The 9th International Conference on Multiscale Materials Modeling

Presentation information

Symposium

B. Challenges in the Multiscale Modelling of Radiation Effects in Nuclear Materials

[SY-B7] Symposium B-7

Thu. Nov 1, 2018 2:00 PM - 3:30 PM Room10

Chair: Marjorie Bertolus(CEA/DEN/DEC, Centre CEA de Cadarache, France)

[SY-B7] Modeling swelling in U3Si2 nuclear fuel using a multi-scale computational approach

Larry Aagesen1, Karim Ahmed2, Benjamin Beeler1, Daniel Schwen1, Yongfeng Zhang1 (1.Idaho National Laboratory, United States of America, 2.Texas A&M University, United States of America)

U3Si2 is a leading candidate for application as an accident-tolerant fuel for commercial nuclear power generation. Due to U3Si2’s high thermal conductivity relative to conventional UO2 fuel, it is believed to have a wider margin to melting/relocation in accident scenarios. However, based on limited experimental data, it is believed that U3Si2 undergoes much more significant swelling. To predict the swelling of U3Si2, a multi-scale computational approach has been developed. A phase-field model of fission gas bubble was developed, which tracks vacancies on the U lattice sites and Xe atoms as defect species. The proportional swelling of the fuel was assumed to be equal to the volume fraction of the bubble phase. The phase-field model was parameterized using density functional theory and molecular dynamics calculations. The incorporation of the swelling predictions to engineering-scale fuel performance models will be discussed.