TY - JOUR

T1 - The accommodation of lithium in bulk ZrO2

AU - Stephens, Gareth Frank

AU - Than, Yan Ren

AU - Nelson, William

AU - Evitts, Lee J.

AU - Wenman, Mark

AU - Murphy, Samuel

AU - Grimes, Robin W.

AU - Cole-Baker, Aidan

AU - Ortner, Susan

AU - Gotham, Natasha

AU - Rushton, Michael

AU - Lee, Bill

AU - Middleburgh, Simon

N1 - GFS is supported by Jacobs and the ESPRC through the Nuclear Energy Futures Centre for Doctoral Training (CDT - EP/S023844/1). The project is part of the Westinghouse led MUZIC-3 research programme and MIDAS project (EP/S01702X/1). We would like to thank Supercomputing Wales for provision of computational resources. SCM, WEL and MJDR are funded through the Sêr Cymru II programme by Welsh European Funding Office (WEFO) under the European Development Fund (ERDF). Computing resources were made available by HPC Wales and Supercomputing Wales. STM and WN acknowledge funding from EPSRCs TRANSCEND project (EP/S01019X/1). Structures were obtained with the use of the EPSRC funded Physical Sciences Data-science Service hosted by the University of Southampton and STFC under grant number EP/S020357/1.

PY - 2021/12/15

Y1 - 2021/12/15

N2 - Lithium is known to accelerate the corrosion of zirconium alloys in light water reactor conditions. Identifying the mechanism by which this occurs will allow alloying additions and alternative coolant chemistries to be proposed with the aim of improved performance. Accommodation mechanisms for Li in bulk ZrO2 were investigated using density functional theory (DFT). Defects including oxygen and zirconium vacancies along with lithium, zirconium and oxygen interstitials and several small clusters were modelled. Predicted formation energies were used to construct Brouwer diagrams. These show how competing defect species concentrations change across the monoclinic and tetragonal oxide layers. The solubility of Li into ZrO2 was determined to be very low indicating that Li solution into the bulk, under equilibrium conditions, is an unlikely cause for accelerated corrosion.

AB - Lithium is known to accelerate the corrosion of zirconium alloys in light water reactor conditions. Identifying the mechanism by which this occurs will allow alloying additions and alternative coolant chemistries to be proposed with the aim of improved performance. Accommodation mechanisms for Li in bulk ZrO2 were investigated using density functional theory (DFT). Defects including oxygen and zirconium vacancies along with lithium, zirconium and oxygen interstitials and several small clusters were modelled. Predicted formation energies were used to construct Brouwer diagrams. These show how competing defect species concentrations change across the monoclinic and tetragonal oxide layers. The solubility of Li into ZrO2 was determined to be very low indicating that Li solution into the bulk, under equilibrium conditions, is an unlikely cause for accelerated corrosion.

KW - Zirconia

KW - Brouwer diagram

KW - Lithium accelerated corrosion

KW - Solubility

KW - Fermi-Dirac

U2 - 10.1016/j.ssi.2021.115813

DO - 10.1016/j.ssi.2021.115813

M3 - Article

VL - 373

JO - Solid State Ionics

JF - Solid State Ionics

SN - 0167-2738

M1 - 115813

ER -