Posted by Jimmc414 5 days ago
No need for an expensive containment dome, or expensive plumbing. If anything goes wrong, the nuclear fuel is already a mile underground. When the fuel is used up, they can leave it where it is since it’s below the water table. No need for expensive and hard to source highly enriched uranium.
The hard part is digging the wells, but that seems trivial compared to Quaise, who’s trying to dig 3-20km wells. The Deep Fission wells can just go anywhere (perhaps next to a disused former coal turbine?).
> When the fuel is used up, they can leave it where it is since it’s below the water table.
To do both, they’ll have to guarantee that that column of water stays isolated from groundwater for a long time after the fuel is used up.
Reading https://www.deepfission.com/faq, they answer that question with
“Importantly, the mile-deep column of water in the borehole is expected to provide the pressure conditions required for safe reactor operation. Water within the borehole is also intended to contribute to the reactor’s thermal management system”. So, what do they do if their drill hole starts leaking, and they lose pressure?
and
“Our boreholes are expected to be lined with multiple layers of casing, including steel casing and concrete intended to maintain structural integrity and isolate surrounding geological formations”
I don’t think those are good answers. They say what they want to do, but almost nothing about how they’ll do that, and try to avoid making hard statements on the what by using “is expected” and “is intended”.
I wonder if just letting the water gradually dissolve the uranium might not be fine, actually. If it is done far from wells and rivers used for drinking water, then the small amount of radioactive minerals that slowly seep out might not pose a danger. I can't find any studies to back it up, but I imagine there are places on Earth at which enriched uranium buried 1.6km underground poses no threat. I am no expert, so I would love to hear what others think.
One possible of measure of danger is median lethal dose LD50:
Uranium LD50 in mice 114 mg/kg (about the same as Cocaine LD50 96 mg/kg)
Plutonium LD50 in dog 320 μg/kg
Caesium-137 LD50 245 μg/kg
Polonium-210 LD50 10 ng/kg (estimated)
https://en.wikipedia.org/wiki/Median_lethal_dose
There are places underground with high concentration of uranium, they are called uranium ore and sometimes they are mined for uranium.
"The deposit is located at depth of 450 m (1,480 ft), surrounded by and isolated within a layer of water-impermeable illite-chlorite clay, within the Athabasca Sandstone formation. Its age is estimated to be 1.3 billion years. Due to natural containment and lack of any traces of radioactive elements on the surface, the deposit is used as an example of an effective natural deep geological repository."
A spend nuclear fuel rod, freshly taken out of nuclear reactor, will kill you in minutes, if stand near it without any shielding. Therefor manipulation with spend nuclear fuel is done remotely under water. Few meters of water are excellent radiation shield.
With each year radioactive products decay into stable elements.
After about 400 years in storage, the most radioactive elements decay away and the dominant part radiotoxicity of spend nuclear fuel is now Plutonium. From the point of toxicity, you could now handle the spend nuclear fuel as other industrial toxic waste - you have to breathe in, or ingest the spend nuclear fuel to be dangerous.
On the other hand, from the geopolitical point of view, spend nuclear fuel is dangerous from many thousands of years (in contrast to other industrial toxic waste), because for many thousands of years Plutonium can be used make a nuclear weapons. This is the real reason why spend nuclear fuel gets so much attention.
Steel and concrete are what we use above ground so.....
>They say what they want to do, but almost nothing about how they’ll do that, and try to avoid making hard statements on the what by using “is expected” and “is intended”.
They say nothing about how because those are trivial problems in the well (and oil) drilling industry.
Ah yes, an industry well known for its adherence to safety standards and never having surprising blowouts.
Also the actual article it seems has nothing to do with fission, they are focusing on extracting the heat already down there. "superhot rock needed for next-generation geothermal power"
https://en.wikipedia.org/wiki/Hot_dry_rock_geothermal_energy
Here the biggest obstacle to economy of the geothermal power is the very low heat conductivity of rock.
"The conductive heat flux averages 0.1 MW/km2. These values are much higher near tectonic plate boundaries where the crust is thinner. They may be further augmented by combinations of fluid circulation, either through magma conduits, hot springs, hydrothermal circulation. "
https://en.wikipedia.org/wiki/Geothermal_energy#Resources
For comparison: Thus the solar energy arriving at the surface with the sun directly overhead can vary from 550 MW/km2 with cirrus clouds to 1025 MW/km2 with a clear sky
https://ifp.org/nuclear-power-plant-construction-costs/
"Nuclear-grade components don’t necessarily have higher performance requirements than conventional components. Reinforcing steel in nuclear-grade concrete, for instance, is the same material used in conventional concrete. Instead, the additional cost often comes from the additional documentation and testing required. Documentation requirements also increase costs indirectly, by reducing market competition among manufacturers. Because these requirements are difficult for manufacturers to implement, many simply don’t bother to manufacture nuclear-grade components."
"Sources of Cost Overrun in Nuclear Power Plant Construction Call for a New Approach to Engineering Design"
https://www.sciencedirect.com/science/article/pii/S254243512...
"Similarly, while our analysis identifies the rebar density in reinforced concrete as the most influential variable for cost decrease, changes to the amount and composition of containment concrete are constrained by safety regulations, most notably the requirement for containment structures to withstand commercial aircraft impacts. New plant designs with underground (embedded) reactors could allow for thinner containment walls. However, these designs are still under development and pose the risk of high excavation costs in areas or at sites with low productivity."
Agree. What I don't understand is: why has it never been done before? They can't possibly be the first to come up with this idea, which doesn't seem to rely on any novel technology.
And even if you are stupid enough to actually do this, the fuel efficiency will be terrible. Your only negative feedback for fission is the Doppler effect and thermal expansion. So you will only be able to utilize a tiny percentage of the fissionable materials.
BTW, this tradeoff can be acceptable for some very specific applications. Kilopower ( https://en.wikipedia.org/wiki/Kilopower ) is designed to use passive regulation.
Or partially fill it and drop another reactor on top.
The only projects that overrun more than nuclear is nuclear waste disposal. This kills two birds with one stone.
It's even _more_ stupid!
It's a stupid idea designed to filter out investors who are stupid enough to fall for it.
Again, this is a monumentally stupid idea for no reason whatsoever.
And modern reactors are already passively safe. Even if the core melts down, it'll be contained in a core catcher: https://en.wikipedia.org/wiki/Core_catcher
Yes?
> And you don't need a core catcher when you are already 1 mile deep in bedrock.
Yes, you do. Because if the shaft explodes or gets blocked near the top, the fission products can travel up the water column.
perfectly safe /s
It should be pretty trivial to pick and choose geologies and depth where it is safe. Maybe that's a lot of places. Maybe that's a few. But it should be trivial regardless.
So should nuclear fission reactors. The concept is absurdly simple.
In practice, however ...
What could possibly go wrong!?!?
https://www.world-nuclear-news.org/articles/fourth-finnish-m...
"Feasibility of small modular reactors for decarbonizing district heating systems: a case study of the Helsinki metropolitan area"
https://www.sciencedirect.com/science/article/pii/S002954932...
Haiyang’s District Heating Project in China
https://www.iaea.org/newscenter/news/carbon-free-heating-kee...
It's certainly possible and not even very hard (by nuclear standards) because the reactor can operate at ambient pressure.
The biggest issue is inefficiency and cost of district heating except for places like Finland. It's now cheaper to install heatpumps instead.
I'm very pro-nuclear, but these kinds of projects are just scams.
The only reason we are in this shithole is because of the lack of political will. It would have been comparable trivial to solve if we just had started 30 years ago when scientists started to yell about that it was getting urgent.
[0] https://www.theguardian.com/world/live/2026/jun/24/europe-he...
Because of lack of political will in US and many European countries we continued to burn fuels to generate electric energy.
https://world-nuclear.org/information-library/country-profil...
Developing countries like China and India prioritized cheap coal power generation.
This sounds like the worst idea I've ever heard.
Fill with unshielded nuclear reactor of novel type: super skinny.
Gently lower down until depth of 1 mile is reached.
Repeat 1000x for a 1 GWe power plant.
What could possibly go wrong? Best horror story of the year in 15 slides.
Or are you also burying the turbine and power lines a mile deep?
seems it usually happened at lesser depths, and for ones deep enough to contain debris, the main effects were geological, from the actual explosion? not what i expected tbh
"For the application in EGS drilling, this device uses a metallic waveguide to carry the millimeter wave (MMW) beam to a standoff distance from the crystalline rock. Argon gas is used as the waveguide fill medium due to its ability to stay transparent to MMW’s at such deep depths and thus higher pressures [12]. Purge gas is also used to pump out the excess material that has been transformed into smaller particles (Figure 2.4). "
As a former geologist involved in drilling, thats going to get real expensive, real fast, in terms relative to regular mechanical drilling thanks to the requirement for argon. Perhaps theres an economically efficient changeover point at depth as mechanical drilling becomes less capable due to increasingly plastic deformation.
It's possible there exists a material that is transparent to mm waves, airtight, and can survive the conditions at the bottom of the hole. In such a case they could cap the waveguide and prevent any gas leakage.
I'm quite sure Quaise is well aware that Argon isn't cheap and are already exploring multiple avenues for reducing its usage.
It is interesting that they have to use Argon instead of the more typical Nitrogen or SF6. A waveguide with such a significant pressure differential is decidedly unusual and a unique challenger for what they are doing.
This is such a sketchy company. Their "Demo" video doesn't demo anything.
At least this is progress though. In previous hype videos they just pretended you don't need to extract anything!
I doubt argon is the purge gas.
I'd be curious if anyone (perhaps the parent) knows why – my assumption is that it's more expensive and/or not as reliable to drill higher up with mmWave, not least because the ground might be uneven materials, etc., and then it becomes something predictable and harder to rotary drill lower down, incl. as you would spend more time doing things like replacing bits low down and sending things up and down?
To be clear though, I'd love to have one of these rigs on my old project and compare rate of progression and hole quality. Particularly when establishing the hole in sedimentary gravels and clays. I imagine casing will still be required.
One thing that I'd be concerned about is the ability to collect samples if most of the material is being vaporised or melted. Similarly, the cooking of the side of the hole on the way down could make geophysical responses much more difficult to interpret. Sonic velocity would probably increase, televised would probably be harder to interpret, harder to spot hydrothermal infill in sedimentary cover, would it affect gamma tools (probably not)
Edit: also wondering how the hole holds up around aquifers. Does the super heating cause wall instability immediately above the non geothermal aquifers as superheated steam is created? How does this affect the hole stability if we are not casing?
Edit 2: if we are not casing, how does the hole hold up around aquifer sands, loose fill, fractured or brecciated mass?
Edit 3: Also! Do we ream open the top of the hole to down past the last aquifers before the geothermal horizon? If not, how are we stopping stopping aquifers interplay and interaquifer contamination?
Some shale formations in Michigan, for example, sometimes requires drilling to a 4" thick target. You don't know the exact depth because the depth of that 4" thick layer can vary by many feet from an another spot 100m north/south.
I'm aware that if you search "thickness of Antrim shale" or "thickness of Collingswood shale", Google will happily tell you that it's 20-40 feet thick, but for modern drilling techniques, the economics of the well depend on hitting a much more narrow target than that, which can be delicately guided in by analyzing fossils that come up.
I started designing a combined unit for this (mmwave + ultrasound) with TLA+ and Rust, but don't have any use for drilling and tunneling myself.
I got into this because a bronze scepter of certain dimensions might carry a 28 khz resonance for ~30s, which - with nanodiamond drilling sand from e.g. pyrolyzed ash and sand - could explain the observed ancient copper core drilling speeds.
Nice article on an earlier demo: https://newatlas.com/energy/quaise-energy-millimeter-wave-dr... ; linked from this (nice but lots lots of ads): https://newatlas.com/energy/quaise-energy-millimeter-wave-dr... .
Company https://www.quaise.com/ on YT https://www.youtube.com/@quaise
MS thesis (2024; browsable) on the vitrified wall, for that and its intro: https://www.proquest.com/openview/624989df3cdd8055a6cee9affc...
Search for papers "Millimeter Wave Drilling for Deep Geothermal Energy Production" https://scholar.google.com/scholar?hl=en&as_sdt=0%2C33&q=Mil...
But why are there no near-term products? If you can cut through granite and such this way, it ought to be useful for other cutting jobs. There should be useful tools, such as small units for drilling pipe holes through concrete and rock. Going for a 10km hole as the initial product raises the suspicion that the real product is the stock.
In case of something like underground tunnels these problems are avoided by having hole big enough to fit the drilling machine as well as all the equipment and crew to reinforce the walls with concrete.
The fact that people have made a way to drill few hundred to few km using mechanical means is already an engineering marvel. In the context of everyday manufacturing beyond the hole depth to diameter ratio of 5:1 things already start to get more complicated. With more specialized techniques you might get 10:1 - 100:1. A bit easier for softer materials like wood or if you don't care about precision. But for deep underground drilling we are talking about ratio of thousands to 1.
It's not like they are not making tests at shorter depths. Once technology is sufficiently developed it might also trickle down to some shorter few km holes if geological conditions are right. Although probably never for something like few dozen meter water wells or making a hole in concrete at construction site. Not sure how well it works in soft dirt. Who knows about distant future, we now have relatively cheap desktop laser cutters, laser pointers, measuring equipment, microwave ovens, but those were not the initial products when developing those technologies. On the other hand some tech like wire EDM has remained niche manufacturing technology, even though modern electronics and software could allow making it much cheaper.
We already have cheap and effective mechanical drills capable of these tasks, and it's unlikely a brand new technology can compete with those on cost.
Unlike in the actual design niche, where mechanical tools are infeasible due to the temperatures involved.
Very interesting application of radio waves.
For generating the highest possible power of radio waves, vacuum tubes remain the only solution.
This drilling method resembles more a microwave oven (which uses a magnetron), than a laser.
I have been hearing about them for years in connection with enhanced geothermal, and while other companies are out drilling functional wells, Quaise is just getting basic drilling going, with seemingly zero promise of being cheaper than the alternatives.