Forgot your password?
typodupeerror
Power United Kingdom Science

GE To Turn World's Biggest Civilian Plutonium Stockpile Into Electricity 241

Posted by samzenpus
from the use-it-or-lose-it dept.
First time accepted submitter ambermichelle writes "GE Hitachi Nuclear Energy has proposed to the U.K. government to build an advanced nuclear reactor that would consume the country's stockpile of radioactive plutonium. The technology called PRISM, or Power Reactor Innovative Small Module, would use the plutonium to generate low-carbon electricity. The U.K. has the world's largest civilian stockpile of plutonium. The size of the stockpile is 87 tons and growing. Nuclear reactors unlock energy by splitting atoms of the material stored in fuel rods. This process is called fission. For fission to be effective, neutrons – the nuclear particles that do the splitting and keep the reaction going – must maintain the right speed. Conventional reactors use water to cool and slow down neutrons, keeping fission effective. But water-cooled reactors leave some 95 percent of the fuel's potential energy untapped."
This discussion has been archived. No new comments can be posted.

GE To Turn World's Biggest Civilian Plutonium Stockpile Into Electricity

Comments Filter:
  • Nuclear reactors unlock energy by splitting atoms of the material stored in fuel rods. This process is called fission.

    This is /. I'm pretty sure everyone here knows about fission.

  • by timeOday (582209) on Wednesday December 07, 2011 @04:55PM (#38295126)
    I am amazed that conventional water-cooled reactors are only 5% efficient. It sure casts the seemingly low efficiency factors of other alternative fuels(such as the cheapest solar panels) into a different light.
    • Re: (Score:2, Informative)

      by Anonymous Coward

      Save solar, wind and various methods of deriving hydroelectric power, all electric power generators boil down to the downright caveman primitive method of heating water into steam to drive turbines. No one has yet figured out anything better.

    • by Chrisq (894406) on Wednesday December 07, 2011 @05:08PM (#38295284)

      I am amazed that conventional water-cooled reactors are only 5% efficient. It sure casts the seemingly low efficiency factors of other alternative fuels(such as the cheapest solar panels) into a different light.

      But you are talking about 5% of the energy from a fuel with an energy density which is about 1,000,000 times the energy density of coal

      • by haruchai (17472)
        Nevertheless, it's unbelievable that after 50 years of nuke plants, we've not moved on to more efficient plants or don't do reprocessing on a mass scale. It's rank stupidity to rip up the earth to extract a fairly rare substance for 5% of its potential and then have to find safe methods to store the 95% for 10,000 years.
    • Re: (Score:2, Interesting)

      by Anonymous Coward

      It's not the thermodynamical efficiency. The usual water cooled
      reactors use slow neutrons (water slows the initially fast neutrons from
      fission to slower speeds). These reactors can only extract a fraction of available
      energy from the fuel. Liquid metal cooled reactors use heavy metal
      atoms (sodium, eutectic lead/bismuth) as primary coolant which does not slow
      neutrons. The fast neutrons are used in fast breeder reactors, which can burn
      the fuel more thoroughly or create new fuel (U-239/Pu) as they run.

    • Re: (Score:3, Informative)

      by Anonymous Coward

      It's not 5% efficiency. Of the thermal energy they produce, in fact, more of it can be used than coal, since nuclear reactors can operate at higher temperatures than coal furnaces. However, if someone came up with a coal fuel cell, perhaps it could be even more efficient, since it wouldn't lose energy to thermalization. Muscles are not heat engines, they are like 95% efficient.

      Only 5% of the nuclei that can be fissioned are. In a different reactor, more of the fuel could be fissioned; with current react

    • And the energy density of a chunk of Uranium is still orders of magnitude higher than any other practical fuel source. Also, it's not as if we couldn't refine and recycle the fuel and squeeze more of the energy out of it later. Today's nuclear waste storage is tomorrow's 'unlimited energy source'.

    • by Andy Dodd (701)

      I don't know if "efficiency" is the right word... This implies that 95% of the energy available is wasted as heat which can never be used again.

      That isn't the case with traditional light water reactors - they don't waste much more heat than any other heat-engine-based plant - however, 95% of the potential energy in their fuel simply can't be used in the first place!

      I believe one of the statistics of the Integral Fast Reactor project was that the United States' existing spent fuel stockpiles would be able t

    • by jo_ham (604554) <joham999 AT gmail DOT com> on Wednesday December 07, 2011 @05:42PM (#38295758)

      It's not that it's not that efficient, it's that it really doesn't need to be. The energy from fission is mostly captured (although you are dumping a lot of heat), but crucially it leaves high energy products behind in the fuel. It's what makes the spent fuel so hazardous to deal with, which is why it's crazy to suggest burying it in the ground!

      Why bury something that has so much juicy energy still in it that we can extract with current technology? The answer is political, of course.

      The other factor to consider is the sheer magnitude of the energy we're talking about here. E = mc^2 is not just a handy soundbite.

      • by AmiMoJo (196126)

        Why bury something that has so much juicy energy still in it that we can extract with current technology? The answer is political, of course.

        The UK used to lead the world with nuclear power. We had more of it than anyone in the 60s, but then we started trying to build new advanced designs which turned out to be harder than we thought. By the time they were coming online in the early 80s the Conservative government was busy selling off all energy infrastructure, but no-one would buy the nuclear bits because of the enormous costs and enormous liabilities.

        So now when someone comes along with a fantastic new technology that will solve all our proble

        • by jo_ham (604554)

          Who said anything about new technology? We have the technology we need right now to reprocess and use spent fuel from PWRs in breeders and other types of reactors, but it's politically sensitive to build reactors that can be purposed to make Pu for weapons if desired. No need for any new pie in the sky technology.

          • by arose (644256)

            Who said anything about new technology?

            Anyone who goes on about failsafe designs and thorium?

    • by Hentes (2461350)

      Which is why nuclear plants still have a lot of room to grow, unlike alternative sources.

  • by khallow (566160) on Wednesday December 07, 2011 @04:55PM (#38295128)

    But water-cooled reactors leave some 95 percent of the fuel's potential energy untapped."

    I gather the problem is that decay products poison the fuel after it's been run for a while. One would still need to reprocess fuel rods on a regular basis. But once that's done, you can get more than 5% of the energy from a fuel rod.

    • Not with light water reactors you can't. You run out of fissile material - natural uranium is more than 99% U-238, which isn't fissile. Some of this is converted to Pu-239 by neutron capture, but light water reactors only have a conversion ratio of 0.5 or so. For every 10 uranium atoms fissioned, you only get 5 plutonium ones. So at best you can only double the fuel utilisation, and in practice less.

      The point of fast reactors was that the conversion ratio can be over 1, so there's no net consumption of fiss

  • What if Iaran gets the bomb, we'd be better using all out plutonium to bomb them into oblivion.
    • by LWATCDR (28044)

      Uranium works fine.

    • If Iran gets the bomb, I hope for all Iranians its government won't be stupid enough to use it (in any way, like running a test explosion somewhere).

      And if any country would feel the urge to stop Iran from obtaining a nuclear bomb, let's hope for all our sakes conventional bombs would be used for that job.

      In the meanwhile, "The PRISM reactor actually disposes of a great majority of the plutonium as opposed to simply reusing it over again without ever actually ridding the planet of the substance." sounds lik

  • by Anomalyst (742352) on Wednesday December 07, 2011 @05:14PM (#38295366)
    Is there a kind of plutonium that isn't radioactive?
    • Technically speaking, anything in the periodic table over Pb208 (Lead) is radioactive. It's just some of these elements have REALLY long half lives. And the longer the half life, the lower the radioactivity...

    • by Amouth (879122)

      considering all atoms have some half life and there for are in some way radio active i'd have to say no.. but if you don't consider normal every day stuff radioactive then i'd point you at Plutonium 244

      http://en.wikipedia.org/wiki/Plutonium-244 [wikipedia.org]

      with a half-life of ~80 million years the radio activity from it would be very minimal

    • by iggymanz (596061) on Wednesday December 07, 2011 @05:54PM (#38295932)

      no. but the usual Pu-239 isn't very radioactive, just emits alphas slowly with a very long half life of 24,200 years. That radiation can't even penetrate your skin or go through a piece of paper. Pu-240 is artificial, usually decays by alpha but sometimes spontaneously fissions, it too has long half-life of more than 6500 years. Then there is Pu-238, emits huge amounts of alphas with its short half-life of 88 years, it's used in RTG batteries and also radioisotope heater units. A kilogram of the stuff gives off 500 watts.

      • by StikyPad (445176)

        500 watts per what?

        • by treeves (963993)

          No, just 500W. As in Joules/second. The real question is "how long does it give off 500W?" Just the first day, or for one year, or for ten years, etc.?

          • The real question is "how long does it give off 500W?" Just the first day, or for one year, or for ten years, etc.?

            Half life of 88 years. That means it'll be giving 250W after 44 years.

            About 350W after 22 years.

            About 420W after 11 years.

            After one year, 490W...

  • CANDU (Score:4, Interesting)

    by FeatherBoa (469218) on Wednesday December 07, 2011 @05:29PM (#38295568)

    But water-cooled reactors leave some 95 percent of the fuel's potential energy untapped.

    Light water reactors, sure. But heavy water reactors are a whole different kettle of fish. CANDU can already burn anything from natural uranium through plutonium. Hot stuff you just dilute down.

    No need to invent some new crazy reactor, just burn it at Bruce or Pickering.

    • by Andy Dodd (701)

      I think even CANDU has limitations of energy extraction that prevent it from extracting as much energy from the fuel as a breeder+reprocessing cycle like the IFR (and PRISM seems to be very similar to the IFR).

      • by tlhIngan (30335)

        Yes, CANDU is actually very inefficient - it doesn't extract all the usable fuel as other reactors can.

        However, it does have the advantage that it's impossible to have a meltdown - heavy water is a great moderator. In fact, it's required in order to have a reaction - if there's no heavy water, the fuel's inert. And normal water impedes the reaction as well, so if the cooling system leaks, the reaction stops as well.

        Plus, the fuel that comes out needs even heavier processing to become weapons grade.

        • CANDUs have decay heat like any other reactor, so are quite as vulnerable to meltdowns in the event of loss of cooling.

          They're also better at making weapons grade plutonium than LWRs thanks to online refuelling - you can irradiate the fuel elements for a short time only to avoid the buildup of heavier isotopes of plutonium.

    • by AmiMoJo (196126)

      Right, and TFA is just a page on the manufacturer's web site. I smell the foul aroma of bullshit. After all if it were as good as they make out why are they trying to sell one to the UK and not just building on in the US or Japan? The US doesn't even have a long term storage facility at the moment and spent fuel is building up at reactor sties, and once that lot is burned up they could charge the UK to deal with their waste.

  • wording (Score:4, Insightful)

    by StuffMaster (412029) on Wednesday December 07, 2011 @05:32PM (#38295608)

    I'm getting tired of all these posts saying "some entity to do something" when the summary says "proposed".

    Assuming that "to" means "going to" to everybody else as it does me, I'd appreciate it if the editors could stop doing or allowing that.

  • by mmontour (2208)

    Don't forget about CANDU reactors [ccnr.org]. They use a heavy-water moderator and are able to burn a wide variety of fuels including plutonium, natural uranium, or "spent" fuel from a light-water reactor.

  • the history of liquid sodium reactors has been a sad one, look up the Fermi #1 unit in Detroit some time. basically the job of keeping the liquid sodium, which is mightily explosive and gets mightily radioactive as a moderator, inside away from air and water is something that hasn't been solved yet. I would not be stumping the countryside trying to site one.

  • Geeky density fun (Score:5, Interesting)

    by thatseattleguy (897282) on Wednesday December 07, 2011 @06:07PM (#38296110) Homepage
    Just 'cuz I was curious, and it has some peripheral bearing on the question - assuming 19.816 gm/cm^3 for the density of Pu (more than lead) and also assuming (since it's the UK) we're talking "tons" = metric tonnes = 1000kg = 10^6 gm -

    87 x 10^6 gm / 19.816 gm/cm^3 = 4.39 x 10^6 cm^3 = 4.39 m^3.

    4.39 cubic meters is a single cube 1.637 meters on a side (or a little more than 5 feet/side, for us backward Yanks). More or less the size of a smallish SUV, yes?

    Of course their Pu isn't, one hopes, stored all in one solid cube, which would probably exceed critical mass by some large factor. But still, it's not a massive physical quantity of material you're talking about here. /TSG/
  • Has Slashdot fallen so far that we need hand-holding on what fission is, and we accept FUD on reactor efficiency in the summary?

    For shame, samzenpus.

  • Does anyone have a rough idea of how much electricity could be produced by this type of reactor using the 87 tons plutonium stockpile? Please express in terms of % of annual electricity consumption by Britain, or another unit readable by laymen.
    • Nearly all of it. THink of it this way: UK has 18-25% of their electricity nukes (basically, 18 reactors). [world-nuclear.org] Now, not a big deal, it is about the same as America. What is interesting is that they have accumulated all that fuel since 1967 (average appears to be 35 years). And that is less than 5% burned. So, if UK, puts in these reactors, then they will be able to burn the rest of the fuel. How long will it take? Over a 100 years depending on how many reactors they put in.

      Note that this is simply GE's IFR [wikipedia.org]
  • Basically, not only will it be burning WASTE fuel, but, it is actually cheaper to burn this then to try and handle the 'waste' fuel. Look at WIPP. It is a true cluster. OTH, these can actually be built for a fraction of what it costs to store all that waste but instead makes money.

    In addition, because it is modular, these can be added at the sites that are already handling nuke reactors. With this approach, it allows a plant that is already built to handle large power but heading towards closure to switch
  • This is simply an IFR. [wikipedia.org] But the amazing thing is that this is going into America already.

"Floggings will continue until morale improves." -- anonymous flyer being distributed at Exxon USA

Working...