ACRS Membership

The ACRS is composed of individuals with a wide variety of engineering expertise. The membership currently includes expertise in nuclear engineering, risk assessment, chemistry, facility operations management, severe accident phenomena, materials science and metallurgy, digital instrumentation and control systems, thermal hydraulic and heat transfer, and mechanical, civil, and electrical engineering. Consultants are engaged to provide technical assistance on specific issues when required. ACRS members are appointed for four-year terms and normally serve no more than three terms.

Committee Members

Select one of the following names for biographical information about that member:

Matthew Sunseri, Chairman, is an independent nuclear industry consultant with over thirty-five years of experience in the safe operation of large commercial reactors. more…

Joy L. Rempe, Vice Chairman, is the Principal of Rempe and Associates, LLC, Idaho Falls, Idaho. more…

Walter L. Kirchner, Member-at-Large most recently served as an institutional liaison manager for Argonne National Laboratory following, analyzing, and advising Laboratory leadership on science and technology policy and programmatic developments in the Administration, Department of Energy, other federal agencies and Congress. more…

Ronald Ballinger is a professor of nuclear science, materials science and engineering and is head of the H.H. Uhlig Corrosion Laboratory at the Massachusetts Institute of Technology (MIT). more…

Vicki M. Bier is a professor emerita in the Department of Industrial and Systems Engineering and the Department of Engineering Physics at the University of Wisconsin-Madison. more…

Dennis C. Bley, is the President of Buttonwood Consulting, Inc., Albuquerque, NM more…

Charles H. Brown, Jr. is the Senior Advisor for Electrical Systems for BMT Syntek Technologies, Inc., Arlington, VA. more…

Vesna B. Dimitrijevic has more than 40 years of experience in the area of Probabilistic Risk Assessment (PRA), development and application. more…

Gregory H. Halnon is an independent nuclear industry consultant who has 40 years of experience in the nuclear and utility industries. more…

Jose March-Leuba is the principal of MRU, which specializes on measurements, regulatory and uncertainty analysis, and an Associate Professor in the nuclear engineering department of the University of Tennessee, Knoxville. more…

David A. Petti brings more than 30 years of experience in technology leadership and principal investigator of nuclear science and engineering materials-related technologies. more…

Peter Riccardella, has more than 45 years' experience working on the structural integrity of nuclear power plant components. more…

See also the Committee Membership Lists Since 1957.

Matthew W. Sunseri, Chairman

Matthew Sunseri is an independent nuclear industry consultant with over thirty-five years of experience in the safe operation of large commercial reactors. Prior to starting his own executive consulting practice, he was president and chief executive officer of Wolf Creek Nuclear Operating Corporation. Mr. Sunseri has a wide-range of experience in the operation, maintenance, engineering, oversight and security of the nation’s commercial nuclear power fleet. He started his career as a nuclear engineer assigned to the construction, licensing, startup and operation of the Comanche Peak nuclear power plant. Throughout his career, he has supervised, managed or provided oversight for activities at several commercial power stations. Mr. Sunseri has served on philanthropic and corporate boards of directors and has been a member of the American Nuclear Society since 1979.

Mr. Sunseri earned his Bachelor of Science degree in nuclear engineering from Texas A&M University and is a graduate of the Advanced General Management Program at Northwestern University and the Directors Institute at Emory University. Mr. Sunseri is a registered professional engineer in the state of Texas.

Joy L. Rempe, Vice Chairman

Dr. Joy Rempe has over 30 years of experience in the areas of reactor safety and irradiation testing. Prior to retiring as a Laboratory Fellow at the Idaho National Laboratory (INL), Dr. Rempe founded an instrumentation development and deployment laboratory to support a wide range of applications, including irradiation testing at US and international material test reactors. During her tenure at INL, she also led numerous severe accident research efforts for the NRC, DOE, and several international organizations, including inspection and analysis efforts to support post-accident Three Mile Island Unit 2 evaluations and experimental and analytical efforts to investigate in-vessel retention issues in light water reactors. As Principal of Rempe and Associates, LLC, Idaho Falls, Idaho, Dr. Rempe provides consulting assistance to US and international organizations on reactor safety and instrumentation issues.

Dr. Rempe has authored or co-authored over 300 archival peer-reviewed journal publications, book chapters, technical reports, and peer-reviewed conference papers on reactor safety, severe accident phenomena, high temperature testing, and in-pile instrumentation. She is an inventor/co-inventor on four patents with one patent pending. Dr. Rempe received NRC and Organization for Economic Cooperation and Development (OECD) recognition awards for achievements accomplished in the TMI-2 Vessel Investigation Project; and in 2011, she was awarded a US DOE Secretarial Honors Award for her contributions in the US response to the events at Fukushima. Dr. Rempe is a Fellow of the American Nuclear Society. In 2009, she was elected to the ANS Board of Directors. Between 2015 and 2019, she served as co-chair for the Department of Energy Nuclear Energy Advisory Committee. She holds a M.S. and a Ph.D. in Nuclear Engineering from the Massachusetts Institute of Technology and a B.S. in Nuclear Engineering from the University of Missouri – Rolla.

Walter L. Kirchner, Member-at-Large

Dr. Walter L. Kirchner most recently served as an institutional liaison manager for Argonne National Laboratory following, analyzing, and advising Laboratory leadership on science and technology policy and programmatic developments in the Administration, Department of Energy, other federal agencies and Congress. He served concurrently as chief technologist (in residence) for the Council on Competitiveness. In that capacity, he directed the High-Performance Computing Advisory Committee working to broaden deployment of advanced computing-based modeling and simulation, particularly of manufacturing and clean energy technologies. He began his career as a reactor operator/engineering officer on the N.S. Savannah before joining the staff at Los Alamos National Laboratory. During his 29 years at Los Alamos, he held division and group leader line management positions in construction project management, defense programs, nuclear reactor design and safety projects, and applied energy research and development activities. Dr. Kirchner’s technical expertise is in nuclear reactor design, thermal-hydraulics and nuclear reactor safety.

Dr. Kirchner holds a Bachelor of Science degree in marine engineering from the U.S. Merchant Marine Academy, and a M.S. and Ph.D. in nuclear engineering from the Massachusetts Institute of Technology.

Ronald Ballinger

Dr. Ronald Ballinger is a professor of nuclear science, materials science and engineering and is head of the H.H. Uhlig Corrosion Laboratory at the Massachusetts Institute of Technology (MIT). His areas of specialization are materials selection, nuclear engineering systems, environmental degradation and life assessment of these systems. In addition to the courses he has taught at MIT, Dr. Ballinger has also developed and taught several industrial courses on environmental degradation with EPRI and the Materials Aging Institute.

Dr. Ballinger has a bachelor's in mechanical engineering from Worcester Polytechnic Institute. He earned master's degrees in nuclear engineering and materials science and a doctorate in nuclear materials engineering from MIT. He is a member of several professional societies and has chaired the Materials Science and Technology Division of the American Nuclear Society.

Vicki M. Bier

Dr. Vicki M. Bier is a professor emerita in the Department of Industrial and Systems Engineering and the Department of Engineering Physics at the University of Wisconsin-Madison.  Her areas of specialization include risk analysis, decision analysis, and operations research.  She has more than 40 years of experience in risk analysis for the nuclear power, chemical, petrochemical, and aerospace industries, as well as homeland security and critical-infrastructure protection. 

Dr. Bier is a past president of the Decision Analysis Society, a fellow of both the Society for Risk Analysis and the Institute for Operations Research and the Management Sciences, and the editor-in-chief of Decision Analysis.  She has served on the Radiation Advisory Committee, the Homeland Security Advisory Committee of the Science Advisory Board for the U.S. Environmental Protection Agency, and on several panels, committees, and boards for the National Research Council.  Dr. Bier earned a bachelor's in mathematical sciences from Stanford University and a doctorate in operations research from the Massachusetts Institute of Technology.

Dennis Bley

Dr. Dennis C. Bley is President of Buttonwood Consulting, Inc. and a Principal of The WreathWood Group in Albuquerque, N.M. With more than 40 years’ experience in nuclear and electrical engineering, he has served on a number of technical review panels for NRC and Department of Energy programs and National Research Council committees, and has been a lecturer in short courses for universities, industry and government agencies. He holds a B.S. in electrical engineering from the University of Cincinnati and a doctorate in nuclear reactor engineering from the Massachusetts Institute of Technology. In addition, he attended Centre College of Kentucky, the U.S. Navy Nuclear Power School and Cornell University. He is a registered nuclear engineer in the State of California.

Dr. Bley began his career as a staff engineer at the Cincinnati and Suburban Bell Telephone Co., followed by service in the Navy nuclear propulsion program. Since that time, his primary research interests have been reliability and risk analysis and its relationship with human performance. He is recognized for the application of probabilistic risk assessment to a wide range of engineered facilities in various industries and for the development of methods for human reliability analysis. He has authored more than 100 articles, book chapters and conference papers.

Charles H. Brown, Jr.

Mr. Charles H. Brown, Jr. earned his M.S. in Engineering and his B.S. in Electrical Engineering with honors from the University of Louisville.

Currently, Mr. Brown is the Senior Advisor for Electrical Systems with BMT Syntek Technologies, Inc., in Arlington, VA. Previously, he spent 22 years as Director of Instrumentation and Control Division of the Naval Nuclear Propulsion Program with the Naval Sea Systems Command. He has more than 35 years of experience in engineering management involving policy setting, planning, and technical direction for reactor plant instrumentations, control, protection, and technical systems equipment design; development and systems integration; procurement; and long-term support programs management for all nuclear powered ships for the Naval Nuclear Propulsion Program of the U.S. Navy.

Mr. Brown is a Registered Professional Engineer in the state of Virginia. He is a Senior Member of the Institute of Electrical and Electronic Engineers and a Life Member of the American Society of Naval Engineers.

Vesna B. Dimitrijevic

Dr. Vesna Dimitrijevic has more than 40 years of experience in the area of Probabilistic Risk Assessment (PRA), development and application. She was technical lead for AREVA's U.S. EPR Design certification. As a technical expert, Dr. Dimitrijevic has participated in the development of diverse PRA methods: Risk Informed Applications for Generation 3 plants, EPRI Risk Informed Inservice Inspection, Internal Flooding and Fire PRA guidance. She has provided leadership for over 30 risk-informed PRA applications, and for various PRA developments in numerous U.S. nuclear plants. She served as an instructor in the Risk Informed PRA courses offered by the International Atomic Energy Agency, and is one of the lecturers for the MIT graduate course on the integration of reactor design, operations, and safety. Dr. Dimitrijevic holds a B.S. in electrical engineering and a M.S. in nuclear engineering from the University of Belgrade, and a Ph.D. in nuclear engineering from the Massachusetts Institute of Technology.

Gregory H. Halnon

Mr. Gregory H. Halnon is an independent nuclear industry consultant who has more than 40 years of experience in the nuclear and utility industries.  He has held positions ranging from systems engineer and operations management to executive leadership at operating and decommissioned nuclear plants including Chief Nuclear Officer of Three Miles Island Unit 2.  Mr. Halnon has expertise in all aspects of nuclear plant operations as well as quality standards, security, maintenance and engineering processes. He currently holds professional engineering licenses in two states and has held two Senior Reactor Operator licenses in his career.  He has led numerous industry groups in both engineering and regulatory areas as well as two industry consortiums for separate small modular reactor technologies.

Mr. Halnon is a graduate of the Senior Nuclear Plant Managers course from the Institute of Nuclear Power Operations, a past nuclear academic program evaluator for the Accreditation Board for Engineering and Technology and is a life member of the American Nuclear Society.  Mr. Halnon earned a Bachelor of Science in Engineering from the University of Central Florida with an emphasis on mechanical and thermal-hydraulics. 

Jose March-Leuba

Dr. March-Leuba is the principal of MRU, which specializes on measurements, regulatory and uncertainty analysis, and an Associate Professor in the nuclear engineering department of the University of Tennessee, Knoxville. He began his career at the Oak Ridge National Laboratory, where he did research into noise analysis and dynamic modeling, and ran tests to determine the stability of commercial boiling water reactors. He also developed and installed instrumentation in Russian facilities to monitor the down-blending of highly enriched uranium. During his 37-year career as a nuclear engineer, Dr. March-Leuba developed expertise in reactor thermal hydraulics and dynamics, reactor instrumentation and control and protection systems, software development and testing, and instrumentation development for international safeguards.

Dr. March-Leuba has a Master of Science in industrial engineering from the Universidad Politécnica de Valencia in Spain, as well as an M.S. and Ph.D. in nuclear engineering from the University of Tennessee, Knoxville. He is a Fellow of the American Nuclear Society and has close to 300 publications and reports.

David A. Petti

Dr. Petti brings more than 30 years of experience in technology leadership and principal investigator of nuclear science and engineering materials-related technologies. His work includes numerous lead and chief scientist positions at the US Department of Energy, Idaho National Engineering Laboratory, University of Idaho and the Phebus Facility at the Cadarache Nuclear Site in France.

Dr. Petti has expertise on large nuclear technology development projects with national and international impacts. He currently holds positions as a Laboratory Fellow and Chief Scientist for Nuclear Science and Technology Directorate and Director Nuclear Fuels and Materials Division at Idaho National Laboratory (INL) and a Joint Appointment with the Massachusetts Institute of Technology (MIT).

Dr. Petti holds a Bachelor of Science degree, Master of Science degree and Doctor of Science degree in Nuclear Engineering from MIT. Dr. Petti has published two book chapters and has peer reviewed numerous journal articles. Dr. Petti is a recipient of numerous awards including the Lifetime Achievement Award for an INL Publisher.

Peter Riccardella

Dr. Peter Riccardella has more than 45 years’ experience working on the structural integrity of nuclear power plant components. He is an authority in the application of fracture mechanics to nuclear pressure vessels and piping and has made significant contributions to the diagnosis and correction of materials degradation concerns at operating plants. He has been a principal investigator on a number of Electric Power Research Institute (EPRI) projects and served more than 20 years as a member of the American Society of Mechanical Engineers (ASME) Subcommittee on Nuclear Power Plant Inservice Inspection.

Dr. Riccardella earned his bachelor's, master's and doctorate degrees in mechanical engineering from Carnegie Mellon University, and is a Fellow and Life Member of the ASME.