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Charles W. Forsberg

Charles W. Forsberg

Principal Research Scientist
Executive Director, MIT Nuclear Fuel Cycle Project
Director and PI, Fluoride Salt-Cooled High-Temperature Reactor Project
University Lead, Idaho National Laboratory Hybrid Energy Systems
617-258-8863 (fax)


  • B.S., Chemical Engineering, University of Minnesota, 1969
  • M.S., Nuclear Engineering, Massachusetts Institute of Technology, 1971
  • Sc.D., Nuclear Engineering, Massachusetts Institute of Technology, 1974


Dr. Charles Forsberg directed the MIT Nuclear Fuel Cycle Study, is the Director and principle investigator for the MIT Fluoride Salt-Cooled High-Temperature Reactor Project, and the Idaho National Laboratory University lead for Hybrid Energy Systems. Before joining MIT he was a Corporate Fellow at Oak Ridge National Laboratory (ORNL). He is a Fellow of the American Nuclear Society (ANS) and the American Association for the Advancement of Science. Dr. Forsberg received the 2002 ANS Special Award for Innovative Nuclear Reactors (Fluoride-salt-cooled high-temperature reactors and PIUS-BWR), and in 2005 the American Institute of Chemical Engineers Robert E. Wilson Award in recognition of chemical engineering contributions to nuclear energy, including his work on reprocessing, waste management, repositories, and production of liquid fuels using nuclear energy. He received the 2014 Seaborg Award from the ANS for advancements in nuclear energy. He holds 11 patents and has published more than 250 papers. He is a licensed professional engineer.

Research Interests

Fluoride Salt-Cooled High Temperature Reactors (FHRs): Improving Economics, Providing Electricity Without the Need for Cooling Water, and Assuring Safety

The FHR is a new reactor concept (pdf) developed within the last decade (pdf) with the goal to create a reactor with three characteristics: (1) increased revenue by 50 to 100% relative to a base-load nuclear plant, (2) the enabling technology for a zero-carbon nuclear renewable electricity grid with variable power plant output while the reactor core operates at steady state and (3) no major fuel failures and thus no significant off-site consequences under severe accident conditions.  The FHR couples a high-temperature salt-cooled reactor to a Nuclear Air-Brayton Combined Cycle (NACC) with Firebrick Resistance-Heated Energy Storage (FIRES). Such a reactor could not have existed 15 years ago. It is made possible by advances in natural gas combined cycle plants and high-temperature nuclear fuels (long pdf).  Dr. Forsberg led an Integrated Research Project with U.S. Department of Energy support over three years to develop the concept and a pathway to commercial deployment. The project included MIT, the University of California at Berkeley (UCB) and the University of Wisconsin at Madison (UW) with assistance from Westinghouse. This project was completed in December 2014 and a new 3-year FHR project was initiated with MIT, UCB, UW and the addition of the University of New Mexico. Four major project reports have been released.

  1. Commercial Basis and Commercialization Strategy: Fluoride-salt-cooled High-Temperature Reactor (FHR) Commercial  Basis and Commercialization Strategy, MIT-ANP-TR-153, Massachusetts Institute of Technology, Cambridge, MA., Dec. 2014.
  2. Commercial Reactor Point Design: Technical Description of the “Mark 1” Pebble-Bed Fluoride-Salt-Cooled High-Temperature Reactor (PB-FHR) Power Plant, UCBTH-14-002, Department of Nuclear Engineering , University of California, Berkeley, Sept. 30, 2014.
  3. Test Reactor Goals, Strategy, and Design: Fluoride-salt-cooled High-temperature Test Reactor (FHTR): Goals, Options, Ownership, Requirements, Design, Licensing, and Support Facilities, MIT-ANP-TR-154, Massachusetts Institute of Technology, Cambridge, MA, Dec. 2014.
  4. Final Project Report: Fluoride-salt-cooled High-Temperature Reactor for Power and Process Heat: Final Project Report, MIT-ANP-TR-157, Massachusetts Institute of Technology, Cambridge, MA., Dec. 2014.

Zero-Carbon and Hybrid Energy Systems: Combining Nuclear, Renewable and Fossil Energy Sources for Liquid Fuels and Variable Electricity Production

The long-term energy goals include (1) eliminating dependence on foreign oil and (2) low greenhouse gas emissions. The question is how to couple nuclear with other energy sources to meet these goals (pdf). Options for liquid fuels production include nuclear liquid biofuels and low-environmental impact nuclear shale oil production (pdf). The other challenge is integrating nuclear and renewable energy sources to meet variable electricity and other energy needs. This requires hybrid energy systems that enable capital intensive nuclear and renewable systems to operate at full capacity while meeting variable electricity demand. It involves development of technologies such as nuclear-geothermal gigawatt-year energy storage, nuclear wind hydrogen systems, and nuclear renewable shale-oil electricity systems. There remain major technical questions and challenges.

  1. C. W. Forsberg, “Hybrid Systems to Address Seasonal Mismatches Between Electricity Production and Demand in Nuclear Renewable Electrical Grids,” Energy Policy, 62, 333-341, 2013.
  2. C. W. Forsberg, Nuclear Energy for Variable Electricity and Liquid Fuels Production: Integrating Nuclear with Renewables, Fossil Fuels, and Biomass for a Low Carbon World, MIT-NES-TR-015 (September 2011).
  3. C. W. Forsberg, “Sustainability by combining nuclear, fossil, and renewable energy sources," Progress in Nuclear Energy, V. 51:1, Jan 2009, pp. 192-200
  4. C. W. Forsberg, “Is Hydrogen the Future of Nuclear Energy?” Nuclear Technology, V. 166: 1, PP. 3-10 (April 2009).
  5. C. W. Forsberg, “Nuclear Energy for a Low-Carbon-Dioxide-Emission Transportation System with Liquid Fuels,” Nuclear Technology, 164, 348-367, December 2008.

Nuclear Fuel Cycles: Rethinking How Fuel Cycles are Organized

Nuclear fuel cycles, including disposal of wastes, are central to nuclear power. Dr. Forsberg was the executive director of MIT Future of the Nuclear Fuel Cycle study that issued its report in 2011. A series of critical questions were identified that are the basis of future research. One top-level question is how the fuel cycle should be organized (pdf)—including whether backend fuel cycle facilities should be collocated at the repository to improve economics, repository performance, nonproliferation characteristics, and public acceptance. This question leads to a broad set of research questions that define our research interests.

  1. C. Forsberg, “Implications of Plutonium Isotopic Separation on Closed Fuel Cycles and Repository Design,” Nuclear Technology, 189 (1), 63-70, Jan. 2015
  2. C. W. Forsberg, “Coupling Repositories with Fuel Cycles”, Nuclear News, November 2011. (pdf)
  3. M. Kazimi, E. Moniz, C. Forsberg, et. al., The Future of the Nuclear Fuel Cycle, an Interdisciplinary Study, Massachusetts Institute of Technology, April 2011. website
  4. C. W. Forsberg, “Alternative Fuel-Cycle Repository Designs,” International High-Level Radioactive Waste Management Conference, Paper 3213, Albuquerque, New Mexico (April 10-14, 2010)
  5. C. W. Forsberg, C. M. Hopper, J. L. Richter, and H.C. Vantine. Definition of Weapons-usable Uranium-233, ORNL/TM-13517, Oak Ridge National Laboratory, Oak Ridge, Tennessee (March 1998). (pdf coming soon)

High-Temperature Solar Thermal Power Systems

The Concentrated Solar Power on Demand system (CSPond) (pdf) is a new type of high-efficiency solar power system with near-term operating temperatures of ~500°C and ultimately operating temperatures between 700 and 950°C. The high-temperature salt technology and power systems are similar or identical to those required for fluoride salt-cooled high-temperature reactors. This is a joint project between NSE and the Mechanical Engineering Department. It is part of a broader effort to develop high-temperature salt-cooled power systems that includes the FHR and CSPond. There is a strong common technical foundation across these different power systems. A small prototype is being designed as part of a joint program between MIT and the Masdar Institute, Abu Dhabi, UAE. Initial hot salt is expected sometime in 2015.

  1. A. H. Slocum, D. S. Codd, J. Buongiorno, C. Forsberg, T. McKrell, J. Nave, C. N. Papanicolas, A. Ghobeity, C. J. Noone, S. Passerini, F. Rojas, and “A. Mitsos “Concentrated Solar Power on Demand,” Solar Energy 85, 1519-1529 (2011)


22.911 Seminar in Nuclear Engineering
22.912 Seminar in Nuclear Engineering
22.78   Principles in Nuclear Chemical Engineering and Waste Management


  • Seaborg Medal (ANS) 2014

Recent Invited Lectures

Oxford University, Alternative Nuclear Energy Futures: Peak Electricity, Hydrogen, and Liquid Fuels, 2011 World Nuclear University Institute, Christ Church, England, July 10, 2011.

National Renewables Energy Laboratory, Nuclear Wind Hydrogen Systems for Variable Electricity and Hydrogen Production, Bolder, Colorado, September 12, 2011.

National Association of Regulatory Utility Commissioners, The MIT Future of the Nuclear Fuel Cycle Study, Los Angeles, California, July 19, 2010.

Recent Professional Service

U.S. Department of Energy Nuclear Energy Innovation Workshop, March 2015.

American Nuclear Society. Director, Nuclear Fuel Cycle and Waste Management Division

National Research Council of the Academy of Science (Planning committee), Improving the Assessment of Proliferation Risk in Nuclear Fuel Cycles: Workshop Summary, Washington D.C., August 1-2, 2011.

U.S. Department of Energy (Organizer), Technology and Applied R&D Needs for Nuclear Fuel Resources (Uranium resources), Norwood, Massachusetts, October 13-15, 2010.

Department of Nuclear Science & Engineering

Massachusetts Institute of Technology
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