Building the Safety Case

MetroVolt’s safety case rests on D-³He’s low neutron output and inherent fusion safety, documented rather than assumed.

Why fusion, and this fuel, helps

Fusion cannot run away: the plasma is hard to sustain, and any disturbance stops it. There is no chain reaction and no long-lived high-level waste of the fission kind. D-³He goes further, with a neutron fraction near 5.44% — far below a D-T machine — which reduces activation and shielding demands. These properties are the foundation of the safety case.

A foundation is not a finished case. Building it means documenting every hazard — magnetic energy, cryogenics, tritium byproduct, activation, high-power electronics — and showing each is controlled. At design stage this is in progress, informed by the breeder’s tritium and radiological work.

What the case still needs

The conventional industrial hazards — stored magnetic energy, cryogens, high-power electronics — are real and must be engineered and documented like any plant. The activation and tritium-byproduct handling draw on breeder practice. The full case is completed alongside the machine, not ahead of it.

• Strengths: no runaway, no fission-type waste, low neutron output.
• To document: activation, tritium byproduct, industrial hazards.
• Basis: breeder radiological and tritium experience.