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Science

Uranium Pebbles May Light the Way 629

Posted by simoniker
from the glowing-green-goodness dept.
kristy_christie writes "According to Wired News, South Africa's state-run utility giant Eskom and its international partners want to build the world's first commercial 'pebble bed' reactor, which, instead of using fuel rods, 'is packed with tennis ball-size graphite "pebbles," each containing thousands of tiny uranium dioxide particles'. To developers, the Pebble Bed Modular Reactor promises a rebirth of nuclear energy. Proponents insist that the reactor's design features make it 'meltdown-proof' and 'walk-away safe'."
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Uranium Pebbles May Light the Way

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  • Sweet (Score:5, Insightful)

    by tehdely (690619) * on Thursday November 20, 2003 @06:20AM (#7518408) Journal
    I applaud this kind of work.

    Nuclear Power, despite the cries of environmentalists, is possibly the cleanest mass power source. On a scale of power generated per ton of input material it is incredibly efficient (bested only by those power sources which require no nonrenewable input, like wind/tidal/etc.), generates no effluent or air pollution, and needs only a competent staff (and, unfortunately, security), to stay running properly.

    Nuclear plants may be prohibitively expensive to build these days, but if "pebble bed" reactors cost significantly less, then they may lead the way back towards what I view as our ideal energy source.

    It's time to give nuclear a second chance.
    • Re:Sweet (Score:2, Insightful)

      by Anonymous Coward
      Nuclear power is definitely efficient. Nuclear waste, on the other hand, is not clean, and that's the problem environmentalists have with fission power.
      • Re:Sweet (Score:5, Informative)

        by Anonymous Coward on Thursday November 20, 2003 @06:32AM (#7518448)
        However, coal power plants release more radioactive waste into the enviroment than nuclear power plants and still provide most of the power in the US.

        There's big money in keeping things the way they are. Nuclear power is so heavily regulated that it is too expensive. Thats the only reason we don't have more of it. If the other types of plants were regulated just as strictly we'd switch over as quickly as we could build them.
        • Partly true... (Score:3, Insightful)

          by pdhenry (671887)
          However, coal power plants release more radioactive waste into the enviroment than nuclear power plants and still provide most of the power in the US.

          True, if you only consider what is legally released into the environment while the nuclear plant is operating. If you consider the fission byproducts and their "disposal" (e.g. long term storage) then this isn't true. Yucca Mountain nonwithstanding, the problems associated with nuclear waste may not be worth the benefit (and I'm a nuclear-trained engineer)

          • Re:Partly true... (Score:5, Interesting)

            by mwood (25379) on Thursday November 20, 2003 @11:19AM (#7519870)
            Whatever happened to vitrification? Mix the stuff into glass, cast into handy-sized lumps, bury in moist earth, post a guard to keep the bad guys from digging it up. As deep as they want to bury it, any post-catastrophe society capable of reaching the stuff should be developed enough to figure out that it is dangerous, particularly since, unlike natural ores (which are also dangerous), the stuff will be *marked*.

            Also, we've done well with Reduce and Recycle, but how are we doing with Re-use? It seems to me that much rad"waste" is just a resource for which nobody has tried hard enough to find a use. Medicine, nondestructive testing, long-term preservation of organic matter, etc. all have uses for long-lasting sources of radiation. (I tell my kids to remember where the landfills are, because their grandchildren will want to mine them.)
            • Re:Partly true... (Score:5, Insightful)

              by Martin Blank (154261) on Thursday November 20, 2003 @01:05PM (#7520887) Journal
              Most of the re-use part of nuclear fuel is, as I understand it, prohibited by government regulation, something having to do with plutonium generation. My understanding of a possible use involving breeder reactors, though, involves using the plutonium's natural decay to enrich uranium fuel, allowing the plutonium to break down into less harmful byproducts while the uranium is enriched for fuel in the near future. This seems a more complete use of the fuel to me, and could result in less hazardous waste.

              However, use of plutonium is rather taboo for some reason -- witness the furor over Cassini's radioisotope generator, which some environmentalists claimed could kill thousands in the event of an accident on launch in 1997 or during the flyby of Earth in 1999, with one site suggesting a 10-micron particle could result in the exposure of a person inhaling it to thousands of REMs. Their argument was that the release of the 72 pounds of plutonium would be catastrophic over centuries.

              An article in a 1993 Oak Ridge National Laboratories Review states, "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. ... 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."

              Even factoring in mining -- where radioactive dust presumably goes into the air -- and disposal -- where various bits of radioactive dust and water are released -- nuclear plants produced only about a quarter of the average radiation dosage that coal plants do over their lives. I've seen the strip mines that are used to get at uranium, and while it's not pretty, it's not nearly as bad as the destruction of entire mountains in the Appalachians. There is also research going into extracting uranium from seawater for about $120 per pound, which, although about 10 times the current rate, could be more environmentally safe and could provide thousands of years of power, presuming we operated on nuclear power for that length of time.

              I'm all for nuclear energy. While I am also a proponent of renewable sources, I don't like the environmental damage caused by hydroelectric. Solar has issues of night-time electricity use, and it is reportedly a messy thing to make, with some pretty dangerous chemicals involved, not including any batteries that would be needed for cloudy days and night use. Wind has issues of reliability, and tidal generators have a range issue, not to mention that I wonder how it would affect the beaches to have thousands of them operating.

              I recognize the dangers of nuclear energy. I know that it's hard to clean up, and that there are significant security risks; I'd much rather be in a room with an exposed piece of coal than an exposed piece of reactor-grade uranium. But that piece of uranium will be useful long after the ash from the coal has been carted off and buried. It will have given off no CO2 or nitrogen or sulfur oxides during its use (save whatever transportation is used for it), and less radioactivity.

              In balance, I believe that nuclear reactors are a far better source of energy than anything else we have at the moment.
              • Re:Partly true... (Score:5, Interesting)

                by Rorschach1 (174480) on Thursday November 20, 2003 @02:25PM (#7521692) Homepage
                For what it's worth, you can get your piece of reactor-grade uranium at United Nuclear [unitednuclear.com]. The interesting part is that it's slightly LESS radioactive than the natural chunk of uranium ore I've got in my bedroom. That's about 30,000 counts/minute on my Geiger counter in direct contact, but three feet away it's almost undetectable against the background radiation. I keep it in a small tin that blocks a large portion of the radiation, and helps keep it from getting lost in the clutter of my desk.


                I don't think I'd want to carry it around as a good luck charm, though.

                • For what it's worth, you can get your piece of reactor-grade uranium at United Nuclear. The interesting part is that it's slightly LESS radioactive than the natural chunk of uranium ore I've got in my bedroom.

                  That's because the chunk of ore will be far from pure uranium, it will contain traces of the decay products - such as polonium, radium and radon, all of which have shorter half lives (and are hence more radioactive).

                  Glad to hear that you're taking basic safety precautions though.

                  Best wishes,
                  Mi

              • Re:Partly true... (Score:5, Interesting)

                by mwood (25379) on Thursday November 20, 2003 @02:33PM (#7521787)
                Well, reprocessing "spent" fuel to get the unconsumed U back was what I meant by "recycling". It's a good idea and, if we can do it right, we ought to do it.

                By "reuse" I meant take the stuff that's no good for large-scale power reactor fuel and use it for something else. Like sterilization or probing metal castings for flaws. And if all else fails, someone else pointed out that the gunk still produces quite a bit of heat -- not enough for a commercial electric plant, but maybe enough for something that has to sit in an inaccessible place for decades without resupply.

                Hydro...yeah, come to Indianapolis and ask the old-timers where Dandy Trail is. (It's at the bottom of a reservoir now, not such a fun place to go anymore.)

                Stuff like solar, wind, tides, etc. can be stored as compressed air, used to extract hydrogen from water, pushed into high-performance flywheels, etc. so batteries are not necessarily needed.

                Tidal generation might actually be a good thing for e.g. the barrier island systems of the North American east coast. Hmmm.

                Oh, and coal mines are hard to clean up too. Ask about all the acid runoff. Ditto the mines that produce whatever materials go into your favorite alternative energy source.

                We could boil all this down pretty compactly: energy production is messy and dangerous. So's millions dying of cold or fighting the wolves off with sharp sticks, though.
          • Re:Partly true... (Score:3, Interesting)

            by Anonymous Coward
            You are mistaken.

            A nuke plant produces about 6.5 ounces of waste per minute, or about 20 tons per year for a typical thousand megawatt plant. A single coal plant produces about 10 tons of waste per minute, or about 300,000 tons of waste per year. Since the radioactives don't burn, they get concentrated in the ash. That thousand-megawatt coal plant releases about 20 tons of uranium and thorium (alone) from the 4 million tons of coal it burns.

            All waste is an "emission", whether it literally goes up in sm
      • Re:Sweet (Score:5, Insightful)

        by gl4ss (559668) on Thursday November 20, 2003 @06:49AM (#7518492) Homepage Journal
        the problem that most people have with nuclear power is tchernobyl(or similar catastrophy that would release radioactivity to a wide area).

        'most people' don't know even the basics of how the energy is generated, all they know is that the place can explode and then there's going to be 3eyed fishes. the problem is that even if it's a 'failsafe'(won't explode) plant there's going to be hell explaining it to the people who are against nuclear power for mainly emonational reasons(and assume that people defend nuclear power for similar reasons because they hate the environment or something silly like that, or just for pure greed).

        it's like that old joke... "what we need nuclear power for? i only need electricity"(dunno how the variation goes in english actually, but you get the idea).

        around here there's a need for another reactor(industry needs the juice) but there's quite many people who are against it, yet they don't complain when we need to buy the same amount of electricity from russia(that is generated by nuclear reactor there, just over the border, at lower safety standards than what would be in place if the reactor were on our side of the border).
        • by cr0z01d (670262) on Thursday November 20, 2003 @08:36AM (#7518796)
          Chernobyl had a lot of things that were just wrong.

          The reactor increased in efficiency as temperature increased. This is a nice little feedback loop. Most reactors lose efficiency as temperature increases, meaning that it is difficult to try and overload the reactor, even on purpose.

          The reactor was designed to be cheap, and it did not have a dome. Domes contain radioactive material very well. Tests have shown that an aircraft hitting a dome would hardly scratch it.

          As another cost-cutting measure, the reactor didn't have any good backup power. It may seem silly to have a power plant that needs power, but nuclear power plants do need power to start up and in case of emergencies. Western plants have batteries and generators.

          As if these technological blunders weren't enough, some bonehead transfered control of the power plants from the ministry that designed and built them, where all the trained personnel are employed, to the ministry of energy. There are reports of operators sitting on the control board and people showing up to work drunk.

          Basically, in 1986, the Chernobyl reactor demonstrated a bunch of "don'ts" to a world that should have already known.

          There will always be technology out there that can be misused. The amount of that technology will only increase. Do we ban knives because people get stabbed? Do we ban nuclear power because a couple of Russians cut costs?

          The 'ball' nuclear reactors are basically foolproof. You put a bunch of balls next to each other and you get heat. This is not weapons grade Uranium.

          I only see one problem with nuclear -- the small amount of waste that is generated needs to be handled properly. It can be done, but it just has to be done right.
          • Another problem, it was also a totalitarian state with no press freedom.

            The press is essential to things like safety. In the UK, someone blew the whistle on results being falsified at Sellafield. BNFL immediately sacked 5 staff.

            Let's say hypothetically BNFL hadn't, and just decided to cover it up, and then the press had found out about it - the uproar against the power industry would have been massive. Then, if government did nothing that would have damaged them.

            The totalitarian equivalent is - nuclea

          • When the Three Mile Island reactor had its partial core meltdown, note that there was still enough safety margins active that its radioactive release was very small indeed. It definitely helped that the reactor was inside a strongly-built containment building, which essentially confined the radioactive release.

            Since Chernobyl had NO containment structure, when that reactor's fissile material pile exploded there was NOTHING to stop its release into the atmosphere.
          • Just for your info (Score:3, Informative)

            by Skuld-Chan (302449)
            Chernobyl is also a good example of a RBMK reactor which is a unique design in that it is graphite rod moderated. The less you cool it the more efficent it gets - what is called a "positive void coefficient" - after Chernobyl many of the same RBMK reactors were fitted with many safety systems including containment. They still don't meet western safety standards, but there are several still in operation today - some of them are even connected to Europe's grid and producing electricity continent wide as a wri
        • by BigBlockMopar (191202) on Thursday November 20, 2003 @12:08PM (#7520367) Homepage

          the problem that most people have with nuclear power is tchernobyl(or similar catastrophy that would release radioactivity to a wide area).

          I'm glad you mentioned Chernobyl...

          'is packed with tennis ball-size graphite "pebbles," each containing thousands of tiny uranium dioxide particles'... Proponents insist that the reactor's design features make it 'meltdown-proof' and 'walk-away safe'."

          ... because apparently these people haven't learned anything from it.

          The most important lesson of Chernobyl is that graphite burns. So if you lose control of this thing, it will catch fire. And the fire will spread radioactive decay daughters all over the place.

          I am a big proponent of nuclear power, but only of one design: CANDU (CANadian Deuterium-Uranium). It's inherently impossible for it to melt down. It uses U-238 (natural uranium, in the form of "ceramic" pellets of uranium dioxide) which is NOT capable of a chain reaction without a heavy water moderator. (Heavy water is just water where the hydrogens have neutrons. Non-radioactive, naturally occurring, and just slightly heavier than normal water.)

          As a result, if you lose control of a CANDU reactor, the reactor will overheat. Pressure will build up in the heavy water system until something breaks. The moderator will escape as steam, and since the fuel is essentially non-water soluble, with only extraordinarily small trace amounts of radioactive materials. With no moderator, the chain reaction stops, and the reactor cools down. This process occurs as a result of the laws of physics; in other words, Chernobyl cannot happen at Pickering or Darlington even if all the control systems fail or someone goes to extraordinary lengths to circumvent them.

          The other great lesson is not to let boobs run the reactor. All nuclear power programs have had problems with this in the past; a "walk away" approach simply encourages this.

          • by joib (70841) on Thursday November 20, 2003 @12:58PM (#7520814)
            Incidentally, almost every power producing reactor in the western hemisphere is water moderated. And, discounting RBMK and their ilk, also in the rest of the world, for that matter. As you say, water moderation means that if the coolant boils off the chain reaction will stop. CANDU is in no way unique in this aspect. The problem is that the fuel will continue to generate a significant amount of heat even after the chain reaction is stopped, because of the radioactive decay of very short-lived fission products. This heat is enough to melt the reactor core if it's not cooled. This is essentially what happened at three mile island. That's why all nuclear power plants have all kinds of emergency power supplies etc. so that they can continue cooling the reactor after they shut it down.
          • The pebble reactors achieve the same effect using a different design principle.

            Each pebble is a sphere.

            A large number of spheres are arranged in a pile.

            The density of the uranium is a function of the radius of the spheres.

            Like most things, the pebbles expand as they get hot.

            In turn, this creates a negative feedback loop which should prevent a catostrophic failure.
    • Re:Sweet (Score:2, Informative)

      by SteveAstro (209000)
      On a scale of power generated per ton of input material it is incredibly efficient (bested only by those power sources which require no nonrenewable input, like wind/tidal/etc.) Possibly not true, because for the same energy output you need a lot more material and maintenance with the "renewable" systems - a gigawatt of wind power would be 100 10MW windturbines - and 10meg windturbines would be VERY big. Steve
  • by Tim C (15259) on Thursday November 20, 2003 @06:26AM (#7518426)
    It's how to handle the waste. That represents a real engineering challenge - some of that stuff is going to remain toxic for tens of thousands of years. Not only does it have to be stored safely and securely, but you have to work out some way of marking it so that should anyone stumble across it in a couple of thousand years, they understand not to touch it. The amount languages and cultures change, you can't just write on it, and even things like skull pictures could be interpreted as meaning "burial chamber - archaelogists, get digging!".

    That said, I'm not against nuclear power (from fusion) per se. Of the options we have, it's one of the best at the moment. "Alternative" power sources need a lot more work, and fusion, whilst extrememly promising, just isn't practicable yet (unless I've missed a major breakthrough in the last couple of years). I'm just pointing out that there are still other problems that need to be addressed.
    • by Znork (31774) on Thursday November 20, 2003 @06:49AM (#7518489)
      The solution to that is simple. You make new fuel of the waste. The technology to do it already exists, so instead of using a miniscule amount of the fuel and then considering it 'spent' and trying to store that highly radioactive material you can run it through a breeder reactor and use it again. And again. And again. And again.

      That way you dont get a lot of waste, and you get many many times more use out of the fuel you have.

      Nuclear waste is a problem that already has a solution, and a solution that is ecologically sound and very much in line with recycling and reuse.
      • Indeed, reprocessing spent uranium is the best solution, both from a commercial and an environmental standpoint. However, re-enriching uranium is banned under international treaty, since the uranium could then be used to make nuclear weapons. Yet another example of why sometimes there are non-technical considerations in a seemingly technical problem.
        • by Znork (31774) on Thursday November 20, 2003 @07:17AM (#7518568)
          As far as I know there are no international treaties banning breeder reactors; the bans that exists in the US for example, are internal to the country.

          Maybe it's time to reconsider those bans, as it is becoming quite apparent that there is no near term solution to the energy problem apart from nuclear energy and there is no other good way to handle nuclear waste.
        • However, re-enriching uranium is banned under international treaty


          I would be very surprised if this is true, care to provide some links? I have had dealings with BNFL - British Nuclear Fuels Limited. They carry out this reprocessing of spent Uraniaum on facilities less than 50 miles from where my parents lived all their lives.
      • The problem in this field is that there are solutions that look good in theory, but there bump up practical issues when you start implementing them. And once practical issues come up, then you need to assure that people don't start cutting corners.

        That's the main problem with nuclear energy, not that it is not technically sound, the problem is that people are much too inclined to ignore engineers and cut corners. Especially for profit.

        I would like to see more research into accellerator based fusion. The

      • The problem with reprocessing is that

        a) it's quite messy, dangerous and difficult to do safely. Not impossible, but neither easy nor cheap.

        b) You turn a lot of moderately radioactive waste into a smaller amount of highly radioactive waste (purified fission products) and some reusable fuel (some of which is plutonium, which raises certain accounting and security issues) and in the process create a whole lot of medium level waste (irradiated machinery and such).

        Neither is insuperable, but recycling is not
    • Check out this page [pbmr.com]

      It would seem, critically, that the waste can be stored on site for 40 years, does not need to be transported elsewhere, and is inherently more stable than the waste in a typical water reactor.

    • by chthonicdaemon (670385) on Thursday November 20, 2003 @06:59AM (#7518518) Homepage Journal
      That's kinda the point of these pebbles. I have seen a lot of work on this reactor technology, and waste is an important concern. The Fuel spere pebbles safely encase the nuclear material -- you can handle them and throw them around a bit. "The silicon carbide coatings that surround the uranium fuel particles within the pebble form a miniature pressure vessel. This pressure vessel provides a highly efficient barrier against the release of fission products during operation." - from the linked-to [pbmr.com] site
  • by Dancin_Santa (265275) <DancinSanta@gmail.com> on Thursday November 20, 2003 @06:27AM (#7518431) Journal
    I think it is important to move away from the current reliance on fossil fuels as quickly as possible and move towards nuclear power generation as the only realistic sustainable alternative power generation scheme.

    Many of the world's problems exist because of the small patch of oil-soaked land out in the Middle East and the lack of trustworthy stewards of those fields. With Gulf War II over and those oil fields finally in the hands of Western democracies we may see some improvement in global stability vis a vis the opening of OPEC to its main customers. However, because we continue to rely on oil as our primary power source we will likely continue to have problems as the oil fields run drier and drier.

    It is good to see Africa (of all nations!) take the lead in this new system of nuclear power generation. Older systems like the ones in Canada and France are fine, however it would be a stretch to say that they are perfect. There is plenty of room for improvement in those power plants. This usage of uranium pebbles is one such improvement, but there are more.

    It is a problem that people would be willing to block the development of Africa because they object to the usage of these newer power systems. Especially so because for the most part the same protesters unwittingly reap the benefits of their own country's nuclear power generation systems.
    • Are you saying that the US is a "trustworthy steward"? Maybe from the point of view of a Patriotic American, since it's a bit like trusting yourself.

      Global instability over the past, oh... how about all of recorded history, has been about power struggles (that usually have very little to do with oil). Imperialism, world wars, revolutions, slave revolts, coups, violent protests, terrorism - all these examples of instability are caused by struggles for power (freedom being a power). Oil may seem like the cau
  • Waste disposal (Score:4, Insightful)

    by Space cowboy (13680) on Thursday November 20, 2003 @06:28AM (#7518435) Journal
    The perennial question is one of waste disposal. It's all very well having a realtively clean source of energy right now, but if you have to guard against people getting hurt for X years, where X is a very large number...

    They claim the graphite and silicon carbide around the pebbles will keep it sealed for ~ 1 million years, which is impressive. It'll be interesting to see if humanity is around in ~1 million years ...

    It also produces about 19 tons of radioactive waste (in the form of these coated pebbles) every year. That's going to be some landfill site, if the technology takes off...

    Simon.
    • Re:Waste disposal (Score:5, Informative)

      by netwiz (33291) on Thursday November 20, 2003 @06:41AM (#7518471) Homepage
      19 tons of heavy metal radioisotope doesn't take up much space. These elements are quite dense.

      I remember seeing a demo of this stuff in school.. It's so safe to use in a reactor it's crazy; they referred to it as "walk-away" safe. Lose _all_ cooling in the core, leave it over the weekend, fix it on Monday. It was going to bring about a revolution in safety WRT nuclear power generation. It's nice to see this finally coming to fruition.
    • People blather on and on about long-term storage of waste, and how it's got to be out of everyone's hands.

      The key error in this thinking is the assumption that the site has to be stable.

      I propose a deep sea trench, like the Marianas.

      1) The depth of the trench will provide more security than can ever be achieved on land, given the pressures of miles of ocean water.

      2) The waste will have to be packaged in non-water-soluable form. These ceramic pebbles seem to be just the thing.

      3) Any waste rel
  • -1 Flamebait (Score:4, Insightful)

    by Dancin_Santa (265275) <DancinSanta@gmail.com> on Thursday November 20, 2003 @06:33AM (#7518452) Journal
    Reading some of the comments in this article, I have to wonder when 'Geek' and 'Nerd' transformed into 'Reactionary Luddite'.
  • by Anonymous Coward on Thursday November 20, 2003 @06:35AM (#7518457)
    "Africa's state-run utility giant"... WTF?
    Africa is not a state or a single country for that matter, it's a continent made up of many states. Please be specific, ppl are very ignorant about this, just like many think that all africans speak the same langauge (there are over 200 langauges in Nigeria alone for example).
    • The sheer ignorance of the post also shocked me. Of course they meant South Africa, but c'mon...

      It should be high-school knowledge that culturally and genetically, there is more variation in Africa than in the entire rest of the world, by a huge factor. It's easy just to lump this huge, seething continent together into an amorphous lump, but it's very far from the truth, which is that even a small part of a country like Nigeria has measurably more human variety than anything we're used to.

      Ehrojue, bioju
  • I hate ignorance! (Score:5, Informative)

    by Rico_za (702279) on Thursday November 20, 2003 @06:51AM (#7518494)
    Africa's state-run utility giant Eskom
    I'm going to pop a vein! Afirca is not a country, it's a continent [reference.com] . South Africa, the country where Eskom resides, is a country in Africa (easily confused with South America by Americans. South America is a continent south of North America, the continent with three different countries on it, including the USA). There are 54 independent, different countries in Africa, each with their own government. Africa is not simply a big ol' jungle where everyone speaks Swahili (only 50 million of the more than 700 million people in Africa speak Swahili). /rant
    OK, now that I got that off my chest: Eskom has been talking about this for a while now, and they are facing some resistance to the idea. The problem being the general conception that "nuclear is evil".
    • South Africa, the country where Eskom resides, is a country in Africa (easily confused with South America by Americans. South America is a continent south of North America, the continent with three different countries on it, including the USA).

      Er, so it isn't ignorant to confuse a Slashdot story poster with "Americans"?

      I've never confused South America with South Africa, nor has anybody I know.

    • North America, the continent with three different countries on it, including the USA).

      When you're done correcting the original poster's grotesque ignorance of geography, you might spend a little time correcting your own. There are ten nations on the North American continent. The seven you forgot are: Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama.
  • by lostnihilist (679855) on Thursday November 20, 2003 @06:52AM (#7518501)
    We (USA in the 90s) promised two of these (or very simiar to these) to North Korea so that they a) could have plenty of power and thus might spend money on economic growth/feeding their people and b) couldn't develop nuclear weapons from the material. but oops, congress wouldn't approve it. Now look where we are with them. big mistake

    though many popular activists site environmental reasons as opposition to nuclear energy, disposing of nuclear waste really isn't that difficult. Most scientists (at least those in the field) object to nuclear power because of the potential of the spread and proliferation of weapons. while environmental issues ARE a concern (there's always some governmental dweeb that screws things up), it is something that can fairly easily be isolated given the proper precautions. Part of the reason that these reactors get so much attention is that these same experts have much fewer qualms with them precisely because they are so much more difficult to make weapons-grade uranium/plutonium from. (i cite Howard Margolis, Dealing with Risk as a decent summary of this topic).
  • Africa isn't a state (Score:4, Informative)

    by Bozovision (107228) on Thursday November 20, 2003 @06:52AM (#7518503) Homepage
    For you geographically challenged people. Africa is a whole continent. Like North America, South America and Australia.

    South Africa is a country. It's at the tip of Africa. You'll never guess where it is in Africa.

    It was a British Colony, but gained independence about 55 or so years ago, and promptly began to institutionalise pernicious racially-based discrimination. It was called Apartheid. After a long struggle (40 years) the white people agreed to share power and democratic elections took place. Nelson Mandela (you may have heard of him) was elected president.

    The economy of South Africa is split - there's a strong first world component, and a large third world component. The first world component rivals the economies of Europe and the USA in sophistication - though it's much smaller. The third world component - i.e. subsistence farming, and subsistence trading - involves many more people. Unemployment rate is high - a few years ago it was 40%. Not sure what it is now. HIV/Aids rate is probably the highest in the world - hitting around 10% of population. Some places have rates as high as 40%. The current government until recently has ignored the problem.

    Eskom is a world-class power utility. They have existing nuclear reactors, which were learning grounds for the Apartheid state in their quest for nuclear weapons. (Ten or so years ago South Africa admitted that they had nukes, and then destroyed them. Thank you Nelson Mandela and South Africa for making the world a safer place.)

    It's questionable whether South Africa needs more nuclear power plants but Eskom has traditionally had a strong technocratic streak. (I was an employee a long time ago.) SA is rich in coal and natural gas.

    I personally think that the money could be better spent given South Africa's problems - the only justification would be to export the technology. And maybe greater access to nuclear expertise is not what the world needs.

    Jeff Veit
  • by Savage-Rabbit (308260) on Thursday November 20, 2003 @06:58AM (#7518517)
    This technology has been around for at least 30 years. The Germans even built an example pebble bed reactor at Hamm-Uentrop which has led to the technology being heavily criticized by enviromentalists. Normally I would be hesitant to swallow raw what enviromentalists feed onto the internet, especially the religiously fanatical German anti nuclear lobby, but in this case their claims are reenforced by the fact that their opinions of pebble bed reactors are shared by the German state who shut the Hamm-Uentrop plant down in 1989 after the management covered up serious problems with the reactor. The whole affair has led the People of Hamm-Uentrop to start a citizens group [thtr-a.de] which among other things aims to start an Information exchange with the people of South so that the Africans can take into account the German experiences before one of these things gets built in their back yard. Feel free to call this a troll but with so many people singing the "See!! I told you nuclear is safe" psalm here I figured the other side of the coin deserved a mention.
    • This technology has been around for at least 30 years.

      And it is possible that it has improved in that time.
      • by Savage-Rabbit (308260) on Thursday November 20, 2003 @08:06AM (#7518685)
        No not really, the parties behind the S-African reactor are the same ones as were behind the Hamm-Uentrop fiasco, which by the way is only 13 years old. And the Germans at least have significantly scaled down their interest in the technology. By the time construction started Hamm-Uentrop drew on 20+ years of research and testing. Even so took 3 times as long to build as planned, it went way ahead of budget and due to amont other things fuel handling problems never functioned 100% reliably. So if the S-African reactor is based on German PB-reactor technology which has not evolved much since Hamm Uentrop due to lack of funding I rather think these people are trying to restart development of a troubled technology in a place where they think resistance will be weaker. They are betting the S-Africans will allow them to do something that would have the Europeans picketing by the thousands at the construction site faster that you can say "pebble bed".
    • The basis for this technology has been around for at least 30 years, as you would know if you read the background [pbmr.com] on the site. The PBMR is not the same technology as the AVR or THTR at Hamm-Uentrop.

      The THTR reactor was not closed due to technical problems. The problems it experienced were related to the loading of fuel, an issue addressed by the PBMR. Even Greenpeace admits regarding the THTR "In 1989 the reactor was permanently closed due to both economic and political reasons."

      Whenever the issue of pebble-bed reactors has been discussed there has been allusion to "problems" in all reactors produced so far (in Germany, Japan and the US) -- without indicating that none of these reactors have been closed down for safety reasons! The biggest problem with these reactors so far has been getting them to reliably and economically perform their purpose.

      As for information exchange so that South Africans know whats getting build "in their back yard" - we have a strong anti-nuclear lobby already. Unfortunately we also live in a country where 16% of the populate are illiterate and only 25% have completed secondary education -- so just how do you think it is possible for the public to make an educated decision on how long our coal reserves are going to last, whether a particular incarnation of nuclear technology is better or worse than pumping out greenhouse gasses, and what our electricity requirements are going to be in 2010?

  • by Anonymous Coward on Thursday November 20, 2003 @07:00AM (#7518524)
    Such reactors are not new, e.g. there was/is one in Hamm-Uentrop, Germany called "THTR 300".

    Building started 1970, reaction started 1983, shut down 1988, disassembling started 1991.

    Its output was 308MWe, so I assume it was not just a toy.

    AFAIK they had problems with the moderation and breaking of the balls.

    Nothin' new, actually.
  • by Powercntrl (458442) on Thursday November 20, 2003 @07:01AM (#7518527)
    Seriously. I hate buying gas. Would be nice not to have to buy gas again - ever.

    Oh sure, what happens if I get into an accident? Well, that's why you build the reactor compartment the same way as an airplane's black box, if that can survive a plane crash, a car crash should be a walk in the park.

    There's a problem with terroists getting uranium and making dirty bombs you say? Not a problem either! Just outlaw radiation suits so anyone that opens the reactor is instantly nuked like a frozen chicken pot pie. Of course, that means no more tinkering with your car, but would you really miss it if you never had to buy gas again?

    I want my nuclear car, damnit.
  • by phooka.de (302970) on Thursday November 20, 2003 @07:27AM (#7518590)
    It's been done before. In Germany. It was called "schneller Brueter". It never went operational.

    The rationale was that it would be vatsly more efficient. In practice, those "balls" were harder to control than the normal rods. In testruns they would jam as they were processed in the facility.

    So it's neither the first time this is being built, nor is it the answer to all energy-questions in the world.
  • Sellafield Beach, Cumbria, UK, obviously.


    Just go here [iop.org].

  • by lateralus (582425) <yoni-r.actcom@com> on Thursday November 20, 2003 @07:41AM (#7518626) Journal
    "Uranium Pebbles" Sounds like a great name for a breakfast cereal. Makes your teeth glow!
  • by salesgeek (263995) on Thursday November 20, 2003 @08:22AM (#7518728) Homepage
    Nuclear power is a subject that is near and dear to my heart having spent a part of my life working in the industry for Uncle Sam. There are three real issues with Nuclear power that keep it a hot button issue:

    * Proliferation of WMD. Widespread use of nuclear power creates huge opportunites for people to get their hands on fissile material or highly radioactive material. A "dirty bomb" consisting of a few hundred pounds of waste and a few hundred pounds of explosives could do incalcuable damage. Nuclear power and nuclear weapons are NOT high tech. It's technology from the era of propeller airplanes, black and white movies, radio and vaccum tube electronics.

    * Economics: widespread use of nuclear power would render a large sector of the global economy useless. There is a substantial interest in keeping the world dependent on our dwindling supplies of fossil fuel -- remember suply and demand? What happens when the supply decreases and demand increases? Many nations, corporations, and ultimately individuals stand to get very, very rich by monopolizing the resource (OPEC is a benign example compared to what we'll see in the future)

    * Finally, there is a more practical issue: much of today's power challenges are demand side issues. Most people are blissfully unaware of what it takes to supply a couple of killowatt hours to their homes and especially businesses.

  • by advocate_one (662832) on Thursday November 20, 2003 @08:27AM (#7518751)
    If I'm not mistaken, hot Graphite burns when exposed in air (and this stuff is at 900 deg Celcius plus and under pressure, 8.4 Mega Pascals)...... and we've already had one too many of those "burning Graphite" disasters already... Windscale back in 1957 [british-energy.com], and they changed the name to get around the public memory of the original disaster.
    Sorry, but I have no faith in any process which combines a combustible material run at high temperatures and relying on keeping air out...
  • by craenor (623901) on Thursday November 20, 2003 @08:44AM (#7518831) Homepage
    I would like to see the Department of Naval Reactors, in conjuction with the Department of Energy and the U.S. Navy be contracted to design, build, man and run nuclear power plants for commercial power consumption. Then turn around and sell that power to the utilities companies.

    They already buy power from one another on a regular basis and the more importantly the track record of the U.S. Navy in Nuclear Power useage is impeccable. The training program, security, design protocols, safety record and tradition of excellence make them the only people in the world I would trust 100% to run a nuclear power plant.
  • Fires? (Score:5, Interesting)

    by RayBender (525745) on Thursday November 20, 2003 @09:11AM (#7518917) Homepage
    I have a question about these reactors: what happens when air gets into the reactor vessel? Don't you get a pretty big fire? It's notable that both Sellafield and Chernobyl were graphite-moderated reactors that ended up with graphite fires. Graphite is actually a difficult material to use in a reactor, it stores up energy in the lattice that can then be released at unpredicatble times. "Wigner energy" [antenna.nl]. The link provides some interesting information, but take the nuclear-phobic tone with a grain of salt.

    Another problem with pebble-beds is that they use natural or low-enriched uranium in a cycle where the fuel passes through the reactor relatively quickly and continuously (no big refueling outages). This makes them ideal Plutonium factories, which is obviously a matter of concern. Most of the graphite-moderated reactors ever built were designed primarily to produce Plutonium, including the Soviet RBMK's and the piles at Sellafield.

    Don't get me wrong - I'm all for nuclear power for many reasons, but I'm not sure the pebble bed is that much of a breakthrough, and I don't think graphite is the best choice of material. And any operator of a plant in trouble that went home for the weekend should be shot. "Walk-away safe" my ass.

  • Xtra useage (Score:3, Informative)

    by WindBourne (631190) on Thursday November 20, 2003 @10:31AM (#7519428) Journal
    While I do think that nuclear power will make up more energy in the future, I also think that with a bit of inginutity we can lessen the need for plants. Basically, by storing excess power, we can add 33% to 100% power to the plant. This would also allow for alternative energy input. One approach is via 2 water resoivors with hydro power and simply use excess power to pump the water back.
    Perhaps a better way is for us to spend money on high thermal storage with salts. Ideally, we would do small units and spread them out to provide emergency power in local areas (think hospitals, anywhere on the coast esp, Florida, Texas, and California).
  • by pvanheus (186787) on Thursday November 20, 2003 @11:03AM (#7519723)
    I've done quite abit of research on this PBMR design, and specifically the economics of it.

    The latest cost estimates for building a 'demo model' is about R10 billion, and will be completed in 2008. That's about 5 years over schedule, if my memory serves me. The PBMR company ltd., not Eskom directly, is building this thing. That company's shareholders are currently Eskom and BNFL. Since BNFL is currently being restructured, as the cleanup costs for Sellafield have forced it into bankruptcy, Eskom is the only real player. (US company Exelon was involved, but now they've pulled out)

    R10 billion is way more than Eskom can afford. Therefore they are looking for external partners to invest in the project, and that depends on selling PBMRs being commercially viable. Now, nuclear electricity is very expensive - one of the reasons that the world nuclear industry is in the doldrums. There was a paper in the South African Journal of Science about this some time back, which examined the economic models Eskom was using for PBMR, and found them to be wildly optimistic.

    So if the economics are so screwy, why is Eskom pursuing this project? No one really knows, but I'm sure the fact that the chairperson of Eskom, Reuel Khoza, effectively controls one of the main contractors (IST), through a holding company has got something to do with it. Even if the PBMR project fails, Khoza and buddies will end up much richer. IST got handed a R260 million (?) contract, which is about as much as its previous annual turnover. Their shareprice went through the roof, making Khoza and co's share options worth a lot more.

    Besides the Reuel Khoza link, there is an argument to be made that difficult-to-manage technologies like PBMR will be an incentive for the government to keep a much more centralised and powerful Eskom around for much longer. Eskom is currently facing deregulation and restructuring, and this Apartheid-legacy parastatal needs to justify why it still needs to exist. Experience in other companies has shown that deregulating nuclear power is very hard, so PBMR might be a bargaining chip in the complicated game around Eskom's future.

    Funnily enough, the Wired article and the Slashdot responses have all the hallmarks of engineers - in love with 'sexy technology' while pretty much ignoring the bigger political/economic picture.

    Peter

  • Go nukes! (Score:3, Interesting)

    by mwood (25379) on Thursday November 20, 2003 @11:07AM (#7519756)
    Sounds good so far. Maybe we can begin ignoring those for whom antinuclearity is a religion, when they point to _The China Syndrome_, and move on.

    I *would* like to suggest that, in a setting with such grave consequences for error, engineers tell themselves daily that "meltdown-proof" really means "all failure modes are unknown." I think that would lead to a healthier attitued toward the whole thing.
  • by Xeger (20906) <slashdot@NoSPaM.tracker.xeger.net> on Thursday November 20, 2003 @02:08PM (#7521523) Homepage
    Direct quotes from the PBMR web page:

    "This turbine forms part of the High-pressure Turbo...Next, the helium flows through the Low-pressure Turbine, which is part of the Low-pressure Turbo Unit...The helium is then cooled in the inter-cooler. "

    In other words: they're going to build a twin-turbo nuclear reactor with an intercooler.

    I didn't see any mention of chrome exhaust tips, cupholders, cruise control or racing stripes, but how far behind can these things possibly be? That's gonna be one decked out nuclear reactor...I wonder what kind of stereo system they'll put into it?

    Perhaps for the opening ceremony I'll fly to Africa and plant a "Type R" decal on the side of the reactor building.

What this country needs is a good five dollar plasma weapon.

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