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Mark Williams

Reactor and Nuclear Systems Division, ORNL


Mark Williams is currently a Distinguished R&D Staff Member in the Reactor Physics Group of the Reactor and Nuclear Systems Division at Oak Ridge National Laboratory where he has been employed since 2003.  F

rom 1974-1983, he worked at ORNL in the Neutron Physics Division, and was on the faculty at Louisiana State University from 1983-2003.  While at LSU he held the positions of Professor of Nuclear Science, Director of the Nuclear Science Center, Professor of Physics, and Head of the Medical Physics Program.  At LSU, Dr. Williams taught a wide variety of courses, including Reactor Analysis, Radiation Shielding and Dosimetry, Monte Carlo Methods, and Radiation Transport Theory.  He has a PhD in Nuclear Engineering, and currently works on methods development and applications in the areas of reactor physics, perturbation and sensitivity theory, nuclear data for reactor analysis, and radiation transport.  Dr. Williams is a member of the development team for the SCALE code system which is used internationally for nuclear analysis applications.  He is author of 150 refereed publications, and has given numerous talks at conferences and workshops. 

Dr. Williams also is an adjunct professor at the University of Tennessee’s Nuclear Engineering Department where he teaches classes on radiation shielding and reactor physics.


M. L. Williams, “Resonance Self-Shielding Methodologies in SCALE,” Nuclear Technology 174, (in press)

M. L. Williams, B. T. Rearden, “Sensitivity/Uncertainty Analysis Capabilities and Covariance Data Libraries in SCALE,” Nuclear Data Sheets 109: Issue 12, 2796-2800, December 2008.

M. L. Williams, “Sensitivity and Uncertainty Analysis for Eigenvalue-Difference Responses,” Nucl. Sci. & Engr. 155, pp. 18-36, 2007.

M. L. Williams, J. C. Gehin and K. T. Clarno , “Sensitivity Analysis of Reactivity Responses Using One-Dimensional Discrete Ordinates and Three-Dimensional Monte Carlo Methods,” PHYSOR 2006 Topical Reactor Physics Meeting on Advances in Nuclear Analysis and Simulation, Vancouver, Canada, September 2006.

M. L. Williams, D. Ilas, E. Sajo, D. B. Jones and K. E. Watkins "Deterministic Photon Transport Calculations in General 3D Geometry for External Beam Radiation Therapy," Medical Physics Vol. 30, 12, pp. 3183-3195, 2004.