|About this Abstract
|MS&T23: Materials Science & Technology
|Ceramics for New Generation Nuclear Energy System Application
|Creep Predictions in UO2 by Atomistic to Meso-scale Simulations
|Conor Galvin, William Neilson, Christopher Matthews, David Andersson, Michael Cooper
|On-Site Speaker (Planned)
Creep in UO2 nuclear fuel contributes to deformation of fuel pellets during operation of light water reactors. The creep rate depends on the fuel operating conditions, which manifests itself through a dependence on temperature, fission rate, UO2±x non-stoichiometry, and microstructure, specifically grain size. Current fuel performance models are empirical and were developed based on historical experimental data, for which the models are accurate. However, application to new fuels with different chemistry and grain size or new operating conditions may be hindered by the lack of mechanistic model foundation. This problem is addressed by use of the Centipede cluster dynamics code to simulate point defect evolution in UO2±x under thermal equilibrium and irradiation conditions, with emphasis on how to extend predictions for bulk UO2 to grain boundaries. The point defect behavior in bulk and at grain boundaries is then transformed to creep rates through analytical models and compared to experimental data.