Nuclear Power for AI? Microsoft Eyes Three Mile Island
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Nuclear Power for AI? Microsoft Eyes Three Mile Island

By Dr. Zoomie

Dr. Zoomie – I saw something today that Microsoft might be restarting the reactors at Three Mile Island to power their data centers? And other articles about Amazon wanting to buy a data center powered by nuclear reactors, and another piece saying that nuclear-powered data centers are the wave of the future. What gives? Do we really want to build nuclear reactors just so people can watch cat videos and use ChatGPT? Is this even safe?

Wow – there’s a lot to go over here – let’s see if I can break it down into some simpler questions.

  1. Are tech firms (including Microsoft) thinking about using nuclear reactors to power their data centers?
  2. Is Microsoft really looking into powering up the Three Mile Island reactors to power a data center?
  3. Is nuclear energy (and Three Mile Island in particular) safe enough to be worth providing energy for all the many frivolous uses of the internet?
  4. And I’ll add one – what in the world is a data center and why do they use so much energy?

So let me take these one at a time, and I hope you’ll forgive me if I answer them out of sequence.

Let’s start off with the final question:

  • What’s a data center and why do they use so much energy?

Right now I’m streaming a show on NetFlix, along with tens of millions of other NetFlix subscribers. The episode I’m streaming takes up…let’s call it a gigabyte (GB) of data on a computer; the entire series takes up tens or even hundreds of gigs, depending on the number and length of individual episodes and the video resolution. At any one time, there are people all over the world logged into NetFlix, streaming the shows they’re interested in, each of which takes up hundreds of megabytes or GB of data. The more popular a show is, the more people will be streaming it. The episode I’m watching right now is stored on a hard drive or SSD on a computer somewhere – that “somewhere” is on a computer in a data center, maybe with duplicate copies in other data centers. Add in the entire NetFlix catalog, plus Hulu and Peacock and Amazon Prime and all the shows on all the other streaming services, logged into by all their customers…we’re looking at millions of computers around the world just to feed our video-watching. And then there’s Amazon’s shopping site, FreshDirect, CostCo, Walmart, eBay, Etsy, and all the other companies selling things online; there’s YouTube and Facebook, Instagram and Twitter (sorry – X), and all the other social media sites; CNN and the New York Times and the Wall Street Journal and all the other news feeds; and on and on and on…and don’t even get me started on the computationally intensive crypto and AI. All of the data that we want to download (and, yes, a cat video is composed of data) is stored somewhere, and each of these somewheres need to be able to feed that data at a moment’s notice to those who decide they need it. And then there’s AI, which threatens to use even more computers to store even more data and processing capability than anything else in the tech sector.

The vast array of computers in each data center sucks down energy like there’s no tomorrow, as do the fans and cooling systems to keep the processors from melting down. Data centers are powering our internet-based lives, and what’s powering the data centers at the moment is largely fossil fuels. What Microsoft and Amazon and other companies are starting to look at is using CO2-free nuclear energy to power their data centers to make them as carbon-free as possible – yes, they’ll still be sucking down the gigawatts, but at least they’ll be carbon-free gigawatts. And, to address the first question, there are other tech companies considering using nuclear reactors to power their data centers as well.

  • Is Microsoft really looking into powering up the Three Mile Island reactor to power a data center?

Apparently they are – in collaboration with Constellation Energy, which owns a dozen nuclear power plants, primarily in the East. Microsoft’s thinking seems to be that, given the public’s fondness of streaming cat videos (and NetFlix) and asking ChatGPT to translate the procedures for operating household electronics into Elizabethan English, perhaps powering their data centers with nuclear energy will impost a reduced burden on the Earth’s climate. But – and I’m sure both Constellation and Microsoft realize this – powering up the reactors, which have been shut down for nearly a half-century is going to be both complicated and expensive, will require regulatory approval (including public meetings, among other hurdles), and is far from certain. But if things work out, sometime in the next decade, the remaining reactor at Three Mile Island (which operated safely until 2019) could well be up and running again and helping to feed cat videos to an insatiable public.

And that brings us to the final question:

  • Is nuclear energy (and Three Mile Island in particular) safe enough to be worth providing energy for all the many frivolous uses of the internet?

Well…quite likely, yes. To address the proverbial elephant in the room, I know that one of the reactors at the Three Mile Island site suffered an accident that culminated in a partial core meltdown. That reactor was ruined, and it’s currently being dismantled; the other one operated safely for more than three decades after the Unit 2 reactor accident. Worrying about the other reactor…I can understand that – the submarine I served on was built to the same plans as the USS Thresher, which sank during sea trials in 1963. Did I think about this when we pulled out to sea? Of course I did – it was almost impossible not to, especially when we had annual training on factors contributing to the sinking. But at the time I was in the Navy there were 14 submarines built to these same plans, most of which had been operating – safely – for two decades after the loss of the Thresher. I was aware of the accident – but the Navy learned a lot from it and it was never repeated. Similarly, I am aware of what happened at Three Mile Island – but the nuclear industry learned a lot from it and it has not been repeated. And there’s no reason to expect that it will.

As to the frivolous uses of the internet – people will likely be watching cat videos and porn and YouTube regardless of the type of energy used to power the data centers that serve it all up to us. Wouldn’t it be nice to know that they’re not adding to whatever it is that’s happening to our weather?