Latest milestone
DOE reported that the Mark-0 completed zero-power fueled criticality at Idaho National Laboratory.
2026-06 · DOE criticality announcement
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Antares R1 Mark-0
A zero-power fueled experiment that validates reactor physics but does not generate electricity.
Lead company · Antares Nuclear →
Program · Reactor Pilot Program
Initial criticality achievedHigh confidence
Deployment stage7 / 8Operational
Deployment trajectory
1Interest
2Preliminary
3Development
4Contractual
5Ready
6Physical
7Operational
8Replication
Next milestone
Complete further testing and establish the NRC licensing and customer pathway for a power-producing reactor.
- Responsible
- Antares Nuclear
- Key blocker
- Powered demonstration, NRC licensing, fuel, and commercial project execution
GenerationGen IV
ScaleCritical experiment
Reactor familyHeat-pipe
RoleCritical experiment
CapacityZero-power critical experiment
Reporting basisGovernment-reported