Projects / prj-antares-mark0-inl
Antares Mark-0 at Idaho National Laboratory
First DOE Reactor Pilot Program reactor to reach criticality. Zero-power demonstration at INL on 4 Jun 2026. DOE said the test supports later reactors producing electricity in 2027 or after. This unit's electrical operation is not claimed.
- Stage
- Commissioning
- Design
- Antares Mark-0 (Microreactor)
- Technology
- Other · other
- Operator(s)
- Antares Nuclear
- Vendor(s)
- Antares Nuclear
- Location
- Idaho National Laboratory reactor-pilot area · United States · precision: approximate
Same approximate INL campus pin already used for the Aurora record. Experiment pads for Aalo-X, Mark-0, and Unity were not separately surveyed in the opened DOE notices. The NuclearChain Aalo Idaho pin near 43.52, -112.05 falls on Idaho Falls and is not used. - Coordinates
- 43.533, -112.947
- Electrical capacity
- thermal only (no MWe) · scope: module
- Thermal capacity
- —
- Modules planned
- 1
- Inclusion basis
- microreactor_labeled
- Confidence
- medium
- Last verified
- 2026-10-01 (publication/verification date)
Milestones & dated events
- Antares Mark-0 zero-power criticality: 2026-06-04 · actual · day · first_criticality
Regulatory actions
- None recorded in this release.
Sources
- DOE: first advanced reactor criticality, Antares Mark-0 (government_primary, accessed 2026-10-01)
- DOE EM note on four Reactor Pilot criticality reviews (government_primary, accessed 2026-10-01)