On the US 250th Independence Day, four experimental nuclear microreactors in the United States hit the crucial milestone of criticality, surpassing the Trump administration’s goal and marking a significant step forward for nuclear energy innovation. Meanwhile, China plans to authorize leading AI companies to purchase Nvidia’s advanced H200 chips, despite earlier restrictions.
- Four US microreactors achieve nuclear criticality milestone
- China to permit top AI firms to buy Nvidia H200 chips
- Nuclear and AI advancements signal broader tech and energy race
What happened
On July 4, 2026, four nuclear microreactors in the United States achieved criticality, a state where a nuclear reactor sustains a controlled chain reaction. This milestone exceeds the prior goal set under the Trump administration, which aimed for three reactors to reach this stage by the nation’s 250th anniversary. While criticality is essential, it does not automatically mean these reactors are ready to deliver electricity to the power grid.
Why it matters
Reaching criticality in multiple US microreactors is a pivotal moment for nuclear energy, offering a potential path toward more flexible, smaller-scale nuclear power solutions that could address rising electricity demands while reducing carbon emissions. This progress may influence energy policy and drive innovation in emissions-free technologies.
The lifting of restrictions by China on Nvidia chip purchases signifies a strategic shift in the global AI and semiconductor domain. Access to these advanced chips, critical for training large AI models, could bolster Chinese companies’ competitiveness in AI innovation and research, impacting the balance of technological power between the US and China.
What to watch next
For the US nuclear sector, the key developments to monitor include whether these microreactors can transition from achieving criticality to delivering reliable power to the grid, and how regulatory and commercial frameworks evolve to support wider deployment of such reactors.
Regarding AI hardware, observers should watch how quickly Chinese firms integrate Nvidia’s H200 chips into their AI projects and whether this leads to significant advancements in AI capabilities or new partnerships. Responses from US policymakers on chip exports and strategic controls will also be critical to watch.