Tritium Inventory And Decay

Tritium's 12.3-year half-life means a working inventory must be managed actively, but it also guarantees no long-lived fuel legacy.

A short-lived working fuel

Tritium decays with a half-life of about 12.3 years. Roughly half of any inventory converts to helium-3 over that period. This has two consequences: the plant must breed and recover tritium continuously to maintain a working stock, and any tritium left behind at end of life decays away rather than persisting for millennia.

Decay as a feature

The same decay that requires active inventory management also means tritium is not a long-lived waste problem. What is not consumed becomes stable, valuable helium-3. There is no scenario in which a large tritium inventory lingers dangerously for geological time — physics removes it on a decadal scale.

• Half-life about 12.3 years — decadal, not geological
• Continuous breeding sustains the working inventory
• Uncaptured tritium decays to useful helium-3
• No long-lived fuel legacy at end of life

This decay behavior links the fuel cycle to the waste case. See tritium to helium-3 and self-sufficiency.

Management now, no legacy later

The 12.3-year half-life imposes a discipline and grants a reprieve at the same time. It requires continuous breeding and recovery to keep a working stock, so inventory management is a live operational task. But it also guarantees that nothing accumulates for the long term: within decades any tritium either is consumed, is recovered, or has decayed into stable helium-3, leaving no lingering fuel hazard.