Fuel Purity Requirements

Fusion plasmas are sensitive to impurities, so fuel must be prepared and kept clean — a handling requirement, not a supply constraint.

Why purity matters to the plasma

A fusion plasma performs best when the fuel is clean. Heavier impurity atoms radiate energy away and dilute the reacting ions, degrading performance. Deuterium, tritium, and helium-3 must therefore be prepared to high purity and kept free of contamination as they cycle through the plant.

A handling task, not a scarcity

Purity is a processing requirement, not a limit on how much fuel exists. The isotopes are abundant or bred; the work is in cleaning and maintaining them. Recovered fuel — unburned deuterium, tritium, and helium products — is reprocessed and returned to the required purity rather than discarded, keeping the cycle efficient.

• Impurities radiate energy and dilute the fuel
• Fuel isotopes are purified before entering the plasma
• Recovered fuel is cleaned and recycled, not wasted
• Purity is about processing, not fuel availability

Fits the closed cycle

Reprocessing recovered fuel to purity is part of what makes the closed cycle efficient, and it applies to both machines. See the closed fuel cycle and storage and handling.

A processing task, comfortably bounded

Purity is sometimes mistaken for a supply limit, but it is a processing requirement that the closed cycle already accommodates. Fuel is cleaned before it enters the plasma and recovered fuel is recleaned rather than discarded, so purity work supports efficiency rather than constraining availability. The isotopes remain abundant or bred; keeping them clean is ordinary, well-bounded chemistry.