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Fusion and Fission Energy and Science Directorate

Delivering world-leading nuclear science and engineering

The Fusion and Fission Energy and Science Directorate (FFESD) addresses compelling challenges in fission and fusion energy systems, enabling Oak Ridge National Laboratory to pursue national priorities in current and advanced nuclear research, development, and deployment.

FFESD traces its roots to the X-10 Graphite Reactor, the world’s first continuously operated nuclear reactor, and to early innovations in fusion research and engineering. The directorate’s unique facilities, capabilities, and talented scientists and engineers are currently tackling such challenges as extended operations of the current US nuclear reactor fleet; investigating economical and flexible advanced reactor systems; and making fusion energy a viable power source. The directorate leverages synergies between fusion and fission across domestic and international programs.

FFESD leads US ITER, which has the responsibility of designing, fabricating, and delivering hardware for the international ITER fusion project. The directorate also leads the Transformational Challenge Reactor program and the Material Plasma Exposure eXperiment (MPEX), a future world-leading capability that will produce the extreme plasma environments to test materials for use in fusion energy devices.



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Users of the SCALE Code System, a nuclear analysis package developed at ORNL
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Nations collaborating to build ITER
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ORNL is developing testing facilities that simulate these conditions for developing materials for fusion reactors