The Download: a nuclear landmark, and China eyes Nvidia chips

This is today’s edition of The Download , our weekday newsletter that provides a daily dose of what’s going on in the world of technology. Four nuclear reactors hit a big milestone in the US —Casey Crownhart I was really looking forward to July 4, and not just because I love a poolside barbecue. This year the American holiday also marked a big symbolic deadline for US nuclear power. Last year the Trump administration set a goal to see three new microreactors achieve criticality, a technical milestone establishing that a reactor can sustain a chain reaction, by the nation’s 250th birthday. And just in time, not just three, but four reactors did so. It’s a positive sign for nuclear technologies at a time of increasing need for electricity and emissions-free energy sources. But achieving criticality doesn’t mean a reactor is ready to provide electricity for the grid (or at all, for that matter). Here’s what the milestone could mean for nuclear power in the US—and where the four companies might go next . This story is from The Spark, our weekly climate tech newsletter. Sign up to receive it in your inbox every Wednesday. The must-reads I’ve combed the internet to find you today’s most fun/important/scary/fascinating stories about technology. 1 China plans to let its top AI firms buy Nvidia H200 chips Alibaba, ByteDance, and DeepSeek are set to get permission. ( Information $) + China had previously withheld approval despite US authorization. ( Reuters $) 2 NATO is building a network to stop Russian attackers in their tracks It will use sensors, drones, satellites, and AI to detect them. ( Business Insider ) + Troops are donning odd camouflage to elude drones. ( Economist $) + The US wants cheaper drones as Iran’s wrecking its Reapers. ( Ars Technica ) 3 Researchers have a new idea to fight future El Niños: dimming the sun Deflecting solar energy could cool the ocean and mitigate the risks. ( Wired $) + But there could be unexpected consequences. ( New Scientist $) + And