3 Nuclear Startups Hit a Big Milestone. Why It Matters-and Why It Doesn’t

Key Points:

• Three startups have successfully turned on new nuclear reactors as part of a Department of Energy pilot program aimed at advancing next-generation atomic energy, marking a milestone in America’s nuclear renaissance.
• The pilot program, initiated by a 2025 executive order from President Trump, set an aggressive timeline for reactors to reach criticality by July 4, coinciding with the U.S. 250th anniversary, with several companies meeting or nearing this goal.
• Regulatory streamlining by the Department of Energy and support from national laboratories have accelerated progress, enabling startups like Valar Atomics and Antares Nuclear to achieve criticality faster than traditional nuclear projects.
• Despite these advances, experts emphasize that these reactors are still prototypes and not yet commercial products, with significant challenges remaining in licensing, supply chains, and scaling to grid-ready, cost-effective power generation.
• While the pilot program has improved industry perception and attracted investment interest, financial and regulatory hurdles continue to pose risks for the commercialization and widespread deployment of small, advanced nuclear reactors.