About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
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Computational Materials Science and Engineering of Materials in Nuclear Reactors
|
Presentation Title |
Shape and Stability of Voids and Fission Gas Bubbles in UO2 |
Author(s) |
Conor OT Galvin, Michael JD Rushton, Michael WD Cooper, David A Andersson, Robin W Grimes, Patrick A. Burr |
On-Site Speaker (Planned) |
Patrick A. Burr |
Abstract Scope |
The formation of fission gas bubbles is a performance limiting factor in nuclear fuel as it degrades mechanical properties and leads to fuel swelling. However, there are significant gaps in the knowledge of the properties of fission gas bubbles. Many experimental studies report faceted voids and bubbles, but MD studies have only considered spherical shapes for simplicity.
Here we systematically construct all Wulff shapes composed of {100}, {110} and {111} planes, and identify the most stables void/bubble geometries. MD simulations were performed for different sizes (up to 10 nm), pressures (up to 1.25 Xe/Schottky) and temperatures. We show that faceted bubbles and voids are always more thermodynamically favorable over spherical counterparts, however the energy difference decreases with increasing temperatures and decreasing pressure. The optimal ratio of {111}:{100} also varies with temperature.
The results can inform higher-order models and fuel performance codes to predict fission gas behavior in fuel. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |