Ryan Stewart is a nuclear engineering in the Advanced Reactor Design and Technology group at INL. His work is in the computational analysis of advanced reactor designs to better understand their operations, gain insight into safeguarding advanced reactors, and understanding nuclear non-proliferation consequences. Much of this work has been focused on modeling and simulating sodium fast reactors, pebble bed reactors, and pressurized heavy water reactors. In addition to this he has developed reactor physics models for the Idaho State University AGN-201 reactor, which are used in a digital which can accurately predict normal and off-normal operations.