A Short Readiness Glossary

Plain definitions of the readiness terms used across this section, so the honest claims are unambiguous.

Core terms

• Design and Validation stage — the machine exists only in models; every number is computed, not measured
• FOAK / NOAK / BOAK — first-, nth-, and best-of-a-kind units in a staged build
• TRL — technology readiness level, 1 (principles) to 9 (proven in operation)
• Gate — a quantified physics or engineering distance between the current design and a fielded machine
• Post-diction — reproducing a device already operated; the basis for trusting an extrapolation

The four gate terms

• Plug overstress (3–3.9x) — coil stress above allowable at the 26.49 T design bore
• Regime distance (166–830x) — how far the plug point sits beyond any operated device
• Fuel gap (~400x) — unit helium-3 demand versus today's domestic supply
• Availability shortfall (30–100x) — modelled downtime versus Tier III (0.99982)

Timeline terms

Construction (breeder, Q2 2027), first tritium (breeder FOAK, ~2030), test burner (~2032), commercial burner (~2036). Each later date is contingent on the earlier milestone's evidence.

These definitions are collected so that the honest claims elsewhere in the section cannot be misread. Where a term carries a number — 3–3.9x, 166–830x, ~400x, 30–100x against 0.99982 — the number is the frozen canonical value, quoted identically wherever it appears. When a page says a result is simulated rather than demonstrated, these definitions are what that distinction rests on.

See how to read the gates and the overview.