Antares achieves criticality of Mark-0 microreactor at Idaho National Laboratory
Tags Infrastructure · AI
Antares became the first private company to bring an advanced reactor to criticality under the DOE Reactor Pilot Program, achieving initial criticality of its Mark-0 microreactor at Idaho National Laboratory in collaboration with DOE, INL, BWXT, and the US Army. The reactor uses TRISO fuel fabricated by BWXT under the Project Pele program. Antares delivered the milestone on its stated timeline of criticality in 2026, electricity production in 2027, and power to military installations by 2028. The demonstration establishes a replicable licensing pathway for future reactor deployments and validates reactor physics parameters for Antares' commercial reactor design.
Technical significance
Achieving criticality in under 12 months from concept represents a significant acceleration in nuclear reactor development timelines, which have historically been measured in decades. The DOE Reactor Pilot Program's streamlined licensing pathway could serve as a model for other advanced energy technologies. For defense applications, deployable microreactors could provide forward operating bases with reliable power without vulnerable fuel supply lines. The data from this demonstration also supports the broader US nuclear renaissance and could accelerate commercial microreactor deployments for data centers.