As common as uranium is in the ground around us, the world’s oceans contain a thousand times more uranium (~4.5 billion tons) than can be mined today. This makes extracting uranium as well as other resources from seawater a very interesting proposition, albeit it one that requires finding a technological solution to not only filter out these highly diluted substances, but also do so in a way that’s economically viable. Now it seems that Chinese researchers have recently come tantalizingly close to achieving this goal.
The used electrochemical method is described in the paper (gift link) by [Yanjing Wang] et al., as published in Nature Sustainability. The claimed recovery cost of up to 100% of the uranium in the seawater is approximately $83/kilogram, which would be much cheaper than previous methods and is within striking distance of current uranium spot prices at about $70 – 85.
Of course, the challenge is to scale up this lab-sized prototype into something more industrial-sized. What’s interesting about this low-voltage method is that the conversion of uranium oxide ions to solid uranium oxides occurs at both the anode and cathode unlike with previous electrochemical methods. The copper anode becomes part of the electrochemical process, with UO2 deposited on the cathode and U3O8 on the anode.
Among the reported performance statistics of this prototype are the ability to extract UO22+ ions from an NaCl solution at concentrations ranging from 1 – 50 ppm. At 20 ppm and in the presence of Cl– ions (as is typical in seawater), the extraction rate was about 100%, compared to ~9.1% for the adsorption method. All of this required only a cell voltage of 0.6 V with 50 mA current, while being highly uranium-selective. Copper pollution of the water is also prevented, as the dissolved copper from the anode was found on the cathode after testing.
The process was tested on actual seawater (East & South China Sea), with ten hours of operation resulting in a recovery rate of 100% and 85.3% respectively. With potential electrode optimizations suggested by the authors, this extraction method might prove to be a viable way to not only recover uranium from seawater, but also at uranium mining facilities and more.
This can be used to recover uranium from cooling water used in NPPs instead of dumping it to rivers.
“If time machines existed, this could have been used to recover uranium for cooling water used in 1950s and 1960s Soviet-Era Russian research reactors instead of dumping it into the rivers.” Fixed the typo in your comment for you. No need for an edit button.
Anti-nuclear fanatics are so clueless about modern nuclear technology.
You laugh at him now.
But when your spirit’s sewer line collapses and you need a trenchless fix…
(I had to edit that, ‘rooting a spirit’s sewer line’ is just too aussie gay.)
Is that when I’m supposed to laugh at him or is it when I’m supposed to inform him about modern nuclear technology? ;)
modern technology still breaks down the old fashioned way.
its not the technology, its the people, stupid (or should that be stupid people…)
Cooling water of any currently operating nuclear reactor in the world, is never getting into contact with the nuclear fuel.
Typically, the nuclear fuel is within a steel container, where a primary, closed-loop cooling circuit will transfer the heat to a secondary open-loop water cooling circuit. The heat transfer between the two loops is done with an heat exchanger. That secondary loop is where the actual steam is made, and transfer the heat to outside. In no cases the water of the loops is mixed or even in contact.
Someone’s been sleeping through an entire article series. But don’t worry, we got you covered.
https://hackaday.com/2023/01/10/the-intricacies-of-creating-fuel-for-nuclear-reactors/
https://hackaday.com/2024/12/08/silicon-carbide-may-replace-zirconium-alloys-for-nuclear-fuel-rod-cladding/
https://hackaday.com/2025/05/19/3d-printing-uranium-carbide-structures-for-nuclear-applications/
Seriously? <Insert comment allowed on X that isn’t on HAD>
Is this limited to uranium or can it be applied to other radiogenic elements?
It’s wild to think this is economically viable at these concentrations. Let alone the electricity to pump these unspeakable amounts of cubic metres of water through the apparatus. Or is it just submerged? I didn’t full process the all the details yet, but kudos if it works! Makes you wonder what great achievements lie ahead of us in other fields by thinking a bit out of the box.
Most people would immediately dismiss the idea. 20 ppm only? Wild!
Extracting uranium is one thing, extracting U235 is another one. The ratio of U235/U238 isotope is what makes an Uranium ore interesting or not. And there’s no mention of the expected isotopic ratio in the sea water. The cost to separate isotope is probably a lot larger than the cost of sourcing Uranium at first.
I didn’t say I don’t know about UF6 and ultracentrifuges. Why would you explain me common knowledge? Greetings from Abdul Qadeer Khan!
About 1 part U-235 to 137 parts U-238. About same as in naturally occurring uranium.
Many reactor types can run on natural uranium.
The ratio of isotopes is the same everywhere on Earth, and has been since the planet formed; the proportion has changed due to U235 decaying faster than U238, but this happens at the same rate everywhere. The processes that concentrate uranium in particular mineral deposits, or in seawater, don’t change the isotopic composition since all uranium is chemically identical (which is why it’s so very hard to enrich).
As @Hirudinea says, reactors can be designed to run on natural uranium, as with the original RBMK design, for instance. The overall economics seems to favor slightly enriched fuel designs for power generation, though that might have been different if the weapons industry hadn’t made enrichment available already. Natural uranium reactors might be harder to control at low power levels (I gather that is/was an issue for RBMK), but that sounds like “just” an engineering problem.
No, there are famously depleted deposits.
https://www.iaea.org/newscenter/news/meet-oklo-the-earths-two-billion-year-old-only-known-natural-nuclear-reactor
“Extracting uranium is one thing, extracting U235 is another one.” In the Speciousest Wrongheadedest category we have a winner. There will probably be wheels involved so great! Now we have to invent that too. It never ends!
Unless such process is installed on the already existing flow of water.
It”s like using mining rig as a heater. It have exactly same performance as regular electric heater, but additionally bring some tiny profit. It will never cover all electricity consumed, but why not if you have to spent electricity for heating regardless.
Rather than pump the water through, attach it to the side of the nuclear power outboards from the previous article, and they can extract their own fuel from the sea as they go… 😂
this is a great start to an adventure novel. Also if there’s a spill just send another ship to slurp up the uranium. The scavengers feed on the corpse of the glowing steel whale.
Jules Verne could have used something like this.
Weirdly, that is not as insane as it seems but keeping it entirely as an outboard motor would be a non-starter due to reliability issues with extraction and refinement. While it is commercially infeasible it also isn’t impossible. However, an initial amount of nuclear fuel would be needed to start the reaction.
Presumably you could add a device on to every desalination plant. Added benefit for the process, is that the brine coming off is already concentrated. Probably 100M m^3 of seawater passes through them every day.
Also, all offshore wind turbines could have one attached. Hardly any pumping, and free electricity for the electrolysis.
Do this with Gold instead of Uranium and then you’ve got something.
If the gold were ions. One gram of gold for every 100 million metric tons of ocean water is going to be time consuming.
Do it with plastic, and save the world.
Do it with fish and feed every poor child in Africa.
That’s called fishing.
And you can’t really do it in places like Afghanistan, Bolivia, Nepal or Switzerland. Industrial-scale fish extraction with electric current could be used to feed literaly every human on the planet no matter if he is rich or poor.
Do it with electricity and … oh, wait, nevermind
There’s no money in saving the world.
Chemist here. The idea is not new, but if it worked, this would be indeed very nice. Back in the day, I worked in a lab that made some decent progress in that direction, using a different approach. Unfortunately, this paper has a series of big red flags.
There is no details on how the 100% extraction performance was measured. Actually, we avoid using 100%. We would typically say 99%, if the method is sensitive to 1% (99.9% for a very sensitive method at 0.1%, etc.).
Similarly, there is very little info on how this amazing electrode was prepared.
The source data is described as “Unprocessed western blots.” (unrelated biochemistry method) and contains some Excel files instead of primary experimental data.
And many others.
Finally, the claim of extracting from seawater at 20 ppm is also misleading, since (as stated in the introduction) seawater contains only about 3 ppb of Uranium. The 20 ppm were artificially added, and arguably do not represent seawater any more. Nothing wrong with working at 20 ppm, but it is good to be clear about it.
A lot of work has been done in the “get XXX from seawater” space, and to be fair, it seems to be making slow, steady progress.
Seawater is problematic for most of the ideas because of low concentrations, and bio-fouling.
However geothermal fluids have much higher mineral concentrations, and in fact are responsible for natural deposition of gold, silver and others.
If the proposals for large scale deep drilled geothermal outside of natural geothermal zones materialise, this tech might become quite significant. Geothermal already has to deal with most of it’s issues, leaving this mineral extraction from the fluid as a no extra cost add on. It could have much less environmental impact than existing precious metal mining, as there is no mine, and no tailings pile.
Could electrolysis be used to separate 235 from 238. Imagine you has a single atom wide plate of U (Or a plate with a single atom layer of U on top). When you apply an electric field all U atoms will leave the plate but travel at different velocities based on their mass. If the time that the electric field is applied was only long enough for the 235 to make the journey to the plate and then switched off. And then a third (waste) plate was energized to capture the 238.
Not exactly what you’re talking about, but there was considerable work in Japan on an electrochemical method of enrichment: https://www.sciencedirect.com/science/article/abs/pii/S0149197011000771
“Imagine you has a single atom wide plate of U”
A single atom wide plate is the world’s thinness wire. Even for pie in the sky the phrase you want is “Imagine you has a single atom thick plate”. Unless length is just really thick width, meanings have meaning.
My brain was thinking height, length and width. Sorry for any problem caused by me in transferring the idea from inside my head to yours.
Height, length, width? What is the height of a plate? Now rotate the plate 90 degrees. What is the height of the plate now? With the exception of the sphere whose height is always and everywhere 2r, objects qua objects do not have height. I’m sorry you got it wrong.
Thinnest.
I think I finally see your problem in understanding a (metal) plate is a flat dish, it can be circular or as in this case rectangular.
What is the height of an either circular or as in this case rectangular plate? Now rotate the plate 90 degrees. What is the height of the either circular or as in this case rectangular plate now?
Both this diffusion idea and the mass spectrometer separation have been used since the Manhattan Project.
I suppose the chinese researchers are thinking about nuclear subs that fuel themselves.
85USD a kilo? Where can I buy now 100kg of the stuff and sell it back (including the decay particles and minus the heat) when it becomes sparse? For sure I wont keep it in my lead coated matress. Or would I?
How this techology will impact the environement? What efect will taking the uranium from the water have and the waste product/spills being thrown back. What side effects will be produced (other byproducts/transitory compounds being spilled)?
While I’m not Greta, I wonder what Jacques-Yves Cousteau would say about it.
I would say leave the Ocean alone. It’s the last place that will have life if we mess the ground and air. On a second thought I’ll say “place that might preserve life”.
On a happy ending tone I’ll ask: when the flying cars will become available for everyone?
Can we chain other extraction operations on other valable substances on the exit ‘water’ ?
Could it be that some extractions become economically viable if/when previous stages removed other substances ? Or that a lot of stages with little gains outweight a massively non profitable extraction ?