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Science

U.S. and China Join Fusion Project 80

Garp writes "According to the BBC News website, the U.S. has finally decided to join the international Fusion project, Iter, along with China, with the aim of building the worlds first commercially viable Fusion reactor. Fusion is one of the cleanest forms of energy conversion, excluding renewable natural sources, like wind farms, tidal generators, and solar cells."
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U.S. and China Join Fusion Project

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  • This was in the BBC news thingy on my right sidebar a few days ago.
    • Re:Old news (Score:2, Insightful)

      by Jahf ( 21968 )
      And if everyone monitored every news site, /. would be less than useless. But, we don't, so it's not. I found the article very interesting.
  • Cleanest? (Score:5, Interesting)

    by Otter ( 3800 ) on Wednesday February 26, 2003 @02:54PM (#5388980) Journal
    Fusion is one of the cleanest forms of energy conversion, excluding renewable natural sources, like wind farms, tidal generators, and solar cells.

    I suppose "cleanest" may be literally true, but in terms of overall environmental impact, fusion has got to easily whip at least the first two. The environmental footprint of windmills and tidal hydroelectric is huge. And, of course, most of the world doesn't have a tide to draw on, and I'm not even getting into the "draining the angular momentum of the planet" issue.

    • The third is a bitch, too, because of the Huge area that needs to be covered per kWh.
    • Actually, most of the types of fusion reactions are dirty as hell; the lowest temperature one, that we are most likely to manage first, is pretty bad- most of the energy comes out in fast neutrons, not heat, hard radiation. So in order to liberate this energy, well, it's difficult.

      One scheme was to clad the inside of the reactor with lithium, transmute that with the neutrons and then take the resultant material and put that in a fission reactor and then boil steam.

      All this mucking about of course makes for a lot of pretty hot nuclear waste and it would never be environmentally friendly.

      This is the Deuterium-Tritium, but the tritium-tritium reaction is essential clean; no fast neatrons; however the temperature and pressure is so much higher, that the problems to achieve break-even are greater.

      • ...aren't even those examples better than fission? It seems like the first-gen fusion plants will be only as bad as fission plants, and it will get better from there.

        Also, there's the safety factor - with fusion, if containment is breached (as you know, I'm sure) the pressure and temperature drop to the point of no reaction very quickly. Also, couldn't less mass of material be used to shield the reactor (compared to fission)? That would very much reduce the environmental impact of low-level waste when the plants are decommissioned. And there isn't much high-level waste at all, is there?

        • ...aren't even those examples better than fission?

          Not really. The hazards are about identical- the lithium reactor can still melt down, the fusion reactors certainly become radioactive in and of themselves, and have a finite life due to radiation damage. It's not clean, it may very well not be cheap either.

          The tritium-tritium reaction is a different beast though; that's potentially pretty clean, and pretty safe- no fission reactors need be involved. But very much more difficult to ignite.

          • Not really. The hazards are about identical- the lithium reactor can still melt down,

            While the lithium blanket can certainly melt, this does not in any way resemble the catastrophic runaway reaction that is called "meltdown" in a fission reactor. It's caused by inductive heating from the same currents used to heat the plasma. If anything, your reactor would stall if the blanket melted or boiled off, as you'd be losing more neutrons (as opposed to breeding more tritium from neutrons impacting the blanket).

            Re. fission, all tritium breeding from the lithium blanket is far into the sub-critical regime. If a runaway fission cascade in lithium were possible, we'd have bigger problems than unstable fusion reactors to worry about (fission reactors and weapons would be a lot easier to build, for one).

            The tritium-tritium reaction is a different beast though; that's potentially pretty clean, and pretty safe

            Um, no. It's dirtier than D+D or D+T (more neutrons for the likely reaction paths; you get 4He + 2n in the best case, and you don't just get the best case).
          • The tritium-tritium reaction is a different beast though; that's potentially pretty clean, and pretty safe

            Err, it's actually pretty dirty.

            A much cleaner reaction is deuterium and helium-3 which generates primarily He-4, a proton and a gamma-ray. The charged particles slow down rapidly, giving up energy, and the gamma is absorbed in the shielding, again producing heat, and doesn't produce any significant induced radioactivity.

            The main advantage of D+T is that it's easy to ignite (relatively speaking) and both reactants are readily available. The double electric charge of He-3 makes ignition harder and its relative scarcity doesn't help much. Although scarcity doesn't matter much for prototype reactors, it could become a serious limitation if D+He-3 becomes a commercial success. Proposals have been made for harvesting it from the solar wind or the atmospheres of Jupiter or Saturn, but you can be pretty sure that the start-up costs will be pretty large.

            Paul

      • Re:Cleanest? (Score:3, Informative)

        As of the late 80's (last time I was at the Princeton Plasma Physics Lab) the strategy was to clad the reactor in a copper shield. This would create a radioactive copper shield over time, which would need to be stored as radioactive waste. The half-life is only 37 years though.

        disclaimer: data from my non-ECC memory
        • Yes, the big issue isn't the fusion reactor itself (although a half life of 37 years is problematic because it tends to be radioactive enough to be an issue, and can remain significantly radioactive even 100 years later.)

          No, the big issue is the fissioning of the lithium. That's the dirty step- and the fission reactors are rather more awkward.

    • I'm not even getting into the "draining the angular momentum of the planet" issue.

      I can't speak for anyone else, but 25 hour days is fine by me :)

      -
    • IANAThermodynamics prof, but all energy conversion processes require a heat dump. More heat windes up in the dump when: 1. the incoming energy is larger and; 2. the process is less efficient. Even a perfect process generates heat.

      When attending a high school field trip to a nuclear power plant, I recall the plant rep saying that the river water (their heat dump) is 2-3 degrees higher in the surrounding area. However, I didn't know how much to trust any of the info provided because she also said that cigarettes are cancerous due to extremely minute amounts of plutonium found within.

      Either way, a heat dump is required. This WILL affect the neighboring environment, but (by extension) so will any other power generator. I guess the real question of generator pollution excludes the issue of heat. In that case, fusion does look more attractive.

      One last note:
      And, of course, most of the world doesn't have a tide to draw on...
      But, most of the world is covered by water. Of course, practically speaking, I'm just being stupid here...
  • by GuyMannDude ( 574364 ) on Wednesday February 26, 2003 @02:59PM (#5389036) Journal

    I see from the Iter website that this reactor is essentially trying to get fusion to occur using the magnetic-confinement technique of the Tokamak reactor. The other approach to controlled fusion studyied over the last few decades is inertially-confined fusion. Can anyone tell us what the state of inertially-confined fusion is? Does the US's and China's joining of the Iter project signify that the mainstream thought is that inertially-confined fusion is dying? My understanding is that both were hot research topics in the 90s but I don't know what the current thinking is. Any help would be greatly appreciated.

    GMD

    • by Peter T Ermit ( 577444 ) on Wednesday February 26, 2003 @04:07PM (#5389690)
      ICF was never principally for power generation; it was a weapons-lab project with energy thrown in as an afterthought to make it look like it had peaceful purposes. The big ICF facility in the states, NIF, is just coming online now... and the future of ICF will have nothing to do with what happens with ITER.
      • Back when I was working with the ICF team it sure seemed to me like the "peaceful purposes" were designed to get Clinton to *increase* funding when most other science - especially weapons related science - was being cut. Sure enough. Most of Los Alamos got slashed to hell while those groups doing ICF got funding increases justified by power generation. (It also assimilated most of the tokomat folks)

        As the saying goes, bureaucracies attempt to surive as if they were living things. . .

    • This is a method that you'll get quite a charge [peter-thomson.co.uk] out of, and will spin you out.

      As an added bonus, it seems likely that it can double as a generator, that is, electricity can be pulled out directly with no extra moving parts.

    • I have much more faith in magnetic confinement. ICF relies on the idea that you'll vaporize little fuel pellets several times a second with multiple high energy lasers and be able to do it reliably and accurately. Science has come a long way, but ICF seems like a technique prone to failure. Also, there have been some recent suggestions that the thermonuclear explosions caused by pellet vaporization may create significant turbulence, making it difficult to vaporize another pellet in rapid succession. Of course, magnetic confinement has its problems, too. ITER will probably result in "ignition", but even so, it'll produce a machine so large and unwieldy (requiring an army of PhDs to operate) that no power company would ever invest in it. Also, I believe actual experiments in the generation of electrical power are intended for the successor to the ITER machine. Tell your congressman to increase funding for alternative fusion concepts!
  • by RobKow ( 1787 ) on Wednesday February 26, 2003 @03:08PM (#5389131)
    The hideously low efficiency of solar cells makes them a waste of -other- natural resources to manufacture, transport, purchase, install, and maintain.

    That is, you burn more fossil fuel energy deploying photovoltaic arrays than you regain during their (short) usable lifetime. That doesn't make them any less-convenient for remote off-grid applications, but they're not going to replace other power sources anytime soon.

    Solar energy is still viable for heating (obvious) as well as power generation using mirror concentrators.
    • Relatively yes (Score:4, Interesting)

      by Yokaze ( 70883 ) on Wednesday February 26, 2003 @03:35PM (#5389375)
      Could you please back your statements up with some sort of facts, preferably from a reliable source?

      This source [ecotopia.com] seems to suggest otherwise. Btw, the mass-production of solar-cells has begun after the publishing of this paper.

      >during their (short) usable lifetime
      I don't know about your experience. But I've had a solar cell, which has been serving me well for longer than 20 years. Guarantees are usually issued for 20 years lifetime.

      Interestingly, I've heard similar stories about nuclear plants. Not that I'm claiming that they are true.

      • Does your solar cell completely power your home/whatever? Or does it just supplement the electricity from PG&E? If solar cell users are completely self-sufficient, I'm surprised that more people in California don't use them after the years of power outages and escalating rates.
        • Re:Relatively yes (Score:3, Interesting)

          by Yokaze ( 70883 )
          Well, it is more of a summer house, which is off-grid. So being self-powered is no achievement, since only a radio and some light require some energy.

          The point of mentioning it was the life-time of the solar cell.

          Being completely self-sufficient in a (more or less) normal life-stile is a little bit more complicated. One cannot rely on photo-voltaic alone.

          One has to be a little bit more intelligent in building the house and selecting the equipment.
          The keyword is: Zero-Energy Home [google.co.jp].

          IIRC, those houses are cost effective. But the critical part is, that the initial costs are much higher. But don't take my word for it.

          Concerning the cost effectiveness in California, new taxes [slashdot.org] might totally void it.
      • I did a good deal research on this nearly 10 years ago. I'll freely admit that the situation may be different now as they have gotten much better.

        It's probably a good time to do some research on this again. But the biggest thing that's usually overlooked is the kWh in fossil fuels expended (not just $) in the cost of manufacture. I'm not quite sure how that works out now, but I'm pretty sure it hasn't changed much.

        So take my reply above with a grain of salt, I guess. Also keep in mind that anti-solar findings will be very unpopular academicallyand most of the research I've seen published (with some notable exceptions) doesn't take into account the holistic effects of solar power.
        • Re:Relatively yes (Score:2, Interesting)

          by foolish ( 46697 )
          Actually, you WILL find the kWh figures added into the costs of most current solar studies.

          As you say, back about ten years, the solar people were getting lambasted for posting only operational and amoritized financial costs, and excluding the 'lifecycle' costs. They now usually make sure to post that information, though sometimes not in the sales literature, but almost always where investors can read it.

          --foolish
    • This has been false for years, and it gets +4 insightful?
    • This [uic.com.au] is a good summary of the energy returns of various methods of power generation. To summarise: (Figures are the precentage of the energy that you get as a net return)

      Hydro: 98%

      Nuclear fission: 90-98%

      Coal: 95%

      Natural gas, piped: 96%

      Natural gas, LNG imports: 83%

      Solar: 73-90%

      Wind: 83-98%

  • self sustaining? (Score:4, Interesting)

    by k3v0 ( 592611 ) on Wednesday February 26, 2003 @03:44PM (#5389445) Journal
    it may produce 500 megawatts of fusion power for 500 seconds or longer, but how much energy is required to initiate the process? i'm not really that familiar with fusion, but it would seem that quite a bit of energy would be required to heat the elements to the balmy 100 million Celsius.
    • Re:self sustaining? (Score:3, Informative)

      by Pyromage ( 19360 )
      Less than that. I can't give you any numbers, but /.'s history has stories on fusion. Basically, we've long since gotten past the point of getting more energy out than we put in. We just can't sustain it for more than about 2 minutes, yet.
      • Um... can you point me to an experiment that's reached breakeven? The closest I know of is a late '90s claim by JT-60 that claimed a "breakeven equivalent" -- basically, they said if they had run the machine in a different configuration, they should have had breakeven. (Read: they didn't reach breakeven in the experiment they ran.)

        AFAIK, we haven't gotten more energy out than we put in yet, much less "long since gotten past" that point.

    • Take a look at the National Ignition Facility [llnl.gov] at Lawrence Livermore National Laboratory.

      Basically, it's a stadium sized facility to research and test inertial-confinement fusion (using lasers to produce extreme heat and pressure).

      The way they've designed the system, they can produce a total of 1.8 MegaJoule in laser power that all starts from piddly lasers in the nano-joule range.

      So, for about $5's worth of electricity and lots of huge slabs of perfect laser glass and crystal, they can more than break even. Theoretically, NIF will generate about 500 TeraWatts of laser power. Sounds promising.

      -Cyc

      • The way they've designed the system, they can produce a total of 1.8 MegaJoule in laser power that all starts from piddly lasers in the nano-joule range.

        So, for about $5's worth of electricity and lots of huge slabs of perfect laser glass and crystal, they can more than break even.


        To get a 1.8 MJ laser beam, you need to put a minimum of 1.8 MJ into the gain media. The amount of energy in the initiating pulse is irrelevant - it still takes power to amplify it.

        In practice, you need to put much more energy than this in. Typical non-semiconductor solid-state lasers have wall-plug efficiencies in the 0.1%-5% range.

        Theoretically, NIF will generate about 500 TeraWatts of laser power.

        ...Over a few picoseconds.

        Inertial confinement fusion works by dumping a lot of energy (1.8 MJ, in this case) into the target in a very short time. Of course power figures are huge. They're also not relevant. The real question is, do you get more energy out of the pellet (from fusion) than you dumped in.

        So far, inertial confinement fusion is nowhere close to breakeven. The energy from ICF is also a lot harder to capture than from magnetically confined fusion, as in the former you're pretty much stuck with heating an ordinary material and running a heat engine. With MCF, you can at least in principle run the hot plasma into some kind of MHD generation scheme, though in practice the fact that some of your fusion energy ends up in neutron and gamma emission make this less efficient than it could be.

        In summary, you have been distracted by the shiny numbers and are't looking at the real characteristics of the machine.
    • From the ITER website:
      The principal physics goals of ITER are:

      1. to achieve extended burn in inductively driven plasmas with the ratio of fusion power to auxiliary heating power (Q) of at least 10 for a range of operating scenarios and with a duration sufficient to achieve stationary conditions on the timescales characteristic of plasma processes;

      2. to aim at demonstrating steady-state operation using non-inductive current drive with a ratio of fusion power to input power for current drive (Q) of at least 5.
      So in other words they're attempting to get 10 times the output power as input heating for long term burns, and 5 times for a "steady-state", which I assume means continuous burn.
  • problems with fusion (Score:2, Interesting)

    by Anonymous Coward
    the main problem with fusion and fission is that not many people understand the technology. thermal, hydro-electric power station technology is understood for the last 100 years or so. fission technology can be used in bomb making and hence there are sever restriction on technology exchange. fusion can be used in bomb making, but that requires having fission bomb. So the restrictions are less. however, the fusion technology is inherently too complex for today's scientists and engineers to understand. there are very few independently reproducible experiments which demonstrates that fusion can be used commercially.

    I have visited thermal, hydro-electric and nuclear power plants. At thermal and hydro-electric plants, even low level workers had some idea how the things work and what control panel indicator means what. At nuclear plant, all they could say was, "if this light is red, we are screwed" (well, this is oversimplication). When you have such things, it is hard to expect, safe, reliable and cheap power. The same remains true for fusion tech. Only few qualified people exists and hence, it would be too costly atleast for next 30-50 years to use fusion to replace other types of power. We are still at early experimental stage and nowhere close to commercial exploitation of fusion power.

    • by Anonymous Coward
      the fusion technology is inherently too complex for today's scientists and engineers to understand

      What the hell are you talking about? Prototypes have been around for years. Do a search for "fusion power" on google. It's a really, really simple process. That just happens to be really, really difficult because it's so delicate.

      Prototypes have achieved 1KW output. This is effectively free energy from alchemy. Build it, feed it hydrogen - you get helium and energy out. Actually, oxygen is another output, since you'd probably electrolise water to get the hydrogen in the first place (and even with this taken inton consideration you'd still produce considerably more energy out than you put in).

      At nuclear plant, all they could say was, "if this light is red, we are screwed"

      My car is too complex for me to understand, but that doesn't mean that I can't operate it without killing myself.

      There isn't much that can go wrong at a modern pebble bed nuclear fission reactor either. Even if, say, you accidentally removed all the coolant. The core gets warm and you waste energy. But that's it. It is physically unable to explode or reach a critical state. You have to go out of your way to make it dangerous to anyone by trying to destroy it.

      And there isn't _anything_ that can go wrong at a fusion reactor. The absolute worst case is that the containment magnets could cut out - letting the superheated plasma hit and scar the chamber wall. This causes the operator to swear and fetch another cup of coffee before restarting the reaction.

      If the chamber was ever breached through accident or sabotage - well - there's the slight smell of burning and the reaction stops because air entered the chamber.
      • by Xilman ( 191715 )
        And there isn't _anything_ that can go wrong at a fusion reactor. The absolute worst case is that the containment magnets could cut out - letting the superheated plasma hit and scar the chamber wall. This causes the operator to swear and fetch another cup of coffee before restarting the reaction.

        Tell this to the people at JET. A few years ago the plasma accidentally touched the chamber wall. The tokamak was converted into a single-turn electromagnetic motor carrying a hell of a lot of current. The entire system, weighing hundreds of tons, leapt almost a foot into the air. The resultant thump when it landed was picked up on seismographs all over Europe. IIRC, it was equivalent to an earthquake measuring about 3 on the Richter scale.

        Paul

    • I seem to recall (from some of my copious SciFi reading) that a key problem to long term and widespread use of fusion is actually from waste heat. Since a fusion reactor would generate temperatures in the millions of degrees Kelvin, and since any generation system will capture only a fraction of that heat for conversion to other forms of energy (albeit how much I don't pretend to know), the remaining heat needs to be disposed of. This will probably occur through a complex series of coolant mechanisms that all boil down to radiation into the atmosphere. How long before that added heat starts to become a problem?

      I'm no physicist (although I'm married to one, but she isn't handy right now), so if one would care to reply and correct me or back me up, I welcome it.

    • by Vellmont ( 569020 ) on Wednesday February 26, 2003 @05:51PM (#5390664) Homepage
      So we'd have fusion technology today if Joe Scmuchatelli had a weak inkling of what happens in a nuclear reactor? I'm afraid you're vastly uninformed about fusion. The problem isn't that Joe Sixpack doesn't know a little, the problem is that Joe Scientist doesn't know the intricacies of how to maintain a fusion reaction. That's why this facility is being built.

      Fusion research has reached a stage where the only way to get closer to commercial production is to scale the whole experiment up. You state that there haven't been any experiments to show fusion can be used commercially... Well Duh! Researchers have only recently gotten past the break even point. That's why we call it "experiment", and not "commercial implementation". The problem is not one of not enough qualified workers and thus it's too expensive, the problem is we just don't know how to make a sustainable fusion reactor yet.
      • I am the original AC who wrote this message, so i will try to reply.

        First, I am not mis-informed. I have taken graduate level courses on plasma fusion in a top university in 90's. I am also in personal touch with several people who work on plasma research. Second, there were Joe Sixpacks who caused Chernobyl accident and also there was some news about potential chain reaction in Japan nuclear material storage facility which too was caused by Joe Sixpacks. Further, if you read, I said that the technology inherently is too complex for today's scientists and engineers to understand. Joe only comes into picture when we talk about cost (for commercial exploitation). In future, you will need lots of them and failure to find them would result into same as what happened to fission power (very limited use).

        You are claiming that the only way to go is upward, but then when wasn't that the case? Has anyone demonstrated either theoretically or through scaled down prototype that that would be commercially viable? Absolutely not. I never said to give up plasma research. I simply said that we are still at experimental stage only and nowhere close to commercial exploitation. That is atleast 30-50 (or more) years away. Saying otherwise would be to raise false hope which many scientists do to get funding.

        Your whole article tone is such that it implies you oppose everything what I said. However, you are just picking out couple lines out of context and replying by saying the same thing what I have said in the rest of the article.

        • Fair enough. Perhaps I misinterpreted the intent of your post. You didn't provide much context, so I assumed your main intent was to say the reason fusion hasn't advanced was because too many people don't know anything about it.
      • Another important reason for scaling up is that the dominant loss terms scale as the surface area of the plasma, whereas (theoretical) output power scales as the density. So larger volumes have smaller relative losses.

        This is actually one of the impediments to commercial fusion power: reactors efficient enough to generate commerical power will have to be big, which is a problem because "big" translates to "takes a long time to build" and no one knows what the demand for power will be two years from now, much less ten or fifteen.

        Getting capital together for such a project won't be easy, and there are only a few locations where a 20 GW plant makes any kind of sense.

        So the economic problems faced by the fusion power industry will be a large multiple of those faced by the fission power industry.

        --Tom

  • Cleanest my foot (Score:3, Interesting)

    by Euphonious Coward ( 189818 ) on Wednesday February 26, 2003 @04:24PM (#5389818)
    Fusion is one of the cleanest forms of energy conversion, excluding renewable natural sources, like wind farms, tidal generators, and solar cells.

    They don't like to mention how many hundreds of tons of material would be made radioactive by the heavy neutron bombardment from hydrogen reactors. The whole apparatus would have to be replaced frequently as it gets too damaged by the bombardment to hold itself up, and the scrap would have to be put somewhere safe, just as with fission reactors.

    (These remarks apply to thermal neutron processes, not those that extract electromagnetic energy from kinetic charged particles. For some reason nobody likes to talk about those.)

    • Not to mention the huge amounts of Helium produced - what do we do with that, vent it into the atmosphere? In the future we may all sound like chipmunks!

      Seriously, though, where can I learn about the direct electromagnetic approach you allude to? How does it avoid having neutrons bombarding everything and making it radioactive?

      • "...where can I learn about the direct electromagnetic approach..."

        Google is your friend. Look for lithium fusion, fusion and charged particles, electromagnetic kinetic energy extraction. Russia used to loft fission reactors in satellites, based on the principle. (In fact one of their reactors which they brought to a conference as a demo was confiscated and held for many years as a result of a confused export law on the books.)

        The method avoids neutron bombardment by not emitting neutrons, but only whole nuclei, which may be confined and guided to traps to release their kinetic energy.

      • Not to mention the huge amounts of Helium produced - what do we do with that, vent it into the atmosphere? In the future we may all sound like chipmunks!

        Not to worry. The average atomic velocity of He at room temperature exceeds escape velocity - it will simply blow off into space.

    • by fuzzykitty ( 265256 ) on Wednesday February 26, 2003 @05:09PM (#5390227)
      While it is true that the result from Iter will be a lot of radioactive waste, this project must continue because it is vital to fusion research. The radioactive waste will result because of the plan to use stainless steel in the reactor construction. Stainless steel is easy to activate (because of the nickle and other elements in it) however it is one of the few materials that can take the reactor wall loading that we know how to work with (Vanadium would be an excellent replacement and have a very short halflife (on the order of decades) except for the fact nobody really knows how to roll it, weld it, make it into a pipe etc...). Don't forget that the vast majority of our industrial complex is built on the understaning of steel.

      As with any prototype, there are issues. Fusion by itself is clean and if low activation materials can be used, such a silicon carbide and vanadium, which will result in very little radioactive waste with short halflifes.

      The other aspect of ITER, which is a boon for fusion research, is that it is the first comercial "scale up" of a fusion reactor. Current research reactors are small and thus too small to generate enough fusion power to be useful on a grid. Fusion does occur, but it is not at a "density" (I am taking a bit of liberty with the nomenclature for a simplified explanation) that is sufficient to offset the power put into the system (ie other lossy effects are not overcome until there are more fusion reactions per unit time in a given volume)

      In short future reactors will be a LOT cleaner after ITER. It's sort of like the early days of fission. A crude graphite pile lead to intrinsically safe and efficient boiling water reactors. It seems to me that a little bit of pain to jumpstart the research is worthwhile.
      • One very good point about ITER is that the temperatures and plasma densities they're talking about are getting tantalizingly close to what's needed for the proton-boron-11 reaction. [pppl.gov] They should be even closer to what would be needed for the deuterium-helium-3 reaction. (What a pity that helium-3 doesn't occur naturally at the Earth's surface!)

        Both of these reactions yield no neutrons, and hence don't present a problem of radioactive waste, which comes from neutron activation of the reactor wall.

    • by Anonymous Coward
      That's why a lot of us like the prospect of aneutronic reactions, like B11-p. Vessel activation isn't really an issue anyways, if you build your reactor vessel with the correct materials (I wasn't aware steel was the only structural material around). Activation is not a long term problem in fusion. Doing self-sustaining fusion is. BTW, I am not a fan of ITER. It is pronounced "Eater", by the way, as in "it ate my budget". Fusion will never be economical using current 'build big = better' methods. We need to learn how to do self-sustaining fusion at smaller scales. 1000 small experiments net more knowledge than one humongous one. Yes, IAFP. Yes, these views are heretical. Yes, I've already pissed off most of the fusion community. Particle physics has its small science proponents (they tend to live on mountaintops), why don't we?
    • Re:Cleanest my foot (Score:4, Informative)

      by the eric conspiracy ( 20178 ) on Wednesday February 26, 2003 @09:46PM (#5392472)
      They don't like to mention how many hundreds of tons of material would be made radioactive by the heavy neutron bombardment from hydrogen reactors.

      Fusion reactors do not generate high level radioactive waste that must be isolated for geological lengths of time in the way fission reactors do. The radioactive by products from a fusion reactor are low level and with short half-lives (less than 100 years). The short half-life makes in place storage of the irradiated structural components quite feasible - they don't need to be transported etc.

      In addition a fusion reactor is fail safe - there is no danger of a meltdown or similar event.

      The real attraction of fusion is that it is potentially extremely scalable. Alternative energy sources like solar, wind, etc. are attractive within the near term framework of reducing greenhouse gases over the next decade or two. Ultimately however it is hard to imagine how these dilute, funtamentally limited sources of energy will supply what is needed for strong economic growth into the next century, or a world population that exceeds 10 billions.


  • "Iter officials are hoping to decide where the fusion reactor will be based within the next few years or so and have agreed to meet in Vienna in May."

    Being the only internationally shared landmass, and being a very nice distance away, I humbly suggest putting it in Antarctica.

    OR they could spend the next 3 years dickering over who gets it.
  • At $5bn each the US could buy 10 of these things for the projected cost of the current action on Iraq ($95bn) and remove the need to protect interests the Middle East at all. (The remaining money would be needed to research replacements for fossil fuel equipment)
    • It may be cheap in comparison to the possible Iraq-conflict. The biggest problem with fusion reactors is the time to develop and build a working reactor. It will take at least 30 years to master the reaction and produce more energy than it costs to start up the reaction.

      30 Years ago they said the same and see how far they have come yet. I once visited a fusion reactor and they said money was a big problem. There are not much companies interested in funding a project that will only become profitable in 30 years.

  • This is no good. This article has made me come to the conclusion that Osama Bin Laden was the spark set in motion a process that caused the US to realize, finally, that dependence on Oil is a very dangerous thing. It makes you dependent on oil-rich countries, which gets you into all kinds of nasty nations and their politics, which just pisses off just about everybody and causes war and terrorism, and still we have limited energy. It causes mean old bastards who are happy living in a desert, if it means money for them, to have a substantial amount of power in the world. Mean old bastards shouldn't have that kind of power.

    Fusion power is the obvious way out, and with the US behind fusion for real, we'll get the thing worked out.

    A lack of energy is really the root cause of most of life's problems. The cost of making goods trends towards zero as you have more power to feed into a system - Clarke points out your real pollution problem becomes heat in a couple hundred years' time, but I digress. Fusion can provide the energy that will provide most people with essentially unlimited power, raising the standard of living all over the world. Stop and think about this for a minute or two. This will cause a socio-political reorganization on Earth that will allow, for the first time in history, a real chance at world peace.

    Now this is all great news, but look at the cause and the effect. Sure, it's just the 10000-foot overview, but, fuck, that doesn't fit anywhere in my moral framework. "It adds up. You just don't like what it adds up to."
    • of course, we already have a fusion generator in the sky that showers the earth with usable energy. We also have 100,000's of square miles of rocky deserted nothingness in every continent. Instead of billions on a fusion plant (and billions on ways to concentrate the fusable isotopes of hydrogen), why not just work on solar power, more efficient lighting (perhaps biochemical), better motors (synthetic muscles or superconductivity), low power semiconductors, etc.
      • Because then the resultant technology of all that expenditure is forever tied to a planet.
        • But it solves many near term problems, including heat pollution if we only intercept sunlight that was going to hit the earth's surface anyway. After our energy & heat/emission problems fixed, then we can worry about spaceship drives and power supplies for colonies far from the sun
  • The construction cost for Iter is put at about $5bn. However, the cost will be shared among all of the collaborators, who will provide most of the components in kind.

    I expect the US DoE(nergy) to build a copy of it, and do it faster that the Iter project. I would not be at all surprised if the USA has a copy of this fusion power plant before the official version is built. I would also not be surprised if it were a secret until it is producing power optimally. After all, we all saw Contact: "Why buy only one, when you can buy two for twice the price?" It's only $5B.
    • The US has been unenamoured with fusion for several reasons, however the fact that we are primarily an oil economy is a big one.
  • by reverseengineer ( 580922 ) on Wednesday February 26, 2003 @10:16PM (#5392677)
    The problem with nuclear fusion is that it has been the classic example of a tech that's 50 years away- and it's been that way for the last 50 years. It's turned out to be a much more thorny problem than people anticipated- uncontrolled fusion reactions are fairly easy to produce after all- just direct the energy from a fission primary at an appropriate quantity of tritium. Unfortunately, this is a hydrogen bomb, and makes for a rather inefficient power source.

    However, controlled confinement of plasma has proven to be much harder. ITER will use the most popular confinement method, a tokamak, which is a design devised by the Soviets (Tamm and Sakharov) back in the 1960s. So essentially, the basic plan is 40 years old, but there have been a number of obstacles- political and economic as well as technical to making this work. It will be interesting to see if their tokamak avoids the key problem of the design; in a tokamak, the plasma itself has an internal current running through it (as opposed to other designs like stellarators) and has proved rather deifficult to contain in the torus. I believe the Joint European Torus has had several "disruptions" of this sort that have lifted the several hundred ton vessel off its bolts. The good news, of course, is that such events (which are rare, and should be much more rare in a non-experimental reactor) are really the worst things that can happen to a fusion reactor. Although the plasma is extremely hot, it is not very dense at all (obtaining a critical density is really the greatest challenge) and thus there exists no possibility of 300 million Kelvin plasma vaporizing the container walls in some sort of runaway accident. Also, while they are not completely clean (no power generation method is) the radioactivity produced is low level, especially in comparision with fission reactor spent fuel rods.

Ya'll hear about the geometer who went to the beach to catch some rays and became a tangent ?

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