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ANTARES NUCLEAR REACTOR HITS CRITICALITY MILESTONE

INDUSTRY DESK1 MIN READ
MON, JUL 20, 2026

■ AI-SUMMARIZED FROM 1 SOURCE ▸ TIMELINE

Antares, a nuclear startup, has achieved criticality in its small modular reactor design for the first time. The test represents a key technical checkpoint, though the reactor is not yet generating power.

The successful criticality test demonstrates that Antares's reactor can sustain a controlled nuclear chain reaction, a fundamental requirement for operation. Criticality marks the point at which a nuclear reaction becomes self-sustaining. Small modular reactors (SMRs) have attracted growing interest as potential alternatives to large conventional reactors. They can be manufactured at scale and deployed in diverse locations, including remote areas and industrial facilities requiring process heat. Antares's achievement follows increased investment in SMR technology from both private companies and government agencies. The U.S. Department of Energy and other organizations view SMRs as part of the broader decarbonization strategy. The company must complete additional testing and safety validation before the reactor can transition to power generation. Timeline and next steps remain undisclosed. Other SMR developers, including NuScale and TerraPower, continue advancing their own designs toward commercial deployment.

■ SOURCES

Ars Technica

■ SUMMARY WRITTEN BY AI FROM THE LINKS ABOVE

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