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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?"

49 of 785 comments (clear)

  1. Of course we will! by Anonymous Coward · · Score: 4, Funny

    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.

  2. "Splitting atoms" by Dancin_Santa · · Score: 3, Informative

    While I believe that fusion will likely be the only sustainable energy source as our current supplies of oil and uranium eventually run out, nuclear fission is about the only 'safe' alternative in the meantime. Generating many orders of magnitude less radioactive waste than current fossil fuel plants, they are inherently better for the environment on a purely objective level.

    What I object to, though, is the insinuation that we are the ones splitting the nuclei of the radioactive elements. These things are radioactive precisely because of their tendency to decay and in fact split themselves. They don't even split into other elements. You can't turn uranium into gold, for example, even though it ought to be a straightforward process of splitting off the required number of protons from each atom (if the "we're splitting atoms" camp claims are correct).

    We use the heat generated by the decay of radioactive elements to fuel our generators. We do nothing like smashing atoms into smaller bits.

    Just a pet peeve of mine whenever I see a nuclear power article.

    1. Re:"Splitting atoms" by Viol8 · · Score: 4, Insightful

      "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.

    2. Re:"Splitting atoms" by Anonymous Coward · · Score: 3, Insightful

      My favourite peice of braindead kneejerk quasi-science claptrap has been the reaction to mobile phone cell masts here in the UK. I've seen masts which have been graffited with an "Ionising Radiation" warning sign, neatly confirming what I had suspected for some time; The people who scream the loudest are usually the most clueless.

    3. Re:"Splitting atoms" by StrawberryFrog · · Score: 5, Insightful

      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

    4. Re:"Splitting atoms" by starman97 · · Score: 3, Insightful

      Decay?
      You mean all those extra neutrons flying about dont have anything to do with it? Those neutrons traveling at carefully determined energies intended to impact the nucleus of the U238 atoms and cause it to become unstable and break apart into two smaller ones that are usually highly radioactive?
      As opposed to the normal decay which merely sheds a single alpha, beta or gamma ray, leaving the original nucleus largely intact. This results in less radioactivity, not more.

      --
      Starman97@Gmail.com (bring it on spammers)
    5. Re:"Splitting atoms" by calibanDNS · · Score: 3, Informative
      try telling that to the kneejerk reaction anti nuclear fanatics who can't see the wood for their own foolishly planted trees

      I was having a discussion with my wife and several friends a few nights ago, and the topic turned to energy concerns. I was amazed to find that I was the only person in the room who wasn't opposed to nuclear power plants, but then I remembered that I was the only person in the room with an engineering background and anything more than a high school physics class under my belt. I showed them all this Wired article and it actually seems to have helped their understanding of how nuclear power can be safe. That's a hard concept to sell to almost anyone who's spent years being convinced, or convincing themselves, that nuclear power cannot be safe, but I've found that it is possible to convince some. I'm also very proud of my wife, who has abandoned her "They can build it, just not near our house" attitude.
    6. Re:"Splitting atoms" by Enigma_Man · · Score: 5, Insightful

      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.
    7. Re:"Splitting atoms" by ohsoot · · Score: 3, Informative

      since when does a fossil fuel power plant produce radioactive waste? :)

      heh heh. Actually coal plants do produce radioactive waste. Instead of putting it in a container and storing it, they disperse it in the atmosphere.

      Look at this link

      Notice that you get more than 3 times more dose if you live near a coal plant than if you live near a nuclear plant. (If you live within 50 miles of a nuke plant you get 0.009 mrem as opposed to 0.03 mrem if you live within 50 miles of a coal plant.)

    8. Re:"Splitting atoms" by Junior+J.+Junior+III · · Score: 3, Insightful

      The amount of radiation *generated* by burning coal and oil may indeed be less than the amount *generated* by nuclear fission, for the same amount of energy produced. But, ALL of the fossil fuel radiation is *released* into the atmosphere, whereas the nuclear fission radiation is *contained* unless containment is breached in an accident. Therefore, as long as containment holds, nuclear fission is cleaner and safer than fossil fuels.

      --
      You see? You see? Your stupid minds! Stupid! Stupid!
    9. Re:"Splitting atoms" by swillden · · Score: 3, Interesting

      there are no satisfying solutions on how to deal with that waste IMO/AFAIK.

      Put it in torpedos that bury themselves in the edge of the deepest part of the Marianas Trench. The trench is the meeting point of the Pacific and Phillipine tectonic plates, and subduction would pull the waste under the Pacific plate and into the mantle.

      Actually, various forms of deep ocean disposal, whether at plate edges or, perhaps better, in the center of geologically inert areas, are an excellent option. Wastes buried a few meters deep in the soft, inert and lifeless sediments in the deeps would ensure that the waste will not migrate into the biosphere before it decays to a safe level and would make recovery by anyone nearly impossible, which means that the wastes would be safe from terrorists wanting to make dirty bombs.

      The only obstacle, really, is an international treaty, the London Convention, which is just an agreement and could be modified through an appropriate political process.

      --
      Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
    10. Re:"Splitting atoms" by Mt._Honkey · · Score: 3, Insightful
      What I object to, though, is the insinuation that we are the ones splitting the nuclei of the radioactive elements. These things are radioactive precisely because of their tendency to decay and in fact split themselves. They don't even split into other elements. You can't turn uranium into gold, for example, even though it ought to be a straightforward process of splitting off the required number of protons from each atom (if the "we're splitting atoms" camp claims are correct).
      We use the heat generated by the decay of radioactive elements to fuel our generators. We do nothing like smashing atoms into smaller bits.
      Just a pet peeve of mine whenever I see a nuclear power article.
      And a pet peeve of mine is people posting on slashdot in an authoritative fashion when they know nothing about what they're saying.

      It is true that Uranium does decay naturally and emit radiation. This decay, however, is the emission of one or very few particles, rather than splitting the nucleus into two large pieces:
      U-235 -> U*236 -> Th-231 + alpha
      U-238 -> U*236 -> Th-234 + alpha


      In nuclear reactors used for power production on Earth, we use the neutrons emitted in radioactive decay to split nuclei of Uranium-235. These two new nuclei are indeed new atoms. A couple common fission processes are:
      n + U-235 -> Xe-140 + Sr-94 + 2n
      n + U-235 -> La-139 + Mo-95 + 2n

      The masses of the two nuclei that come off tend to be between 72 and 160 AMU. Gold is not typically produced, as it's atomic mass is 197 AMU--too heavy to be made in the usual U-235 fission. I think that spontaneus fission might occur, but if it does it is at a much lower rate than is useful.

      Energy derived solely from radioactive decay without any fission is sometimes used, but to my knowledge only on deep-space probes such as Voyager and Cassini. IIRC they use the natural heat decay of Plutonium, which is produced from U-238 in reactors.
      --

      Don't Bogart the fish sticks
    11. Re:"Splitting atoms" by tootlemonde · · Score: 3, Informative

      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...

      According to this Report to Congress on Wastes from the Combustion of Fossil Fuels, radioactivty in fossil fuels is not a problem.

      The report says (page 44) that because the radioactive elements are not burned, they concentrate in the ash instead of spreading in atmosphere.

      As for the danger of the ash, the report says:

      EPA has reviewed radionuclide concentrations in coal and ash in connection with other regulatory programs (EPA 1989a, 1989b, 1995c). One of these studies examined potential exposures of worker and nearby resident to radioactivity from ash released from coal pile through wind and runoff erosion. Exposure from direct contact, inhalation, and ingestion were estimated to fall below natural background radiation exposure levels even for a worker standing on the ash pile.

      The report concludes that the risks from non-radioactive elements in coal (selenium, arsenic, aluminum, and boron) are of much more concern.

    12. Re:"Splitting atoms" by sjames · · Score: 4, Informative

      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.

  3. HUrray! by jim_v2000 · · Score: 4, Funny

    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.
  4. Re:Christian? by jim_v2000 · · Score: 3, Informative

    It's not a theological magazine, it's an actual newspaper. The have World/US/Science/etc news.

    http://www.csmonitor.com/aboutus/about_the_monitor .html

    --
    Don't take life so seriously. No one makes it out alive.
  5. Re:Cheap? Clean? when will we learn by 0123456 · · Score: 4, Insightful

    "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.

  6. Re:Cheap? Clean? when will we learn by Viol8 · · Score: 4, Informative

    "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.

  7. Re:Years away by Eric_Cartman_South_P · · Score: 5, Funny
    "Nuclear Fusion has always been 15 years away, and always will be"

    I think you mis-spelled "Duke Nukem Forever".

  8. The problems aren't insurmountable by Rik+Sweeney · · Score: 3, Insightful

    Just because we can't do it right now doesn't mean we never will.

    100 years ago we would never have dreamed space exploration would be possible. Why's this so different?

    1. Re:The problems aren't insurmountable by AbbyNormal · · Score: 3, Insightful

      True, but without any other market incentive does it ever go anywhere? Look where space exploration is now...35 years since we've landed on the moon.

      --
      Sig it.
    2. Re:The problems aren't insurmountable by CrimsonAvenger · · Score: 4, Interesting
      100 years ago we would never have dreamed space exploration would be possible. Why's this so different?

      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"
  9. Ask Slashdot? by anum · · Score: 5, Insightful

    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.
    1. Re:Ask Slashdot? by d_strand · · Score: 3, Informative
      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.

      That isn't a problem any more. The EU decided a few weeks ago to build ITER in france by themselves and inviting the Japanese to join if they like (dont know what's happening with the US participation, but considering that they didn't join until a short while ago and wasn't paying much anyway it hardly matters)
  10. Re:Years away by Anonymous Coward · · Score: 5, Funny

    Nuclear Fusion is about 8 minutes away, and will always be*

    * At least until the sun finishes its main phase

  11. Re:Years away by sillybilly · · Score: 4, Insightful

    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.

  12. Re:Years away by Decaff · · Score: 5, Interesting

    "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!

  13. Reason for Low Funding by Mr_Blank · · Score: 3, Informative
    Whenever fusion comes up I gotta refer to this Economist article:
    SOME say that a dollar spent on nuclear fusion is a dollar wasted. And many, many dollars have been spent on it, as physicists try to duplicate, in a controlled setting, the process by which the sun shines. Since 1951, America alone has devoted more than $17 billion (see chart) to working out how to fuse atomic nuclei so as to generate an inexhaustible supply of clean, safe power.

    The claim that this money is wholly wasted may not be entirely fair, though. Fusion science has made a big return on this investment in the form of a new universal constant. This constant is the number 30, a figure that has for the past half-century or so been cited almost religiously by researchers as the number of years that it will take before fusion power becomes a commercial reality. ...[continues]

    With observations like that in reputable news sources like the Economist it is no wonder that investment in fusion waxes and wanes. People want a return on investment before the next election, not 30 years from now.
    1. Re:Reason for Low Funding by R.Caley · · Score: 5, Insightful
      People want a return on investment before the next election, not 30 years from now.

      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
  14. Biodiesel is better fusion power by ScrewTivo · · Score: 3, Interesting

    use the suns fusion to grow biodiesel. A lot cheaper and it will clean the atmosphere. My understanding is that all carbon in plant is extracted from the atmosphere. Extracting the oil leaves carbon waste, so even dirty engines cannot put more carbon back into air then was extracted.
    Although we may end up with oxygen pollution :)
    biodiesel home page

    1. Re:Biodiesel is better fusion power by henrygb · · Score: 3, Interesting
      First you have to ensure that all the inputs come from biodiesel and are not just some energy intensive subsidy to farmers.

      UK duty on ordinary diesel 47.1 p/litre
      duty on biodiesel 27.1 p/litre
      duty on ordinary diesel paid by farmers 5.22 p/litre

  15. Re:Cheap? Clean? when will we learn by Qzukk · · Score: 4, Interesting

    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.
  16. Re:Christian? by Scarblac · · Score: 3, Informative

    I'm sorry, we're looking at a theological magazine for technical articles?

    I'm a total atheist, but the Christian Science Monitor is an extremely good publication, very independent.

    It was apparently originally founded by a wealthy and religious woman about a century back. It is owned by a church, but you couldn't tell from the content. What you can tell is that it's not just another news organization for which profit is the all important thing.

    --
    I believe posters are recognized by their sig. So I made one.
  17. Re:Years away by Binestar · · Score: 3, Insightful

    Given the challenges facing today's nuclear reactors, they have long dreamed of harnessing the same energy source that powers the sun.

    Uh...Solar power anyone?


    The sun powers solar power, Fusion powers the sun.

    --
    Do you Gentoo!?
  18. Step one - increase the cost of alternatives by coyote_oww · · Score: 3, Insightful

    I think we're getting closer to "cost-effective" fusion, if for no other reason than that the alternatives are getting more expensive. If the cost of fusion just stays constant, fusion will eventually win out. Other energy sources will simply become more expensive, leaving fusion the "bargain" energy source.

  19. It'll Never Happen by occamboy · · Score: 5, Insightful

    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.

  20. Silicone Carbide? Fusion in breast implants? by jakedata · · Score: 3, Informative

    I have a sneaking suspicion that the article meant to refer to SILICON carbide.

    Silicon and Silicone are often confused.

    OTOH, perhaps this will be the next big thing. Talk about too hot to handle...

    -j

  21. Re:Years away by anorlunda · · Score: 5, Insightful

    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.

  22. Yeah, tritium's too rare. by MickLinux · · Score: 4, Insightful

    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
    1. Re:Yeah, tritium's too rare. by kravlor · · Score: 3, Informative
      Actually, in ITER, the reactor discussed in the article, tritium will be bred in the reactor vessel itself.

      The first wall will contain lithium, which can transmute to T when bombarded by the fast neutrons generated by the fusion reactions. For more info, see Boeing's blurb on the shield/breeding blanket designs.

      Of course, with improving technology, higher beta (a measure of fusion plasma confinement capability), and hotter plasmas, D-T can be forsaken for other reactions. :)

  23. Re:Cheap? Clean? when will we learn by Anonymous Coward · · Score: 5, Informative

    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.

  24. Re:The Law of Thermodynamics by Pd-D20 · · Score: 5, Informative

    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?
  25. Re:Years away by HMA2000 · · Score: 4, Insightful
    Even with fusion power "too cheap to meter" there will still be limited resources. Trust me, there is no government of a developed nation on earth that doesn't want the incredible economic boost free power will have.

    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.

  26. science is as science does by Doc+Ruby · · Score: 3, Insightful

    Does anyone else find it dissonant that the Christian Science Monitor, generally a fine paper, is primarily a journal for a community of Americans who shun medicine in favor of faith healing, yet reports other miraculous science like fusion without complaint?

    --

    --
    make install -not war

    1. Re:science is as science does by bhima · · Score: 3, Informative
      Cherckout: http://csmonitor.com/aboutus/about_the_monitor.htm l

      "It's a real newspaper published by a church -- The First Church of Christ, Scientist in Boston, Mass., USA.... let's be clear: The Christian Science church doesn't publish news to propagate denominational doctrine; it provides news purely as a public service. Here's why: If the basic theology of that church says that what reaches and affects thought shapes experience, it follows that a newspaper would have significant impact on the lives of those who read it.

      A newspaper whose motive is "to injure no man, but to bless all mankind," as its founder charged, would have a "leavening" effect on society, as well as on individual lives -- to use a metaphor Eddy herself appreciated and used. The idea is that the unblemished truth is freeing (as a fundamental human right); with it, citizens can make informed decisions and take intelligent action, for themselves and for society."

      On a side note, I've just read throught the comments and I'm amazed at the number people that have made comments showing that they know no science... did IQs suddenly drop while I was away?

      --
      Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.
  27. Re:"Splitting atoms" - yes, we do (I'm a Nuke) by syrynxx · · Score: 5, Informative

    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.]

  28. Coal plants do release more radioactivity. by Firethorn · · Score: 3, Interesting

    according to Alex Gabbard

    For comparison, according to NCRP Reports No. 92 and No. 95, population exposure from operation of 1000-MWe nuclear and coal-fired power plants amounts to 490 person-rem/year for coal plants and 4.8 person-rem/year for nuclear plants. Thus, the population effective dose equivalent from coal plants is 100 times that from nuclear plants. For the complete nuclear fuel cycle, from mining to reactor operation to waste disposal, the radiation dose is cited as 136 person-rem/year; the equivalent dose for coal use, from mining to power plant operation to waste disposal, is not listed in this report and is probably unknown.

    For a large number of coal samples, according to Environmental Protection Agency figures released in 1984, average values of uranium and thorium content have been determined to be 1.3 ppm and 3.2 ppm, respectively

    And a 1,000 megawatt plant uses 4 million tons of coal a year, resulting in the release of 5.2 tons of Uranium and 12.8 tones of thorium.

    A 1000 megawatt light water nuclear plant of the type used in the USA uses about 25 tons of uranium a year.

    If you're willing to use breeder reactors and their ilk, you can actually get more power out the the uranium in the ash than you got burning the coal!

    --
    I don't read AC A human right
  29. Read the Post, Pinhead by occamboy · · Score: 3, Insightful

    The parent post says nothing whatsoever about the Bush family being the root of all evil, nor does it say anything in regard to Clinton, etc.

    It simply suggests that the Bush family and their buddies are in the oil business, are extraordinarily greedy, and play hardball. All of these things are perfectly consistent with history.

    What we see in SnarfQuest's response is the typical fringe-right tactic of attempting to refute reality by somehow changing the topic to something that they can attack. How utterly unhelpful.

  30. Re:Years away by Rei · · Score: 4, Interesting

    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.