TY - GEN

T1 - Lithium Accomodation in ZrO2

AU - Stephens, Gareth Frank

AU - Evitts, Lee J.

AU - Rushton, Michael

AU - Lee, Bill

AU - Middleburgh, Simon

AU - Than, Yan Ren

AU - Cole-Baker, Aidan

AU - Neilson, William

AU - Murphy, Samuel

AU - Wenman, M.R.

AU - Grimes, R.W.

AU - Gotham, Natasha

AU - Ortner, Susan

PY - 2021/10/29

Y1 - 2021/10/29

N2 - With efforts being made to prolong the burnup of nuclear fuels and increaseefficiency of pressurised water reactors (PWRs), there is a focus on extendedresidence times of fuel. In addition, there are potentially significant cost benefitsthrough plant simplification if a soluble boron-free lithiated primary water chemistry can be demonstrated to be a viable route for PWR-based small modular reactor operation. However, the corrosion of the zirconium alloy clad material under lithiated conditions remains a concern as the mechanisms that underpin this have yet to be fully identified. Identifying the mechanism by which Li accelerates zirconium alloy corrosion will allow new alloying additions to be considered and new water chemistry regimes to be investigated, improving the efficiency and performance of future nuclear power reactors. Therefore, in this work the behavior of Li in ZrO2 by using density functional theory (DFT), to identify the most stable accommodation mechanisms for Li in ZrO2. A Brouwer diagram has been developed that predicts the nature of the defects present at given Li concentrations and partial pressures of oxygen. The solubility of Li in bulk ZrO2 is predicted to be low.

AB - With efforts being made to prolong the burnup of nuclear fuels and increaseefficiency of pressurised water reactors (PWRs), there is a focus on extendedresidence times of fuel. In addition, there are potentially significant cost benefitsthrough plant simplification if a soluble boron-free lithiated primary water chemistry can be demonstrated to be a viable route for PWR-based small modular reactor operation. However, the corrosion of the zirconium alloy clad material under lithiated conditions remains a concern as the mechanisms that underpin this have yet to be fully identified. Identifying the mechanism by which Li accelerates zirconium alloy corrosion will allow new alloying additions to be considered and new water chemistry regimes to be investigated, improving the efficiency and performance of future nuclear power reactors. Therefore, in this work the behavior of Li in ZrO2 by using density functional theory (DFT), to identify the most stable accommodation mechanisms for Li in ZrO2. A Brouwer diagram has been developed that predicts the nature of the defects present at given Li concentrations and partial pressures of oxygen. The solubility of Li in bulk ZrO2 is predicted to be low.

M3 - Conference contribution

BT - ENS TopFuel 2021 Conference proceedings

PB - ENS TopFuel

T2 - TopFuel

Y2 - 25 October 2021 through 28 October 2021

ER -