Neutrons must be captured in the breeder blanket in order to:
- shield the magnets
- capture heat
- breed tritium
In the SPARC reactor, FLiBe is being considered as a liquid blanket material. Unfortunately, FLiBe poses health and environmental risks.
According to the 2023 Fusion Fuel Cycle & Blanket Roadmap Workshop, the KPIs for breeder blankets are:
- Tritium breeding ratio > 1
- Timeline: Final design by 2028-2032 to enable A Fusion Pilot Plant (FPP) by 2035
- Low activation: neutron activation will create large amounts of radionuclide inventories. Need to optimize for safety, waste volume minimization, and maintenance.