One Company's Plan to Sink Nuclear Reactors Deep Underground (ieee.org)
- Reference: 0180186945
- News link: https://hardware.slashdot.org/story/25/11/23/1850236/one-companys-plan-to-sink-nuclear-reactors-deep-underground
- Source link: https://spectrum.ieee.org/underground-nuclear-reactor-deep-fission
> By dropping a nuclear reactor 1.6 kilometers (1 mile) underground, Deep Fission aims to use the weight of a billion tons of rock and water as a natural containment system comparable to concrete domes and cooling towers. With the fission reaction occurring far below the surface, steam can safely circulate in a closed loop to generate power.
>
> The California-based startup [3]announced in October that prospective customers had signed non-binding letters of intent for 12.5 gigawatts of power involving data center developers, industrial parks, and other (mostly undisclosed) strategic partners, with initial sites under consideration in Kansas, Texas, and Utah... The company [4]says its modular approach allows multiple 15-megawatt reactors to be clustered on a single site: A block of 10 would total 150 MW, and Deep Fission claims that larger groupings could scale to 1.5 GW. Deep Fission claims that using geological depth as containment could make nuclear energy cheaper, safer, and deployable in months at a fraction of a conventional plant's footprint...
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> The company aims to finalize its reactor design and confirm the pilot site in the coming months. [Company founder Liz] Muller says the plan is to drill the borehole, lower the canister, load the fuel, and bring the reactor to criticality underground in 2026. Sites in Utah, Texas, and Kansas are among the leading candidates for the first commercial-scale projects, which could begin construction in 2027 or 2028, depending on the speed of DOE and NRC approvals. Deep Fission expects to start manufacturing components for the first unit in 2026 and does not anticipate major bottlenecks aside from typical long-lead items.
In short "The same oil and gas drilling techniques that reliably reach kilometer-deep wells can be adapted to host nuclear reactors..." the article points out. Their design would also streamline construction, since "Locating the reactors under a deep water column subjects them to roughly 160 atmospheres of pressure — the same conditions maintained inside a conventional nuclear reactor — which forms a natural seal to keep any radioactive coolant or steam contained at depth, preventing leaks from reaching the surface."
Other interesting points from the article:
They plan on operating and controlling the reactor remotely from the surface.
Company founder Muller says if an earthquake ever disrupted the site, "you seal it off at the bottom of the borehole, plug up the borehole, and you have your waste in safe disposal."
For waste management, the company "is eyeing deep geological disposal in the very borehole systems they deploy for their reactors."
"The company claims it can cut overall costs by 70 to 80 percent compared with full-scale nuclear plants."
"Among its competition are projects like [5]TerraPower's Natrium , notes [6]the tech news site Hackaday , saying TerraPower's fast neutron reactors "are already under construction and offer much more power per reactor, along with Natrium in particular also providing built-in grid-level storage.
"One thing is definitely for certain..." they add. "The commercial power sector in the US has stopped being mind-numbingly boring."
[1] https://www.slashdot.org/~jenningsthecat
[2] https://spectrum.ieee.org/underground-nuclear-reactor-deep-fission
[3] https://www.businesswire.com/news/home/20251015263249/en/Deep-Fission-Expands-Customer-Pipeline-to-12.5-Gigawatts
[4] https://deepfission.com/technology/
[5] https://hackaday.com/2021/07/06/terrapowers-natrium-combining-a-fast-neutron-reactor-with-built-in-grid-level-storage/
[6] https://hackaday.com/2025/11/23/deep-fission-wants-to-put-nuclear-reactors-deep-underground/
I'm no nuclear engineer (Score:3, Insightful)
But the cost of building this installation sounds like it would be prohibitive unless you're using slave labor and letting a lot of those slaves die.
Even then I don't know if you could pull something like this off. This sounds like a scam.
Keep in mind if you are in North America then nuclear is basically a scam right now anyway unless you're restarting an old reactor. That's because the investment cost for wind and solar even with the current administration interfering with your deployment is substantially cheaper than any nuclear reactor you could possibly build, again even with the administration looking the other way on safety.
Japan might have a reason to fire up their nuclear reactors because they have so little viable land. But the one thing America has a fuckload of is land. So it just doesn't make economic sense to build a nuclear reactor in America.
I'm not quite sure why so many people over 50 though are so hung up on nuclear. I guess it was the future when you were a kid and it's a future that never happened so I think a lot of old farts are obsessed with it. Libertarian types seem to be really really into nuclear too and I don't understand why. Maybe the small footprint size of the reactors seems more individualistic? I don't know but it's all kind of pointless when we can just build out solar or wind installations.
Re: (Score:2, Informative)
[1]After Solyndra Loss, U.S. Energy Loan Program Turning A Profit [npr.org]
[1] https://www.npr.org/2014/11/13/363572151/after-solyndra-loss-u-s-energy-loan-program-turning-a-profit
Re: I'm no nuclear engineer (Score:1, Insightful)
The power output of nuclear is very stable â" essentially a flat 2GW over time, for the one active reactor in California (see caiso website, which shows live plots). Wind and solar are not, even with batteries (eg recent Spain outage).
Wind and solar have been doing base power (Score:1)
For something like 15 years now. There are plenty of dirt cheap battery solutions like those crazy sand batteries. You don't have to use rare Earth minerals to store energy there's plenty of other ways.
There really is no economic case to be made for nuclear power in America. The only reason we may see any new nuclear energy come online is people bringing up old plants that got shut down because AI has so much money right now.
Which isn't a good thing. I mean we're combining a weak regulatory environm
I googled the Spain outage (Score:2)
It had nothing to do with renewables they had a voltage surge and the hadn't prepared for it. They could have been running their entire grade off nuclear and they still would have had the outage.
It's a classic case of not spending the money to keep infrastructure of to date in order to prevent disasters. The basic problem is that nobody ever gets a pat on the back for stopping a disaster they get it for the cleanup afterwards...
Put another way nobody likes spending money on preventative maintenance.
Re: I'm no nuclear engineer (Score:4, Insightful)
The Spain outage would have happened with Nuclear exactly the same way. It was not a problem of not enough power. It was a problem of too much power, which was not absorbed by the consumers, and caused a build-up of over-voltage, which could not be dumped anywhere. When the grid automatically switched off power sources to damp the swing, it over-corrected, leading to a power loss of more than 2 GW, which then caused the shut-down of large electricity consumers. With a fat nuclear reactor, you would not have changed anything. Still, the grid regulation would have overreacted, with the same consequences.
Re: (Score:2)
Technicality: Diablo Canyon has two reactors, each making around 1.1 GW.
Re: (Score:3, Insightful)
First, you need to translate this:
> The California-based startup announced in October that prospective customers had signed non-binding letters of intent
Startup = Scam company looking to make some quick money for the CEO and then disappear.
Non-binding letters of intent = Never going to happen.
Re: (Score:2)
I mean... that's how we've built all the great things throughout history, right? Old slavery. Modern slavery... All the same to me.
Re: (Score:2)
> But the cost of building this installation sounds like it would be prohibitive ...
More expensive, sure, but probably way less risky than "dropping" it. :-)
> By dropping a nuclear reactor 1.6 kilometers (1 mile) underground ...
Re: (Score:1)
Again though you have to compare it to alternatives. And the fact is wind and solar installations with batteries to make up for the gaps are infinitely cheaper than even well understood nuclear plant designs.
Re: (Score:2)
> Even then I don't know if you could pull something like this off. This sounds like a scam.
It is an otherwise unnecessary solution to people like you.
Just keep digging (Score:5, Funny)
Dig a bit deeper and you can save money by skipping the nuclear-reactor part; just heat the water for your steam turbines with the geothermal heat that's already present down there.
Re: (Score:1)
Maybe if you're in Iceland. In some places you need to go 10 or 20 times as deep. There are also challenges with heat and melting drill heads, but I believe there are people working on that as well.
Re: (Score:3)
A mile down is nearly deep to have enough geothermal power to boil water just about anywhere on earth. If you can make it to 2 miles you would easily be over 100C.
Maintenance? (Score:3)
How do you maintain this thing? Or is it a "bury it and buy a new one when the o-ring wears out" deal?
Re: (Score:2)
No one is burying anything. They are lowering something under a water pressure column. The same way you get it down you get it up: winch and cable.
Is this oversimplified? Could be, but that is literally in their marketing materials discussing maintenance.
Honestly their bigger problem is cost. Combine the expense of nuclear, with the added expensive of horrendously small economies of scale building small reactors, and add the expense of a geological work and you've made the most expensive form of power gener
Are we starting a nuclear bubble now? (Score:3)
I appreciate the efforts of some of these new nuclear companies but this is starting to feel like VC bait, there's all of sudden more cheap money flowing and everyone is after it no matter how impractical the idea.
I get the idea but we have enough good locations and enough problems to sort out building reactors above ground before we start building them a mile underground.
"Hey, what are the two most expensive infrastructure projects currently available? Deep tunnels and nuclear reactors. Well chocolate and peanut butter go together, why not those?!"
Fuck it here's an idea, just build reactors on the bottom of the sea floor. Now give me money you venture capital dopes.
Also I've always thought there was GenIV reactor concepts for this type of "bury it and forget it" system already, [1]the Lead Cooled Fast Reactor [wikipedia.org]
[1] https://en.wikipedia.org/wiki/Lead-cooled_fast_reactor
Shenanigans (Score:3)
Considering any kind of nuclear plant that we currently use requires daily maintenance, there are a lot of pieces to break not to mention fuel cycling, this is completely spurious.
Re: (Score:1)
Well false, and covered.
Firstly no, nuclear plants do not require daily maintenance. In fact the core / steam loops are largely maintenance free outside of planned shutdowns years in advance. Maintenance is usually only carried out every 24 months.
As to how, it's not exactly rocket surgery. This proposal just lowers two components to the bottom of a hole in a water column, just shut it down, cool it off (like you would do with a normal one), and then all you've got is the extra hour or so it takes to winch
Re: (Score:2)
> Well false, and covered.
> Firstly no, nuclear plants do not require daily maintenance. In fact the core / steam loops are largely maintenance free outside of planned shutdowns years in advance. Maintenance is usually only carried out every 24 months.
They actually do require frequent routine maintenance, from dealing with everything from packing leaks, checking unusual equipment readings, etc. There is a reason someone is walking around secondary and taking readings and checking equipment. Having to shut it down every time would really impact its output.
The Meg 3 (Score:2)
The return of a giant goldfish.
Great thinking... (Score:3)
So... irreversibly irradiating our groundwater supply, but with more steps.
Re: (Score:2)
That was my first thought, and if water did hit it, it may create a massive explosion, except, I believe this will be well below any 'water table', or aquifer. Something feels "off" about the idea, but I can't articulate it yet.
Re: (Score:2)
> So... irreversibly irradiating our groundwater supply, but with more steps.
Do ... you have even the slightest idea what you mean by that, lol?
The real plan (Score:2)
Make it unrealistically difficult and expensive to cleanup a meltdown. The problem with Fukushima was that it was realistic, but insanely expensive to deal with. By burying this further underground they can ensure even approaching the meltdown is ridiculously difficult since the radiation and leakage will be channeled into tight tunnels.
Such BS (Score:5, Insightful)
Digging is expensive.
Nuclear hardware is expensive.
Getting an intact reactor into the bottom of a hole that deep will be prohibitively expensive and difficult.
Groundwater can go more than a mile deep.
If something breaks, repairs will be almost impossible and prohibitively expensive.
I can understand some of the arguments for nuclear. However, this is just sheer idiocy.
A less stupid version of this would be installing a nuclear plant deep in a decommissioned mine, perhaps one under a mountain. Still doesn't seem very smart, though.
Re: (Score:2)
> Getting an intact reactor into the bottom of a hole that deep will be prohibitively expensive and difficult.
Actually this will be the easy part. They are talking about tiny modular reactors. It's not exactly complex to drill a 30" hole and it's not exactly complex to hook a gizmo to a winch capable of lowing something 1 mile. We actually have mining elevators that lift and lower workers continuously all day every day that are longer, deeper, and physically larger than this.
Containment vessel? (Score:2)
I'm not clear on the justification for siting these things a mile underground. The article mentions "a natural containment system comparable to concrete domes and cooling towers" but I'm not seeing the other SMR projects talk about building large above-ground containment vessels and cooling towers. And speaking of which, the company website describes this as;
"The heat produced is transferred to a steam generator at depth to boil water, and the non-radioactive steam rises rapidly to the surface, where a stan
Re: (Score:2)
You'll want to time your attack on the facility so that the reactor is raised to only 30m below the surface.
What ?!? (Score:2)
"The same oil and gas drilling techniques that reliably reach kilometer-deep wells can be adapted to host nuclear reactors"
Who wrote this never looked at the borehole diameter of an oil well...
Aerating the Earth? (Score:2)
Isn't this the same thing as aerating your lawn? Pull out plugs of dirt so the soil loosens up. Between digging out holes for nuclear reactors to digging out holes next to a volcano to use its heat, aren't we loosening tectonic plates by relieving pressure?
Adapted? (Score:2)
> "The same oil and gas drilling techniques that reliably reach kilometer-deep wells can be adapted to host nuclear reactors..."
The last time I looked, oil and gas drilling was done with strings of pipe a few inches in diameter. Unless they're proposing constructing everything in a ship-in-a-bottle fashion, the bore-hole is going to need to be more like a mine-shaft - which is certainly doable, but is not going to be nearly as easy or cheap as they claim.
As well as the reactors, they've also got to get the heat-exchangers, turbines and generators down there too - all of which will require regular maintenance.
Oh, and then it's all go
Re: (Score:2)
The whole thing is an obvious scam. Hence details do not matter.
mind-numbingly boring. (Score:2)
a more stupid thing has never been said by a tech-minded optimizer. The power sector is mind-numbingly boring because it has to be mind-numbingly reliable you dumb idiot.
Re: (Score:2)
Indeed. "Exciting" is for products you do not need.
Uranium poisoning in the water (Score:2)
We'll call it "seepout", like fallout but now the cancer comes directly from your tap after the uranium and daughter products seep out from the borehole into ground water supplies, where over a third of the world's water comes from. And now you don't even need a meltdown or nuclear war for it to happen!
Nice vaporware (Score:2)
But with the usual non-working minds of the nuclear fanbois, this will probably sell.
One reactor for each AI office (Score:2)
Every new nuclear reactor type has had its own accidents, which leads me to believe that there is no such thing as a nuclear accident. I have studied not only Chernobyl, Three Mile Island, and Fukishima accidents, but also the SL-1(Agonne Low-Power Reactor), SRE, NRX, EBR-I, Godiva, and Demon-Core, accidents, as well as Hisashi Ouchi's terrible fate. They show you how small, compact, and sexy a fuel core is, but they down show you all the nitric acid and tailings. They don't show you this: [1]https://youtu.be/ [youtu.be]
[1] https://youtu.be/MJ6667Noex0?si=hLDymzH8Ps2WE1lL&t=881
Oh boy (Score:2)
Yet another "If only I can get this to work" concept.
Meanwhile, RE is absolutely killing nuclear on cost, availability, timelines, and more.
No safety needed (Score:2)
How convenient. If something happens, just bury the whole mess.
Re: (Score:2)
I'm sure you're being sarcastic, but I'm not sure why.
Re: No safety needed (Score:2)
Probably because there are other implications such as ground water contamination in the event of a serious meltdown?
Re: (Score:2)
They'll be all over that. Water tables, for one, only go so deep. Even for oil drilling they are pretty successful at avoiding ground water contamination and the site selection for this will be much, much more restrictive.
Re: No safety needed (Score:2)
Itâ(TM)s kind of like having Deep Water, on the horizon.
If thereâ(TM)s a problem âoejust seal it offâ.
Weâ(TM)ll have Slum Burger check the concrete casing and declare that it is âoejust greatâ, then leave.
Then when there is a problemâ"magenta warning lights, flames, mutated earthworms coming out of the ground, a spokes hole can go on tv and declare that itâ(TM)s âoeunder controlâ.
Then executives can go out on their yachts and declare âoewell this h