Hyperion's tritium breeding ratio is 1.8 — but the important claim is that breeding ratio is a lever the design sets, computed from the blanket scan's own values, not a fixed constant of nature.
Tritium breeding ratio depends on blanket geometry, material, and neutron spectrum — all design variables. Hyperion's 1.8 comes out of a scan over those variables, so it can be traded against other requirements rather than quoted as an immovable given.
Treating breeding ratio as a lever is what lets Hyperion be sized to a customer's tritium requirement instead of to a physics optimum. The surplus above 1.0 is the margin that lets the machine supply the national requirement and seed the helium-3 stream at once.
| Tritium breeding ratio | 1.8 (design lever) |
| Source | blanket scan values |
| Not | a fixed constant |
| Surplus over self-supply | 0.8 |
| Enables | sizing to the requirement |