DOE demos (Hermes) transitioning to NRC commercial (KP-FHR)
The machines being built, in order, and what each one proves.
Non-power demonstration reactor.
Two-unit plant; first US utility PPA for a Gen IV reactor (TVA). Sits between Hermes 1 and KP-FHR — a sequence the single criticality_proven_by edge cannot express.
Commercial fluoride salt-cooled high-temperature reactor.
3 in the tracker
| Design | Stage | Type | Coolant | MWe | Site | Criticality | Open in |
|---|---|---|---|---|---|---|---|
| Hermes 1 | Demo | MSR | Molten Salt (FLiBe) | — | Oak Ridge | Target - 2029 | TimelineBuildoutAnatomy |
| Hermes 2 | Demo | MSR | Molten Salt (FLiBe) | — | Oak Ridge | TBD | TimelineBuildoutAnatomy |
| KP-FHR | Commercial | MSR | Molten Salt (FLiBe) | 140 | Site TBD | Pending | TimelineLCOEDesign spaceAnatomy |
1 facility · components in-house, reactors assembled on site
Component manufacturing, pressure vessels, modular construction, fuel fabrication process development and non-nuclear prototype testing. A molten salt production facility on the campus is targeted to be producing salt in 2026. Kairos publishes no reactor-per-year throughput, so this is recorded as a component facility, not a reactor line.
2 deals · 550 MWe announced · 50 MWe firm
| Customer | Site | Design | Units | MWe | Firm MWe | Commitment |
|---|---|---|---|---|---|---|
| TVA / Google | Oak Ridge | Hermes 2 | 1 | 50 | 50 | binding |
| Site TBD | KP-FHR | — | 500 | — | non-binding |
1 tracked events