In America, nuclear power has been burdened by a few unpleasant place names for decades. Island of Three Miles. Chernobyl. Fukushima. Even if the actual history is more complicated than the shorthand implies, people fill in the blanks when you say them. No fatalities were reported from the Pennsylvania partial meltdown in 1979, and the long-term health data has always been, at best, unclear. However, it was irrelevant. Days earlier, The China Syndrome, a thriller starring Jane Fonda, had been released; the timing took care of the rest. For the next forty years, an industry apologized for an accident that, by most accounts, did not result in any fatalities.
This is why the present moment is so peculiar. The reason Three Mile Island is making headlines again is not because something went wrong, but rather because Microsoft agreed to purchase electricity from its remaining reactor. It’s difficult to ignore the awkward symbolism as you watch this play out. The location that Americans were taught to be afraid of is being subtly rebranded as the source of energy for artificial intelligence in the future.
| Field | Detail |
|---|---|
| Topic | Big Tech’s pivot toward next-generation nuclear reactors |
| Key Companies Involved | Microsoft, Google, Amazon, Meta |
| Primary Technology | Small Modular Reactors (SMRs) and restarted legacy plants |
| Notable Deal | Microsoft’s 20-year power purchase agreement to restart Three Mile Island Unit 1 by 2028 |
| Amazon’s Investment | £380m into X-energy’s Xe-100 reactor, targeting up to 5 GW by 2039 |
| Google’s Order | 6–7 SMRs, totalling around 500 MW of capacity |
| Industry Lobby Group | World Nuclear Association (Microsoft recently joined) |
| Main Driver | Powering AI data centres with 24/7 carbon-free electricity |
| Expert Skepticism | Allison Macfarlane, former chair of the US Nuclear Regulatory Commission, warns most SMRs are still “on paper” |
| Projected European Demand | Data centre electricity use expected to more than double by 2030 |
The explanation is both commonplace and profound. AI is a glutton. It is powered by chips in data centers that consume electricity at a rate that grids were not intended to supply, and most definitely not on the always-on, zero-carbon basis that tech companies have promised shareholders and customers who care about the environment. At night, Solar sleeps. It’s a moody wind. Gas is unclean. The only option that awkwardly checks all the boxes at once is nuclear.
Thus, Google announced an order for six or seven small modular reactors, totaling about 500 megawatts, and Microsoft joined the World Nuclear Association (yes, the lobbying group). Amazon invested £380 million in X-energy and plans to build about 5 gigawatts by 2039, which is equivalent to the UK’s entire current nuclear fleet. The concept of constructing data centers adjacent to gigawatt-scale plants has been proposed by Meta. Given that Nick Clegg, of all people, once dismissed UK nuclear as unnecessary and too slow, this is an incredible turn of events.
Speaking with those in the field gives me the impression that something has actually changed. The big tech companies are no longer waiting on utilities to increase capacity. They’re getting their own. The CEO of AWS, Matt Garman, has been refreshingly direct about it: nuclear is scalable and carbon-free. The pitch is that.
The issue is that the majority of these reactors are currently nonexistent. There are currently two SMRs in operation, one in the far east of Russia and one in China, and they generate a small amount of electricity. The former chair of the US Nuclear Regulatory Commission, Allison Macfarlane, states that everything else is “on paper.” You should listen to her. Reactors with smaller cores are less efficient, and economies of scale are not eliminated by Silicon Valley. “These are fun ideas,” she recently remarked. “But the tech bros don’t seem to be grounded in reality.”
The timeline math’s viability is still up for debate. It is feasible to restart Three Mile Island Unit 1 by 2028. It’s a completely different story to build a fleet of new SMRs to meet the demand for AI by the early 2030s. Public hearings, fuel sourcing, supply chains, and regulatory approval all proceed more slowly than a chip release cycle.
Nevertheless, the money continues to flow. Four American tech companies have already committed to host data centers in the UK, bringing in £6 billion. The next obvious question is where the electricity comes from. Ministers may eventually need to use the word “nuclear” and mean it if they want those investments to remain. In any case, the AI build-out is taking place. The part that is still unknown is the reactors.