FuSion Nuclear Science Facility (FNSF): Motivation and required capabilities

A compact (R₀∼1.2-1.3m), low aspect ratio, low-Q (<3) Fusion Nuclear Science Facility (FNSF) was recently assessed to provide a fully integrated, D-T-fueled, continuously driven plasma, volumetric nuclear environment of copious neutrons. This environment would be used, for the first time, to carry out discovery-driven research in fusion nuclear science and materials, in parallel with and complementary to ITER. This research would aim to test, discover, and understand new nuclear-nonnuclear synergistic interactions involving plasma material interactions, neutron material interactions, tritium fuel breeding and transport, and power extraction, and innovate and develop solutions for DEMO components. This facility properly designed could provide, initially using conservative JET-level D-T plasmas in Hot-Ion H-Mode, and an outboard fusion neutron flux of ∼0.33 MW/m ². If the research, facility operation, and component solutions were successful, the performance could be raised to 1 MW/m² (fusion power ∼76 MW) by reaching for twice the JET plasma pressure and Q. Stable high-safety factor q and β plasmas would be chosen to minimize plasma-induced disruptions, and deliver reliably a neutron fluence of 1 MW-yr/m², if duty factors of ∼10% (accumulated plasma burn time in a year) can be achieved. Such duty factors would therefore require time-efficient installation and replacement of all components using remote handling (RH). These in turn would require RH-compatible modular designs for all internal components, a single-turn toroidal field coil center-post, and placement of support structures and vacuum seal welds behind the internal and shielding components. RH-enabled hot-cell laboratories would enable preparation and investigations of damages of the internal test components. The scientific and technical basis for such an FNSF, and the research needed in the next decade to manage the potential risks in its research capabilities, will be described.