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Nuclear Science and Engineering Directorate

Delivering world-leading nuclear science and engineering

The Nuclear Science and Engineering Directorate (NSED) addresses compelling challenges in nuclear science and technology that enables ORNL to respond to national priorities.

NSED focuses on the following mission areas:

  • Research and development (R&D) for both fission and fusion technologies
  • Advanced modeling and simulation
  • Stable and radioactive isotope R&D and production
  • Research, development, and deployment of technologies to address nuclear security challenges globally

Through our unique facilities, capabilities, and talented scientists and engineers, we perform world-class R&D to confront difficult issues such as:

  • extending the life of the current US nuclear reactor fleet, while investigating advanced reactor systems for the future,
  • making fusion energy a viable power source, and
  • enabling the peaceful use of nuclear technologies through non-proliferation programs.

We also provide high-impact research and production of isotopes that are used to:

  • fuel deep space exploration missions,
  • treat cancer and other medical conditions, and
  • enhance national security.

NSED consists of three research divisions (Fusion Energy, Isotope and Fuel Cycle Technology, and Reactor and Nuclear Systems), one operating division (Nonreactor Nuclear Facilities), and the Consortium for Advanced Simulation of Light Water Reactors, the US Department of Energy’s first energy innovation hub. 


ORNL’s Radiochemical Engineering Development Center was recognized in 2018 by the American Nuclear Society as a Nuclear Historic Landmark. For more than 50 years, REDC has been a global leader in isotope production and nuclear fuel cycle research.