Fusion Fuel Cycle Cluster 3 Network ↗

Material Science for Nuclear Fusion

The fuel cycle runs on four materials most people have never heard of.

Tritium, Lithium-6, Beryllium, Tungsten. Most fusion power plants run deuterium and tritium in a loop — injecting it, burning it in the plasma, recovering unused gas and newly bred tritium, reprocessing it, and injecting it again. Cluster 3 maps every stage of that cycle to the specialized Swiss industry that makes it possible.

See the materials Meet the network →
Deuterium-tritium fusion reaction

01 — The Cycle

Fuel in, plasma, fuel out, fuel back in again.

Deuterium and tritium fuse in the plasma at over 100 million °C. Almost none of it burns on the first pass — the rest has to be recovered, cleaned, and re-injected, while new tritium is continuously bred to replace what's consumed.

Simplified fusion fuel cycle diagram: inject, store, manage, recover, and reprocess fuel

Simplified fusion fuel cycle — injection, storage, management, and exhaust/impurity processing, in continuous loop.

02 — The Materials

Four materials, four very different supply problems.

Each one is either scarce, hazardous to handle, or both — which is exactly where specialized industrial know-how matters more than raw material access.

T

Tritium

~20–25 kg world reserve

Doesn't occur naturally in usable quantities — must be bred in the reactor itself via lithium breeder blankets (breeding ratio > 1 required). ~USD 35,000/g.

Li-6

Lithium-6

~7.6% of natural lithium

The feedstock for tritium breeding. Isotopically pure Li-6 is limited and requires extensive isotope separation — the limiting factor for many breeding-blanket concepts.

Be

Beryllium

~480 t/yr global production

Neutron multiplier in breeder blankets — needed as FLiBe (fluorine-lithium-beryllium) breeder and coolant. Handling requires dedicated equipment and engineering.

W

Tungsten

~100,000 t/yr global production

The plasma-facing material of choice — highest melting point of any metal, used for divertor components that face the reactor's most extreme heat loads.

Tritium isotope data card: half-life, density, melting and boiling points, flammability, toxicity

03 — Why Tritium Is Hard

Twelve years is not a long time to work with.

Tritium's 12.32-year half-life means it can't simply be stockpiled — a fusion power plant has to breed its own supply continuously, in the reactor, faster than it decays.

  • Extreme permeation: tritium moves through metal walls that would stop almost any other gas — full containment is a genuine engineering challenge, not a formality.
  • Highly flammable: forms explosive mixtures with air/O₂, like hydrogen — handling systems need the same rigor as any flammable-gas industrial process.
  • Radiologically hazardous, chemically inert: low external radiation risk, but a real hazard if inhaled or ingested — driving strict glovebox and containment design.

This is what Cluster 3's network actually builds.

Every stage of this cycle — breeding, injection, recovery, storage, analysis — maps to specialized Swiss suppliers, engineers, and research labs already working the problem.

Explore what Cluster 3 offers ↗