Fusion Plasma Plant in The Future 640
NightWulf writes "The BBC reports that Europe and Japan are currently looking to host a new JET power plant. This new plant creates plasma, which is akin to creating a star on Earth. Interesting to note that 1kg of fusion fuel would produce the same amount of energy as 10,000,000kg of fossil fuels."
Yes, indeed (Score:5, Funny)
In the same sense, my logging on to slashdot today is akin to designing TCP/IP.
NOT a fusion plant! (Score:5, Informative)
Re:NOT a fusion plant! (Score:5, Funny)
Re:NOT a fusion plant! Or anything new! (Score:5, Informative)
Oh, and as an added bonus for geeks in that area, they have a public open house [pppl.gov] coming up on June 12!
someone should tell Creator of the Gaia Hypothesis (Score:5, Informative)
Re:someone should tell Creator of the Gaia Hypothe (Score:5, Informative)
Iter - latin for "road" - is the next stage, but not the final.
It will produce more energy than put in, will will not create electricity as such.
"Creating" electricity, as a normal powerplant does, will be the next stage. As in DEMO.
So another year before knowing where to build iter, it should have been decided long ago. A few years to build it. 20 to 30 years of research. A few years op political maneuvering for deciding demo, building and doing research for another generation.
So 50 or 60 years before we have an electricity producing fusion plant.
How much energy? (Score:5, Interesting)
How much energy do they estimate it will take to create (and control?) that one kilogram of "fusion fuel"?
Re:How much energy? (Score:4, Funny)
Re:How much energy? (Score:5, Informative)
Deuterium... cheap. The oceans are full of the stuff. Tritium and helium-3 are harder to come by; we'd probably need a lunar harvesting operation if we were going to go for fusion on a commercial scale.
Re:How much energy? (Score:5, Insightful)
Re:How much energy? (Score:5, Informative)
No, but you can get helium-3 out of the regolith [asi.org], where it's been collecting in small quantities for a few billion years out of the solar wind.
Re:How much energy? (Score:4, Funny)
No no, we all know that different fossil fuels have different efficiencies by weight.. e.g. a kilogram of pure natural gas produces a different amount of energy when burned than a kilogram of kerosene.
So the REAL question is, how many Libraries of Congress would we have to burn to generate equivalent energy.
Sweet! (Score:4, Insightful)
It would be the first fusion device to produce thermal energy at the level of conventional electricity-producing power stations, and would pave the way for commercial power production.
This is awsome. Expensive for the amount of power though. Anything that can reduce our dependency on oil, deserves some research in my eyes.
Re:Sweet! (Score:3, Informative)
I've been hearing about fusion power being *just* over the next hurdle since I was born. White elephant.
Re:Sweet! (Score:4, Insightful)
Just over the next hurdle, in terms of developing new power sources, could equal a significant period, possibly longer than your entire life.
Toxic waste, but not much of it (Score:4, Insightful)
Of course, fusion is better than fission in this regard, but the same arguments hold in either case.
Same argument with electric cars (Score:3, Insightful)
The attraction (Score:5, Insightful)
Yeah, at the moment this electricity or hydrogen would be probably just generated using fossil fuels. But the catch is it doesn't *have* to be. You could substitute a nuclear power plant for that coal-burning one and the electric cars would continue to run just the same... it makes productive change much easier. Whereas if you buy a gasoline-based automobile, it's going to be running on burned fossil fuels forever*.
* Unless you are Doc Brown and you do some retrofitting.
Re:Toxic waste, but not much of it (Score:5, Insightful)
As one of last season's Penn & Teller's Bullshit pointed out, the environmental movement is being highjacked by anti-corporate groups. Honest environmentalists only want to be sure we think about how what we do will affect the future world; they don't want to prevent all progress indiscriminately.
Agreed, (Score:4, Insightful)
Currently, the DOE has so many clean up sites, not because the nuclear energy projects were not successful and profitable, but the fact that the DOE is required, COME WHAT MAY, to take care of any finality issue with a nuclear based energy company. So the companies have a whopping zero cost for failure or liability, and remember, we're talking nuclear.
So, when they think their operating costs get too high, or they just don't want to do it anymore, the nuclear companies can literally drop what they are doing right there, walk out, and it is all a Department of Energy (DOE) problem from then on. Guess what? DAMN NEAR EVERY ONE OF THEM DOES. That is their little perk. This stuff is too dangerous without permanent government supervision. The US doesn't want some weird Iranian group that they don't trust buying up their workplace (because if anyone is going to sell something to Iranians we don't trust, by god, it should be bought direct from the US government), and after all, businessmen don't care what they have to do as long as they get the cash for doing it. So, as a protection, they have no responsibility for their nuclear actions.
"We leaked some sludge? WHOOPS. That's it, it is now too expensive with the lawyers. Close shop. Call the DOE. It is their child now. Thanks for the BILLIONS, and see ya later, suckers!"
The best analogy would be that the government would now be responsible for auto manufacturing recalls. "Sorry we made some bad cars. Call the government, it is their problem now."
Re:Toxic waste, but not much of it (Score:5, Interesting)
Exactly. If you look at something like the Clinton EPA new source review regulations, which punished corporations for more efficient energy production, and which environmentalists defend passionately, then its hard to reach any conclusion but that envnironmentalists are now pursuing an environmentally reckless anti-corporate agenda. As a result, there is new demand for legitimate environmentalism. This demand has spawned a conservative environmentalist movement. Among the tenets of conservative environmentalism:
- If the government internalizes externalities by imposing fees for despoiling or consuming public goods (air, water) then this eliminates the "tragedy of the commons" problem and incentivizes business to reduce environmental impact. When resources cost money, the market will favor business which produce the most efficiently, that is, the most output for the least monetary (and therefore environmental) cost. The key idea here is that no government regulations are required. You don't need regulators in the EPA to approve powerplant designs. Just license for the right to pollute, measure the output and enforce the law, and the market works to develop and choose new technology to reduce the overall level of pollution. Liberal environmentalists oppose this plan. Sierra Club and other groups lobby against tradable pollution credits because they "give corporations a license to pollute." But that's just not true. They are selling, not giving, corporations a license to pollute. The selling part is the crucial aspect.
- The primary goal of environmentalism should be to preserve and expand the land area of natural habitat. Liberal environmentalism, on the other hand, has set a whole bunch of additonal goals, such as advancing renewable energy resources, opposing fission, regulating private land use and regulating genetic diversity. These other actually work against expanding natural habitat.
- Reneable energy resources are anti-environmental because they have low-energy density; They take up too much space, displacing natural habitat. Ethanol fuel and solar power both require destruction of vast areas of natural habitat. The flux density of sunlight, collected either by crops or photovoltaics, is just too low to satisfy world energy demands without taking over a large surface area of the planet. The density of an energy source is the correct measure of environmental correctness. High density energy sources produce the most energy in the least space, displacing the least natural habitat. By this measure, petroleum is good. You only need about enough space to drill a hole in the ground and build a refinery. Fission has an even higher energy density. Geneticaly modified crops are good because they produce more food on less crop land, shrinking cropland and expaning natural habitat.
There are books about this stuff. I suggest "Hard Green: Saving the Environment from the Environmentalists". The phrasing is overstylized, manifesto screedish. Like a poor immitations of Abi Hoffman. (Though a more acurrate imitation would be worse). Nonetheless, IMHO its a fact-filled, well-reasoned argument.
Re:Toxic waste, but not much of it (Score:5, Insightful)
And we hold our breath in anticipation as....
absolutely nothing happens.
People, it may be "radioactive waste", but it's only radioactive waste! 1 kg is not a significant amount delivered that way.
You are just perpetuating those downright evil myths about radioactivity and radioactive waste that is preventing all rational progress in this area. To hear people talk, radioactive waste is billions or trillions of times more toxic then the nasties routinely produced by, hell, farting!, and will magically seek you out and jump you in the night, probably targetting Your Children for extra special treatment.
It's just a moderately nasty form of waste; there's other forms which are much worse, pound for pound. It's not even close to "the most toxic substance on Earth". Radioactivity is just radioactivity, not a malicious force intelligently hellbent on seeking out and destroying all humans.
We will have to wait for our robotic overlords for that day.
Helium (Score:5, Funny)
Rus
Re:Helium (Score:3, Interesting)
Re:Helium (Score:5, Interesting)
Estimates for remaining Helium supplies suggest we may run out in about 20 years. Here's a little more for those who don't know as much about Helium as CodeMonkey.
Taken from here [k12.ca.us]:
For most of this century the world's precious supply of helium has escaped from natural gas wells into the air. Only in 1958 did politicians heed the warnings of influential scientists including John Bardeen, the inventor of the transistor, that all our helium would be gone by 1980. Congress reacted by spending $1 billion--an astonishing sum in the 1950s--on a separation plant in Amarillo, Texas, and began stockpiling helium in empty gas wells.
As it happened, helium turned out to be crucial to the success of NASA's space--programme. The most powerful rocket motors are fueled by hydrogen and oxygen, both of which have to be carried in liquid form, and helium is the ideal refrigerant. In fact, it was helium carried to the Moon on the Apollo spacecraft that determined how long the astronauts could stay on the lunar surface. Once the helium had boiled off it would have been impossible to keep hydrogen and oxygen in liquid form and the spacecraft would have been stranded.
Thanks to the conservation measures, helium supplies were not exhausted by 1980. and other rich sources of the gas were discovered. however, sources of helium have remained few and far between because the geology of natural gas wells must be very special in order to hold onto it in commercial quantities.
Against this background, the worldwide consumption of helium has increased by between 5 and 10 percent a year in the past decade, which the biggest growth in its use as a coolant for the superconducting magnets in magnetic resonance imaging (MRI) body scanners. Present helium consumption is estimated to be about 100 million cubic metres, and is predicted to continue rising by 4 to 5 percent a year.
No one is claiming that we are in imminent danger of running out of helium--there should be at least 20 years supply left. However, new sources of the gas will have to be found to meet the ever-growing demand. If not, God forbid, we may have to celebrate helium's 200th birthday in the year 2095--without any Mickey Mouse balloons.
Re:DO NOT INHALE HELIUM! (Score:4, Informative)
"Helium causes death??? Come on; get real. Helium is an inert gas (if you don't know what inert means, look it up). It is not a poison and it cannot hurt you by breathing it. Divers use a mixture of helium and oxygen when they go deep because pressurized nitrogen is poisoness. The only way that helium could hurt you is if you were breathing pure helium (no oxygen). You would pass out and eventually die from a lack of oxygen not from any property of helium. This is true of any gas that you might breath that does not contain oxygen.
If you are sucking on a helium filled balloon and start to get light headed, just pull the balloon out of your mouth and take a breath of normal air. If you don't stop sucking on the balloon when you get light headed, you will probably drop it when you pass out and the problem will fix itself."
Please stop spouting Urban Legends that have no validity.
strange fascination... (Score:5, Funny)
What the article doesn't mention... (Score:5, Interesting)
Re:What the article doesn't mention... (Score:3, Interesting)
One reason the next machine will be larger is because it is easier to control the plasma (shown by the work done at JET).
Re:What the article doesn't mention... (Score:4, Informative)
It's also designed to be repairable in the event of a failure (in the way a commercial reactor would need to be), and its designers have benefitted considerably from the experience of JET. The BBC has covered this reactor for some time: I'm surprised slashdot has only picked up on it now.
Re:What the article doesn't mention... (Score:5, Insightful)
Another problem is that if the current in the plasma passes through the walls of the vessel it creates a magnetic field around them which kicks against the plasma's own magnetic field with incredible force. This is called a disruption, and it kills the plasma. Back in the project's infancy a particularly bad disruption actually caused the entire torus to jump a clear centimetre off the floor. If that doesn't sound impressive then you need to have another look at a picture of the torus [efda.org]!
I had the privlidge of working at JET during the third year of my degree*, and I can say that JET has some of the coolest gear and cleverest people working there that I have ever seen.
For anyone who's wondering about the computing equipment they use: they have a lot of big Sun servers which host X sessions from Linux PCs or some Xterminal like things called Igels (they also still use some original X Terminals.. I don't know if those are still in production?) on which most development is done. They use Linux in as many places as they can, including a ~80 node analysis cluster (JET produces data at a rate of about a gigabyte a day during operations). Windows PCs are available for desktop use by those who prefer them.
* If anyone thinks my very basic description of the physics is a sign of BS, I should point out that I was there as a Software Engineering student, not a physicist.
More on containment and break-even points (Score:5, Interesting)
"The most advanced test reactors, the Tokomak Fusion Test Reactor (TFTR) in the U.S. and the Joint European Torus (JET), use the tokomak design and have come close to break even conditions. In fact, in November, 1991, the British-based Tokomak reported break even conditions. This occurs when the energy given off by the fusion reaction is equal to the energy input required to sustain the reaction. In order for a fusion reaction to generate useful amounts of electricity, the energy given off must be many times greater than that required to sustain the reaction. Even the most optimistic researchers feel that it will be well into the next century before this stage is reached." (from This site [iclei.org])
Japan (Score:3, Funny)
I would have thought that decision to build the project in Japan would have been unanimous. How else could Gozilla be resurrected?
JET info and pictures (Score:5, Informative)
Including some pretty cool pictures of their kit [efda.org].
Am I being too skeptical? (Score:3, Funny)
On the other hand, I don't know enough about it to confidently say it's crap. So - anyone out there able to tell me what, exactly, this "kg of fusion fuel" is made up of? And, if possible, provide support/debunking for the 10,000,000x as much energy claim?
Re:Am I being too skeptical? (Score:4, Informative)
No need for us to prove it. You can do it yourself. The equation is E=mc^2. c is a really big number.
Re:Am I being too skeptical? (Score:4, Interesting)
Let's get the facts straight (Score:5, Informative)
Wikipedia has a good article on Fusion Power [wikipedia.org]. Read it, then post.
Wow just to boil water (Score:4, Interesting)
Re:Wow just to boil water (Score:4, Informative)
Alpha particles - helium core - and neutrons are created in a fusion reaction. The alpha particles carry about 20% of the energy, the neutrons about 80%.
After the alpha particles give of their energy to the surrounding plasma, the have to be removed in order to keep the fusion reactions going.
So left are the neutrons. These are neutral particles. So forget about something like an ion-separator (sorry, don't know the correct english term. same principle as an ion-engine. Using lorentz force: f= qE + qvxB).
So you use the energy of the neutrons to boil water.
Re:Wow just to boil water (Score:3, Informative)
Awesome! (Score:3, Informative)
We will always depend on Arab oil in some way or another.
Oil is used to make plastics, and from what I see it seems like everything is made out of plastic.
American cars for one.
So the Arabs will find a way to still charge $100.00 a barrel.
Fusion vs. Anti-matter for energy (Score:5, Interesting)
I started thinking about that and the two biggest problems with that are: A> It takes a huge amount of energy to create anti-matter, a hell of a lot more goes into the production than comes from using it. B> We don't really have a system for containing significant amounts of anti-matter.
So I started thinking about alternative energy sources and one of them was fusion. Pound for pound, fusion produces about 1/27th of the energy of anti-matter (based on my naive calculations, so I may be way off) whereas other types of fuel are several orders of magnitude less efficient.
To me, that makes fusion a pretty good option. The only problems I have encountered so far with the idea are:
1: Fusion isn't quite ready for real applications, though by the time we're capable of sending an interstellar craft, I believe it will be.
2: For an interstellar journey, you'll need a power plant that can survive for no less than decades, if not centuries, without maintenance. That's a serious issue given the harsh environment it would be operating in.
I'm sure there are additional problems I haven't thought of yet, but I'm still thinking it might be a good option. Perhaps some sort of self-repairing reactor could be built to solve #2.
But another huge advantage of hydrogen is that you could collect fuel along the way using the Bussard Ramjet [wikipedia.org] idea. You'd just need a way of separating out deuterium and tritium from the hydrogen that doesn't suffer from problem #2 as well, but it should be doable. As most here are probably aware, fuel mass is a serious issue for space travel.
Anyway, I think fusion has a great deal to offer in a number of ways. Maybe I ought to work on my NIAC proposal
Re:Fusion vs. Anti-matter for energy (Score:5, Interesting)
Nobody has ever seriously considered antimatter as a fuel source, aside from a few science fiction writers. It's simply too impractical for exactly the reasons you mention. Impractical to the point where it's pointless to even think about it, at least not right now.
Fusion isn't quite ready for real applications
Electric power generation isn't real enough for you?
For an interstellar journey, you'll need a power plant that can survive for no less than decades, if not centuries, without maintenance.
There already are these huge fusion plants which survive in space for billions of years with no maintenance. They're called "stars." :-) More seriously, the engineering issues involved in designing a fusion reactor center exclusively on the multi-million-degree plasma which must be confined. In comparison to that, the problem of making the thing run in outer space is a toy issue. What's more difficult to design for: the emptyness and relative quiet of space on the outside of the reactor, or the extremely hot, energetic, radiation-soaked interior of the reactor? I think once we have fusion figured out, flying in space will be a piece of cake in comparison.
As most here are probably aware, fuel mass is a serious issue for space travel.
Fuel mass is important because it determines the momentum of the escaping exhaust. But momentum is the product of two numbers: mass and velocity. You can make up for low propellant mass by increasing the exhaust velocity. A high-power reactor like a fusion reactor is precisely the way to do this.
And a reactor capable of producing a few megawatts could drive a high-power laser, and the craft could use pure light pressure to propel itself: no propellant required. Of course, this depends on how light you can make the craft, because even 100 megawatts of power will only produce 0.33 newtons of thrust :-)
Yet another step, not at the destination yet (Score:3, Interesting)
That said, this is the stuff that sci-fi dreams are made of. Maybe now that less geeks are going for CS degrees, they'll take some hard-science classes- that stuff is still sorely needed. As well as cool.
I was once a physics major who couldn't cut it because of a lack of discipline to be able to master the difficulties of engineering calculus. Props.
I have to wonder... (Score:3, Insightful)
- Steve
Re:I have to wonder... (Score:4, Funny)
I don't know, but if you think it even approaches 10000000 kilograms of fossil fuels, you need to get your head checked.
Re:I have to wonder... (Score:4, Informative)
Big screens for everyone!! (Score:3, Funny)
Tokamak was always a sham. (Score:5, Informative)
Fusion 40 years ago, at the 1964 World's Fair (Score:3, Informative)
Forty years later, there's still no useful fusion power technology.
The US Department of Energy is terminating all work on fusion [ucsd.edu] effective September 30, 2004. That's probably a good thing; it will free up activities in the EU and Japan from US interference.
Re:I had predicted 2050, actually (Score:3, Informative)
Re:I had predicted 2050, actually (Score:5, Insightful)
Re:I had predicted 2050, actually (Score:3, Funny)
You say that, but just try putting one in a microwave and you might change your opinion! ;)
Re:I had predicted 2050, actually (Score:5, Funny)
Re:I had predicted 2050, actually (Score:4, Insightful)
What do you think happens to the Neutron bombarded materials? (Hint: They can become radioactive.) Fusion produces a tremendously strong neutron flux. So strong, that very few materials survive being near the process. Obviously, your choice in containment materials can make all the difference in HOW radioactive we're talking.
Personally, I don't think we'll quite get the hang of fusion inside Earth's gravity well. Once in space, we can allow the Fusion to bleed off its neutron flux like the Sun does. Thus it might be very useful for space-based power generation and propulsion. But here on Earth, fission is a much more viable energy source. Our biggest problem is that most of the reactor designs are from the 50's and 60's, when we were just starting to understand nuclear power. With hindsight firmly in place, plus ~500 commercial reactors, a hundred or so military reactors, and a few hundred research reactors currently in service, we have the knowledge and technology to create very safe reactor designs. Hell, just removing the 19th century boiler design out of the equation makes something like Chernobyl impossible.
The real problem right now is government fear over terrorism. The U.S. government forces plants to keep potentially useful materials sitting in pools of water or buried in the ground instead of being used in commercial ventures. Some of that stuff can be reprocessed into nuclear fuel, and some of it has uses in medical, electronic, and aerospace fields. None of it is useful to "terrorists" until it's reprocessed into fissionable fuel. (Don't get me started on the uselessness of a dirty bomb.)
Re:I had predicted 2050, actually (Score:5, Insightful)
Re:I had predicted 2050, actually (Score:3, Insightful)
Did you ever consider that the stuff that lasts thousands of years isn't very radioactive? You still have a conservation of mass and energy issue. If it lasts 10 seconds, it's radioactive enough to kill you were you stand. If it lasts 10,000 years, then it's probably not much more radioactive than the potassium in your bones.
Re:I had predicted 2050, actually (Score:5, Informative)
Re:I had predicted 2050, actually (Score:5, Informative)
The part that becomes radioactive from neutron bombardment is called the "reactor vessel". It weighs about 1000 times as much as the fuel in a fission reactor. The irradiatted iron/nickel/chromium/cobalt/whatever-else-is-in-yo ur-alloy-of choice has a much shorter half-life, and this is far more radioactive than the spent fuel rods.
You'd probably get more irradiated metal in a fusion reactor than a fission reactor, though this no doubt depends on design details. But the neutron flux will be higher, per watt, so expect it to tend toward more radiatted metal rather than less.
In other words, don't expect fusion to be cleaner than fission. There'll be a different mix of radioactive byproducts, but it is by no means clear that there will be less, or that said byproducts will be easier to dispose of.
Re:But does that matter? (Score:4, Informative)
Prolonged neutron bombardment makes many metals brittle. Fortunately it is a relatively well understood phenomenon which is familiar from the operation of current reactors - some of which have run for over 40 years [bnfl.com].
Fusion reactors can expect some embrittlement with time, but the consequences are much less likely to be serious than with a pressurised vessel such as a PWR.
The biggest problem will be that the plant will have to be mothballed for a period before dismantling at the end of its life. Again that is something we know about as the US and UK are already dismantling their first generation of nuclear reactors.
Best wishes,
Mike.
Re:But does that matter? (Score:4, Interesting)
What he said.
Neutrons running amok in the reactor vessel (which, if it wasn't obvious, is a big metal container with the reactor core inside) cause two things to happen:
1. Some small fraction of the metal atoms absorb neutrons and change from stable isotopes to non-stable ones. Cobalt-60, with a half-life short enough to be pretty radioactive, and long enough to be a nuisance, is the biggest issue here.
2. Neutron embrittlement occurs. The reactor vessel becomes more prone to cracking instead of stretching under pressure changes. This is likely to be less of an issue in a low-pressure fusion reactor than in a high-pressure fission reactor. Both effects are known in advance, and designed around, though the earliest reactors were built without this (later) information. I don't know how many of the "earliest" reactors are still operational. My guess is none, but that's a guess.
Only real long term issue is the radioisotopes in the reactor vessel. This is why you have to mothball the reactor before dismantling it. Ideally, once you dismantle the things, you'd recover the Co-60 and related radioisotopes, but practically, it doesn't occur in amounts that are worth the trouble.
So you have to dispose of it in some "safe" way. Sealing it in glass bricks and stacking it in some out-of-the-way corner of the desert would do nicely.
Re:I had predicted 2050, actually (Score:3, Insightful)
I would say that a coal, oil, or natural gas plant has a hell of a lot more fire potential and if the reactant leaks it isn't really that big a deal. The quantity of reactant used in this type of system is miniscule, deuterium isn't a problem at ALL and tritium isn't really all that bad either. I would say that a leak of ANY of the reacta
Re:I had predicted 2050, actually (Score:3, Interesting)
Re:I had predicted 2050, actually (Score:3, Informative)
Average solar power high in a winter month (I think it was from a winter month) = 6 KWh/M2/Day taken from here [state.mo.us]
Should equal 2190 kwh/M2/year
1 acre = 4046.85642 M2
Should equal 8862615.5598 kwh/acre/year
High (maybe overstated based on PDF?) of 20 thousand megawatthours (MWh / year) from coal taken from here [state.mo.us] (Specifically this pdf [state.mo.us])
or 20,000,000 kwh / year total
vs 8,862,615 kwh / year (for one acre of cells)
So, the question that I think it hangs on, which
Re:Finally (Score:4, Informative)
read about Fusion from Wikipedia please and cure your ignorance before you start some crazy anti-fusion lobby
Re:Finally (Score:5, Funny)
But helium at 100,000,000 degrees celsius might have slightly different effect if you tried to use it to make yourself sound like a munchkin...
Re:Finally (Score:5, Informative)
The plasma is VERY thin... and there's a reason why they have to try very hard to keep it away from the reactor walls. Not because the walls will melt but because the plasma will instantly cool down and stop doing its fusion thing.
Re:Finally (Score:3, Funny)
Better there than many other places I can think of.
Re:Finally (Score:5, Interesting)
Re:Finally (Score:3, Informative)
Well, considering the risk for a Chernobyl
At the risk of being redundant... there is no risk of a fusion plant going "Chernobyl". A fusion plant requires active control in order to maintain the reaction. Meanwhile, a fission plant requires active control to suppress the reaction from getting out of control. In other words, a fusion plant cannot experience a runaway reaction; it is "fail-safe".
Re:I bought my own Plasma generator (Score:3, Interesting)
Re:I bought my own Plasma generator (Score:3, Insightful)
Re:Risks? (Score:5, Informative)
Not much. The waste produced by a fusion reactor is helium - probably the most harmless stuff you can get. The process of fusion produces neutrons, so the fusion container itself will become mildly radioactive, but nowhere near the kind of nastiness you get with fission.
In addition, fusion is inherently fail-safe. If something goes horribly wrong with a fission reactor, you can get a runaway reaction. Meltdown. Not good. But in a fusion reactor, you have to carefully maintain the right conditions for the reaction to happen at all. Screw up and the light goes out, that's about it.
Re:Risks? (Score:3, Informative)
Well, the most significant damage would be to our understanding of physics, since there is no possible way that a fusion reactor can "run away" like a fission reactor can.
Think about it this way: for a fusion reaction to happen, the outside control is critically important: in typical designs, the control is provided by huge electromagnets (magnetic confinement) or by powerful lasers (intertial confinement). If the reaction
Re:And a plant explosion... (Score:5, Informative)
Nothing like a world ending 'meltdown' can happen, a magnetically confided plasma has so many different ways to dissipate energy. The trick has always been and always will be to get enough nuclear reactions out of this plasmas to make it worth while to build them as an energy source, becuase running them invovles using lots of energy just to create the plasmas conditions at all.
Re:And a plant explosion... (Score:5, Interesting)
Fission is a stable reaction, fusion is very unstable. The difficulty in sustaining fusion is due to the fact that it is so hard to sustain the conditions under which it will occur.
The implications for safety are obvious: current generation fission designs require all kinds of redundant safety systems to prevent an ongoing and very dirty accident. Such systems would not be needed in a fusion reactor, becuase the least hiccup, such as weakening of magnetic containment or the leaking of tiny amounts of contaminants into the reactor would cause the reaction to collapse. There is no possibility of anything like the reactor catching fire driven by the heat of a runaway reaction.
That said, I'm skeptical we're going to see practical fusion in my lifetime, because it is so difficult to sustain, although you can always hope. A more promising technology would be a stable fission designs, that would require intervention to maintain fission, or which would only output heat at a limited rate.
Re:And a plant explosion... (Score:5, Insightful)
Fusion reactions occur at an energetic peak. Basically, for fusion, we're trying to balance a ball on top of a hill. If we lose our balance, the ball rolls down the hill and the energy production ceases.
By contrast, fission reactors operate at an energetic low (this is simplifying, but true for illustrative purposes.) We're trying to stay in the bottom of a valley, while the reaction tries to force us to climb up the walls. If we lose our balance, the reaction can shoot up a wall and then you get meltdown.
notes on this: fission reactors can be designed to be negative coefficient, such that an increase in output leads to a cycle that will decrease output, but the reaction itself is still positive coefficient.
Re:And a plant explosion... (Score:5, Informative)
My understanding is that these designs have been ignored in the US due to the costs to get approval from the Nuclear Regulatory Commision are too high.
http://www.wordiq.com/definition/Pebble_bed_rea
Re:And a plant explosion... (Score:5, Insightful)
1: Fossil fuels aren't necessarily fossil. It's possible that oil is produced in a way that doesn't involve life. Abiogenic theory might turn out to be correct after all. Remember how in the 1960s everyone believed "the oil is going to run out in forty years"?
2: We're not choking as much as you think.
3: There were despots in the middle east before the Oil Age began.
4: If TMI was (if you will excuse the pun) blown out of all proportion, what about Chernobyl?
I agree that the anti-nuclear lobby can be mischevious, but that's one of the aspects of lobbies. At the other extreme, arguing that if we embraced nuclear power then we would be living in paradise is also well, I mean, hello?, look at France. They have totally bought into nuclear power and they still can't come up with a good pop song or a decent car.
Re:And a plant explosion... (Score:5, Informative)
Aside from the initial jumpstart of energy required could it not sustain itself afterward using its own energy, perpetually maintaining itself once stability has been established?
Keeping the plasma hot enough for fusion to be possible is only part of the picture; you also have to solve the confinement issue. You not only have to keep the ionized plasma confined (and no, a material "containment vessel" similar to what's used in fission reactors doesn't work; you need something nonmaterial, such as strong magnetic fields), you also need that confinement to be within a very small volume for reaction rates to be sufficiently high (for any kinetic "collision"-ish process, reaction rates are proportional to the square of the density). Heat is necessary for the nuclei to be moving fast enough for fusion to take place; but heat is also the enemy of keeping the plasma at high density.
Re:And a plant explosion... (Score:4, Interesting)
As we can't create miniature stars at the moment, we have to compensate by supplying the heat and containment ourselves. One of the major barriers to a useful fusion reactor is getting it to produce more power than it draws.
Re:And a plant explosion... (Score:5, Informative)
-jef
Re:And a plant explosion... (Score:5, Informative)
The goal of course of any fusion reactor is to get enough energy out than it takes to produce the fields and other things...to produce net energy that can be put to use. The point at which this happens is called break-even, there is a handy dandy ratio called Q=power-out/power-in that gets used to describe the reactor power. Q=1 is break even...the reactor produces just enough energy via nuclear reactions to make up for the energy needed to be spent by humans to power the reactor. Of course what goes into defining Q is sort of dependant on who you talk to. The efficiency of turning the energy released in the nuclear reactions into electricity is a matter of debate. The process we do most efficiently is turning steam into electricity...turning fast moving energetic nuclear particles into steam is something we aren't really good at doing. Anyways...i digrest.
The point at which a plasma is self-sustaining is Q=infinity and is called ignition. Plasmas that ignite, don't need external power sources to continue their fusion processes. They go about their business all by themselves if given a supply of fuel.
Production reactor designs aim between something like Q=5 to Q=20. At first glance a higher Q value would seem to be a better thing. But actually it isn't. Q isn't just a measure of how much net power your are getting out, but its also a measure of how much control you have over the plasma itself by external means. It could very well be the case that the most economical reactors long term are ones that can be better controlled at Q=5 than higher performing Q=20 reactors.
-jef
Re:And a plant explosion... (Score:5, Informative)
Re:And a plant explosion... (Score:3, Insightful)
This has the word nuclear in it. The nuclear boogieman will derail this a lot faster than anything else.
For example, the correct term for and MRI is Nuclear Magnetic Resonance Imaging. The nuclear here has nothing to do with nuclear power, it just means that the magnets make the nuclei of the atoms move in certain ways and that the images are created by iterpreting those movements. The Nuclear part was dropped
Re:And a plant explosion... (Score:5, Interesting)
Please don't paint all environmentalists with one big brush!
I like to consider myself a "green" kinda guy. I recycle, don't drive a SUV, etc. However, that said, bring on the nuclear power plants (provided we can properly secure them from whoever may want to crash a small plane into them... another story tho). Nuclear power is much cleaner than coal power, and the waste, while icky, isn't produced in huge quantities.
Some environmentalists will agree with me, some will disagree. But don't paint everyone with the same label. That'd be like me saying that most republicans are christian conservatives who want to turn the United States into a Christian version of Iran.
See how annoying that is?
Re:And a plant explosion... (Score:3, Interesting)
Last I heard, "christians" mainly get negatively involved in life sciences. I'm not sure how this relates to the topic at hand or why it would even be a concern. Especially since this is heavily a physics topic and not a life sciences topic. Worse, even if it were a concern, why would it matter. Unless you have proof that fusion creates souls, no one but zealots are
France Electrical production (Score:4, Informative)
77% Nuclear
14% Hydro
8 % Fossil
1 % Other
Thanks,
Ex-MislTech
Re:And a plant explosion... (Score:4, Informative)
Re:And a plant explosion... (Score:3, Insightful)
The plant is trying to *uphold* a process, not *restrain* a process.
Re:And a plant explosion... (Score:3, Funny)
Re:Hotter than the sun? (Score:3, Informative)
Re:Hotter than the sun? (Score:5, Informative)
Exactly. Let me spew some physics for a moment.
The temperature of a gas is related to how fast the particles of the gas are moving. The hotter the gas, the faster the average kinetic energy. However, not all the particles move at the same speed. There is a distribution of speeds, with most of the particles at or below the average speed. However, a very thin "tail" of particles travels at speeds much, much higher than the average. In the Sun, it is these very high-speed nuclei, way above the average kinetic energy of the plasma, which collide and fuse.
So, why can't we get fusion with temperatures equivalent to the center of the Sun? Pressure. We can't hope to achieve pressures anywhere near that in the Sun. In the sun, the pressure is so immense that the particles are squeezed extremely close together. Imagine these particles moving at insane velocities, in such close quarters. They will collide with each other extremely often. This extremely high collision rate allows fusion to occur, because it brings the super-high-energy nuclei together more often.
On Earth, at very low pressures (at least relative to the core of the Sun), the particles are moving fast enough to fuse, but they just don't collide often enough. They aren't close enough together. Thus, to make up for this, we must increase the temperature so that a larger fraction of the particles are in the kinetic energy realm where fusion can occur. In other words, we make up for the lack of pressure by increasing the temperature.
Re:500 seconds?? (Score:4, Insightful)
One of the problems with previous attempts to build a fusion reactor is that they couldn't keep it running for more than a few seconds. The holy grail of fusion physics is to build a reactor that can maintain a sustained reaction; and, does so without requiring more energy input than the amount of energy produced in the reaction.
Re:"In the Future" (Score:3, Funny)
*(Yes this is meant to be at least a partly humorous post, you insensitive clod moderators. However I am not kidding about the "buying from Japan" part, since it is my understanding they are waaaay ahead of us and everyone else in fusion research.)
Re:Not very optimistic about it... (Score:5, Insightful)
Now, fusion offers a great deal of possibilities, but there are two very large problems with it even when it is 'worked out'. First, it will be expensive. It is a major task to build such a plants. Building enough to power the world would take many decades and cost far more then I imagine most nations would be willing to spend. I am not saying that it couldn't eventually be done, but don't expect it to happen over night. Further, even if the world was covered in fusion plants, that energy would not be free. You still need to pay for all the parts and labor it takes to keep such a plant going. Sure, you might cut costs on material expenses, but they would rise everywhere else. Electricty wouldn't suddenly become cheap, just abundent. Second, fusion is large. You can't throw a fusion engine in your car and electric motors just don't have the capacity of a gas engine. If electricity was free tomorrow we still wouldn't hav electric cars.
I doubt energy companies are cowering at the prospects of fusion. Even if fusion was to completely upset the need for oil and coal, there is still the fact that people need energy and in a nation like the US that energy is going to be brought by a corportation. An energy company is in a perfect position to fill that need. At worst it means they have to shift their bussiness to focus less on oil and coal and move to fussion. The world won't end for them.
Re:It won't matter in the US (Score:4, Insightful)
By then, I wouldn't be surprised if we switch back to coal, given the advances in plant designs over the last 30 years. That's a fuel that the eastern US has an overabundance of, yet is frowned upon by the environmentalist lobby because of the tendancy of existing plants to just vent the waste products into the atmosphere. Good thing the DoE is already working on it [doe.gov]. It's amazing what the free markets can provide, when you let them work...
Re:It won't matter in the US (Score:3, Insightful)
Re:What's that about Magnetic energy? (Score:3, Interesting)
It would also probably cause objects to projectile towards the reactor rather than away from it (think MRI machine)
A magnetic field of that strength, thrown out of balance, could probably do nifty things like diflect electron orbits, and magnetize non-magnetic materials. However, since strength varies with the inverse cube of distance, the effective radius would be very small.
Nothing more to worry ab