Antares, Last Energy, and Radiant hit DOE authorization milestones

[Marlin]

Antares, Last Energy, and Radiant hit DOE authorization milestones

https://www.ans.org/news/2026-11-02/article-8549/antares-last-energy-and-radiant-hit-doe-authorization-milestones/

[Core Content]

Three companies advanced their Department of Energy authorization processes in October by securing safety approvals for advanced reactor projects. Antares obtained a nuclear safety design approval for its Mark-1 system, while Last Energy and Radiant received approved documented safety analyses for their respective microreactor pilots. These milestones clear the way for upcoming testing and deployment phases at national laboratories and military installations.

The month of October saw three of the original Reactor Pilot Program companies hit a handful of milestones as each pursues Department of Energy authorization for the operation of various reactor projects. Both Last Energy and Radiant earned documented safety analyses (DSAs) for their first reactors, and Antares earned its nuclear safety design...

Approval breakdown: Companies working toward DOE authorization for the operation of their test and demonstration reactors through either the Reactor Pilot Program or the Nuclear Energy Launch Pad must pass through five milestones:

Antares milestone: On October 23, Antares announced that the DOE had approved the NSDA for Mark-1, which the company calls its first "electricity-producing reactor." Mark-1 builds on the lessons learned by Mark-0, the company's first reactor, which reached zero-power criticality at Idaho National Laboratory in June. Antares ultimately is pursuing a 100 kWe–1 MWe reactor design that uses TRISO fuel, sodium heat pipes for cooling, and a nitrogen-based Brayton cycle for power conversion. That...

Read the full article at ans.org:
https://www.ans.org/news/2026-11-02/article-8549/antares-last-energy-and-radiant-hit-doe-authorization-milestones/