Molecular dynamics simulation of helium and oxygen diffusion in UO2+-x

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Molecular dynamics simulation of helium and oxygen diffusion in UO2+-x. / Govers, Kevin; Lemehov, Sergei; Hou, Marc; Verwerft, Marc.

In: Journal of Nuclear Materials, Vol. 395, No. 1-3, 12.2009, p. 131-139.

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Govers, Kevin ; Lemehov, Sergei ; Hou, Marc ; Verwerft, Marc. / Molecular dynamics simulation of helium and oxygen diffusion in UO2+-x. In: Journal of Nuclear Materials. 2009 ; Vol. 395, No. 1-3. pp. 131-139.

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@article{9db3cea5693845afa09a97ac2a993be1,
title = "Molecular dynamics simulation of helium and oxygen diffusion in UO2+-x",
abstract = "Atomic scale simulation techniques based on empirical potentials have been considered in the present work to get insight on helium diffusion in uranium dioxide. By varying the stoichiometry, together with the system temperature, the performed molecular dynamics simulations indicate two diffusion regimes for He. The first one presents a low activation energy (0.5 eV) and suggests oxygen vacancies assisted migration. This regime seems to provide the major contribution to diffusion when structural defects are present (extrinsic defects, imposed, e.g. by the stoichiometry). The second regime presents a higher activation energy, around 2 eV, and dominates in the higher temperature range or at perfect stoichiometry, suggesting an intrinsic migration process. Considering the dependance of He behaviour with oxygen defects, oxygen diffusion has been considered as well in the different stoichiometry domains. Finally, further investigations were made with nudged elastic bands calculations for a better interpretation of the operating migration mechanisms, both for He and O.",
keywords = "MD, molecular dynamics, UO2, He, uranium dioxide, nuclear fuel, helium",
author = "Kevin Govers and Sergei Lemehov and Marc Hou and Marc Verwerft",
note = "Score = 10",
year = "2009",
month = "12",
doi = "10.1016/j.jnucmat.2009.10.043",
language = "English",
volume = "395",
pages = "131--139",
journal = "Journal of Nuclear Materials",
issn = "0022-3115",
publisher = "Elsevier",
number = "1-3",

}

RIS - Download

TY - JOUR

T1 - Molecular dynamics simulation of helium and oxygen diffusion in UO2+-x

AU - Govers, Kevin

AU - Lemehov, Sergei

AU - Hou, Marc

AU - Verwerft, Marc

N1 - Score = 10

PY - 2009/12

Y1 - 2009/12

N2 - Atomic scale simulation techniques based on empirical potentials have been considered in the present work to get insight on helium diffusion in uranium dioxide. By varying the stoichiometry, together with the system temperature, the performed molecular dynamics simulations indicate two diffusion regimes for He. The first one presents a low activation energy (0.5 eV) and suggests oxygen vacancies assisted migration. This regime seems to provide the major contribution to diffusion when structural defects are present (extrinsic defects, imposed, e.g. by the stoichiometry). The second regime presents a higher activation energy, around 2 eV, and dominates in the higher temperature range or at perfect stoichiometry, suggesting an intrinsic migration process. Considering the dependance of He behaviour with oxygen defects, oxygen diffusion has been considered as well in the different stoichiometry domains. Finally, further investigations were made with nudged elastic bands calculations for a better interpretation of the operating migration mechanisms, both for He and O.

AB - Atomic scale simulation techniques based on empirical potentials have been considered in the present work to get insight on helium diffusion in uranium dioxide. By varying the stoichiometry, together with the system temperature, the performed molecular dynamics simulations indicate two diffusion regimes for He. The first one presents a low activation energy (0.5 eV) and suggests oxygen vacancies assisted migration. This regime seems to provide the major contribution to diffusion when structural defects are present (extrinsic defects, imposed, e.g. by the stoichiometry). The second regime presents a higher activation energy, around 2 eV, and dominates in the higher temperature range or at perfect stoichiometry, suggesting an intrinsic migration process. Considering the dependance of He behaviour with oxygen defects, oxygen diffusion has been considered as well in the different stoichiometry domains. Finally, further investigations were made with nudged elastic bands calculations for a better interpretation of the operating migration mechanisms, both for He and O.

KW - MD

KW - molecular dynamics

KW - UO2

KW - He

KW - uranium dioxide

KW - nuclear fuel

KW - helium

UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_101346

UR - http://knowledgecentre.sckcen.be/so2/bibref/6246

U2 - 10.1016/j.jnucmat.2009.10.043

DO - 10.1016/j.jnucmat.2009.10.043

M3 - Article

VL - 395

SP - 131

EP - 139

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

SN - 0022-3115

IS - 1-3

ER -

ID: 82619