Improvement of the BISON <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"><mml:mrow><mml:msub><mml:mtext>U</mml:mtext><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mtext>Si</mml:mtext><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> modeling capabilities based on multiscale developments to modeling fission gas behavior

Uranium silicide (U3Si2) is a concept explored as potential alternative to UO2 fuel used in light water reactors (LWRs) since it may improve accident tolerance and economics due its higher thermal conductivity increased uranium density. U3Si2 has been previously research the form of dispersion which operates at lower temperatures than commercial LWRs. The reactor data illustrated that significant gaseous swelling occurs burnup increases. Therefore, imperative understand fission gas behavior under temperature LWR operating conditions. In this work, molecular dynamics phase-field modeling techniques are reduce uncertainty select assumptions made developing model for BISON performance code. To support implementation BISON, cluster simulations irradiation enhanced Xe diffusion have carried out. Similarly, MD were predict athermal contribution atomic mixing during ballistic damage cascades. By combining our results with literature DFT equilibrium diffusion, diffusivity described over wide range in-reactor These length scale informed models then utilized assessment capabilities by simulating ATF-1 experiments irradiated Advanced Test Reactor (ATR). Sensitivity analysis (SA) quantification (UQ) included part process identify where further would be beneficial. multiscale approach work can applied new concepts being both LWRs advanced (e.g., nitride, carbide).