Slashdot Mirror
New Advances Bring Fusion Closer to Reality
An anonymous reader writes "The Christian Science Monitor reports on new advances in nuclear fusion research. For years we've been waiting for the technical breakthroughs that would make cost-effective fusion energy a reality. Are we getting close, or are the problems insurmountable?"
Are we getting close, or are the problems insurmountable?
According to this documentary, we'll have fusion powering our homes and cars within 10 years.
Does this mean I'll finally be getting a Mr. Fusion to put on my Delorean?
Don't take life so seriously. No one makes it out alive.
"nuclear fission is about the only 'safe' alternative in the meantime. Generating many orders of magnitude less radioactive waste than current fossil fuel plants,"
I completely agree with you , but try telling that to the kneejerk reaction anti nuclear fanatics who can't see the wood for their own foolishly planted trees. Mind you, I've met some of these people and half of them couldn't even spell "radioactivity" never mind tell you what it was. They work purely on a fevered emotional level and no amount of rational discussion will convince them otherwise. They are the same sorts of people who dunked old women in ponds back in the 17th century because they talked to their cat and someone got ill in the village shortly afterwards.
"What will happen to the material that stops all those neutrons?"
Assuming you don't use aneutronic fusion, it will get mildly radioactive. So bury it in the middle of nowhere... who cares? We're not talking about 'hot' fission fuel here.
"What is the failure mode for a collapsed fusuion capable magnetic field?"
The confinement vessel warms up by about two degrees C, you fix the problem and restart it. You've been watching too many SF movies if you think that a confinement failure will cause a nuclear explosion.
"Fusuion power will NEVER be safe"
Fusion is extremely safe compared to fission: you appear to be just a typical ill-informed knee-jerk anti-nukleah.
"What is the failure mode for a collapsed fusuion capable magnetic field?"
The plasma disperses and the fusion stops. What do you think happens when they shut the field down now after their tests?
"Wow, these are bad, very very very bad also."
Really? Why?
"The folks that came to our little burg for a 'rah rah' meeting claimed that power would be so cheap, it wouldn't be metered."
And it would have been had the anti-nuclear nutters who stopped the whole thing in its tracks. Yes 3 mile island happened and then chernobyl. So what? When an airliner crashes 400 people die. Do we stop all flight? Tens of thousands of people die in car crashes every year. Do we ban cars? No.
"The situation with nuclear power has not changed just becuase we are looking at 'new and improved' fusion"
If the halfwitted political loudmouths of society can be convinced this new form is "better" than the old form (whether it is or not) then we may get somewhere with it. If it ever works that is.
I think you mis-spelled "Duke Nukem Forever".
I object to the insinuation that we are the ones splitting the nuclei of the radioactive elements
Well, fine. But you can say that by refining the uranium, and bringing sub-critical amounts of together in a pile, or supercritical amount together in a bomb, we are utilising the nucleus's innate tendency to split, and to thereby trigger a chain reaction in nearby uranium nuclei, in order to generate a self-sustaining level of radioactivity that would not have otherwise occured.
You could also say when making tea that we are not the ones boiling water, we are merely allowing electricity to flow through a restisting metal rod, which generates heat which when transfered to the water causes a rise in temperatre to boiling point that would not have otherwise occured. But that would be very, very pedantic.
My Karma: ran over your Dogma
StrawberryFrog
Is this an Ask Slashdot?
If so then my answer is yes! I mean no! err..What was the question again?
IANANE (I am not a nuclear engineer) but if I read that article correctly then it seems some of the many problems have theoretical solutions. In other words, it worked in the simulation. We need to get this thing built and do real tests before we can even think about being "close" to having fusion plants.
They can't even decide where to build it! Why can't I vote to spend my (US) tax money on putting one of these over here. Even as a test bed it will give the contry it's in some home field advantage.
You can use my back yard if you want! Don't listen to my whiney neighbors, they don't know what's good for them!
I don't think, Therefore I'm not.
Nuclear Fusion is about 8 minutes away, and will always be*
* At least until the sun finishes its main phase
You know what bugs me? The world is squabbling over where to build the 6 billion dollar ITER (international thermonuclear reactor.) See http://fire.pppl.gov/ They've been negotiating over locations between France and Japan, neither party willing to yield, for over a year now. 6 billion dollars? Screw it, build two of them, one in Japan, one in France, but that's not the point. They don't want to build it, because if anyone can make cheap energy out of rainwater, then how do you control them? The powers that be actually like the setup where they can fight and take over any limited resources, then have people come beg them for a piece of the pie. It doesn't matter to them if billions of people die, as long as they are not one of them. But civil war and social chaos is not picky.
"Nuclear Fusion has always been 15 years away, and always will be"
This glib statement seriously underestimates the achievements in this area in the past few years. We have gone from doubts as to whether controlled fusion could ever be achieved to a point where we are working on stabilising the reaction to the level where it produces commercial results.
And by the way, the classic quote was '50' years, not 15!
since when does a fossil fuel power plant produce radioactive waste? :)
Take a look at some of the research and data on how much naturally radioactive particles are released into the atmosphere through burning of fossil fuels, you'll probably be surprised. I believe it's a few orders of magnitude more than the amount generated in current fission plants.
-Jesse
Nothing says "unprofessional job" like wrinkles in your duct tape.
What is the failure mode for a collapsed fusuion capable magnetic field?
The reaction stops. No, seriously, current fusion reactor designs require the magentic field to cause the fusion to happen. Thats why its currently so expensive, most of the time it takes more electricity to power the magnet than you can get from the fusion.
Current nuclear reactors have a GREAT track record, by any other industry standard. However, those who worked on the years of clean up at three mile island
Guess what, the reactor there wasn't a current design. In fact, I believe none of the reactors in operation in the US is a current design, since instead of replacing them with better designs that have been in use for almost a decade now, little "know it alls" like you complain and prevent new plants from being built to replace the old.
The situation with nuclear power has not changed just becuase we are looking at 'new and improved' fusion.
The situation with nuclear power changed decades ago with the invention of reactors that could burn fuel that would have otherwise been considered "spent", reducing the need for disposal. It changed years ago with the invention of better fission reactors that are resistant to meltdown in emergency situations, and it will change yet again with the invention of fusion reactors that operate by converting small atoms (Helium) into slightly larger ones, rather than using heavy metals like uranium and plutonium.
If I have been able to see further than others, it is because I bought a pair of binoculars.
Sorry to be a nathering nabob of negativism, but...
Practical nuclear fusion would be the best thing that ever happened to our planet: we'd lose our dependence on the Middle East for energy, and dramatically cut pollution. If it were up to me, I'd launch a nuclear fusion program on the scale of the Manhattan Project.
However, the Bush family and that crowd will never allow nuclear fusion to become a reality - they make too darned much money on oil, and cash is all they understand.
Not to reveal my age, but when I was an engineering student in the early 60s the big science news was that flat screen TV was only 2 years away, and that CRTs would be rendered obsolete. Flat screen TV was perpetually 2 years away in the future for most of my life, but it finally did arrive.
Our goal should be to have commercially useful fusion energy in operation by the end of the 21st century. It's vital, but not easy, for the public to support such long-term goals. That's particularly true when we can't visualize the links in the chain that will connect now with then.
The actual breakthroughs that make energy power cheap and safe are likely to come closer to the end of the century, and we can't imagine what they might be. Still, we must support constant inquiry and scientific research to create the fertile conditions for breakthrough discoveries.
The only reservation I have about supporting big science is a serious one. Money should go for science, not to feed the egos of the pricipals. The bigger the project, the harder it is to assure that.
Yep, my father quoted that one on his PhD thesis.
Granted, they do have fusion -- but not practical fusion.
But to prove his statement, he pointed out how expensive it is to generate tritium for the DT reaction, and how little there is.
If we're ever going to have practical fusion, it's going to be cold fusion. Use a molecule with an explosive bond that shoves two other molecules on a predefined pathway into a range where you get a 1% chance of reaction between two hydrogen nuclei, by tunnelling, and you could do it.
But that would take a pretty complicated and well-designed molecule.
There may be some ways of doing it once we have better molecular manufacturing, but as for right now, cold fusion is also dead.
For that matter, unless we're using it in space, I hope they don't get cold fusion.
To quote Don Lancaster (www.tinaja.com), if anyone finds a free energy source and manufactures it without also providing a free energy sink, they'll be the worst criminal in human history. Oh, and our planet will glow like a star too.
I think the proper solution to our energy problems needs to be wind and wave. Those take care of the energy source/sink problem. Sorry, just my two cents.
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
The Joint European Torus (JET) fusion lab in Culham, Oxfordshire, UK 'jumped' a few years ago. The plasma touched the wall of the reactor vessel and dissipated. The entire reactor 'jumped', and the event is visible on seismograph traces. (The reactor, in total, was quite heavy)
This is not good for the retaining magnets - the magnetic field quenches, and the energy goes into heating up the magnets. Even the superconducting (and therefore cooled) ones warm up - boiling off a lot of refrigerant, and possibly/prbably distorting/damaging the coils..
Afer this event, th reactor was shut down for a long period (I think months), while the coils were checked for damage and realigned.
As for the amount of energy in the plasma itself - it's relatively small. Although the temperature is high, the particle density is actually quite low, so the total energy contained is (relatively) small. It *won't* go up like a hydrogen bomb.
The core lining in JET was lithium. It gets mildly radioactive due to being bombarded by neutrons all the time, but this is not a big deal. The neutron activation of the concrete and steel rebar used in the construction of the core (it has to withstand high mechanical forces from the magnetic fields) is more of an issue.
The plasma isn't meant to touch the tokamak wall, as it causes long and expensive downtime, but it's not as catastophic as (say) setting light to an oil well.
I think you are missing the point the writer was making. The 30 is a constant, ie we are always 30 years from fussion. This is not a return in 30 years, but a return an infinite amount of time in the future.
Now, I think the fusion experiments are worth funding because they are fun. I think it's a shame that the political environment is such that the scientists need to pretend there is gold at the end of the rainbow, when the rainbow is so beautiful itself.
We aren't talking big money here in government terms. Eg IIRC the proposed ITER budget is 10 billion Euro over 30 years. The EU pours approximately 100 billion into the common agrecultural policy every year and I presume the USA is operating on basicly the same level, just to prop up buisinesses who produce food no one wants to eat.
_O_
.|< The named which can be named is not the true named
I am a Nuclear Enginneer,and work in Britain on the Joint European Torus Fusion Device. Check it out... http://www.fusion.org.uk When we fuse together the hydrogen, the helium formed is more stable and highly energetic. The thing to consider here is potential energy too. Just as there is chemical potential energy in the gun powder of a bullet, which allows the weapon to be fully automatic, so there too is nuclear potential energy. For large enough plasmas it is possible to use the highly energetic helium to sustain the fusion reaction, in a process known as ignition, so more energy can be retrieved than was put in. If all energies are considered, no laws are violated. You are right about the electricity generating process. The use of steam pressure and turbines is limited by the laws of thermodynamics, namely the Carnot cycle, so can only ever be approximately 40% efficient. The next step is the International Thermonuclear Experimental Reactor (ITER). As the politicians couldn't decide whether to build it in Japan or France, Europe has declared its going to build it anyway, and we're now just waiting for people to take sides :)
What are the civilian applications?
I will never understand where this hyper cynicism comes from. On one hand our "evil rulers" will do anything to make a buck. On the other hand they will not do something that will save trillions of bucks because they don't want to lose influnence and power.
It's a stupid way to go through life and precludes rational analysis of real political actions and motives.
Nuclear fission does split nucleii into fragments. U-235 fission absorbs thermal neutrons (room-temperature kinetic energy) and splits in half, P-239 fission absorbs fast (high-energy) neutrons and splits in half. The resultant atoms form an assymetric distribution called the 'Mae West' curve because it forms two big peaks (mapped # vs Z) that look like mammaries to lonely nuclear engineers that don't see nekkid women that often.
While Uranium/Plutonium do decay naturally (stability of a nucleus is determined by the Nuclear Shell empirical formula, which is a rough analog of the electron shell theory - everybody wants to be Iron Fe/26, the most stable nucleus), there's another form of decay that's an outcome of genuine nucleus splitting. That's is the decay of of these usually-radioactive fragments. This decay is important to the operation of a fission reactor, but only in determining the criticality of a nuclear pile. 'Critical' == exactly as many neutrons are released in any time period as are absorbed, meaning steady power output. Basically, over 99% of the neutrons necessary to keep a steady level of fission events come from 'prompt' neutrons - neutrons that are freed in the splitting of an atomic nucleus. You get one small chunk (which could very well be gold), one big chunk, and a couple free/fast neutrons.
If these 'prompt' neutrons were enough to sustain criticality, then the number of fission events would increase geometrically. Since the time between generations is about a millionth of a section, this means that a reactor core that's 'prompt-critical' would quickly escalate in temperature until the structural integrity of the core failed, and you have a molten slag of Uranium - which is exactly what happened at Chernobyl.
So the way to avoid this, you have to put in neutron-absorbing control rods to keep the number of 'prompt' neutrons below the number necessary to sustain the next generation of fission events. If 'prompt' neutrons were the only neutron source, your nuclear reactor would quickly cool down. But the decay of the fragments (which are ususally radioactive isotopes of stable elements) release additional neutrons. The 'art' of tuning a nuclear reactor is to insert the control rods just enough so that the reactor isn't prompt-critical, but the decay neutrons are just barely enough to make the pile critical.
One of the biggest problems with fusion in general is fuel. The easiest fusion reaction is deuterium-tritium. Deuterium is plentiful - the ocean is full of 'heavy water' where one of the hydrogen atoms in a water molecule has a proton and a neutron. Tritium, however, is radioactive with a pretty short halflife. You have to make tritium by getting Lithium to absorb a neutron, then decay.
Last time I was up-to-date on fusion research, there was only an estimated 300 years of Lithium to sustain the predicted energy needs of the world. However, with fission fast-breeder reactors like they use in France, there would be 5000 estimated years of power. Fission fast-breeder reactors can be built today - it's just that to make them passively safe, you need to use a liquid metal coolant like sodium, and any disaster like Chernobyl (from terrorists, for example) would be catastrophic. Liquid sodium will explode if it gets wet, so it's a huge engineering challenge. Argonne Nat'l Labs has reactor designs like this, but the US population is scared of nuclear power plants (plus, the cost overruns at plants made them economically unfeasible).
[I am a published principal author and presentor of a fusion reactor design (presented at the 8th Topical Meeting on the Topic of Fusion Energy in Salt Lake City), so I have a tiny bit of credibility. I got out of the field specifically because of the 15-year carrot-on-a-stick paradox.]
I refer you to "Exploration of Space by Means of Reactive Apparatus" by Konstantin Eduardovich Tsiolkovsky, written in 1896. That was 108 years ago...
"I do not agree with what you say, but I will defend to the death your right to say it"
it produces very long lasting nuclear waste;
The longevity of some waste is important to consider, but there are three important mitigating factors that are usually overlooked in discussion.
First, longevity and intensity of nuclear waste are inversely related. The really nasty stuff has halflives of hours to days. The mid level stuff on the order of months. It's actually the low level waste that can last such a long time.
Secondly, reprocessing of the low level waste would extract useful plutonium that can be used as fuel again and will further reduce the volume of waste to store. It may even be possible to reduce the volume yet again by irradiating the low level waste to force it to decay faster.
Finally, coal burning releases a great deal of thorium and other radioactives. If coal plants were held to the same standards for release of radioactive waste products as nuclear plants are, each one would produce many tons of low level radioactive waste a year. That waste would also have to be stored for thousands of years.
Perhaps we should measure low-level waste in the unit "hours of coal", that is, in terms of the released radioactive waste per hour from an average coal fired power plant.
The real problem with nuclear power in the U.S. is lack of standardization in plant design and waste management. With standard design, we could build a body of practical operational and engineering knowledge that would apply to every plant. That in turn would allow increased safety.
CSM is actually a surprisingly good paper. Don't denigrate it because of the name.
The human body can be drained of blood in 8.6 seconds given adequate vacuuming systems.