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 |
E-34: Ab-initio Modelling of Iodine Defects in Strained Zirconium and Ordered Zirconium-oxygen Suboxides |
Author(s) |
Vlad Podgurschi, Daniel J.M. King, Jana Smutna, Mark R. Wenman |
On-Site Speaker (Planned) |
Vlad Podgurschi |
Abstract Scope |
In water reactors, iodine stress corrosion cracking is the main cause of pellet cladding interaction failures but the mechanism and chemistry are debated. The protective effect of oxygen is also not fully understood. Density functional theory calculations were performed to investigate the formation energy of iodine defects in bulk zirconium under the effect of hydrostatic strain (-3% to 3%). The formation energy of iodine interstitial defects decreased with increasing strain and became favourable (-0.44 eV) at a strain of 3%. The substitutional energy of iodine was found to be relatively insensitive to strain. In order to gain an understanding into the protective effect of oxygen, various ordered zirconium-oxygen suboxides were considered (Zr6O, Zr3O and Zr2O). The formation energy of iodine defects increased as the oxygen content increased (2.67, 3.51 and 4.82 eV respectively), supporting the idea that oxygen has a protective effect at a stress corrosion crack tip. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |