Tritium Inventory
The plant tritium inventory is small, tracked precisely, and held in engineered containment rather than in the plasma.
Tritium is the radioactive fuel component of the breeder (Hyperion), and its total site inventory — in the plasma, the fuel loop, storage, and processing — is the quantity safety analysis tracks most closely. It is kept as small as practical by processing fuel continuously rather than stockpiling it, and it is confined by the barrier system.
Where the inventory lives
- Plasma: grams, reacting and continuously replenished.
- Fuel cycle: the pumping, separation, and re-injection loop holds the working inventory.
- Storage / getters: a managed reserve, kept minimal by design.
- Breeding blanket: tritium bred by neutrons, extracted and fed back.
The breeder produces roughly a 4 kg/yr tritium class output and about 1.97 kg/yr of helium-3, but the resident inventory at any instant is far smaller than annual throughput because material moves through the loop continuously. A tritium breeding ratio is treated as a design lever across 1.1 / 1.5 / 1.8 to balance self-sufficiency against inventory and blanket requirements.
Why the number matters
The site inventory bounds the accident source term: you cannot release more than you hold. Keeping it small, distributed, and contained is therefore the most direct way to keep worst-case consequences small. See tritium handling.
The burner (Aegis / MetroVolt) burns deuterium and helium-3 and does not require a large tritium inventory, a further reduction in this hazard for that machine.