Antares Nuclear, Inc., a company based in Torrance, California, has announced a significant achievement in the field of nuclear energy. Their Mark-0 microreactor has reached criticality at the Idaho National Laboratory, becoming the first advanced reactor to do so under a U.S. Department of Energy pilot program. This program was established following an executive order by President Donald Trump in 2025, aimed at accelerating nuclear development in the United States.
Historic Milestone in Nuclear Energy
The achievement of criticality, which signifies a self-sustaining nuclear chain reaction, is a major milestone in reactor development. Antares CEO Jordan Bramble emphasized the importance of meeting commitments, stating, “We said criticality in 2026, electricity production in 2027, and power to the warfighter in 2028. Today is the first of those commitments delivered on the schedule we set.”
The Department of Energy confirmed this milestone, highlighting it as the first privately developed non-light-water reactor to reach criticality in the U.S. in over four decades. Energy Secretary Chris Wright praised the achievement, noting the potential of American innovation in the nuclear sector.
Partnerships and Future Plans
The criticality demonstration was conducted in collaboration with the Department of Energy, Idaho National Laboratory, BWX Technologies, and the U.S. Army, which is a future end user of the technology. The Mark-0 reactor utilized TRISO fuel fabricated by BWXT, benefiting from fuel technology developed through Project Pele, a Defense Department initiative for transportable microreactors.
Assistant Secretary of Nuclear Energy Ted Garrish acknowledged the skepticism surrounding the program’s ambitious timeline but celebrated the success of the pilot projects. Antares plans to begin electricity production in 2027 and aims to deploy microreactors to U.S. military installations by 2028.
This achievement demonstrates the potential of the Reactor Pilot Program and underscores the importance of efficient, iterative reactor testing for the success of the American nuclear renaissance.
Original reporting: Fox News (HLL/CB) — read the source article.
