Pipe and grain boundary diffusion of He in UO₂
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Published version
Accepted version
Author(s)
Type
Journal Article
Abstract
Molecular dynamics simulations have been conducted to study the effects of dislocations and
grain boundaries on He diffusion in UO2. Calculations were carried out for the {100}, {110} and
{111} h110i edge dislocations, the screw h110i dislocation and Σ5, Σ13, Σ19 and Σ25 tilt grain
boundaries. He diffusivity as a function of distance from the dislocation core and grain boundaries
was investigated for the temperature range 2300 - 3000 K. An enhancement in diffusivity
was predicted within 20 Å of the dislocations or grain boundaries. Further investigation showed
that He diffusion in the edge dislocations follows anisotropic behaviour along the dislocation
core, suggesting that pipe diffusion occurs. An Arrhenius plot of He diffusivity against the inverse
of temperature was also presented and the activation energy calculated for each structure,
as a function of distance from the dislocation or grain boundary
grain boundaries on He diffusion in UO2. Calculations were carried out for the {100}, {110} and
{111} h110i edge dislocations, the screw h110i dislocation and Σ5, Σ13, Σ19 and Σ25 tilt grain
boundaries. He diffusivity as a function of distance from the dislocation core and grain boundaries
was investigated for the temperature range 2300 - 3000 K. An enhancement in diffusivity
was predicted within 20 Å of the dislocations or grain boundaries. Further investigation showed
that He diffusion in the edge dislocations follows anisotropic behaviour along the dislocation
core, suggesting that pipe diffusion occurs. An Arrhenius plot of He diffusivity against the inverse
of temperature was also presented and the activation energy calculated for each structure,
as a function of distance from the dislocation or grain boundary
Date Issued
2016-08-18
Date Acceptance
2016-07-21
Citation
Journal of Physics: Condensed Matter, 2016, 28
ISSN
0953-8984
Publisher
IOP Publishing
Journal / Book Title
Journal of Physics: Condensed Matter
Volume
28
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of the Creative Commons Attribution 3.0 licence. Any further
distribution of this work must maintain attribution to the author(s) and the title
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License URL
Sponsor
UT Battelle LLC
Grant Number
6400012816
Subjects
Fluids & Plasmas
0204 Condensed Matter Physics
0912 Materials Engineering
1007 Nanotechnology
Publication Status
Published
Article Number
405002