The high-temperature heat capacity of the (Th,U)O2 and (U,Pu)O2 solid solutions

Valu, S. O.; Benes, O.; Manara, D.; Konings, Rudy J. M.; Cooper, Michael William Donald; Grimes, R. W.; Gueneau, C.

doi:10.1016/j.jnucmat.2016.11.010

Title: The high-temperature heat capacity of the (Th,U)O₂ and (U,Pu)O₂ solid solutions

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Abstract

The enthalpy increment data for the (Th,U)O₂ and (U,Pu)O₂ solid solutions are reviewed and complemented with new experimental data (400–1773 K) and many-body potential model simulations. The results of the review show that from room temperature up to about 2000 K the enthalpy data are in agreement with the additivity rule (Neumann-Kopp) in the whole composition range. Above 2000 K the effect of Oxygen Frenkel Pair (OFP) formation leads to an excess enthalpy (heat capacity) that is modeled using the enthalpy and entropy of OFP formation from the end-members. Here, a good agreement with existing experimental work is observed, and a reasonable agreement with the results of the many-body potential model, which indicate the presence of the diffuse Bredig (superionic) transition that is not found in the experimental enthalpy increment data.

Authors:

^[1]; Benes, O. ^[2]; Manara, D. ^[2];

^[1];

^[3]; Grimes, R. W. ^[4]; Gueneau, C. ^[5]

Joint Research Centre, Karlsruhe (Germany); Delft Univ. of Technology, Delft (The Netherlands)
Joint Research Centre, Karlsruhe (Germany)
Imperial College, London (United Kingdom); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Imperial College, London (United Kingdom)
CEA, DANS, DPC, SCCME, LM2T, Gif-sur-Yvette Cedex (France)

Publication Date:: Wed Nov 09 00:00:00 EST 2016

Research Org.:: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1375163

Report Number(s):: LA-UR-16-20239
Journal ID: ISSN 0022-3115

Grant/Contract Number:: AC52-06NA25396

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Nuclear Materials

Additional Journal Information:: Journal Volume: 484; Journal Issue: C; Journal ID: ISSN 0022-3115

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; Actinide mixed oxides; Calorimetry; Heat capacity

Citation Formats


                    Valu, S. O., Benes, O., Manara, D., Konings, Rudy J. M., Cooper, Michael William Donald, Grimes, R. W., and Gueneau, C. The high-temperature heat capacity of the (Th,U)O2 and (U,Pu)O2 solid solutions.  United States: N. p., 2016. 
Web.  doi:10.1016/j.jnucmat.2016.11.010.

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                    Valu, S. O., Benes, O., Manara, D., Konings, Rudy J. M., Cooper, Michael William Donald, Grimes, R. W., & Gueneau, C. The high-temperature heat capacity of the (Th,U)O2 and (U,Pu)O2 solid solutions.  United States.  https://doi.org/10.1016/j.jnucmat.2016.11.010

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                    Valu, S. O., Benes, O., Manara, D., Konings, Rudy J. M., Cooper, Michael William Donald, Grimes, R. W., and Gueneau, C. Wed .  
"The high-temperature heat capacity of the (Th,U)O2 and (U,Pu)O2 solid solutions".  United States.  https://doi.org/10.1016/j.jnucmat.2016.11.010.  https://www.osti.gov/servlets/purl/1375163.

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@article{osti_1375163,

  title        = {The high-temperature heat capacity of the (Th,U)O2 and (U,Pu)O2 solid solutions},

  author       = {Valu, S. O. and Benes, O. and Manara, D. and Konings, Rudy J. M. and Cooper, Michael William Donald and Grimes, R. W. and Gueneau, C.},

  abstractNote = {The enthalpy increment data for the (Th,U)O2 and (U,Pu)O2 solid solutions are reviewed and complemented with new experimental data (400–1773 K) and many-body potential model simulations. The results of the review show that from room temperature up to about 2000 K the enthalpy data are in agreement with the additivity rule (Neumann-Kopp) in the whole composition range. Above 2000 K the effect of Oxygen Frenkel Pair (OFP) formation leads to an excess enthalpy (heat capacity) that is modeled using the enthalpy and entropy of OFP formation from the end-members. Here, a good agreement with existing experimental work is observed, and a reasonable agreement with the results of the many-body potential model, which indicate the presence of the diffuse Bredig (superionic) transition that is not found in the experimental enthalpy increment data.},

  doi          = {10.1016/j.jnucmat.2016.11.010},

  journal      = {Journal of Nuclear Materials},

  number       = C,

  volume       = 484,

  place        = {United States},

  year         = {Wed Nov 09 00:00:00 EST 2016},

  month        = {Wed Nov 09 00:00:00 EST 2016}

}

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Title: The high-temperature heat capacity of the (Th,U)O2 and (U,Pu)O2 solid solutions

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Title: The high-temperature heat capacity of the (Th,U)O₂ and (U,Pu)O₂ solid solutions