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Title: Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels

Authors:
ORCiD logo; ORCiD logo; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1396914
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 490; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 15:29:44; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Hu, Shenyang, Setyawan, Wahyu, Joshi, Vineet V., and Lavender, Curt A.. Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels. Netherlands: N. p., 2017. Web. doi:10.1016/j.jnucmat.2017.04.016.
Hu, Shenyang, Setyawan, Wahyu, Joshi, Vineet V., & Lavender, Curt A.. Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels. Netherlands. doi:10.1016/j.jnucmat.2017.04.016.
Hu, Shenyang, Setyawan, Wahyu, Joshi, Vineet V., and Lavender, Curt A.. Sat . "Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels". Netherlands. doi:10.1016/j.jnucmat.2017.04.016.
@article{osti_1396914,
title = {Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels},
author = {Hu, Shenyang and Setyawan, Wahyu and Joshi, Vineet V. and Lavender, Curt A.},
abstractNote = {},
doi = {10.1016/j.jnucmat.2017.04.016},
journal = {Journal of Nuclear Materials},
number = C,
volume = 490,
place = {Netherlands},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.jnucmat.2017.04.016

Citation Metrics:
Cited by: 3works
Citation information provided by
Web of Science

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  • We study computationally the formation of thermodynamics and morphology of silicon self-interstitial clusters using a suite of methods driven by a recent parameterization of the Tersoff empirical potential. Formation free energies and cluster capture zones are computed across a wide range of cluster sizes (2 < N{sub i} < 150) and temperatures (0.65 < T/T{sub m} < 1). Self-interstitial clusters above a critical size (N{sub i} ∼ 25) are found to exhibit complex morphological behavior in which clusters can assume either a variety of disordered, three-dimensional configurations, or one of two macroscopically distinct planar configurations. The latter correspond to the well-known Frank and perfect dislocation loops observed experimentally in ion-implantedmore » silicon. The relative importance of the different cluster morphologies is a function of cluster size and temperature and is dictated by a balance between energetic and entropic forces. The competition between these thermodynamic forces produces a sharp transition between the three-dimensional and planar configurations, and represents a type of order-disorder transition. By contrast, the smaller state space available to smaller clusters restricts the diversity of possible structures and inhibits this morphological transition.« less
  • Based on density functional theory (DFT) and empirical potential calculations, the diffusivity of fission gas atoms (Xe) in UO2 nuclear fuel has been calculated for a range of non-stoichiometry (i.e. UO2x), under both out-of-pile (no irradiation) and in-pile (irradiation) conditions. This was achieved by first deriving expressions for the activation energy that account for the type of trap site that the fission gas atoms occupy, which includes the corresponding type of mobile cluster, the charge state of these defects and the chemistry acting as boundary condition. In the next step DFT calculations were used to estimate migration barriers and internalmore » energy contributions to the thermodynamic properties and calculations based on empirical potentials were used to estimate defect formation and migration entropies (i.e. pre-exponentials). The diffusivities calculated for out-of-pile conditions as function of the UO2x nonstoichiometrywere used to validate the accuracy of the diffusion models and the DFT calculations against available experimental data. The Xe diffusivity is predicted to depend strongly on the UO2x non-stoichiometry due to a combination of changes in the preferred Xe trap site and in the concentration of uranium vacancies enabling Xe diffusion, which is consistent with experiments. After establishing the validity of the modeling approach, it was used for studying Xe diffusion under in-pile conditions, for which experimental data is very scarce. The radiation-enhanced Xe diffusivity is compared to existing empirical models. Finally, the predicted fission gas diffusion rates were implemented in the BISON fuel performance code and fission gas release from a Risø fuel rod irradiation experiment was simulated. 2014 Elsevier B.V. All rights« less
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