Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics

Tracy, Cameron L.; Chen, Chien-Hung; Park, Sulgiye; Davisson, M. Lee; Ewing, Rodney C.

doi:10.1016/j.jnucmat.2018.01.052

Title: Measurement of UO₂ surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics

Abstract

Nuclear forensics involves determination of the origin and history of interdicted nuclear materials based on the detection of signatures associated with their production and trafficking. The surface oxidation undergone by UO₂ when exposed to air is a potential signature of its atmospheric exposure during handling and transport. To assess the sensitivity of this oxidation to atmospheric parameters, surface sensitive grazing-incidence x-ray diffraction (GIXRD) measurements were performed on UO₂ samples exposed to air of varying relative humidity (34%, 56%, and 95% RH) and temperature (room temperature, 50 °C, and 100 °C). Near-surface unit cell contraction was observed following exposure, indicating oxidation of the surface and accompanying reduction of the uranium cation ionic radii. The extent of unit cell contraction provides a measure of the extent of oxidation, allowing for comparison of the effects of various exposure conditions. No clear influence of relative humidity on the extent of oxidation was observed, with samples exhibiting similar degrees of unit cell contraction at all relative humidities investigated. In contrast, the thickness of the oxidized layers increased substantially with increasing temperature, such that differences on the order of 10 °C yielded readily observable crystallographic signatures of the exposure conditions.

Authors:

Tracy, Cameron L. ^[1]; Chen, Chien-Hung ^[2];

^[2]; Davisson, M. Lee ^[3]; Ewing, Rodney C. ^[2]

Stanford Univ., CA (United States). Dept. of Geological Sciences and Center for International Security and Cooperation
Stanford Univ., CA (United States). Dept. of Geological Sciences
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Physical and Life Sciences Directorate

Publication Date:: 2018-01-31

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation

OSTI Identifier:: 1513109

Alternate Identifier(s):: OSTI ID: 1505855

Report Number(s):: LLNL-JRNL-757741
Journal ID: ISSN 0022-3115; 945687

Grant/Contract Number:: AC52-07NA27344; SC0001089; DMR-1332208

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Nuclear Materials

Additional Journal Information:: Journal Volume: 502; Journal Issue: C; Journal ID: ISSN 0022-3115

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY

Citation Formats


                    Tracy, Cameron L., Chen, Chien-Hung, Park, Sulgiye, Davisson, M. Lee, and Ewing, Rodney C. Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics.  United States: N. p., 2018. 
Web.  doi:10.1016/j.jnucmat.2018.01.052.

Copy to clipboard


                    Tracy, Cameron L., Chen, Chien-Hung, Park, Sulgiye, Davisson, M. Lee, & Ewing, Rodney C. Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics.  United States.  https://doi.org/10.1016/j.jnucmat.2018.01.052

Copy to clipboard


                    Tracy, Cameron L., Chen, Chien-Hung, Park, Sulgiye, Davisson, M. Lee, and Ewing, Rodney C. Wed .  
"Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics".  United States.  https://doi.org/10.1016/j.jnucmat.2018.01.052.  https://www.osti.gov/servlets/purl/1513109.

Copy to clipboard


                    
@article{osti_1513109,

  title        = {Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics},

  author       = {Tracy, Cameron L. and Chen, Chien-Hung and Park, Sulgiye and Davisson, M. Lee and Ewing, Rodney C.},

  abstractNote = {Nuclear forensics involves determination of the origin and history of interdicted nuclear materials based on the detection of signatures associated with their production and trafficking. The surface oxidation undergone by UO2 when exposed to air is a potential signature of its atmospheric exposure during handling and transport. To assess the sensitivity of this oxidation to atmospheric parameters, surface sensitive grazing-incidence x-ray diffraction (GIXRD) measurements were performed on UO2 samples exposed to air of varying relative humidity (34%, 56%, and 95% RH) and temperature (room temperature, 50 °C, and 100 °C). Near-surface unit cell contraction was observed following exposure, indicating oxidation of the surface and accompanying reduction of the uranium cation ionic radii. The extent of unit cell contraction provides a measure of the extent of oxidation, allowing for comparison of the effects of various exposure conditions. No clear influence of relative humidity on the extent of oxidation was observed, with samples exhibiting similar degrees of unit cell contraction at all relative humidities investigated. In contrast, the thickness of the oxidized layers increased substantially with increasing temperature, such that differences on the order of 10 °C yielded readily observable crystallographic signatures of the exposure conditions.},

  doi          = {10.1016/j.jnucmat.2018.01.052},

  journal      = {Journal of Nuclear Materials},

  number       = C,

  volume       = 502,

  place        = {United States},

  year         = {2018},

  month        = {1}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (Publisher)

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1016/j.jnucmat.2018.01.052

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 3 works

Citation information provided by
Web of Science

Figures / Tables:

Fig. 1: A schematic illustration of a GIXRD measurement of an oxidized UO₂ pellet. During data collection, the x-ray incident angle $ω $is fixed while the point detector rotates over the desired 2$θ$ measurement range. By varying $ω$ the penetration of x-rays into the sample surface can be controlled, suchmore »

All figures and tables (6 total)

Save / Share:

Export Metadata

Save to My Library

Figures / Tables found in this record:

Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

Similar Records in DOE PAGES and OSTI.GOV collections:

Trace Impurities Identified as Forensic Signatures in CMX-5 Fuel Pellets Using X-ray Spectroscopic Techniques

Journal Article van Veelen, Arjen ; Hickam, Sarah M. ; Edwards, Nicholas P. ; ... - Analytical Chemistry

We report that small-particle analysis is a highly promising emerging forensic tool for analysis of interdicted special nuclear materials. Integration of microstructural, morphological, compositional, and molecular impurity signatures could provide significant advancements in forensic capabilities. We have applied rapid, high-sensitivity, hard X-ray synchrotron chemical imaging to analyze impurity signatures in two differently fabricated fuel pellets from the 5th Collaborative Materials Exercise (CMX5) of the IAEA Nuclear Forensics International Working Group. The spatial distributions, chemical compositions, and morphological and molecular characteristics of impurities were evaluated using X-ray absorption near-edge structure (XANES) and X-ray fluorescence chemical imaging to discover principal impurities, theirmore »« less
https://doi.org/10.1021/acs.analchem.2c00629
Hydrogen and oxygen stable isotope composition of water in metaschoepite mineralization on U₃O₈

Journal Article Oerter, Erik J. ; Singleton, Michael ; Dai, Zurong ; ... - Applied Geochemistry

When exposed to humidity in an oxidizing atmosphere hydrated uranium oxide grows as a secondary mineral on aged U₃O₈ and may incorporate the oxygen stable isotope signature of the water vapor into the secondary uranium oxide, as well as hydrogen and oxygen stable isotopes into any mineral hydration water. Because geospatial variation in δ²H and δ¹⁸O values of atmospheric humidity and precipitation is well understood, the H and O stable isotope composition of mineral hydration waters can give information on the environment of mineral formation. We exposed powdered U₃O₈ to humidity with known H and O stable isotope composition atmore »« less
https://doi.org/10.1016/j.apgeochem.2019.104469

Full Text Available
U.S. and Russian Collaboration in the Area of Nuclear Forensics

Conference Kristo, M J

Nuclear forensics has become increasingly important in the fight against illicit trafficking in nuclear and other radioactive materials. The illicit trafficking of nuclear materials is, of course, an international problem; nuclear materials may be mined and milled in one country, manufactured in a second country, diverted at a third location, and detected at a fourth. There have been a number of articles in public policy journals in the past year that call for greater interaction between the U. S. and the rest of the world on the topic of nuclear forensics. Some believe that such international cooperation would help providemore »« less
Full Text Available
Nuclear forensic analysis of a non-traditional actinide sample

Journal Article Doyle, Jamie L. ; Kuhn, Kevin John ; Byerly, Benjamin ; ... - Talanta

Nuclear forensic publications, performance tests, and research and development efforts typically target the bulk global inventory of intentionally safeguarded materials, such as plutonium (Pu) and uranium (U). Other materials, such as neptunium (Np), pose a nuclear security risk as well. Trafficking leading to recovery of an interdicted Np sample is a realistic concern especially for materials originating in countries that reprocesses fuel. Using complementary forensic methods, potential signatures for an unknown Np oxide sample were investigated. Measurement results were assessed against published Np processes to present hypotheses as to the original intended use, method of production, and origin for thismore » Np oxide.« less
https://doi.org/10.1016/j.talanta.2016.06.028

Full Text Available
Probing the hydrolytic degradation of UF₄ in humid air

Journal Article Foley, Bryan J. ; Christian, Jonathan H. ; Klug, Christopher A. ; ... - Dalton Transactions

This manuscript describes the chemical transformations that occur during hydrolysis of uranium tetrafluoride (UF₄) due to its storage in humid air (85% and 50% relative humidity) at ambient temperatures. This hydrolysis was previously reported to proceed slowly or not at all (depending on the percent relative humidity); however, previous reports relied primarily on X-ray diffraction methods to probe uranium speciation. Here, we employ a battery of physiochemical probing techniques to explore potential hydrolysis, including Raman spectroscopy, powder X-ray diffraction, ¹⁹F nuclear magnetic resonance spectroscopy, scanning electron microscopy, and focused ion beam microscopy with energy-dispersive X-ray spectroscopy. Of these, only Ramanmore »« less
https://doi.org/10.1039/d2dt00196a

Full Text Available

Similar Records

Title: Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics

Abstract

Citation Formats

Figures / Tables:

Title: Measurement of UO₂ surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics