The advanced nuclear energy company Antares received U.S. Department of Energy (DOE) approval of the Documented Safety Analysis for its Mark-0 reactor under DOE standard 1271. This approval follows Antares’ Preliminary Documented Safety Analysis approval in January 2026. This milestone reflects DOE’s acceptance of the final design for the Mark-0 reactor and the safety case supporting it. Antares now begins the DOE Readiness Review process, the final phase before the DOE approves the startup of our reactor pilot. Antares remains on track to go critical ahead of July 4, 2026. “We are entering the final innings, and that’s incredibly exciting,” said Jordan Bramble, CEO and founder of Antares. “Getting here was only possible with strong support from our partners at Idaho National Laboratory and BWXT, and leadership at DOE, along with relentless work from the Antares team.” “We developed this timeline in 2023, and we have hit every milestone since,” said Bramble. “This is a clear sign that we are proving our safety basis every step of the way, and I’m proud of the way this team has cleared key checkpoints, on schedule, again and again.” The Mark-0 demonstration will validate reactor physics, neutronics models, and the instrumentation and control system that will also be used in the Mark-1 electricity-producing reactor planned for 2027. Fuel fabrication for the company’s first reactors has been underway through BWX Technologies since October 2025, using HALEU fuel secured through a DOE allocation.

Full report : US nuclear startup Antares gets DOE approval for its Mark0 reactor demonstratoris Approval for Mark-0 Demonstration Reactor.

For more see the OODA Company Profile on Antares Industries.