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

S.O. Valu; O. Beneš; D Manara; R. J.M. Konings; M. W.D. Cooper; R. W. Grimes; C Guéneau

doi:10.1016/j.jnucmat.2016.11.010

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

S.O. Valu, O. Beneš, D Manara, R. J.M. Konings^*, M. W.D. Cooper, R. W. Grimes, C Guéneau

^*Corresponding author for this work

Research output: Contribution to journal › Article › Scientific › peer-review

13 Citations (Scopus)

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. 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.

Original language	English
Pages (from-to)	1-6
Number of pages	6
Journal	Journal of Nuclear Materials
Volume	484
DOIs	https://doi.org/10.1016/j.jnucmat.2016.11.010
Publication status	Published - 1 Feb 2017

Keywords

Actinide mixed oxides
Calorimetry
Heat capacity

Access to Document

10.1016/j.jnucmat.2016.11.010

Cite this

@article{d05b0189f85646eeb5d9c8d3cf12e9b0,

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

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. 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.",

keywords = "Actinide mixed oxides, Calorimetry, Heat capacity",

author = "S.O. Valu and O. Bene{\v s} and D Manara and Konings, {R. J.M.} and Cooper, {M. W.D.} and Grimes, {R. W.} and C Gu{\'e}neau",

year = "2017",

month = feb,

day = "1",

doi = "10.1016/j.jnucmat.2016.11.010",

language = "English",

volume = "484",

pages = "1--6",

journal = "Journal of Nuclear Materials",

issn = "0022-3115",

publisher = "Elsevier",

}

TY - JOUR

T1 - The high-temperature heat capacity of the (Th,U)O2 and (U,Pu)O2 solid solutions

AU - Valu, S.O.

AU - Beneš, O.

AU - Manara, D

AU - Konings, R. J.M.

AU - Cooper, M. W.D.

AU - Grimes, R. W.

AU - Guéneau, C

PY - 2017/2/1

Y1 - 2017/2/1

N2 - 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. 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.

AB - 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. 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.

KW - Actinide mixed oxides

KW - Calorimetry

KW - Heat capacity

UR - http://www.scopus.com/inward/record.url?scp=84997470982&partnerID=8YFLogxK

U2 - 10.1016/j.jnucmat.2016.11.010

DO - 10.1016/j.jnucmat.2016.11.010

M3 - Article

AN - SCOPUS:84997470982

SN - 0022-3115

VL - 484

SP - 1

EP - 6

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

ER -

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

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this