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Improving Uranium Extraction From Seawater, Inspired by Shrimp
New submitter Celarent Darii writes "Prospects for harvesting Uranium from seawater turned interesting by using shrimp shells as a sort of catalyst."
Researchers at ORNL presented their findings from a test of a chitin net for harvesting Uranium at the ACS fall meeting. From the ORNL press release: "In a direct comparison to the current state-of-the-art adsorbent, HiCap provides significantly higher uranium adsorption capacity, faster uptake and higher selectivity, according to test results. Specifically, HiCap's adsorption capacity is seven times higher (146 vs. 22 grams of uranium per kilogram of adsorbent) in spiked solutions containing 6 parts per million of uranium at 20 degrees Celsius. In seawater, HiCap's adsorption capacity of 3.94 grams of uranium per kilogram of adsorbent was more than five times higher than the world's best at 0.74 grams of uranium per kilogram of adsorbent. The numbers for selectivity showed HiCap to be seven times higher."
Then Vegas is acquiring it's own nuclear arsenal.
Unlike oil, uranium will be found in comets, asteroids, planets, and deep within the earth. This applies to thorium as well. Effectively, it is an inexhaustible resource. The deeper you mine, the greater density of rock and the greater likeliness you will find uranium. Once we are able to mine the mantle we will be able to travel to the stars.
Chitin is also what makes up the body shells of insects. While these molten salts mentioned may be the best way to extract chitin, it also is soluble in d-limonene, an extract of citrus fruit peels.
This would be very good news, if people valued it properly. As much as a think the LFTR (which doesn't depend on uranium as a fuel) is a better type of reactor, there are limitations on its fuel source, which is thorium. Thorium is more plentiful, but it is not water soluble, so it doesn't benefit from this type of mining technique.
Is that like a "sort of" virgin, or a "sort of" complete ignoramus?
It's a word with a very specific scientific meaning. Use it for that purpose, or find a different one.
If you were blocking sigs, you wouldn't have to read this.
Yes, there is lots of uranium around. But it's locked up in mines, in places such as Niger which are unstable. Japan investigated this seawater uranium source because it wanted a stable source of uranium - one that would not depend on vagaries of geology, mining, and international politics. Because seawater contains approximately the same amount of uranium throughout the world, there is no need to get the uranium - they would let the uranium come to them, via ocean currents. Its a viable idea, even before this newest chitin invention. From what I remember, the cost of ocean uranium recovery was only twice what the market price of uranium was when the Japanese documented this method, and they were confident they could make incremental progress on lowering the cost. I would assume that all of the Japanese research has been cancelled in light of the post-Fukushima madness.
It's not economically feasible now, but the energy balance works out. Even with the previous method that was only 1/5th as efficient, you got much more energy out of the uranium than was required to collect it.
Seawater moves around, and the process still isn't that efficient, so you wouldn't have any problems with decreased concentration.
The reason this is valuable is not so much that it's economical today, as that there's enough uranium in the ocean to provide all our electricity needs for millions of years.
The better question is, why don't more people eat cockroaches?
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
I would guess research into filtering out radioactive elements would only increase...
30 to 150 million cubic metres per second. So 12 minutes of Gulf Stream flow would contain enough uranium to supply our present needs for a year.
Though if you could tap the entire Gulf Stream you'd have another source of energy at hand...
You left out a few prefixes of "million" and "milli", making your analysis way off, at first. There are 30 million cubic meters per sec of gulf stream flow. there are 3 milligrams of Uranium per cubic meter of seawater. So that's 90 Kilos of Uranium per second.
But you're unlikely to be able to intercept more than a thousandth of the gulf stream, so we're back to 90 g per second. the goofs cancel out!
You do realize that, with continued research into sea water extraction, your first four objections go away? It could be extracted from anywhere with access to the sea, as safely as fishing, and there is enough to power all of humanity for thousands of years. As to the rest, proliferation is largely a political problem, one that can't be ignored no doubt but certainly not insurmountable. Waste is a larger issue of course, breeder reactors would help there but you've still got to put it somewhere. I'd say launch it into the sun once we get the rocket tech to do that efficiently but that seems awfully wasteful (after all, if it's energetic enough to be dangerous we can probably find a user for it somewhere in the long term).
Wikipedia says there's 3.3 mg uranium per m^3 of seawater and the volume of the world's oceans adds up to 1.3*10^18 m^3, which means that there's 4.4*10^12 kg of uranium in the oceans, or roughly 400 kg per human in a world with 10 billion humans. That's a lot of uranium...
I don't suppose much is known about the rate at which it replenishes, but I bet scientists will be able to find out about that long before we begin to see measurable depletion of seawater uranium on a global scale.
However, rivers bring more uranium into the sea all the time, in fact 3.2x10^4 tonne per year.
- Source
I'm not sure what 2 even means; "hard to mine?" Lots of things are hard - try raising kids. In economic terms, "hard" just means "expensive". It's either affordable or it isn't.
In context of the total cost of nuclear power, it's been getting expensive and rare lately because of soaring *construction* costs, not fuel costs, since fuel costs are a single-digit percentage of the whole; it's almost all about paying off the multi-billion-dollar mortgage on the plant. Even before this discovery, the Japanese believed they could extract uranium from seawater for a few hundred dollars per kg - that's several times the current price, but should we "run out of uranium" (i.e. nothing but "hard" places left), then a ceiling will be put on the price, since it would take many centuries of "mining the sea" for the concentration to decline.
Before that happens, of course, it'll become affordable to re-process spent nuclear fuel, which means 97% of what is currently regarded as "waste" will become fuel again, because reprocessing costs 3X as much as mining new stuff. That 30:1 ratio will stretch out the supply a ways.
As for "dangerous", your own link to radon notes that new standards for mining procedure were enacted back in 1971. Most of the data on higher lung cancers and so forth come from those exposed some time ago, particularly Navaho uranium miners, where there were many allegations that racism prevented a more serious response to their concerns.
More recently you can run across comments like this one:
On June 18, 2004, the Saskatchewan Uranium Miners' Cohort Study Group released its report on a feasiblity study it had begun in 2002:
"It concludes that it is not scientifically feasible to conduct a study of present and future miners who work in modern Saskatchewan uranium mines (1975 onward). Today’s Saskatchewan uranium miners have radon exposures that are between 100 and 1000 times lower than those of past uranium miners, such as miners from Beaverlodge, because of dose limits, improved mining techniques, and other radiation protection practices. Any higher-than-normal rates of lung cancer from such workplace exposures would be virtually impossible to measure. The feasibility study was completed in October 2003 and it was then reviewed by three internationally respected radiation researchers." [ http://www.wise-uranium.org/uhm.html ]
Simply, this is an engineering and economic issue. Proper safety procedure lowers the risks of mining hazardous materials (where do you think things like arsenic and mercury come from? Somebody has to extract and purify them...), and make the risks tolerable - at least as tolerable as coal mining, your only practical alternative...and they also increase the cost of the extraction, which is then either affordable or it isn't. In the case of the nuclear industry, it would probably only a a tenth-cent per kWh to pay double or triple for uranium, so it's always going to be affordable to mine it - and dispose of it - safely.
The industry doesn't WANT to, any more than slaughterhouses want to pay a decent wage and up the cost of your hamburger by a nickel; but that's a "mere" matter of regulating the activities of very wealthy investors. Hard, (sorry) but possible.