Three US startups have achieved a significant milestone in the nuclear industry by turning on new reactors for a Department of Energy pilot program. This initiative, aimed at reviving America's nuclear sector and kickstarting development of smaller, innovative reactor designs, is generating buzz but may still face lengthy commercialisation processes.

The dream of building smaller, more efficient nuclear reactors has long been sidelined due to regulatory hurdles and high costs. However, the aggressive timeline set by President Trump’s executive order last year has seen some companies reach criticality ahead of July 4th. Yet, these test reactors are far from ready for prime-time commercial use; they're primarily designed for testing purposes.

Regulatory cuts and support from federally funded national laboratories have sped up the process significantly. For instance, Valar Atomics has already demonstrated its reactor powering a Nvidia chip during a lab demonstration, marking the first advanced reactor to provide electricity in the US. But proving that criticality can happen in a lab doesn’t guarantee grid connection or deployment.

The path to commercialisation is still fraught with challenges, particularly around licensing and fuel supply chains. While this initiative changes the narrative on nuclear technology’s potential, it also highlights the long road ahead before smaller reactors become a practical solution for carbon-free energy needs.