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

Plus: NATO is building a network to stop Russian attackers in their tracks. 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. But achieving criticality doesn't mean a reactor is ready to provide electricity for the grid (or at all, for that matter).