D-³He Fuel-Cycle Readiness

Beyond sourcing helium-3, MetroVolt needs fuel processing, injection, and recovery proven — partly inherited from the breeder, partly burner-specific.

More than a fuel supply

A working fuel cycle is not just having helium-3. It is storing, purifying, injecting, and recovering fuel; handling deuterium; and managing the small tritium and neutron activation the burner produces. Each step must be reliable for a machine expected to deliver firm power continuously.

Parts of this are de-risked by the breeder, whose D-T fuel cycle demands mature tritium handling and gas processing. The deuterium and helium-3 handling for the burner draws on that experience, though the D-³He mix and DEC-based machine differ enough to need burner-specific work.

The readiness picture

At design stage the fuel cycle is specified and draws on breeder-adjacent maturity for most steps. The weak point is fleet-scale helium-3 resupply, covered in its own gate. The processing and injection chain will be proven on the ~2032 test unit.

• Specified fuel-handling chain, breeder-adjacent for most steps.
• Burner-specific: D-³He mix, DEC-machine integration.
• Open dependency: fleet-scale helium-3, addressed separately.