Atomic scale analysis of defect clustering and predictions of their concentrations in UO2+x

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Atomic scale analysis of defect clustering and predictions of their concentrations in UO2+x. / Çaglak, Emre; Govers, Kevin; Lamoen, Dirk; Labeau, Pierre-Etienne; Verwerft, Marc.

In: Journal of Nuclear Materials, Vol. 541, 152403, 12.2020.

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Çaglak, Emre ; Govers, Kevin ; Lamoen, Dirk ; Labeau, Pierre-Etienne ; Verwerft, Marc. / Atomic scale analysis of defect clustering and predictions of their concentrations in UO2+x. In: Journal of Nuclear Materials. 2020 ; Vol. 541.

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@article{ed3928195fb143ebb4a99665182fbf2c,
title = "Atomic scale analysis of defect clustering and predictions of their concentrations in UO2+x",
abstract = "The physical properties of uranium dioxide vary greatly with stoichiometry. Oxidation towards hyperstoichiometric UO2 − UO2+x – might be encountered at various stages of the nuclear fuel cycle if oxidative conditions are met; the impact of stoichiometry changes upon physical properties should therefore be properly assessed to ensure safe and reliable operations. These physical properties are intimately linked to the arrangement of atomic defects in the crystalline structure. The evolution of the defect concentration with environmental parameters – oxygen partial pressure and temperature – were evaluated by means of a point defect model where the reaction energies are derived from atomic-scale simulations. To this end, various configurations and net charge states of oxygen interstitial clusters in UO2 have been calculated. Various methodologies have been tested to determine the optimum cluster configurations and a rigid lattice approach turned out to be the most useful strategy to optimize defect configuration structures. Ultimately, results from the point defect model were discussed and compared to experimental measurements of stoichiometry dependence on oxygen partial pressure and temperature.",
keywords = "Uranium dioxide, Point defects, Defect clustering, Defect chemistry, Deviation from stoichiometry",
author = "Emre {\c C}aglak and Kevin Govers and Dirk Lamoen and Pierre-Etienne Labeau and Marc Verwerft",
note = "Score=10",
year = "2020",
month = dec,
doi = "10.1016/j.jnucmat.2020.152403",
language = "English",
volume = "541",
journal = "Journal of Nuclear Materials",
issn = "0022-3115",
publisher = "Elsevier",

}

RIS - Download

TY - JOUR

T1 - Atomic scale analysis of defect clustering and predictions of their concentrations in UO2+x

AU - Çaglak, Emre

AU - Govers, Kevin

AU - Lamoen, Dirk

AU - Labeau, Pierre-Etienne

AU - Verwerft, Marc

N1 - Score=10

PY - 2020/12

Y1 - 2020/12

N2 - The physical properties of uranium dioxide vary greatly with stoichiometry. Oxidation towards hyperstoichiometric UO2 − UO2+x – might be encountered at various stages of the nuclear fuel cycle if oxidative conditions are met; the impact of stoichiometry changes upon physical properties should therefore be properly assessed to ensure safe and reliable operations. These physical properties are intimately linked to the arrangement of atomic defects in the crystalline structure. The evolution of the defect concentration with environmental parameters – oxygen partial pressure and temperature – were evaluated by means of a point defect model where the reaction energies are derived from atomic-scale simulations. To this end, various configurations and net charge states of oxygen interstitial clusters in UO2 have been calculated. Various methodologies have been tested to determine the optimum cluster configurations and a rigid lattice approach turned out to be the most useful strategy to optimize defect configuration structures. Ultimately, results from the point defect model were discussed and compared to experimental measurements of stoichiometry dependence on oxygen partial pressure and temperature.

AB - The physical properties of uranium dioxide vary greatly with stoichiometry. Oxidation towards hyperstoichiometric UO2 − UO2+x – might be encountered at various stages of the nuclear fuel cycle if oxidative conditions are met; the impact of stoichiometry changes upon physical properties should therefore be properly assessed to ensure safe and reliable operations. These physical properties are intimately linked to the arrangement of atomic defects in the crystalline structure. The evolution of the defect concentration with environmental parameters – oxygen partial pressure and temperature – were evaluated by means of a point defect model where the reaction energies are derived from atomic-scale simulations. To this end, various configurations and net charge states of oxygen interstitial clusters in UO2 have been calculated. Various methodologies have been tested to determine the optimum cluster configurations and a rigid lattice approach turned out to be the most useful strategy to optimize defect configuration structures. Ultimately, results from the point defect model were discussed and compared to experimental measurements of stoichiometry dependence on oxygen partial pressure and temperature.

KW - Uranium dioxide

KW - Point defects

KW - Defect clustering

KW - Defect chemistry

KW - Deviation from stoichiometry

UR - https://ecm.sckcen.be/OTCS/llisapi.dll?func=ll&objId=43063285&objAction=download

U2 - 10.1016/j.jnucmat.2020.152403

DO - 10.1016/j.jnucmat.2020.152403

M3 - Article

VL - 541

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

SN - 0022-3115

M1 - 152403

ER -

ID: 7089346