Gate Reviews (G1–G4)

Progress at Kronos is gated on evidence, not enthusiasm. G1 through G4 are the checkpoints.

G1

Physics design freeze — done

Binding gates

Confinement; plug density

The programme is structured around gate reviews: G1 (physics design freeze), then successive gates for component demonstration, an integrated prototype, and a first product. Each gate has explicit criteria that must be met before the next phase begins.

The binding gate criteria are the design's largest open items — confinement assumptions on the breeder side, and the plug-density requirement on the burner side. Naming them as gates keeps the roadmap honest.