Washington DC, June 5 -- In a landmark achievement for American energy, Antares Nuclear's Mark-0 advanced reactor has completed its zero-power fueled criticality demonstration at the US Department of Energy's (DOE) Idaho National Laboratory.

The milestone, achieved on Thursday, marks the first time in over four decades that a privately developed, non-light-water reactor has reached criticality in the United States.

The demonstration serves as a centrepiece of the DOE's Reactor Pilot Program, an ambitious initiative launched in 2025 to accelerate the testing and deployment of next-generation nuclear technologies.

The successful test confirms the safety and operational viability of the Mark-0 design, providing a vital blueprint for futur...