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

JOURNAL OF NUCLEAR MATERIALS

卷:484

Article

Valu, S. O.^1,2  Benes, O.¹  Manara, D.¹  Konings, R. J. M.^1,2  Cooper, M. W. D.^3,4  Grimes, R. W.³  Gueneau, C.⁵ 

[1] European Commiss, Joint Res Ctr, POB 2340, D-76125 Karlsruhe, Germany

[2] Delft Univ Technol, Fac Appl Phys, Mekelweg 15, NL-2629 JB Delft, Netherlands

[3] Imperial Coll, Dept Mat, London SW7 2AZ, England

[4] Los Alamos Lab, Div Mat Sci & Technol, POB 1663, Los Alamos, NM 87545 USA

[5] Ctr Saclay, LM2T, SCCME, CEA,DANS,DPC, Gif Sur Yvette, France

关键词: Actinide mixed oxides;    Calorimetry;    Heat capacity;   

DOI  :  10.1016/j.jnucmat.2016.11.010

来源: Elsevier

【 摘 要 】

The enthalpy increment data for the (Th,U)O-2 and (U,Pu)O-2 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. 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. (C) 2016 Published by Elsevier B.V.

【 授权许可】

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