The first small modular nuclear reactor developed under the Department of Energy's Reactor Pilot Program has achieved criticality, indicating that its nuclear chain reaction is self-sustaining. This milestone was announced by the Department of Energy and pertains to a reactor designed by Antares Nuclear, which successfully completed a zero-power fueled demonstration at the Idaho National Laboratory. The reactor's design, known as Mark-0, is expected to pave the way for similar reactors to produce electricity by 2027.
Energy Secretary Chris Wright stated that this achievement marks a significant moment for American energy, noting that it is the first privately developed non-light-water reactor to reach criticality in the U.S. in over four decades. The Mark-0 is part of a series of advanced reactors expected to reach criticality by July 4, a deadline set by former President Donald Trump to enhance nuclear energy deployment and increase domestic capacity by 2050.
While the achievement of criticality is a significant step, it does not mean the reactor is fully operational or generating electricity. The reactors in this pilot program are intended for testing and demonstration purposes. The Department of Energy aims to use the data from these tests to facilitate commercial licensing through the Nuclear Regulatory Commission. Several developers in the pilot program, including Aalo Atomics, plan to submit license-related applications later this year. Antares expects to produce electricity from its reactors in 2027 and deploy them at military installations by 2028.
