Slashdot Mirror
Centrifuge May Be Superseded by Laser Enrichment
An anonymous reader writes "Australian scientists have discovered, after a decade of tests, a new way to enrich uranium for use in power plants." From the article: "There are at present only two methods for sifting uranium atoms, or isotopes, to create the right mix. One, called diffusion, involves forcing uranium through filters. Being lighter, U-235 passes through more easily and is thus separated from its heavier counterpart. The second method, widely adopted in the 1970s, uses centrifuges to spin the heavier and lighter atoms apart. Both, said Dr Goldsworthy, are 'very crude. You have to repeat the process over and over,' consuming enormous amounts of electricity. The spinning method requires 'thousands and thousands of centrifuges'."
Objective answers - rather than pro-nukular or anti-nuclear spin - preferred (some hope!)
In a survey of 100 programmers, 111111 thought that duck-typing was a good idea.
It's been around for over 20 years. What's new is that the Aussies appear to be commercialising it.
Do you know where I can find detailed information about that new method?
Kisses,
Ahmadinejad
Bingo. One can make a strong arguement for nuclear power. It is efficient and clean. Yet we don't seem to want to let anyone have it because it might be a cover for nuclear weapons. What to do?
I think the solution is to put butt-loads of funding into bringing fuel cell technology to the forefront.
http://blindscribblings.com - Tasty pop-culture in conceptual fashion.
If this is really so novel and useful, surely an analysis of it exists that is not written by the guy trying to sell it!
The article goes on to explain that six other countries have tried laser-enrichment schemes and failed, but this effort has succeeded, and the only possible hint at why is that this new approach is that it is more "elegant and sophisticated".
Even a link to the press release would have provided a bit more information (though more legalistic than technical).
The post mentions diffusion and centripetal enrichment. There is actually a third method that has been used by several nations. The "calutron" separates isotopes using a magnetic field. It is the least efficient and most expensive method, so it is uncommon. However, it was used by the Manhattan Project and Saddam had an array running in Iraq at one time.
Making Uranium enrichment easy is not necessary a good thing. Uranium ore isn't hard to get. Enriching it is the tough part. The same processes used to make fuel lead directly to gun-type "atom" bombs. It's just a matter of degree and some machining.
Get this process down to something small enough to quietly function in a barn and you could build a weapon inside the borders of your target. A gold mine or somesuch would be all you need for cover.
Lurking at the bottom of the gravity well, getting old
Sigh.
The Slashdot Paradox: "100% Overrated"
Fuel cells will do nothing about the demand for power stations. Anyways, this makes fuel for nuclear plants even cheaper, and it's already a 'negligable' cost for the operation of a plant.
;)
I say we build so many nuke plants in 'trustworthy'(IE already nuclear) countries that we're buying all the fuel just to feed all the darn things.
Realistically, it's going to be impossible to prevent any country that wants nuclear weapons from getting them. I'm kinda suprised that we've done as well as we have, as all it takes is a country going 'screw you' and building the stuff themselves. We know it can be done with cutting edge 1940's level technology, and it's been over 60 years. Even countries like Iran have reached the point where they can do it with domestic industry if they truly wanted to.
I don't read AC A human right
The first generation of nuclear reactors in the UK (Magnox) used natural (i.e. unenriched) uranium metal as fuel.
This meant that the fuel was very cheap to make but the fuel cans had to have a low neutron capture cross-section, hence the Magnox. This limited the temperatures at which the reactors could operate.
Moving to enriched uranium allowed the use of stainless steel cladding which keeps its integrity to much higher temperatures and is mechanically stronger.
There have been many developments in nuclear fuel technology since the 1950s, as one might expect. MOX was a good idea, but derailed by BNFL corporate incompetence and "environmentalist" hysteria.
The idea with MOX is that, instead of enriching uranium to increase the proportion of fissile U-235, you mix in fissile plutonium recovered from used nuclear fuel which is then "burnt up" in the new fuel to provide power. Plutonium isotopes are natural byproducts of the nuclear reactions in fission reactors.
Perhaps it would be more economical and environmentally-friendly to use more MOX than enriching fresh uranium?
Stick Men
There is a lot of radioactive material in brown coal. A power station is one of the best ways to distribute it in the atnosphere.
http://michaelsmith.id.au
But in a laser, the Uranians can't go "Wheeeeeeeeee!".
No, I'm just joking, I really do love the Uranian people.
According to Mordechai Vanunu, the Israeli nuclear whistle blower - as quoted by the Sunday Times - Israel had laser enrichment technology, in actual production use, at the early 1980s.
http://en.wikipedia.org/wiki/Mordechai_Vanunu
So - nothing new here, move along, move along.
However, it's a LONG way from lab benchtop enrichment experiments to a functioning enrichment plant. And once you get to that functioning enrichment plant, there's the question of whether or not it was economically justifiable to build in the first place. This is where the American effort "failed" - even on paper, it never made sense to pursue this technology because it was just too expensive. Sure, you need thousands of high-precision centrifuges to run an enrichment cascade. This was still cheaper than building a laser enrichment plant.
The designs for a uranium laser enrichment plant ON AN INDUSTRIAL SCALE are not for the fainthearted. YOu've got to have the uranium in a gaseous state. That means heating it so hot that not only do you have a pool of molten uranium, but it's BOILING. The laser is going through the HOT uranium "steam". The only material that can stand up to these temperatures is pure graphite. The design becomes like a series of rain gutters on a house that carries "more enriched" and "less enriched" streams of molten uranium back for reboiling. Somehow you've got to figure out a way of putting optical ports into this hellhole to fire the laser beams in. The laser beams themselves are a weird wavelength (green) and takes some really expensive gear to generate at all, much less with intense enough power to penetrate deeply into a fog of molten uranium. Doing all of this cheaply? Good luck.
And in the background overshadowing enrichment plant economics was and is the fact that nuclear power plants are still just too expensive a way to generate electricity (primarily due to regulatory costs) compared to coal and natural gas turbine plants. The expected boom in nuclear power plant construction forcast in the 1970s and early 1980s never materialized, mainly due to Thre Mile Island and Chernobyl, and so the need for new-fangled enrichment technology as a support industry never materialized with it either.
Right now the cheapest way to come up with fuel for a nuclear power plant is not laser enrichment or even centrifuge enrichment. It's diluting old Russian warheads, all 30,000 of them, down from 93% enriched uranium back to 3% uranium. This, along with all those Russian brides American men now have access to, are the REAL spoils of winning the Cold War.
There is a third method that has been used on an industrial scale, which is to essentially build a huge mass spectrometer. Mass spectrometers are usually used to separate atoms into their isotopes for analysis but Ernest O. Lawrence proposed this for the Manhattan Project and the Y-12 separator at Oak Ridge, TN, built in 1941, yielded some useful results before being superseded by gaseous diffusion at the K-25 facility and later the S-50 thermal diffusion plant. Indeed the first 200 grams of fissile material delivered to Los Alamos came from the electromagnetic separator, more than a year before the diffusion separator started operation (the uranium bomb dropped on Hiroshima used about 64Kg)
If intelligent life is too complex to evolve on its own, who designed God?
Process heat comes from the Sun, still the best fusion reactor going.
Electrolytic by-products are:
Now if the reaction can be combined with some hydrogen injection to make water and ease the total (electrical) energy required you get a nice sustainable technology. Water, also.
Solar cells are made from the silicon, formed into parabolic mirrors that focus the IR band to the smelting pot. Interference coating the cells is easy with the free nothing called a vacuum
Electricity from the power cells drives the electrolysis and runs the station power.
With all that silicon, I'm betting that some composition can make silicon into something more ductile.
Cheap building material would be nice...
This is progress?
> There are at present only two methods for sifting
> uranium atoms, or isotopes, to create the right mix.
AVLIS has been around since the 1970s, and there is also the South African cyclonic process. There are also hints in the public literature that there are other methods that were examined by the Manhatten Project and not pursued for various reasons.
sPh
Where are you getting the fuel then?
Hydrogen doesn't occur naturally in pure form - it's always combined with something else, like a hydrocarbon chain, or water. To run a fuel cell you either have to:
1) Use hydrocarbons as your fuel source. This is environmentally little different from using a standard internal combustion engine. You're still using natural gas, or possibly some other fossil fuel.
2) Use water electrolysis to get hydrogen. This requires loads of electricity. This in turn means that your hydrogen "fuel" is actually a power storage medium like a battery. You cannot run a power plant this way.
Got a link to the nebraska plant? I'd bet good money they're using option #1, and if they are, then they haven't weaned themselves of fossil fuels.
Option #2 is the only way to use truely "green" fuel cells, but it also requires a source of clean electricity - such as fusion - or else you're just moving the source of pollution from a tailpipe to a power plant.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
MOD PARENT UP!!! Excellent links.
Quote from the first linked article: "In MLIS, an infrared laser is directed at uranium hexafluoride gas. The laser excites uranium 235 hexafluoride gas, while not disturbing the uranium 238 hexafluoride gas."
In 1972 or 1973, I built an apparatus to test whether a flowing gas carbon monoxide laser could excite uranium 235 hexafluoride. My little project was shut down without explanation.
The Silex web site gives almost no information. The "about Silex" web page misspells the word neutrons as "neutrins".
It could be that the U.S. government has been successful at laser enrichment, but has published misleading information about the project. The article linked by Slashdot says, "One US effort involving 500 scientists gave up after spending $2 billion." That doesn't make sense. You know very early, without spending a lot of money, whether you have a laser tuned to the right frequency.
--
Taxpayer Karma: If you contribute money to kill people, expect your own quality of life to diminish.
Two Words : OH SHIT.
I don't mean to be too alarmist, but this is VERY bad news. See, it's easy to get access to uranium ore. Many countries have the mineral, and buying yellowcake is not supposed to be all that hard. Heck, some of it supposedly went through Africa. If you have just a few kilograms of highly enriched uranium, again it is easy to make a bomb. Spherical explosives aren't needed, a simple crashing together of a critical mass is enough. 10-20 kilotons is still enough to cut the heart out of a major world city, and kill hundreds of thousands of people.
But getting from A->B WAS ludicriously expensive. I read that it takes a year for a sample to travel from one side of the centrifuge plant to another, and these plants have to be enormous, costing billions. The laser method as described appears to be much cheaper and generates probably close to 100% pure U-235. Yes, it is a secret technology, but the plans can be stolen or bought, and lasers and all the other stuff needed to make it work are not restricted exports.
It might still cost a billion dollars to make a nuke, but that's it - not 10 billion. Most private individuals without access to nation state resources can't do it, but even the poorest dictatorship in the world can probably scrape together or steal from the U.N. a billion.
If you read up on the Gen-4 reactor designs, you'll find that greenhouse gasses, non-proliferation, safety, and more efficient designs (a LWR reactor is rather wasteful on the scale of designs) have been taken into consideration. Rest assured that the new reactors being built in Florida, and all across the USA are being built with the best, safest technologies available.
Oh, and the thousands of centrifuges? That's just bad journalism. I don't know how lasers are cheaper at all (someone needs to actually write a decent article here), but for what it is worth, Nuclear Energy in the United States is cheaper than coal, but just barely.
Check out www.nukeworker.com and ask your questions there. Those guys know their Uranium from their belly buttons!
It's not just republicans, it's all bad-government conservatives. What happened to the days when conservatives had the balls to just say "centralism sucks, so we're cancelling these programs and lowering taxs"? Nowadays, they fuck up otherwise successfull programs, DON'T lower taxes, create deficits spending money on things that don't work, and lie constantly. Modern conservatives can't even come up with good lies. At least guys like Nixon made it hard to be sure exactly what was going on. You knew he was full of shit, but what kind of shit? Bush just relies on the fact that most Americans are as almost gutless as he is, and are too cowardly to doubt anything. Or my own "leader", Stephen Harper, who tells lies that are contradicted (often within hours) by undeniable evidence. At least Paul Martin's lies left you confused and uncertain about reality... Harper's just embarass us all.
Right now, nobody needs or wants any more U235, except for North Korea, Iran, and various splinter groups.
The US Govt has PILES of the stuff, as does the USSR. Plus many tons of Plutonium. All very expensive stuff, but worth less than zero.
There's more tons of U235 and Plutonium in all the unprocessed fuel elements that have outlived their usefulness in nuclear reactors. The stuff is so worthless it's being stored or buried, not put through a relatively cheap chemical reprocessing cycle to recover the U235 and Plutonium.
If we needed more U235, there are several multi-billion dollar separation plants in mothballs that one could restart with relatively little effort.
So this laser-enrichment, IF it can ever be gotten working on a large scale, is (a) a threat if rogue states and the Mafia get into it and (b) Will produce soemthing nobody needs, and (c) probably riskier and more expensive than just starting up the old plants.
The technology to make weapons that are much more dangerous than gun-nukes are already available to pretty much anyone. Anthrax practically breeds itself. And by "practically" I mean "literally". A variety of super-lethal chemical agents can be synthesized with stuff from your local grocery store, and made into weapons using stuff from your local hardware store. A pack of matches and a forest during the summer can net you a firestorm that will destroy pretty much anything. I could go on and on. Besides, why worry about nukes when the common automobile kills more people per year than all nuclear weapons combined ever have? I'd worry more about the proliferation of the horseless carriage than about the proliferation of uranium.
If a photon of precisely the right frequency (and therefore energy) hits an atom, two things happen:
(1) It gets absorbed, and transfers its momentum to the atom -- i.e., gives it a little push.
(2) One electron in the atom absorbs the photon's energy, exciting it to a higher energy level.
Then, after a random time interval, two more things happen:
(3) The electron drops back down to its old energy level.
(4) The atom emits a photon, carrying the energy given up by the electron, and the photon's momentum delivers another push to the atom.
But while the first push was in the direction of the laser beam, the second one is in a random direction -- so the affected atoms, statistically speaking, wind up with a net gain of momentum in the direction of the laser beam.
So far, the laser is basically just stirring the gas. Now you tune the frequency of the laser a little bit lower. The "average" atom sees the photons at the wrong frequency, and the photons just truck on by. But atoms that happen to be moving toward the laser see the photons Doppler-shifted up to just the right frequency and they receive a push away from it -- so their average speed is reduced. Ba-bing, ba-boom, the gas is colder.
Laser cooling, along with a couple of other techniques, made it possible to get the super-low temperature needed to isolate the Bose-Einstein Condensate which got the 2001 Nobel.
rj
Uranium hexafluoride can be (and is) used in enrichment process:
http://en.wikipedia.org/wiki/Uranium_hexafluoride
This substance is gaseous at 64C, no extreme temperature is needed. Laser enrichment works with this compound.
Use of UF6 is the MLIS process, championed by Los Alamos. Use of atomic vapor is the AVLIS process, championed by Livermore. You would not believe the endless arguments that ensued during the 1980s over which was better. AVLIS won.
TFA states "..[p]ower stations are fuelled by a specific blend of two types of uranium. About 5 per cent must be uranium 235...".
This is of course untrue, for example the CANDU reactor uses heavy water and natural uranium. Not processing uranium is cheaper than processing, laser or not.
Anybody want a peanut?
Your bitterness is mighty. :)
Thanks. I've been cultivating it. :-) I intend to be the world's most curmudgeonly old git when the time comes, hopefully with an entry in the Guinness Book of World Records for being an intolerant, cantankerous old fool with an "I told you so" attitude.
Stick Men
It's not helping that you guys are way down there at the "bottom" of the world, either. I think you should give some serious consideration to relocating a little closer to the population centers of the world; the shipping costs alone have to be just about killing you (besides, why would someone buy stale nucular fuel shipped from almost the South Pole when they can make their own fresh fuel right here at home?!)
In short, until you can overcome the transportation issues inherent in being about a zillion miles away from your customer base your best bet is to just export your ideas and let someone else implement them.
(in all seriousness: the "because they're very far away" answer is so far the ONLY way the wife and I have been able to convince our two three-year-olds we can't just pick up and go visit The Wiggles some weekend...though one of them actually just wants to go because on our globe Australia is pink.)
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You state that there is an excess of uranium. Is that why uranium prices have increased over 500% in the last six years? Commodity prices in general have been soaring, and many other countries use uranium. Electrification of India (nuclea power) and China (also nuclear power) is creating a surge in power consumption.
The Soviet materials have been mostly reprocessed. Consumption has reached 80 thousand tonnes per year, and production is still less than 50 thousand tonnes. Additionally, GE has already signed to build a facility in the US. Obviously someone thinks it's worth the investment.
http://www.accountkiller.com/removal-requested
There would be no reason whatsoever to enrich uranium (Other than to make bombs to kill people) if we were to use the CANDU and IFR technology.
Fuel reprocessing however is necessary.
There is just no way we can supply our energy needs in the long haul other than with nuclear... that is unless we accept a massive change in our life styles!
Oil is peaking now. The actual month may well be in 2007 or even beyond that - but we are effectively already at peak because we cannot signficantly grow our supplies. We can increase our coal consumption and we can liquify it as well. We can also make bio-fuels. But they will not fill the gap created as conventional oil depleats. The short of biomass->ethanol for instance is that a tonne of any biomass (not the refined cooking oils!) is equivalent to about 2 barrels of oil. This is easy to illustrate by looking at the chemisty (CH2O)n -> C(n)H(2n+2).
We are starting to face a major energy crisis and this is only the beginning - barely the tip of the iceberg.
The issue is the current generation of reactors generate a pile of plutonium. While it isn't weapons grade Pu (too much Pu240 relative to the Pu239) it is still dangerous. The best course of action is to burn it up for power.
The CANDU is a near breader design and is quite efficient in its use of neutrons. It is a decent reactor to use until IFR can be put into production. Note that a CANDU can easily burn the spent uranium fuel which is incorrectly called "waste". An IFR can even burn depleated uranium.
Of course we need to allow fuel reprocessing for this to happen. The only reason we don't do it now is political. (for the short term... IFR combines the reprocessing on site and hense is far more secure).
As for the cost of nuclear energy?
The short answer is that enough governmental beauracracy can make _ANY_ industry unprofitable.
If you think I'm making it up, do the research. The amount of Hollywood misinformation that the average person has is obscene. Here's one: you can't blow up a nuclear power plant and get an atomic explosion. What? Yeah, it's basically just glowing green rocks, water, pipes, dynamos, and a lot of concrete. You can blow up a natural gas or oil power plant, however.