Nuclear engineering and radiation science at S&T is committed to delivering innovative computational reactor physics solutions for the advanced Generation IV reactor system. Our group focuses on the broad domains of modeling advanced reactor core; multiphysics modeling for thermal-hydraulics; and robustness analysis using uncertainty quantification and sensitivity analysis. Our ongoing research includes the design of small and micro-size reactors; evaluation of nuclear fuel cycle and nonproliferation; high-fidelity code development; and machine learning and decision-making algorithms for reactor analysis.