Conceptual Design of UNITY-2, the Fuel Cycle Test Facility for Fusion Pilot Plants

UNITY-2 (UNique Integrated Testing facilitY) is a facility designed to replicate the architecture of the deuterium-tritium fuel cycle of a fusion pilot plant (FFP) on a smaller scale. The facility will operate continuously at a steady-state flow rate of 2.3 Pa m³ s⁻¹ using gas puffing, and will allow for the injection of fuel pellets for shorter periods with up to 27.5 Pa m³ s⁻¹. UNITY-2 will demonstrate a fully integrated deuterium-tritium fuel cycle using a license for up to 30 g of tritium at Chalk River Laboratories, therefore reducing the risk of producing a FFP on a decadal timeframe. Its novelty, relative to past and planned fuel cycle experimental demonstrations, lies in the continuous and fully integrated operation, an inner fuel cycle that includes a direct internal recycling loop, an inner and outer loop, and a breeder cycle based on lithium lead coolant. UNITY-2 has a full suite of detritiation systems to demonstrate as low as reasonably achievable releases. Following the successful integrated operation, the technology readiness will reach a maturity to be applied to FFPs.