Energetics of hydration on uranium oxide and peroxide surfaces


Enthalpies of water adsorption on amorphous and crystalline oxides and peroxides of uranium are reported. Despite substantial structural and computational research on reactions between actinides and water, understanding their surface interactions from the energetic perspective remains incomplete. Direct calorimetric measurements of hydration energetics of nano-sized, bulk-sized UO2, U3O8, anhydrous γ-UO3, amorphous UO3, and U2O7 were carried out, and their integral adsorption enthalpies were determined to be −67.0, −70.2, −73.0, −84.1, −61.6, and −83.6 kJ/mol water, with corresponding water coverages of 4.6, 4.5, 4.1, 5.2, 4.4, and 4.1 H2O per nm2, respectively. These energetic constraints are important for understanding the interfacial phenomena between water and U-containing phases. Additionally, this set of data also helps predict the absorption and desorption behavior of water from nuclear waste forms or used nuclear fuels under repository conditions. There are also underlying relations for water coverage among different U compounds. These experimentally determined data can be used as benchmark values for future computational investigations.

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  1. 1.

    T.E. Eriksen, U.B. Eklund, L. Werme, and J. Bruno: Dissolution of irradiated fuel: A radiolytic mass balance study. J. Nucl. Mater. 227, 76 (1995).

    CAS  Article  Google Scholar 

  2. 2.

    D.J. Wronkiewicz, J.K. Bates, S.F. Wolf, and E.C. Buck: Ten-year results from unsaturated drip tests with UO2 at 90 °C: Implications for the corrosion of spent nuclear fuel. J. Nucl. Mater. 238, 78 (1996).

    CAS  Article  Google Scholar 

  3. 3.

    S. Sunder, D.W. Shoesmith, and N.H. Miller: Oxidation and dissolution of nuclear fuel (UO2) by the products of the alpha radiolysis of water. J. Nucl. Mater. 244, 66 (1997).

    CAS  Article  Google Scholar 

  4. 4.

    H. Christensen and S. Sunder: Current state of knowledge of water radiolysis effects on spent nuclear fuel corrosion. Nucl. Technol. 131, 102 (2000).

    CAS  Article  Google Scholar 

  5. 5.

    J.M. Haschke, T.H. Allen, and L.A. Morales: Reaction of plutonium dioxide with water: Formation and properties of PuO2+x. Science 287, 285 (2000).

    CAS  Article  Google Scholar 

  6. 6.

    J.A. La Verne and L. Tandon: H2 production in the radiolysis of water on UO2 and other oxides. J. Phys. Chem. B 107, 13623 (2003).

    Article  CAS  Google Scholar 

  7. 7.

    S.D. Senanayake, G.I.N. Waterhouse, A.S.Y. Chan, T.E. Madey, D.R. Mullins, and H. Idriss: Probing surface oxidation of reduced uranium dioxide thin film using synchrotron radiation. J. Phys. Chem. C 111, 7963 (2007).

    CAS  Article  Google Scholar 

  8. 8.

    S.D. Senanayake, G.I.N. Waterhouse, A.S.Y. Chan, T.E. Madey, D.R. Mullins, and H. Idriss: The reactions of water vapour on the surfaces of stoichiometric and reduced uranium dioxide: A high resolution XPS study. Catal. Today 120, 151 (2007).

    CAS  Article  Google Scholar 

  9. 9.

    H. Idriss: Surface reactions of uranium oxide powder, thin films and single crystals. Surf. Sci. Rep. 65, 67 (2010).

    CAS  Article  Google Scholar 

  10. 10.

    S.B. Donald, Z.R. Dai, M.L. Davisson, J.R. Jeffries, and A.J. Nelson: An XPS study on the impact of relative humidity on the aging of UO2 powders. J. Nucl. Mater. 487, 105 (2017).

    CAS  Article  Google Scholar 

  11. 11.

    J.M. Haschke, T.H. Allen, and L.A. Morales: Surface and corrosion chemistry of plutonium. Los Alamos Sci. 26, 252 (2000).

    CAS  Google Scholar 

  12. 12.

    H.W. Xu, A. Navrotsky, M.D. Nyman, and T.M. Nenoff: Thermochemistry of microporous silicotitanate phases in the Na2O–Cs2O–SiO2–TiO2–H2O system. J. Mater. Res. 15, 815 (2000).

    CAS  Article  Google Scholar 

  13. 13.

    M.L. Balmer, Y. Su, H. Xu, E. Bitten, D. McCready, and A. Navrotsky: Synthesis, structure determination, and aqueous durability of Cs2ZrSi3O9. J. Am. Ceram. Soc. 84, 153 (2001).

    CAS  Article  Google Scholar 

  14. 14.

    F.N. Skomurski, L.C. Shuller, R.C. Ewing, and U. Becker: Corrosion of UO2 and ThO2: A quantum-mechanical investigation. J. Nucl. Mater. 375, 290 (2008).

    CAS  Article  Google Scholar 

  15. 15.

    X. Guo, S.V. Ushakov, S. Labs, H. Curtius, D. Bosbach, and A. Navrotsky: Energetics of metastudtite and implications for nuclear waste alteration. Proc. Natl. Acad. Sci. U.S.A. 111, 17737 (2014).

    CAS  Article  Google Scholar 

  16. 16.

    X. Guo, D. Wu, H. Xu, P.C. Burns, and A. Navrotsky: Thermodynamic studies of studtite thermal decomposition pathways via amorphous intermediates UO3, U2O7, and UO4. J. Nucl. Mater. 478, 158 (2016).

    CAS  Article  Google Scholar 

  17. 17.

    R.G. Haire and J.M. Haschke: Plutonium oxide systems and related corrosion products. MRS Bull. 26, 689 (2001).

    Article  Google Scholar 

  18. 18.

    G. Sattonnay, C. Ardois, C. Corbel, J.F. Lucchini, M.F. Barthe, F. Garrido, and D. Gosset: Alpha-radiolysis effects on UO2 alteration in water. J. Nucl. Mater. 288, 11 (2001).

    CAS  Article  Google Scholar 

  19. 19.

    B. McNamara, E. Buck, and B. Hanson: Observation of studtite and metastudtite on spent fuel. Mater. Res. Soc. Symp. Proc. 757, 401 (2003).

    CAS  Google Scholar 

  20. 20.

    X. Guo, S. Szenknect, A. Mesbah, S. Labs, N. Clavier, C. Poinssot, S.V. Ushakov, H. Curtius, D. Bosbach, R.C. Ewing, P.C. Burns, N. Dacheux, and A. Navrotsky: Thermodynamics of formation of coffinite, USiO4. Proc. Natl. Acad. Sci. U.S.A. 112, 6551 (2015).

    CAS  Article  Google Scholar 

  21. 21.

    K.A.H. Kubatko, K.B. Helean, A. Navrotsky, and P.C. Burns: Stability of peroxide-containing uranyl minerals. Science 302, 1191 (2003).

    Article  CAS  Google Scholar 

  22. 22.

    B. Hanson, B. McNamara, E. Buck, J. Friese, E. Jenson, K. Krupka, and B. Arey: Corrosion of commercial spent nuclear fuel. 1. Formation of studtite and metastudtite. Radiochim. Acta 93, 159 (2005).

    CAS  Article  Google Scholar 

  23. 23.

    C.R. Armstrong, M. Nyman, T. Shvareva, G.E. Sigmon, P.C. Burns, and A. Navrotsky: Uranyl peroxide enhanced nuclear fuel corrosion in seawater. Proc. Natl. Acad. Sci. U.S.A. 109, 1874 (2012).

    CAS  Article  Google Scholar 

  24. 24.

    E. Tiferet, A. Gil, C. Bo, T.Y. Shvareva, M. Nyman, and A. Navrotsky: The energy landscape of uranyl-peroxide species. Chem.–Eur. J. 20, 3646 (2014).

    CAS  Article  Google Scholar 

  25. 25.

    P. Taylor, R.J. Lemire, and D.D. Wood: The influence of moisture on air oxidation of UO2—Calculations and observations. Nucl. Technol. 104, 164 (1993).

    CAS  Article  Google Scholar 

  26. 26.

    M. Abramowski, S.E. Redfern, R.W. Grimes, and S. Owens: Modification of UO2 crystal morphologies through hydroxylation. Surf. Sci. 490, 415 (2001).

    CAS  Article  Google Scholar 

  27. 27.

    M. Jonsson, F. Nielsen, O. Roth, E. Ekeroth, S. Nilsson, and M.M. Hossain: Radiation induced spent nuclear fuel dissolution under deep repository conditions. Environ. Sci. Technol. 41, 7087 (2007).

    CAS  Article  Google Scholar 

  28. 28.

    C. Jegou, R. Caraballo, J. De Bonfils, V. Broudic, S. Peuget, T. Vercouter, and D. Roudil: Oxidizing dissolution of spent MOX47 fuel subjected to water radiolysis: Solution chemistry and surface characterization by Raman spectroscopy. J. Nucl. Mater. 399, 68 (2010).

    CAS  Article  Google Scholar 

  29. 29.

    A. Timofeev, A.A. Migdisov, A.E. Williams-Jones, R. Roback, A.T. Nelson, and H. Xu: Uranium transport in acidic brines under reducing conditions. Nat. Commun. 9, 1469 (2018).

    Article  CAS  Google Scholar 

  30. 30.

    B. Grambow and C. Poinssot: Interactions between nuclear fuel and water at the Fukushima Daiichi reactors. Elements 8, 213 (2012).

    CAS  Article  Google Scholar 

  31. 31.

    P.C. Burns, R.C. Ewing, and A. Navrotsky: Nuclear fuel in a reactor accident. Science 335, 1184 (2012).

    CAS  Article  Google Scholar 

  32. 32.

    X. Guo, J.T. White, A.T. Nelson, A. Migdisov, R. Roback, and H. Xu: Enthalpy of formation of U3Si2: A high-temperature drop calorimetry study. J. Nucl. Mater. 507, 44 (2018).

    CAS  Article  Google Scholar 

  33. 33.

    R. Finch and T. Murakami: Systematics and paragenesis of uranium minerals. Rev. Mineral. 38, 152 (1999).

    Google Scholar 

  34. 34.

    A.S. Icenhour, L.M. Toth, and H.M. Luo: Water sorption and gamma radiolysis studies for uranium oxides. Nucl. Technol. 147, 258 (2004).

    CAS  Article  Google Scholar 

  35. 35.

    H. Geckeis, J. Lutzenkirchen, R. Polly, T. Rabung, and M. Schmidt: Mineral-water interface reactions of actinides. Chem. Rev. 113, 1016 (2013).

    CAS  Article  Google Scholar 

  36. 36.

    J. Janeczek and R.C. Ewing: Coffinitization—A mechanism for the alteration of UO2 under reducing conditions. In Scientific Basis for Nuclear Waste Management XV, Vol. 257 (Materials Research Society, Warrendale, Pennsylvania, 1992); p. 497.

    Google Scholar 

  37. 37.

    A.P. Deditius, S. Utsunomiya, and R.C. Ewing: The chemical stability of coffinite, USiO4·nH2O; 0 < n < 2, associated with organic matter: A case study from grants uranium region, New Mexico, USA. Chem. Geol. 251, 33 (2008).

    CAS  Article  Google Scholar 

  38. 38.

    C. Frondel: Systematic mineralogy of uranium and thorium. U.S. Geol. Surv. Bull. 1064, 400 (1958).

    Google Scholar 

  39. 39.

    M. Deliens and P. Piret: Metastudtite, UO4·2H2O, a new mineral from Shinkolobwe, Shaba, Zaire. Am. Mineral. 68, 456 (1983).

    CAS  Google Scholar 

  40. 40.

    A.H.H. Tan, R.W. Grimes, and S. Owens: Structures of UO2 and PuO2 surfaces with hydroxide coverage. J. Nucl. Mater. 344, 13 (2005).

    CAS  Article  Google Scholar 

  41. 41.

    P.J. Hay: Theoretical studies of hydrogen and water adsorption on actinide oxide surfaces. Mater. Res. Soc. Symp. Proc. 893, 1–6 (2005).

    Article  Google Scholar 

  42. 42.

    F.N. Skomurski, R.C. Ewing, and U. Becker: Adsorption energy trends on UO2 and ThO2 surfaces. Geochim. Cosmochim. Acta 71, A945 (2007).

    Google Scholar 

  43. 43.

    V. Alexandrov, T.Y. Shvareva, S. Hayun, M. Asta, and A. Navrotsky: Actinide dioxides in water: Interactions at the interface. J. Phys. Chem. Lett. 2, 3130 (2011).

    CAS  Article  Google Scholar 

  44. 44.

    Z. Rak, R.C. Ewing, and U. Becker: Hydroxylation-induced surface stability of AnO2 (An = U, Np, Pu) from first-principles. Surf. Sci. 608, 180 (2013).

    CAS  Article  Google Scholar 

  45. 45.

    T. Bo, J.H. Lan, C.Z. Wang, Y.L. Zhao, C.H. He, Y.J. Zhang, Z.F. Chai, and W.Q. Shi: First-principles study of water reaction and H2 formation on UO2 (111) and (110) single crystal surfaces. J. Phys. Chem. C 118, 21935 (2014).

    CAS  Article  Google Scholar 

  46. 46.

    P. Maldonado, L.Z. Evins, and P.M. Oppeneer: Ab initio atomistic thermodynamics of water reacting with uranium dioxide surfaces. J. Phys. Chem. C 118, 8491 (2014).

    CAS  Article  Google Scholar 

  47. 47.

    X-f. Tian, H. Wang, H-x. Xiao, and T. Gao: Adsorption of water on UO2 (111) surface: Density functional theory calculations. Comput. Mater. Sci. 91, 364 (2014).

    CAS  Article  Google Scholar 

  48. 48.

    S.D. Senanayake and H. Idriss: Water reactions over stoichiometric and reduced UO2 (111) single crystal surfaces. Surf. Sci. 563, 135 (2004).

    CAS  Article  Google Scholar 

  49. 49.

    H. Idriss and S.D. Senanayake: Reaction of water on oxygen-defected UO2 (111) single crystal surface. Abstr. Pap. Am. Chem. S. 227, U89 (2004).

    Google Scholar 

  50. 50.

    A. Espriu-Gascon, J. Llorca, M. Domínguez, J. Giménez, I. Casas, and J. de Pablo: UO2 surface oxidation by mixtures of water vapor and hydrogen as a function of temperature. J. Nucl. Mater. 467, 240 (2015).

    CAS  Article  Google Scholar 

  51. 51.

    J.E. Stubbs, A.M. Chaka, E.S. Ilton, C.A. Biwer, M.H. Engelhard, J.R. Bargar, and P.J. Eng: UO2 oxidative corrosion by nonclassical diffusion. Phys. Rev. Lett. 114, 246103 (2015).

    Article  CAS  Google Scholar 

  52. 52.

    L. Shelly, D. Schweke, S. Zalkind, N. Shamir, S. Barzilai, T. Gouder, and S. Hayun: Effect of U content on the activation of H2O on Ce1−xUxO2+δ surfaces. Chem. Mater. 30, 8650–8660 (2018).

    CAS  Article  Google Scholar 

  53. 53.

    M.T. Paffett, D. Kelly, S.A. Joyce, J. Morris, and K. Veirs: A critical examination of the thermodynamics of water adsorption on actinide oxide surfaces. J. Nucl. Mater. 322, 45 (2003).

    CAS  Article  Google Scholar 

  54. 54.

    S.V. Ushakov and A. Navrotsky: Direct measurements of water adsorption enthalpy on hafnia and zirconia. Appl. Phys. Lett. 87, 164103 (2005).

    Article  CAS  Google Scholar 

  55. 55.

    S. Hayun, T.Y. Shvareva, and A. Navrotsky: Nanoceria—Energetics of surfaces, interfaces and water adsorption. J. Am. Ceram. Soc. 94, 3992 (2011).

    CAS  Article  Google Scholar 

  56. 56.

    S.O. Odoh, J. Shamblin, C.A. Colla, S. Hickam, H.L. Lobeck, R.A.K. Lopez, T. Olds, J.E.S. Szymanowski, G.E. Sigmon, J. Neuefeind, W.H. Casey, M. Lang, L. Gagliardi, and P.C. Burns: Structure and reactivity of X-ray amorphous uranyl peroxide, U2O7. Inorg. Chem. 55, 3541 (2016).

    CAS  Article  Google Scholar 

  57. 57.

    D. Wu, X. Guo, H. Sun, and A. Navrotsky: Energy landscape of water and ethanol on silica surfaces. J. Phys. Chem. C 119, 15428 (2015).

    CAS  Article  Google Scholar 

  58. 58.

    G. Li, H. Sun, H. Xu, X. Guo, and D. Wu: Probing the energetics of molecule–material interactions at interfaces and in nanopores. J. Phys. Chem. C 121, 26141 (2017).

    Article  CAS  Google Scholar 

  59. 59.

    R.J. McEachern and P. Taylor: A review of the oxidation of uranium dioxide at temperatures below 400 °C. J. Nucl. Mater. 254, 87 (1998).

    CAS  Article  Google Scholar 

  60. 60.

    G. Leinders, R. Bes, J. Pakarinen, K. Kvashnina, and M. Verwerft: Evolution of the uranium chemical state in mixed-valence oxides. Inorg. Chem. 56, 6784 (2017).

    CAS  Article  Google Scholar 

  61. 61.

    L. Desgranges, G. Baldinozzi, D. Simeone, and H. Fischer: Refinement of the α-U4O9 crystalline structure: New insight into the U4O9 → U3O8 transformation. Inorg. Chem. 50, 6146 (2011).

    CAS  Article  Google Scholar 

  62. 62.

    K. Kvashnina, S.M. Butorin, P. Martin, and P. Glatzel: Chemical state of complex uranium oxides. Phys. Rev. Lett. 111, 253002 (2013).

    CAS  Article  Google Scholar 

  63. 63.

    A.L. Tamasi, K.S. Boland, K. Czerwinski, J.K. Ellis, S.A. Kozimor, R.L. Martin, A.L. Pugmire, D. Reilly, B.L. Scott, A.D. Sutton, G.L. Wagner, J.R. Walensky, and M.P. Wilkerson: Oxidation and hydration of U3O8 materials following controlled exposure to temperature and humidity. Anal. Chem. 87, 4210 (2015).

    CAS  Article  Google Scholar 

  64. 64.

    G. Allen, P. Tempest, and J. Tyler: The formation of U3O8 on crystalline UO2. Philos. Mag. B 54, L67 (1986).

    CAS  Article  Google Scholar 

  65. 65.

    G.C. Allen, P.A. Tempest, and J.W. Tyler: Oxidation of crystalline UO2 studied using X-ray photoelectron spectroscopy and X-ray diffraction. J. Chem. Soc., Faraday Trans. 1 83, 925 (1987).

    CAS  Article  Google Scholar 

  66. 66.

    G. Allen and N. Holmes: A mechanism for the UO2 to α-U3O8 phase transformation. J. Nucl. Mater. 223, 231 (1995).

    CAS  Article  Google Scholar 

  67. 67.

    P. Taylor, D.D. Wood, D.G. Owen, and G-I. Park: Crystallization of U3O8 and hydrated UO3 on UO2 fuel in aerated water near 200 °C. J. Nucl. Mater. 183, 105 (1991).

    CAS  Article  Google Scholar 

  68. 68.

    S.V. Ushakov, N. Dalalo, and A. Navrotsky: Gas adsorption microcalorimetry: Probing energetics of oxide surfaces. Geochim. Cosmochim. Acta 69, A485 (2005).

    Article  CAS  Google Scholar 

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This work was supported by the Materials Science of Actinides (MSA), an Energy Frontier Research Center (EFRC), funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001089, and the Laboratory Directed Research and Development (LDRD) program (Project #20180007 DR) of Los Alamos National Laboratory (LANL). We thank Peter Burns for his support of this work through leading the MSA EFRC, and X.G. acknowledges support through a LANL Seaborg postdoctoral fellowship and, later, institutional funds from the Department of Chemistry at Washington State University. D.W. was also supported by the institutional funds from the Gene and Linda Voiland School of Chemical Engineering and Bioengineering at Washington State University. D.W. and X.G. acknowledge the fund of Alexandra Navrotsky Institute for Experimental Thermodynamics. LANL, an affirmative action/equal opportunity employer, is managed by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract 89233218CNA000001.

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Correspondence to Xiaofeng Guo or Di Wu or Alexandra Navrotsky.

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This author was an editor of this journal during the review and decision stage. For the JMR policy on review and publication of manuscripts authored by editors, please refer to http://www.mrs.org/editor-manuscripts/.

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Guo, X., Wu, D., Ushakov, S.V. et al. Energetics of hydration on uranium oxide and peroxide surfaces. Journal of Materials Research 34, 3319–3325 (2019). https://doi.org/10.1557/jmr.2019.192

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