No Fissile Material
There is no uranium, plutonium, or enriched fuel anywhere in a Kronos plant — the entire fissile hazard class is absent.
The simplest and strongest statement in the fusion safety case is negative: a Kronos plant contains no fissile material. No uranium, no plutonium, no enriched fuel, no special nuclear material. An entire category of hazard and regulation — built around fissile material and criticality — simply does not apply.
What the fuel actually is
- Deuterium: a stable, non-fissile hydrogen isotope from water.
- Tritium: a radioactive hydrogen isotope — mobile, but not fissile.
- Helium-3: a stable, inert, non-fissile isotope (burner fuel).
- Lithium / beryllium (breeder blanket): for breeding and neutron multiplication, not fission.
This absence cascades through the safety case. With no fissile material there is no criticality, no reactivity accident, no meltdown of a fissile core, and no plutonium to safeguard. The hazards that remain — tritium, neutrons, magnets, cryogenics — are bounded and do not include the defining hazards of fission.
A cleaner regulatory fit
Because the plant handles radioactive material (chiefly tritium and activated components) without fissile material or a reactor chain reaction, it fits naturally under the byproduct-material framework. See no chain reaction and proliferation resistance.
The strongest safety features are often the hazards that are absent by construction, and fissile material is the one fusion never has.