The defect chemistry of UO2±x from atomistic simulations

Cooper, Michael William Donald; Murphy, Samuel T; Andersson, Anders David Ragnar

doi:10.1016/j.jnucmat.2018.02.034

Title: The defect chemistry of $U O_{2 \pm x}$ from atomistic simulations

Journal Article · Fri Jun 01 00:00:00 EDT 2018 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2018.02.034· OSTI ID:1524370

^[1]; Murphy, Samuel T ^[2];

^[1]

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Lancaster Univ. (United Kingdom). Dept. of Engineering

Control of the defect chemistry in UO_2±x is important for manipulating nuclear fuel properties and fuel performance. For example, the uranium vacancy concentration is critical for fission gas release and sintering, while all oxygen and uranium defects are known to strongly influence thermal conductivity. Here the point defect concentrations in thermal equilibrium are predicted using defect energies from density functional theory (DFT) and vibrational entropies calculated using empirical potentials. Electrons and holes have been treated in a similar fashion to other charged defects allowing for structural relaxation around the localized electronic defects. Predictions are made for the defect concentrations and non-stoichiometry of UO_2±x as a function of oxygen partial pressure and temperature. If vibrational entropy is omitted, oxygen interstitials are predicted to be the dominant mechanism of excess oxygen accommodation over only a small temperature range (1265 K to 1350 K), in contrast to experimental observation. Conversely, if vibrational entropy is included oxygen interstitials dominate from 1165 K to 1680 K (Busker potential) or from 1275 K to 1630 K (CRG potential). Below these temperature ranges excess oxygen is predicted to be accommodated by uranium vacancies, while above them the system is hypo-stoichiometric with oxygen deficiency accommodated by oxygen vacancies. Our results are discussed in the context of oxygen clustering, formation of U₄O₉, and issues for fuel behavior. In particular, the variation of the uranium vacancy concentrations as a function of temperature and oxygen partial pressure will underpin future studies into fission gas diffusivity and broaden the understanding of UO_2±x sintering.

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Research Organization:: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Organization:: USDOE Office of Nuclear Energy (NE); USDOE National Nuclear Security Administration (NNSA)

Grant/Contract Number:: 89233218CNA000001; AC52-06NA25396

OSTI ID:: 1524370

Alternate ID(s):: OSTI ID: 1550712

Report Number(s):: LA-UR-17-29135

Journal Information:: Journal of Nuclear Materials, Vol. 504, Issue C; ISSN 0022-3115

Publisher:: ElsevierCopyright Statement

Country of Publication:: United States

Language:: English

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Cited by: 31 works

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References (70)

A comparison of the behaviour of fission gases in UO2±x and α-U3O8−z Ball, Richard G. J.; Grimes, Robin W. Journal of Nuclear Materials, Vol. 188 https://doi.org/10.1016/0022-3115(92)90474-Y	journal	June 1992
U and Xe transport in UO $_{2 \pm x}$ : Density functional theory calculations Andersson, D. A.; Uberuaga, B. P.; Nerikar, P. V. Physical Review B, Vol. 84, Issue 5 https://doi.org/10.1103/PhysRevB.84.054105	journal	August 2011
Molecular Dynamics Simulation of Thermal Transport in ${UO}_{2}$ Containing Uranium, Oxygen, and Fission-product Defects Liu, X. -Y.; Cooper, M. W. D.; McClellan, K. J. Physical Review Applied, Vol. 6, Issue 4 https://doi.org/10.1103/PhysRevApplied.6.044015	journal	October 2016
Relations between the Concentrations of Imperfections in Crystalline Solids Kröger, F. A.; Vink, H. J. Solid State Physics https://doi.org/10.1016/S0081-1947(08)60135-6	book	January 1956
The low temperature oxidation of UO2 and U4O9 Hoekstra, H. R.; Santoro, A.; Siegel, S. Journal of Inorganic and Nuclear Chemistry, Vol. 18 https://doi.org/10.1016/0022-1902(61)80384-9	journal	March 1961
Metallographic determination of the UO2-U409 phase diagram Schaner, B. E. Journal of Nuclear Materials, Vol. 2, Issue 2 https://doi.org/10.1016/0022-3115(60)90038-6	journal	June 1960
System UO3+ U3O8: dissociation pressure of ?-UO3 Cordfunke, E. H. P.; Aling, P. Transactions of the Faraday Society, Vol. 61 https://doi.org/10.1039/tf9656100050	journal	January 1965
High‐Temperature Thermodynamic Properties of Oxygen‐Deficient Urania Tetenbaum, M.; Hunt, P. D. The Journal of Chemical Physics, Vol. 49, Issue 11 https://doi.org/10.1063/1.1669953	journal	December 1968
Thermodynamic study of hypostoichiometric urania Javed, N. A. Journal of Nuclear Materials, Vol. 43, Issue 3 https://doi.org/10.1016/0022-3115(72)90053-0	journal	June 1972
Étude thermodynamique des oxydes UO _2+x Gerdanian, Paul; Dodé, Maurice Journal de Chimie Physique, Vol. 62 https://doi.org/10.1051/jcp/1965620171	journal	January 1965
Détermination des pressions partielles d’oxygène en équilibre avec les oxydes non-stœchiométriques du système U — O pour 1 080 < θ °C < 1 150 et 2,19 < O/U < 2,63: I. —Tracé de l’isotherme P _O2 (O/U) à 1 098 °C. Essai d’interprétation de la complexité des phénomènes observés par analogie avec la théorie des « petits systèmes » de Terrell L. HILL Kotlar, Alain; Gerdanian, Paul; Dodé, Maurice Journal de Chimie Physique, Vol. 64 https://doi.org/10.1051/jcp/1967640862	journal	January 1967
Détermination des pressions partielles d’oxygène en équilibre avec les oxydes non-stœchiométriques du système U — O pour 1 050 °C < θ < 1 150 °C et 2,19 < O/U < 2,63: II. — Tracé des isothermes Po ₂ (O/U) pour 1 082 °C — 1 098 °C — 1 123° C — 1137 °C et 1 150 °C. Diagramme des phases Kotlar, Alain; Gerdanian, Paul; Dodé, Maurice Journal de Chimie Physique, Vol. 64 https://doi.org/10.1051/jcp/1967641135	journal	January 1967
N° 57. — Détermination des limites de phases du système U —O par « transfert d’oxygène ». — Diagramme de phase pour la région 2,19 < O/U < 2,63 et 1080 < 0 °C < 1200 Kotlar, Alain; Gerdanian, Paul; Dodé, Maurice Journal de Chimie Physique, Vol. 65 https://doi.org/10.1051/jcp/1968650687	journal	January 1968
Equilibrium oxygen pressures over the nonstoicheiometric uranium oxides UO2+x and U3O8−z at higher temperatures Hagemark, K.; Broli, M. Journal of Inorganic and Nuclear Chemistry, Vol. 28, Issue 12 https://doi.org/10.1016/0022-1902(66)80010-6	journal	December 1966
Oxygen Dissociation Pressures over Uranium Oxides Blackburn, P. E. The Journal of Physical Chemistry, Vol. 62, Issue 8 https://doi.org/10.1021/j150566a001	journal	August 1958
Equilibrium pressures and phase relations in the uranium oxide system Roberts, L. E. J.; Walter, A. J. Journal of Inorganic and Nuclear Chemistry, Vol. 22, Issue 3-4 https://doi.org/10.1016/0022-1902(61)80437-5	journal	December 1961
Nonstoichiometry in uranium dioxide Yasutoshi, Saito Journal of Nuclear Materials, Vol. 51, Issue 1 https://doi.org/10.1016/0022-3115(74)90121-4	journal	May 1974
High-Temperature Electrochemical Study of Uranium Oxides in the UO2-U3O8 Region. Kiukkola, Kalevi; Yhland, Margareta; Krohn, C. Acta Chemica Scandinavica, Vol. 16 https://doi.org/10.3891/acta.chem.scand.16-0327	journal	January 1962
Thermodynamic study of UO2 +x by solid state emf technique Nakamura, Akio; Fujino, Takeo Journal of Nuclear Materials, Vol. 149, Issue 1 https://doi.org/10.1016/0022-3115(87)90501-0	journal	June 1987
The defect structure of hyper-stoichiometric uranium dioxide Willis, B. T. M. Acta Crystallographica Section A, Vol. 34, Issue 1 https://doi.org/10.1107/S0567739478000157	journal	January 1978
First-principles DFT $+ U$ modeling of actinide-based alloys: Application to paramagnetic phases of UO $_{2}$ and (U,Pu) mixed oxides Dorado, Boris; Garcia, Philippe Physical Review B, Vol. 87, Issue 19 https://doi.org/10.1103/PhysRevB.87.195139	journal	May 2013
First-principles calculations of uranium diffusion in uranium dioxide Dorado, Boris; Andersson, David A.; Stanek, Christopher R. Physical Review B, Vol. 86, Issue 3 https://doi.org/10.1103/PhysRevB.86.035110	journal	July 2012
First-principles study of noble gas impurities and defects in UO $_{2}$ Thompson, Alexander E.; Wolverton, C. Physical Review B, Vol. 84, Issue 13 https://doi.org/10.1103/PhysRevB.84.134111	journal	October 2011
Role of di-interstitial clusters in oxygen transport in ${UO}_{2 + x}$ from first principles Andersson, D. A.; Watanabe, T.; Deo, C. Physical Review B, Vol. 80, Issue 6 https://doi.org/10.1103/PhysRevB.80.060101	journal	August 2009
Atomistic modeling of intrinsic and radiation-enhanced fission gas (Xe) diffusion in <mml:math altimg="si236.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd" xmlns:sa="http://www.elsevier.com/xml/common/struct-aff/dtd"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">UO</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>±</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>: Implications for nuclear fuel performance modeling Andersson, D. A.; Garcia, P.; Liu, X. -Y. Journal of Nuclear Materials, Vol. 451, Issue 1-3 https://doi.org/10.1016/j.jnucmat.2014.03.041	journal	August 2014
First-Principles Calculation of Point Defects in Uranium Dioxide Iwasawa, Misako; Chen, Ying; Kaneta, Yasunori MATERIALS TRANSACTIONS, Vol. 47, Issue 11 https://doi.org/10.2320/matertrans.47.2651	journal	January 2006
First-principles study with charge effects of the incorporation of iodine in UO2 Crocombette, Jean-Paul Journal of Nuclear Materials, Vol. 429, Issue 1-3 https://doi.org/10.1016/j.jnucmat.2012.05.037	journal	October 2012
Erratum: DFT + U investigation of charged point defects and clusters in UO ₂ (2014 J. Phys.: Condens. Matter 26 325501) Vathonne, Emerson; Wiktor, Julia; Freyss, Michel Journal of Physics: Condensed Matter, Vol. 26, Issue 34 https://doi.org/10.1088/0953-8984/26/34/349601	journal	August 2014
Stability of oxygen point defects in ${UO}_{2}$ by first-principles $DFT + U$ calculations: Occupation matrix control and Jahn-Teller distortion Dorado, Boris; Jomard, Gérald; Freyss, Michel Physical Review B, Vol. 82, Issue 3 https://doi.org/10.1103/PhysRevB.82.035114	journal	July 2010
Plane-wave pseudopotential study of point defects in uranium dioxide Crocombette, J. P.; Jollet, F.; Nga, L. Thien Physical Review B, Vol. 64, Issue 10 https://doi.org/10.1103/PhysRevB.64.104107	journal	August 2001
Charge states of point defects in uranium oxide calculated with a local hybrid functional for correlated electrons Crocombette, Jean-Paul; Torumba, Doru; Chartier, Alain Physical Review B, Vol. 83, Issue 18 https://doi.org/10.1103/PhysRevB.83.184107	journal	May 2011
First-principles study of defects and phase transition in UO ₂ Yu, Jianguo; Devanathan, Ram; Weber, William J. Journal of Physics: Condensed Matter, Vol. 21, Issue 43 https://doi.org/10.1088/0953-8984/21/43/435401	journal	October 2009
Comparison of interatomic potentials for UO2. Part I: Static calculations Govers, K.; Lemehov, S.; Hou, M. Journal of Nuclear Materials, Vol. 366, Issue 1-2 https://doi.org/10.1016/j.jnucmat.2006.12.070	journal	June 2007
Thermophysical properties and oxygen transport in the (U ,Pu1−)O2 lattice Cooper, M. W. D.; Murphy, S. T.; Rushton, M. J. D. Journal of Nuclear Materials, Vol. 461 https://doi.org/10.1016/j.jnucmat.2015.03.024	journal	June 2015
Vacancy mediated cation migration in uranium dioxide: The influence of cluster configuration Cooper, M. W. D.; Middleburgh, S. C.; Grimes, R. W. Solid State Ionics, Vol. 266 https://doi.org/10.1016/j.ssi.2014.08.010	journal	November 2014
Determination of Krypton Diffusion Coefficients in Uranium Dioxide Using Atomic Scale Calculations Vathonne, Emerson; Andersson, David A.; Freyss, Michel Inorganic Chemistry, Vol. 56, Issue 1 https://doi.org/10.1021/acs.inorgchem.6b01560	journal	December 2016
Point defects and non-stoichiometry in thoria Murphy, S. T.; Cooper, M. W. D.; Grimes, R. W. Solid State Ionics, Vol. 267 https://doi.org/10.1016/j.ssi.2014.09.017	journal	December 2014
Ab initio molecular dynamics for open-shell transition metals Kresse, G.; Hafner, J. Physical Review B, Vol. 48, Issue 17 https://doi.org/10.1103/PhysRevB.48.13115	journal	November 1993
Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set Kresse, G.; Furthmüller, J. Physical Review B, Vol. 54, Issue 16, p. 11169-11186 https://doi.org/10.1103/PhysRevB.54.11169	journal	October 1996
Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set Kresse, G.; Furthmüller, J. Computational Materials Science, Vol. 6, Issue 1, p. 15-50 https://doi.org/10.1016/0927-0256(96)00008-0	journal	July 1996
Projector augmented-wave method Blöchl, P. E. Physical Review B, Vol. 50, Issue 24, p. 17953-17979 https://doi.org/10.1103/PhysRevB.50.17953	journal	December 1994
From ultrasoft pseudopotentials to the projector augmented-wave method Kresse, G.; Joubert, D. Physical Review B, Vol. 59, Issue 3, p. 1758-1775 https://doi.org/10.1103/PhysRevB.59.1758	journal	January 1999
Density-functional theory and strong interactions: Orbital ordering in Mott-Hubbard insulators Liechtenstein, A. I.; Anisimov, V. I.; Zaanen, J. Physical Review B, Vol. 52, Issue 8 https://doi.org/10.1103/PhysRevB.52.R5467	journal	August 1995
Effect of Mott-Hubbard correlations on the electronic structure and structural stability of uranium dioxide Dudarev, S. L.; Manh, D. Nguyen; Sutton, A. P. Philosophical Magazine B, Vol. 75, Issue 5 https://doi.org/10.1080/13642819708202343	journal	May 1997
Method for locating low-energy solutions within $DFT + U$ Meredig, B.; Thompson, A.; Hansen, H. A. Physical Review B, Vol. 82, Issue 19 https://doi.org/10.1103/PhysRevB.82.195128	journal	November 2010
$DFT + U$ calculations of the ground state and metastable states of uranium dioxide Dorado, Boris; Amadon, Bernard; Freyss, Michel Physical Review B, Vol. 79, Issue 23 https://doi.org/10.1103/PhysRevB.79.235125	journal	June 2009
Magnetism of actinide compounds Santini, P.; Lémanski, Romuald; Erdős, Paul Advances in Physics, Vol. 48, Issue 5 https://doi.org/10.1080/000187399243419	journal	September 1999
Special points for Brillouin-zone integrations Monkhorst, Hendrik J.; Pack, James D. Physical Review B, Vol. 13, Issue 12, p. 5188-5192 https://doi.org/10.1103/PhysRevB.13.5188	journal	June 1976
Accurate prediction of defect properties in density functional supercell calculations Lany, Stephan; Zunger, Alex Modelling and Simulation in Materials Science and Engineering, Vol. 17, Issue 8 https://doi.org/10.1088/0965-0393/17/8/084002	journal	November 2009
Anisotropic charge screening and supercell size convergence of defect formation energies Murphy, Samuel T.; Hine, Nicholas D. M. Physical Review B, Vol. 87, Issue 9 https://doi.org/10.1103/PhysRevB.87.094111	journal	March 2013
Dielectric Constant of UO ₂ at 9.4 GHz Gesi, Kazuo; Tateno, Jun Japanese Journal of Applied Physics, Vol. 8, Issue 11 https://doi.org/10.1143/JJAP.8.1358	journal	November 1969
Understanding and correcting the spurious interactions in charged supercells Taylor, Samuel E.; Bruneval, Fabien Physical Review B, Vol. 84, Issue 7 https://doi.org/10.1103/PhysRevB.84.075155	journal	August 2011
GULP: A computer program for the symmetry-adapted simulation of solids Gale, Julian D. Journal of the Chemical Society, Faraday Transactions, Vol. 93, Issue 4 https://doi.org/10.1039/a606455h	journal	January 1997
Solution Mechanisms for Dopant Oxides in Yttria Busker, Gerdjan; Chroneos, Alex; Grimes, Robin W. Journal of the American Ceramic Society, Vol. 82, Issue 6 https://doi.org/10.1111/j.1151-2916.1999.tb01954.x	journal	June 1999
A many-body potential approach to modelling the thermomechanical properties of actinide oxides Cooper, M. W. D.; Rushton, M. J. D.; Grimes, R. W. Journal of Physics: Condensed Matter, Vol. 26, Issue 10 https://doi.org/10.1088/0953-8984/26/10/105401	journal	February 2014
The Crystal Dynamics of Uranium Dioxide Dolling, G.; Cowley, R. A.; Woods, A. D. B. Canadian Journal of Physics, Vol. 43, Issue 8 https://doi.org/10.1139/p65-135	journal	August 1965
Thermophysical properties of uranium dioxide Fink, J. K. Journal of Nuclear Materials, Vol. 279, Issue 1 https://doi.org/10.1016/S0022-3115(99)00273-1	journal	March 2000
THE OXIDATION OF NIAL: What Can We Learn from Ab Initio Calculations? Finnis, M. W.; Lozovoi, A. Y.; Alavi, A. Annual Review of Materials Research, Vol. 35, Issue 1 https://doi.org/10.1146/annurev.matsci.35.101503.091652	journal	August 2005
Point Defects and Non-stoichiometry in Li ₂ TiO ₃ Murphy, Samuel T.; Hine, Nicholas D. M. Chemistry of Materials, Vol. 26, Issue 4 https://doi.org/10.1021/cm4038473	journal	February 2014
Effect of stoichiometry on diffusion of xenon in UO2 Miekeley, W.; Felix, F. W. Journal of Nuclear Materials, Vol. 42, Issue 3 https://doi.org/10.1016/0022-3115(72)90080-3	journal	March 1972
Density Functional Theory Calculations of UO ₂ Oxidation: Evolution of UO _{2+ x} , U ₄ O _{9– y} , U ₃ O ₇ , and U ₃ O ₈ Andersson, D. A.; Baldinozzi, G.; Desgranges, L. Inorganic Chemistry, Vol. 52, Issue 5 https://doi.org/10.1021/ic400118p	journal	February 2013
Computer simulation of defect clusters in UO2 and their dependence on composition Brincat, N. A.; Molinari, M.; Parker, S. C. Journal of Nuclear Materials, Vol. 456 https://doi.org/10.1016/j.jnucmat.2014.10.001	journal	January 2015
Accommodation of excess oxygen in fluorite dioxides Middleburgh, S. C.; Lumpkin, G. R.; Grimes, R. W. Solid State Ionics, Vol. 253 https://doi.org/10.1016/j.ssi.2013.09.020	journal	December 2013
Kinetics of precipitation of U4O9 from hyperstoichiometric UO2+x Higgs, J. D.; Thompson, W. T.; Lewis, B. J. Journal of Nuclear Materials, Vol. 366, Issue 3 https://doi.org/10.1016/j.jnucmat.2007.03.054	journal	July 2007
Les equilibres des composes oxygenes de l'uranium entre 1500 ET 2000° K Anthony, A. M.; Kiyoura, R.; Sata, T. Journal of Nuclear Materials, Vol. 10, Issue 1 https://doi.org/10.1016/0022-3115(63)90112-0	journal	September 1963
On the phase limits of U4O9 Van Lierde, W.; Pelsmaekers, J.; Lecocq-Robert, A. Journal of Nuclear Materials, Vol. 37, Issue 3 https://doi.org/10.1016/0022-3115(70)90157-1	journal	December 1970
X-ray study on a phase transition and a phase diagram in the U4O9 phase Ishii, T.; Naito, K.; Oshima, K. Solid State Communications, Vol. 8, Issue 9 https://doi.org/10.1016/0038-1098(70)90194-8	journal	May 1970
High-temperature X-ray study of uranium oxides in the UO2U3O8 region Grønvold, Fredrik Journal of Inorganic and Nuclear Chemistry, Vol. 1, Issue 6 https://doi.org/10.1016/0022-1902(55)80046-2	journal	December 1955
Electronic transitions, crystal field effects and phonons in UO2 Schoenes, J. Physics Reports, Vol. 63, Issue 6 https://doi.org/10.1016/0370-1573(80)90158-1	journal	August 1980
Optical properties and electronic structure of UO ₂ Schoenes, J. Journal of Applied Physics, Vol. 49, Issue 3 https://doi.org/10.1063/1.324978	journal	March 1978

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