the number of scans required and the measurement time.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2022)
Article
Chemistry, Analytical
Sean D. Reilly, Genna M. Patton, Jesse Murillo, Warren J. Oldham, Jeffrey L. Miller, Stephen P. LaMont, Matthew E. Sanborn, Iain May, Andrew J. Gaunt, Susan K. Hanson
Summary: In nuclear forensic analyses, measuring actinide elements in a sample is crucial for identifying unknown or banned materials. This paper focuses on the measurement of trace actinide concentrations and isotopic profiles in a neptunium-237 oxide sample and suggests that these data could be used to differentiate different sources of neptunium. However, inconsistent results from various radiochronometry systems indicate possible impurities or contamination in the sample. This study highlights the potential of trace actinide constituents in providing unique signatures for identifying illicit materials.
ANALYTICAL CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Jonathan Johnson, Ryan Wilkerson, Stephen DiPietro, Gregory B. Thompson
Summary: Research has shown that providing conformal coatings to tungsten-yttria stabilized zirconia (W-YSZ) surrogate fuel elements can reduce ceramic-ceramic contacts, improve densification of the cermet, decrease the necessary amount of refractory metal matrix, and increase fissile fuel content.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Materials Science, Ceramics
James F. Mudd, Jeremy Watts, Jhonathan Rosales, Ryan P. Wilkerson, Brian Taylor, William Fahrenholtz, Gregory Hilmas, Joseph Graham
Summary: In this study, the thermal properties of MoW-HfN, a surrogate cermet for MoW-UN nuclear thermal propulsion fuel, were characterized. The thermal diffusivity, coefficient of thermal expansion (CTE), and heat capacity were measured, and the microstructure was analyzed using optical and scanning electron microscopy. The study provided important insights into the structure-property correlations of the material.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Energy & Fuels
Irina E. Vlasova, Vasily O. Yapaskurt, Alexei A. Averin, Oleg E. Melnik, Denis A. Zolotov, Roman A. Senin, Tatiana R. Poliakova, Iurii M. Nevolin, Stepan N. Kalmykov, Andrey A. Shiryaev
Summary: Investigation of shocked materials in extreme thermodynamic conditions provides unique information about their behavior. This study examines nuclear fallout particles from historic tests at the Semipalatinsk test site using complementary analytical methods. The distribution of radionuclides in the samples is highly heterogeneous, with high-content domains intermixed with non-active materials. The chemical composition of the glassy matrix does not correlate with the content of radionuclides. The main fraction of radionuclides in aerodynamic fallout is trapped in the outer glassy shell. The study also discusses the temperature-induced transformations of entrapped minerals and reveals the absence of a direct correlation between the degree of decomposition, resulting morphology, and maximum experienced temperature in zircon grains. The temperature history of a nuclear ground glass is estimated for the first time using Zr diffusion profiles from decomposing zircon grain.
Article
Chemistry, Physical
Luojia Zhang, Evgeny Zhuravlev, Jun Yi, Qijie Zhai, Christoph Schick, Yulai Gao, Bingge Zhao
Summary: Crystal nucleation is a crucial step in the crystallization of metallic glasses. However, the nucleation kinetics can deviate from the classical nucleation theory as the undercooling increases. This study examines the nucleation kinetics in glass and undercooled melt using nanocalorimetry. By varying the cooling rate, the processes of crystallization, homogeneous nucleation, and heterogeneous nucleation are distinguished. The critical cooling rates for suppressing crystallization and nucleation are estimated, and a well-identified amorphous phase is produced for nucleation studies. The underlying kinetic mechanism is revealed through the analysis of crystallization heat and overall heat using the Johnson-Mehl-Avrami method.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Mark Moore, Robert Counce, Jack Watson, Howard Hall
SEPARATION SCIENCE AND TECHNOLOGY
(2019)
Article
Instruments & Instrumentation
D. C. Donovan, E. A. Unterberg, P. C. Stangeby, S. Zamperini, J. D. Auxier, D. L. Rudakov, W. R. Wampler, M. Zach, T. Abrams, J. D. Duran, J. D. Elder, A. L. Neff
REVIEW OF SCIENTIFIC INSTRUMENTS
(2018)
Article
Chemistry, Inorganic & Nuclear
Shayan Shahbazi, C. J. Oldham, Austin D. Mullen, John D. Auxier, Howard L. Hall
Article
Physics, Applied
J. R. Chandler, S. Sholom, S. W. S. McKeever, H. L. Hall
JOURNAL OF APPLIED PHYSICS
(2019)
Article
Chemistry, Analytical
Jessica L. Bishop, Will F. Cureton, Miguel L. Crespillo, Michael Koehler, John D. Auxier II, Maik Lang
Summary: The study found that accumulated damage from self-irradiation causes significant modifications in metal oxidation, with the fraction of CuO phase gradually decreasing as the damage level increases. This could potentially serve as a novel forensic signature.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2021)
Article
Chemistry, Analytical
R. Boone Gilbreath, John D. Auxier, Jerrad P. Auxier, Justin M. Alexander
Summary: A method for formulating and producing a new variety of surrogate nuclear explosive melt debris, NUGETS, is presented based on detonation of an improvised nuclear device in an underground environment similar to the Nevada National Security Site. Extensive statistical analyses of precursory geochemical and geophysical characteristics are combined with an augmented surrogate debris cooling technique. The comparison of NUGETS formulation with other NEMD surrogates is reported, suggesting its application to future studies in urban, underground, post-detonation technical nuclear forensic analysis.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Conrad A. P. Goodwin, Jing Su, Lauren M. Stevens, Frankie D. White, Nickolas H. Anderson, John D. Auxier, Thomas E. Albrecht-Schonzart, Enrique R. Batista, Sasha F. Briscoe, Justin N. Cross, William J. Evans, Alyssa N. Gaiser, Andrew J. Gaunt, Michael R. James, Michael T. Janicke, Tener F. Jenkins, Zachary R. Jones, Stosh A. Kozimor, Brian L. Scott, Joseph. M. Sperling, Justin C. Wedal, Cory J. Windorff, Ping Yang, Joseph W. Ziller
Summary: This study revives air-/moisture-sensitive Californium chemistry through the synthesis and characterization of an organometallic complex, providing new insights into Californium chemistry with its unique structural features.
Article
Chemistry, Analytical
Ashwin P. Rao, Phillip R. Jenkins, John D. Auxier, Michael B. Shattan, Anil K. Patnaik
Summary: By using a compact high-resolution spectrometer and self-absorption correction technique in LIBS, the detection sensitivity of trace elements in lanthanide materials can be improved.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2022)
Article
Chemistry, Analytical
Ashwin P. Rao, Phillip R. Jenkins, John D. Auxier, Michael B. Shattan, Anil K. Patnaik
Summary: This study compares a portable LIBS analyzer to a portable XRF device for quantification of gallium in a plutonium surrogate matrix of cerium for the first time. While LIBS can provide nearly instantaneous measurements, its accuracy is limited by self-absorption, while XRF offers superior sensitivity and lower detection limits.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2022)
Article
Chemistry, Analytical
Ashwin P. Rao, Phillip R. Jenkins, Dung M. Vu, John D. Auxier II, Anil K. Patnaik, Michael B. Shattan
Summary: This study presents the first reported quantification of trace elements in plutonium using a portable laser-induced breakdown spectroscopy (LIBS) device, and demonstrates the enhancement of sensitivity and precision through chemometric analysis. Evaluation of different analytical methods showed that partial least squares regression was superior in determining the content of iron and nickel in plutonium metal, with LoDs of 15 and 20 ppm, respectively. These findings are critical for identifying undesirable trace elements in plutonium components for applications such as fabricating radioisotope thermoelectric generators or nuclear fuel.
ANALYTICAL METHODS
(2021)
Article
Physics, Atomic, Molecular & Chemical
Ashwin P. Rao, Matthew T. Cook, Howard L. Hall, Michael B. Shattan
Article
Chemistry, Multidisciplinary
Charles C. Peterson, Deborah A. Penchoff, John D. Auxier, Howard L. Hall
Article
Chemistry, Multidisciplinary
Deborah A. Penchoff, Charles C. Peterson, Jon P. Camden, James A. Bradshaw, John D. Auxier, George K. Schweitzer, David M. Jenkins, Robert J. Harrison, Howard L. Hall
Article
Chemistry, Multidisciplinary
Deborah A. Penchoff, Charles C. Peterson, Mark S. Quint, John D. Auxier, George K. Schweitzer, David M. Jenkins, Robert J. Harrison, Howard L. Hall
