Matthew A Jessee

Senior R&D Staff

Dr. Matthew A. Jessee is a Research and Development staff member in the Reactor Physics Group of the Reactor and Nuclear Systems Division at Oak Ridge National Laboratory. His research interests include methods and software development in lattice physics analysis, multigroup cross section processing, sensitivity analysis, uncertainty quantification, parameter estimation, and reduced order modeling for challenging reactor physics and radiation transport applications. 

Dr. Jessee is the lead code developer for the Polaris lattice physics code in SCALE Code System. Introduced in SCALE 6.2 in April 2016, Polaris is an easy-to-use lattice physics capability for light water reactor assemblies.  Polaris uses advanced calculation methods for performing lattice physics analysis, including the embedded self-shielding method for cross section processing, a new method for the characteristics transport solver, the ORIGEN depletion solver, and automated assembly geometry processing based on simplified user input format.

In addition to Polaris, Dr. Jessee is a senior code developer of the SCALE Code System and member of the SCALE Leadership Team. SCALE is a nuclear modeling and simulation suite developed with the sponsorship of the US Nuclear Regulatory Commission, the US Department of Energy, and the US National Nuclear Security Administration. SCALE provides validated, user-friendly tools for nuclear criticality safety, reactor physics, radiation shielding, radiation source term characterization, and sensitivity and uncertainty analysis. The SCALE code system is used by 8,000 users across 56 nations. Dr. Jessee provides expertise in several research application areas including sensitivity and uncertainty analysis, Bayesian inference methods, multiphysics coupling, and reduced order modeling techniques.

Dr. Jessee completed his PhD in Nuclear Engineering at the North Carolina State University in 2008, where he was funded through the Naval Nuclear Propulsion Fellowship. He completed his Masters of Nuclear Engineering (MNE) at North Carolina State University in 2005 and his BS in Nuclear Engineering at the University of Tennessee in 2003.