Fuel Cycle Design Considerations for the Xcimer Athena Fusion Pilot Plant

Achieving sustainable inertial fusion energy (IFE) requires the development of efficient and safe deuterium-tritium (DT) fuel cycle systems. This paper introduces a preconceptual reference point fuel cycle design based on Xcimer Energy’s Athena Fusion Pilot Plant, a next-generation laser-driven fusion system. We present an integrated approach to recovering unburnt DT fuel, extracting bred tritium from FLiBe, purifying hydrogen isotopes, and minimizing tritium inventory onsite. The fusion fuel processing system is designed around modular, high technology readiness level technologies, including the thermal cycling absorption process, molecular sieve beds, and palladium membranes, while emerging techniques such as vacuum disengagers and the combined redox and extraction are needed to advance FLiBe processing. A steady-state process model in Aspen Plus quantifies the tritium flows and inventories across the system, highlighting gas detritiation and the fabrication and injection system as the largest contributors to in-process tritium holdup. This work establishes a foundational framework for optimizing IFE fuel cycle operations and guiding Athena from concept to commercial viability.