Thomas Downar

Professor, Nuclear Engineering and Radiological Science

Affiliations: Michigan Energy Institute


Thomas Downar


One of the more challenging multi-physics problems in engineering is the solution of the coupled temperature/fluid and neutron/nuclide fields in a nuclear reactor core during accident conditions. The research in Professor Downar’s group over the years has focused on the development of high performance computational methods for solving the Boltzmann Transport Equation (BTE) to determine the neutron and photon flux distributions in a nuclear reactor during normal operating and transient accident conditions. The computer code PARCS developed by Professor Downar and his research group is currently used by the U.S. Nuclear Regulatory Commission NRC to certify the safety performance of all the nuclear reactors operating in the U.S. Currently, Tom’s group is developing the next generation reactor code, MPACT, based on the 3D Method of Characteristics as part of the U.S. Department of Energy’s 120 million dollar Nuclear Reactor Simulation Hub, CASL. The target computational platforms for MPACT are leadership class computers such as TITAN at ORNL with hundreds of thousands of processors.

Research Areas

High Performance Computing