The Fuel That Doesn’t Run Out

Fusion’s fuels are drawn from water and bred in the machine, not dug from a mine — a supply that does not deplete on any human timescale.

Vision, not specification. This page describes a future that fusion could help make possible — not a product promise, forecast, or performance claim. The Kronos machines today are design and simulation studies: the breeder (Hyperion) and the burner (Aegis / MetroVolt). No hardware net-gain has been demonstrated; construction of the first breeder is planned to begin in Q2 2027, with first-of-a-kind first tritium targeted around 2030.

Where the fuel comes from

The breeder runs on deuterium and tritium. Deuterium is a heavy form of hydrogen present in ordinary water — every liter of seawater contains it, and the total in the oceans is effectively inexhaustible on any human timescale. Tritium is not mined at all: the breeder is designed to make its own, treating the tritium breeding ratio as a design lever across 1.1, 1.5, and 1.8.

The burner runs on deuterium and helium-3. Helium-3 is rare terrestrially, but it too can be bred rather than mined — the breeder is designed to produce it in a helium-3 output class alongside its tritium. In both machines, the fuel story avoids the extraction, transport, and geopolitics that fossil fuels carry.

What breeding is a lever for

Treating the tritium breeding ratio as a lever rather than a fixed number is an honest engineering stance: it means the design is studied across a range — 1.1, 1.5, 1.8 — rather than pinned to a single optimistic figure. The vision point is narrower than the engineering detail: the fuel cycle is designed to close on itself rather than lean on a mine.

Kept honest

• Deuterium abundance is a settled physical fact; the plants that use it are still design studies.
• The breeding ratio is a design lever under study, not a demonstrated plant result.
• Helium-3 breeding output is a frozen design figure, not delivered production.

See the security angle in resilience and security and the emissions angle in energy without emissions.