Europe needs hyperscalers (lots of them) [LWN.net]

Europe needs hyperscalers (lots of them)

Posted Feb 12, 2026 12:16 UTC (Thu) by anselm (subscriber, #2796)
In reply to: Europe needs hyperscalers (lots of them) by taladar
Parent article: FOSS in times of war, scarcity, and AI

Current nuclear reactors are very inefficient in the way they use their (imported) fuel. In principle, we know how to build nuclear reactors that would make more efficient use of their fuel, and/or would be able to use existing “nuclear waste” as fuel and, as a side benefit, make it less nasty in the process. The remaining challenge is to make these technologies competitive with renewables on a euros-per-megawatt-hour basis.

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Europe needs hyperscalers (lots of them)

Posted Feb 12, 2026 13:37 UTC (Thu) by Wol (subscriber, #4433) [Link] (3 responses)

> and/or would be able to use existing “nuclear waste” as fuel and, as a side benefit, make it less nasty in the process.

Aka "fast breeders". I've also heard something about thorium burners that apparently burn up pretty much everything.

> The remaining challenge is to make these technologies competitive with renewables on a euros-per-megawatt-hour basis.

So using a fast breeder to turn U-238 into Pu-239 would be one obvious way. Processing (separating) waste into short- and long-lived radio-nuclides, and using the nasty stuff to bulk up new rods from old also seems an obvious way to me to reduce costs - store the nasty stuff inside the reactor, and break it up at the same time!

Of course, there's the political problems, and geo-stability ... the German nuclear industry as an example of the former, the tsunami and Japanese example of the latter. Then of course, we've got Dungeness (now shut down?), but the site is built on an area that was 5 miles out to sea in Roman times, and if we have global warming could very easily become 5 miles out to sea again in a pretty short time ...

Cheers,
Wol

Europe needs hyperscalers (lots of them)

Posted Feb 12, 2026 14:59 UTC (Thu) by malmedal (subscriber, #56172) [Link] (2 responses)

> seems an obvious way to me to reduce costs

These things have been tried, they are not cheap. The reason they(I think France got the furthest) tried was to have the technology ready for when the uranium mines ran dry, not because it would immediately save money.

To run a reactor efficiently and safely you need to know exactly what the fuel is made of down to at least cubic decimeter resolution.

For instance Xenon-135 is a neutron absorber produced by nuclear reactions, when this builds up you need to increase neutron flux to compensate, however being a gas it can escape quickly if it gets the chance, so if the operators make a mistake the reactor can overheat and melt down.
(This is likely a major reason for Chernobyl)

Europe needs hyperscalers (lots of them)

Posted Feb 12, 2026 15:38 UTC (Thu) by Wol (subscriber, #4433) [Link] (1 responses)

Don't remember the technology - was it AGR? I remember our AGR reactor technology got overwhelmed by the American PWR reactors, despite being much safer.

Iirc it used deuterium (heavy water) as the moderator, so if it got hot, the moderator boiled away and the fast neutrons escaped without being captured and driving fission.

(I thought the main reason for Chernobyl was the operators disabling the safety features "to see what will happen"!)

Cheers,
Wol

Europe needs hyperscalers (lots of them)

Posted Feb 12, 2026 17:38 UTC (Thu) by malmedal (subscriber, #56172) [Link]

> I remember our AGR reactor technology got overwhelmed by the American PWR reactors, despite being much safer.

Don't know if they were safer, but it's clear they were more expensive.

> Iirc it used deuterium (heavy water) as the moderator

No, graphite for moderator, CO2 as coolant. They used control rods to control the reactivity.

> "to see what will happen"

There are very conflicting stories about the details, but it is clear that it was a pre-planned test, deemed necessary to verify correct operation. It was supposed to be done by the day-shift, but it was delayed, so the unprepared night-shift got the job.

Europe needs hyperscalers (lots of them)

Posted Feb 12, 2026 17:46 UTC (Thu) by rgmoore (✭ supporter ✭, #75) [Link] (2 responses)

The biggest problem with nuclear is that it's still a heat engine, and just building the heat engine parts of the power plant (i.e. the external steam loop, turbines, and cooling system) is more expensive than equivalent renewable energy. Even if the actual reactor were free- and they're obviously far from it- and it still wouldn't be able to compete on cost with renewable energy. That's today. Renewable energy (including battery storage) is still getting cheaper, so its competitive advantage over nuclear is only going to grow.

Of course renewable energy isn't perfect. It still has problems, and there are probably specific applications where other technologies have non-cost advantages that outweigh renewables' cost advantage. There's also no good reason to stop using nuclear plants that are already paid for and are running well. But we're now at the point that plans for new and replacement, non-renewable power plants need to include a justification for not using renewables instead.

Europe needs hyperscalers (lots of them)

Posted Feb 12, 2026 18:04 UTC (Thu) by Wol (subscriber, #4433) [Link] (1 responses)

> But we're now at the point that plans for new and replacement, non-renewable power plants need to include a justification for not using renewables instead.

The justification for nuclear is "it's not carbon". So much of this carbon-neutral is exactly that - crap. When you burn anything the question should be "how long ago was the sunlight I'm releasing locked up?". Anything more that 100 years or so should be a red flag (nuclear doesn't count here - that's releasing ancient starlight :-)

Renewables, it's possibly measured in hours, which is great. Wood, of course, while not a particularly good fuel in many ways, is measured mostly in a century or two (or less). Coal and oil are adding to the CO2 burden, and from my knowledge of what's going on, I think we passed the point of no return quite a while back. I suspect Khim may be right in saying Europe will be going back to the 17th century, but on current performance I suspect the rest of the world will be joining us!

Cheers,
Wol

Maybe that's enough

Posted Feb 12, 2026 19:41 UTC (Thu) by corbet (editor, #1) [Link]

Can we agree that this has wandered pretty far off-topic, even for an article like this one? Energy issues are certainly of great interest, but we'll not solve them on LWN.