Helium-3 Handling Interface
Helium-3 is a breeder byproduct and the burner's fuel; its handling interface spans separation, inventory, and the 400x supply gate.
Two roles for one isotope
On the breeder, helium-3 appears as a byproduct (~1.97 kg/yr class) chiefly from tritium decay, separated in the tritium plant. On the burner it is the fusion fuel with deuterium. The handling interface therefore links a supply side (breeder plant) to a demand side (burner fueling), and it is where the fourth-order supply constraint becomes concrete.
The supply gate
A single commercial burner unit demands helium-3 at ~400× the domestic terrestrial supply. This is a physics-and-inventory fact, not an economic one: the fuel does not exist at terrestrial scale, which is why breeder-bred helium-3 and, ultimately, lunar helium-3 are part of the fuel strategy. The interface tracks inventory against this gate explicitly.
# helium-3 inventory vs demand (accountancy loop)
supply = breeder_he3_rate + external_receipts # kg/yr class
demand = sum(unit.he3_burn_rate for unit in fleet)
cover = supply / demand
flag('he3_supply_gate', cover) # design study: cover << 1 todayInterface segments
- Separation: cryogenic distillation stream composition from the tritium plant.
- Storage and transfer: getter/adsorption beds, inventory sensing, transfer interlocks.
- Demand link: metered feed to the burner plug fueling.
Owner: L4 for inventory and transfer, L7 for cross-machine accountancy, L1 only for containment trips. Calibration is accountancy-grade and reconciled with the breeder mass balance. All quantities are design-and-simulation class; no fuel flow is claimed before the breeder produces (FOAK ~2030).