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Science

Mother Nature Does Nuclear Power 62

Posted by michael from the global-warming dept.
wjwlsn writes "Back in the day (2 billion years ago), even before the time of iron men and wooden reactors, Mother Nature had mastered nuclear power. She built a passively safe system at Oklo that had fully automatic control and built-in waste containment, and operated it safely for about 150 million years. Now researchers at Washington University in St. Louis have deduced the operational characteristics by examining the isotopic composition of xenon contained in rock samples taken from the reactor site. More details at Eurekalert."
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Mother Nature Does Nuclear Power More

Mother Nature Does Nuclear Power

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  • That brings back memories. (Score:3, Funny)

    by Anonymous Coward on Friday October 29, 2004 @07:25PM (#10668705)
    In my college chemistry class we had this great textbook, and it had a small two page aside on this event.

    It's not wrong to wistfully remember chemistry texts is it?

  • Not just 2 billion years ago. (Score:5, Informative)

    by noselasd ( 594905 ) on Friday October 29, 2004 @07:26PM (#10668709)
    Even today mother nature does nuclear power [wikipedia.org]

    • Re:Not just 2 billion years ago. (Score:5, Funny)

      by n6mod ( 17734 ) on Friday October 29, 2004 @10:18PM (#10669577) Homepage
      I've always wondered about this in the context of Berkeley and Santa Cruz's "Nuclear Free Zones".

      'You! With the solar panel! Don't you know this is a Nuclear Free Zone!'
    • As a matter of fact "Mother Nature (Mother Gaia, Mother Goose???)" still operates the largest nuclear reactor on the planet and I doubt any man-made reactor is ever going to surpass it in Terawatts or size: You are standing on it, it is below your feet! It is the core of the planet. If it weren't for the decay of radioactive isotopes under our feet the oceans would have frozen up billions of years ago. Ground-thermal heat is not a holdover from the planet creations, that energy has long since been dissipate

  • Time spans (Score:4, Insightful)

    by Richard_at_work ( 517087 ) on Friday October 29, 2004 @07:28PM (#10668729)
    Humans really do not have an adequet grasp of timespans when it comes to geology or similiar such things. This happened over 150million years, didnt cause the end of the world, and life went on around it, whereas today we cant run powerstations without people declaring that they will bring about the end of hte human race, anything that comes within a hundred miles will die of radiation poisoning. This shows that the world can cope with nuclear waste, and it can cope pretty damn well. But then the world has always had to deal with bigger issues than anything humanity can throw at it anytime soon.

    We have been around for 50,000 years, give or take. The earth has been around for 4billion years. Give nature some credit.
    • Thank you. I wish I had mod points today. . .

    • Re:Time spans (Score:5, Insightful)

      by Baron_Yam ( 643147 ) on Friday October 29, 2004 @09:40PM (#10669393)
      To quote George Carlin, "The world isn't going anywhere... we are!"

      Just because it's unlikely we'll screw up the environment enough to sterilize the planet doesn't mean there isn't a significant chance we'll screw it up enough it kill off humanity.
      • I think it would be very hard to kill off humanity, even if we tried. Our numbers and our spread are the reason. It is difficult to think of a scenario in which everyone from Siberia to Trinidad, from Tibet to Cape Town, and from Chile to Nova Scotia is killed off, without at least a few surviving somewhere.

    • Re:Time spans (Score:2, Interesting)

      by Anonymous Coward
      Whats killing people today is not nuclear power. Its not using nuclear power thats killing people. Consider that a 2.7 mpg [prospect.org] increase in the fuel efficiency of automobiles would eliminate the need for foreign oil. Considering that the average car has a fuel efficiency of about 22 mpg [bts.gov], and that oil accounts for about 7% [clean-energy.us] of US energy production, if all the oil that was being used for electricity was nuclear instead, we would be independent of foreign oil. If that were the case, our interest in the Middle Ea

      • Re:Time spans (Score:1, Informative)

        by Anonymous Coward
        Faulty argument, but conclusion is true. This article [grinningplanet.com] states that the US electricity is 2% by oil and this article [whitehouse.gov] states that 2/3 of all oil is used in cars. We can assume that the other 1/3 is for electricity (with trivial amounts going to other petroleum products). We can also note that the oil percentage has gone up greatly since California had its energy crisis (and decided to make tons of oil fired plants). You can do the math, but your conclusion appears to be true. If we lost the 20% of power b

    • Re:Time spans (Score:5, Insightful)

      by jfengel ( 409917 ) on Saturday October 30, 2004 @12:47AM (#10670260) Homepage Journal
      This is true. But the existence of a safe nuclear reactor doesn't mean that any particular power plant is safe. The plants currently in existence are run by people, are located within tens of miles of human homes, and are vastly complicated pieces of machinery. When they're done they leave radioactive bits lying around; even self-contained they're potentially dangerous for thousands of years.

      You're right: if somebody were to mimic nature's design by building a totally safe and self-contained a bunch of know-nothing, knee-jerk environmentalists would protest against it anyway. But that doesn't imply that the same know-nothing, knee-jerk environmentalists are wrong to protest current designs.

      The Oklo reactor has a number of design advantages (as it were) over ours. For one thing it doesn't actually have to generate any power, so it can run at an arbitrarily low level and far away from anybody who might care what it does. For another it didn't have to cope with the possibility of somebody attempting to steal its fuels or attempting to destroy it hoping to cause injury.

      For a third, it didn't consider the possibility that its waste products would be a danger to anybody walking by. Our waste products must not only be sealed, but potentially people may even forget where they are, and warnings must be placed for thousands of years.

      I don't think that these problems are insoluble. I believe safe reactors can be built, the risks reduced to acceptable levels. There will be those who don't understand, and I get frustrated at them, too. But neither will I pretend that nuclear power is totally safe, especially in its present implementation. Those opposed to nuclear power are not completely off base, and it's wise to listen to the smart ones. As for the stupid ones... well, there are stupid people on every side of every argument.

      • Re:Time spans (Score:3, Informative)

        by M1FCJ ( 586251 )
        Yep, true. Apparently Oklo genereated around 100 Kilowatt (thremal). A typical nuclear reactor usually generates around 2000 NWatt thermal and 1200 Megawatt electrical.
      • ... than the radioactive rock the ore came from. The reason that radioactive materials remain radioactive for a long time is the same reason that we have radioactive stuff *at all*.
        • Except that radioactive rock is buried well away from things, and it takes a major effort to go get it. People burying radioactive waste have a tendency to go to the minimum level of effort to get rid of it. Radioactive waste at Yucca Mountain won't be buried, not in that sense: the doors will still be open until the thing is sealed. At which point we'll still have radioactive waste, and be looking for another place to put it.

          Also, I'm not convinced that nuclear waste is no more radioactive than radioac
      • >But the existence of a safe nuclear reactor doesn't mean that any particular power plant is safe.

        I can assure you that burning millions of tons of coal isn't safe.

        >When they're done they leave radioactive bits lying around; even self-contained they're potentially dangerous for thousands of years.

        When we burn coal there is no doubt that the pollution IS dangerous for thousands of years. There's no "potentially" about it.

        We need to stop looking at how safe/unsafe a new concept like this is; in

        • Agreed. The point of my post was not that coal power is da shiznit, but that those who were worried about the risks of nuclear power weren't totally off-base, as the top-level poster implied.

          I'd love to see this sort of decision made on a dispassionate basis by experts on the risks and rewards of all approaches. Yeah, right. (You'll have to forgive my cynicism; there's been a national election between my original post and now.)

  • Flaming Hydrogen Ball (Score:3, Interesting)

    by pipingguy ( 566974 ) on Friday October 29, 2004 @07:40PM (#10668806)

    Safe nukes (employ ex-sub engineers as operators at $120K/yr and run by military rules) are the best option in the long run.

    Short run, we have lots of alternatives.
  • about the X is DYING jokes? Maybe we can get the Dept of Homeland Security to sue the writers on Kreskin's behalf (that would be trademark law correct?)

    On another note, I wish X would die.

  • This is news? (Score:2, Funny)

    by Anonymous Coward
    I don't mean that the news is 2 billion years ago, but that a much larger nuclear power reactor has been known for quite some time... We scientists call it: "The Sun."

    • Re:This is news? (Score:3, Informative)

      by PaSTE ( 88128 )
      The sun is a fusion reactor, which is not remarkable by any means--if you put enough light stuff in a tight space, gravity will crush it into a fusion reactor without any sort of quirks or anomolies. What makes this news is that nature had created a fission reactor--something that doesn't just happen if you have a lot of heavy stuff in a tight space. You need enough of relatively uncommon isotopes of Uranium, something created in very, very tiny amounts in supernovae, with enough neutron inhibitor mixed i

  • Of course it does nuclear power. (Score:4, Funny)

    by FooAtWFU ( 699187 ) on Friday October 29, 2004 @11:40PM (#10669927) Homepage
    And not only nuclear power, nuclear fusion power! Take a look at the sun sometime- that's a thermonuclear reaction, right there.

    What's that? You've never seen the sun? Oh, wait... Slashdot... yeah...

    • RTFA much? Its nuclear fission, which is different from the sun (nuclear fusion). In galactic terms, fission is a relatively simple process. All you're doing is crushing a fuckton of matter into a very dense ball, adding energy (heat), and waiting for things to go boom.
      Fission, on the other hand, is a much more delicate process. You need relatively precise concentrations of a rare fissionable material (U235), and an almost exact quantity of water (the moderator in this case). Too little of either, and you

  • cool, but not a practcal method (Score:3, Informative)

    by Mr. Slippery ( 47854 ) <tms&infamous,net> on Saturday October 30, 2004 @01:05AM (#10670354) Homepage
    passively safe system at Oklo that had fully automatic control and built-in waste containment, and operated it safely for about 150 million years

    And with a 30 minute reaction cycle followed by a 150 minute dormant period, in a manner that I would guess is almost useless for power generation.

    • 30 minute reaction cycle is a pretty long time for reactions. Nuclear reactions happen in a fraction of a second. Recent tokamak reactors have been operated for around a fraction of a second to a second. Fission reactors are easier to manage but still 30 minutes of reaction is pretty substantial. If it were just a thermal expansion that stopped a reaction (google for the first man to die because if direct irradiation of a nuclear reaction) it would have taked less than a second. On the other hand, the react

      • Re:cool, but not a practcal method (Score:5, Informative)

        by turgid ( 580780 ) on Saturday October 30, 2004 @07:11AM (#10671460) Journal
        Recent tokamak reactors have been operated for around a fraction of a second to a second.

        When I visited JET [efda.org] back in 2001 they said they were achieving sustained reactions over several tens of seconds (~30) before the plasma became unstable.

        Fission reactors are easier to manage but still 30 minutes of reaction is pretty substantial.

        Well, my old powerstation used to manage several months of continuous fission reactions on each reactor, before thunderstorms or welding operations or rod-drops would cause the reactors to come off. In theory, a reactor could be run continuously for 2 years i.e. between statutory (legal) biennial outages. These were reactors designed in the late 1950s.

        Reactor design is not simple, there are many things to think about, how to moderate, how to cool down, how not to overheat (this is critical because the claddings around the elements usually get weaker when heated and crack. Once cracked, you cannot stop contaminating the water used for the reactor).

        Here in the UK most of our reactors are gas-cooled (using carbon dioxide). We have one commercial PWR in Suffolk (Sizewell B). The Magnoxes were positive-feedback systems and could, in theory, overheat, but in practice the passive safety systems prevented this. The AGRs avoid this problem (caused by plutonium resonance with the thermal neutrons and graphite moderator) by holding the graphite temperature steady, by providing the graphite with it's own cooling loop (actually the first stage of core cooling, the gas then gets passed over the fuel). In effect the cold gas coming in cools the moderator, picking up some heat (being pre-heated) and then cooling the fuel, up to about 650 degrees C IIRC.

        This all relies on active feedback systems as it is a chaotic system (in conjunction with the boilers).

        If an AGR looses forced cooling, it's quite dangerous, as there is a maximum period of time in which you must get the automatic system back up and running. Otherwise you risk ruining your boilers. The "superheat" part of the boilers must under no circumstances get wet or else they are knackered forever, and your powerstation is useless. (AGRs and the two concrete pressure vessel Magnoxes, Oldbury and Wylfa, have "once-through boilers" which are a unique British design developed specifically for nuclear reactors and used nowhere else in the world).

        AGRs are better than PWRs in another respect and that is the reactor pressure vessel is too strong to ever develop a significant breach that would result in a depressurisation and catastrophic release of radioactive substances.

        Unfortunately, Margaret Thatcher chose a PWR for Sizewell B to improve Anglo-American relations. PWRs do not have concrete pressure vessels and are more "dosey" that AGRs (and the two concrete Magnoxes). They od have a sealed containment building, whic saved the day at Three Mile Island, but this is not required in an AGR or PBMR since the pressure vessel is much stronger and the failure modes are different. AGRs can not melt their fuel even with no forced convection, as long as you keep water in the boilers.

        • You said '..."once-through boilers" which are a unique British design developed specifically for nuclear reactors and used nowhere else in the world.'

          I don't believe that's completely true. The Babcock & Wilcox designed PWRs use once-through steam generators as well. There were not too many of these plants built, though. As far as the historical US reactor vendors go, B&W had the fewest units.

          I don't know too much about AGRs. I've never understood why more weren't built... then again, I've never r
    • And with a 30 minute reaction cycle followed by a 150 minute dormant period, in a manner that I would guess is almost useless for power generation.

      Being active for 30 minutes out of 150 isn't necessarily a dealbreaker. Just build six, and have them run sequentially. Actually, build a few more, so you can deal with outages for maintenance and so forth. No biggie.

      Of course, the power output of these natural plants is pretty low--the parent is right that they're probably ultimately useless for us.

  • Big difference in agenda (Score:4, Insightful)

    by foniksonik ( 573572 ) on Saturday October 30, 2004 @03:04AM (#10670751) Homepage Journal
    In nature the reaction may have been a long term sustained process...

    We humans on the other hand want to extract energy from the reaction... which seems to be the big difference here...

    Sure you can have a sustained reaction but can you DO anything with it? Our goal has been to use it as a super steam engine that drives a generator to create electricity. Nature has no such objective...

  • Somebody tell Bush (Score:5, Funny)

    by eap ( 91469 ) on Saturday October 30, 2004 @03:16PM (#10674072) Journal
    We should invade, capture, or kill this "Mother Nature" immediately.
  • I know they're different ballparks but this might be an indirect form of support for the theory of evolution. If a nuclear reaction can occur randomly, without being initiated by an intelligent being, then why not a biological lifeform? (And yes I'm aware of the phenomenon of nuclear fusion occuring in stars across the universe.)

    • Well, I wouldn't want to let you leave without an answer from a right-wing Bible thumper. Before I begin, I should probably mention that I think "evolutionary creation" fits within a figurative interpretation of Genesis, although I don't discount the literal interpretation, either.

      The universe tends toward the lowest energy state. With radioactive atoms, fission (or fusion, if the initial conditions are right) wants to occur if individual atoms can get over the initial energy hump. People are not the lowe

      • ...although I don't discount the literal interpretation, either.

        Well, at least you're honest in your ignorance. This comment is so confused as to be unintelligible. I'll give you some leeway as your screed as written suggests that English isn't your first language.

        The universe tends toward the lowest energy state.

        Obviously, we live in different universes, you and I. In mine, the Universe tends towards equilibrium. Yours must be fscking cold at close to absolute zero, which would be the lowest energy

        • So, MrOrn, laying the smackdown on iamlucky13, sez:

          "No, it doesn't. You do realise that the concept of thermodynamic entropy as used in the second law of thermodynamics is stated as operating in a closed system don't you? Obviously not, like other Creationists, you simply ignore science and fasten onto the words you can then choose to redefine. You ignore the fact that the Earth is not a closed system, as it receives significant amounts of input from the Sun as solar energy. At a more personal level, a pre
        • I originally typed lowest exergy, but assumed that not many people know the difference between energy and exergy, and those who did should be smart enough to figure out what I meant, so I changed it. Oh well. You can't connect with everybody.

          Althought no one has confirmed it, it does appear the universe is a closed system. We haven't observed mass or energy going either in or out.

          Just an FYI: grammatical criticism is not considered a fatal wound.

          You seem very angry. Have you been saying your prayers at n

          • Althought no one has confirmed it, it does appear the universe is a closed system.

            So what? Even if this is found to be true, does the fact that Earth is covered mostly by water mean that I will not die of thirst in the Sahara Desert? We are not discussing whether life evolved in the Universe (of which we can't determine the answer), just whether the Earth (where we can answer that question) is a closed system, which it isn't.

            We haven't observed mass or energy going either in or out.

            This simply sho

  • http://peacecountry0.tripod.com/cold_fusion.htm

    Careful measurements of the calcium intake and output of chickens suggest that chickens transmute silicon into calcium.

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