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Earth Science Technology

Accelerator Driven Treatment of Nuclear Waste 226

quax writes "In the wake of the Fukushima disaster the nuclear industry again faces massive opposition. Germany even decided to abandon nuclear energy altogether and the future of the industry is under a cloud of uncertainty in Japan. But one thing seems to be here to stay for a very, very long time: radioactive waste that has half-lives measured in thousands of years. But there is a technology under development in Belgium that could change all this: A sub-critical reactor design, driven by a particle accelerator can transmute the nuclear waste into something that goes away in about two hundred years. Could this lead to a revival of the nuclear industry and the reprocessing of spent reactor fuel?"
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Accelerator Driven Treatment of Nuclear Waste

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  • by Anonymous Coward on Monday September 24, 2012 @04:23PM (#41442189)
    I'll be long gone by then. Let someone else deal with it. Don't waste a cent of my money on it.
    • Re: (Score:2, Insightful)

      by Anonymous Coward
      You're missing a very important point. Many governments (specifically the US) pay HUGE amounts of money for OTHER people to take the waste. So not only would you not spend a cent creating new energy... but you'd be paid for it.
  • Wasn't it recently discovered that neutrino interactions with unstable neuclei causes an increased rate of decay?

    Placing the waste near a particle accellerator that generates large quantities of neutrino emissions should reduce the time needed for those waste products to decay.

    The neutrino emissions themselves are harmless to living things. You get uncountable numbers of them passing through 1cm of skin every second from sunlight. (Even if you are indoors!)

    • Why waste the perfectly good stuff when it could be used to fuel other reactors that "burn" them into progressively more innocuous things (as in, half-lives of a few years instead of millenia).

      • Re: (Score:2, Insightful)

        by Anonymous Coward

        Uh, material with a half-life of a few years is hardly 'innocuous'. That's what we normally call 'crazy freaking radioactive'.

        People seem to have this bizarre idea that a long half-life makes something dangerous, when it's precisely the opposite.

        • by sjames ( 1099 )

          It is innocuous in terms of waste management because however extremely dangerous it is in the short term, it soon becomes inert.

          • by mellon ( 7048 )

            Not strictly true. Suppose you have a source with a half-life of 200 years, and you have a ton of it. In 200 years, half of that ton will still be radioactive. In 200 more years, a quarter. And so on. So its not like 200 years later, it's all gone. The trouble with the long half-life stuff is that although it isn't radioactive enough to kill you outright, it's more than radioactive enough to cause cancer, and it'll keep doing it for a lot longer.

            The sad thing about all this is that of course the

            • by sjames ( 1099 )

              Ideally, we would separate out the actinides (and so the stuff that makes people wonder how we will store 'waste' for thousands of years) and use them for fuel in conventional reactors. That leaves us the much hotter stuff that could economically drive a low temperature turbine for years without significant interaction.

      • You might want to take a look at the article.

        First, it uses the Thorium fuel cycle. Consider your slant I would think that was a plus.

        Second, they are not talking about “perfectly good“ fuel – they are talking about heavy metals. Most of the waste, by volume, are not the fuel rods but more humdrum stuff, like metal pipes. Not usable for fuel but still very radioactive for a long time.

        • One wonders could they not melt down the pipes and use a centerfuge system like the do with uranium to seperate the hot metel from the stable

    • by dido ( 9125 )

      From what I understand the process that causes neutrinos to speed up radiocative decay is the result of inverse beta decay [everything2.com] (I'd link to a Wikipedia article but WP thinks that the term 'inverse beta decay' is synonymous with electron capture. There seems to be no independent article for this process I refer to, despite the fact that this process was used in the Cowan-Reines experiment that was the first conclusive evidence for the neutrino, and won for Frederick Reines his share of the 1995 Nobel Prize in Ph

    • by quax ( 19371 )

      The article on that can be found here [wavewatching.net]. It is not settled science that this effect is real, and it is a very small effect. That neutrinos may be causing this is conjecture at this point.

      What makes the effect exciting is that it'll hint at new physics if confirmed.

  • A step (Score:4, Insightful)

    by Quantus347 ( 1220456 ) on Monday September 24, 2012 @04:31PM (#41442281)
    Its a step in the right direction, but it wont gain any sort of sustainable foothold until the technology can get the half-life of the waste down to within a single lifetime. In truth, what it really needs to accomplish is a technology that actually breaks even: something that reduces the stockpile at at least an equal rate to what our nuclear power use is producing.

    Either that or productive Fusion, which does not produce near the lasting Radioactive waste.
    • by Hatta ( 162192 )

      If we can convert long half life materials to short halflife materials, would those short halflife materials provide enough decay heat to harvest energy from? Why not hook a turbine up to the waste pools and get some useful work out of that?

    • Re:A step (Score:5, Informative)

      by dargaud ( 518470 ) <slashdot2@@@gdargaud...net> on Monday September 24, 2012 @05:00PM (#41442697) Homepage
      I'm the guy who write the software for the reactor (and the accelerator) of TFA. And yes, it run Linux, on embedded Xilinx cards with custom FPGAs. I can't vouch for the ability of the system to transmute long-life waste in a semi-industrial way as it's only a research reactor, not even a demonstrator. But it's the 3rd prototype of its kind and it's working well enough. More information is available here in french [in2p3.fr], and, as a long time /. member, if you have questions about the control/command software, I'll be happy to answer when I wake up in the morning ! Yeah, the name of the experiment is somewhat confusing: Genepi/Guinevere/3C/Venus/Ganddalf. One is the accelerator, one is the reactor, one is the data acquisition, one is the combined experiment... I get lost too.
      • by quax ( 19371 )

        This is really neat. So is the current control software in Mol using your code? Will MYRRHA use the same code base or does it require a complete re-write?

        Are you using a real-time kernel?

        What kind of quality control are you using to ensure the software performs exactly as designed?

        Are you using a functional programming paradigm?

        Are the reactors computer systems networked to the outside world? If so what kind of security measures do you have in place to safeguard access?

        Is your software a critical compone

        • Re:A step (Score:5, Informative)

          by dargaud ( 518470 ) <slashdot2@@@gdargaud...net> on Tuesday September 25, 2012 @01:46AM (#41446701) Homepage

          This is really neat. So is the current control software in Mol using your code?

          Yes.

          Will MYRRHA use the same code base or does it require a complete re-write?

          Myrrha is only a concept so far: no development yet. It will most likely be a complete rewrite looking as to how far the code has diverged from the original specs.

          Are you using a real-time kernel?

          No. Everything that needs to be real-time is done on FPGAs and then transmitted to the kernel and user app via GPIOs.

          What kind of quality control are you using to ensure the software performs exactly as designed?

          Basically years of testing. Anyway, since it is a subcritical reactor, the security requirements are much less stringent. Some purely security stuff (read: not the control/command and or acquisition), is handled by other systems which have no interaction with mine. And as for the original 'design', well, it is research, meaning that specs start from a white sheet and build from there as we add pieces to the machine.

          Are you using a functional programming paradigm?

          All in C.

          Are the reactors computer systems networked to the outside world? If so what kind of security measures do you have in place to safeguard access?

          They are indirectly accessible (2 sets of firewalls). Like I said it is a research system with much less stringent security requirements, and quite a few researchers work on it and need remote access.

          Is your software a critical component of the control feedback loop e,g. reduces beam intensity based on the measured neutron flux? If so what kind of redundancy is build into the system?

          One set of software runs on the cards themselves: a minimalist BuildRoot install with a basic software that does as few things as possible (transferring acquired data to the network, reacting to commands from the Control/Command, sanity checks, basic security, going into security mode in case contact is lost, ...). One or more linux PCs run the C/C software and communicate with those cards and tell them what to do. If this soft crashes, nothing actually happens, the system keeps running for a while. You can actually shut down one PC and start another and everything keeps running like nothing happened.

          But all the 'real' security is done in hardware: thermal shutdowns, beam intensity shutdowns, etc... It's actually difficult to turn the system on: everything has to be just right and there are plenty of little things that do stop the process.

      • How does a person get into this area without dropping their job, moving to the other side of the country to the only University that has a good Nuclear Physics program and spending forever getting a PhD and kicking off a research project on my idea?

        I've had my own high level schematics drawn for this kind of idea years ago using practically off the shelf parts, i keep the construction price updated every year or whenever i spot new developments that would change things.

        The reason its not built already and d

  • Cue the hippies (Score:5, Insightful)

    by ericloewe ( 2129490 ) on Monday September 24, 2012 @04:31PM (#41442289)

    "Nuclear is bad for everyone!"

    Compared to what? Coal and natural gas, that are bad for us even when they're within normal parameters? Renewables that are nowhere near enough to properly replace what we're currently using without using up massive land areas?

    I'll take a nuclear reactor in my backyard over a natural gas plant in my neighborhood or a coal power plant within a 20 km radius any day.

    • Re:Cue the hippies (Score:4, Informative)

      by CrtxReavr ( 62039 ) <crtxreavr@triopti m u m . com> on Monday September 24, 2012 @04:35PM (#41442343)

      Yes, everyone's so worried about the disposal of the spent nuclear fuel rods, while coal ash is scattered to the wind with reckless abandon: http://www.scientificamerican.com/article.cfm?id=coal-ash-is-more-radioactive-than-nuclear-waste [scientificamerican.com]

      • Re:Cue the hippies (Score:4, Insightful)

        by mellon ( 7048 ) on Monday September 24, 2012 @05:06PM (#41442781) Homepage

        Generally speaking you will find that the same people who oppose nuclear also oppose coal, for precisely the reason you state, as well as a few others—e.g., mountaintop removal, watershed destruction, deforestation. In fact, in general at this point I think you will find that people who oppose both oppose coal more than nuclear. But it's not an either-or proposition—despite widespread naysaying, it turns out that renewables really can work. What we lack is not the technology, but the ability to wean people who depend on extractive industries for a living from the dark teat.

        • That's a very nice concept. In practice, no nuclear means more natural gas and more coal, which will inevitably have ill effects on us, while nuclear is safe if correctly handled.

      • by Qzukk ( 229616 )

        Now, now, they don't just let coal ash scatter to the wind, they keep it in big ponds in your living room [wikipedia.org].

    • Re:Cue the hippies (Score:4, Interesting)

      by Hatta ( 162192 ) on Monday September 24, 2012 @04:53PM (#41442601) Journal

      It's true, many on the left are overly skeptical about nuclear power. But at least liberals change their opinions [salon.com] when educated.

      Nuclear power is a classic test case for liberal biasesâ"kind of the flip side of the global warming issueâ"for the following reason. Itâ(TM)s well known that liberals tend to start out distrustful of nuclear energy: Thereâ(TM)s a long history of this on the left. But this impulse puts them at odds with the views of the scientific community on the matter (scientists tend to think nuclear power risks are overblown, especially in light of the dangers of other energy sources, like coal).

      So are liberals âoesmart idiotsâ on nukes? Not in Kahanâ(TM)s study. As members of the âoeegalitarian communitarianâ group in the studyâ"people with more liberal valuesâ"knew more science and math, they did not become more worried, overall, about the risks of nuclear power. Rather, they moved in the opposite direction from where these initial impulses would have taken them. They become less worriedâ"and, I might add, closer to the opinion of the scientific community on the matter.

      You may or may not support nuclear power personally, but letâ(TM)s face it: This is not the âoesmart idiotâ effect. It looks a lot more like open-mindedness.

    • Germany is full of highly reactive Green sentiment, they'll do just about anything "Green" without regard for the actual consequences. High school yearbook? make it from recycled paper that disintegrates in less than 5 years. Nuclear power? abolish and replace with coal. Stuck waiting for train crossing for more than 5 seconds? Shut down idling engines (debatable, but when first instituted stop/restart cycles ultimately causing more pollution than the idle due to increased maintenance / decreased engine

      • Indeed. The political establishment was having trouble getting re-elected, so they merged with whoever they could find to keep themselves in power. Nevermind that it's slowly crippling them.

    • by LWATCDR ( 28044 )

      Kind of like the lie that Germany is abandoning nuclear power. Germany is just outsourcing nuclear power too France. All the same risks but without any control over the safety requirements but the Greens believe it so all is good.

  • by goombah99 ( 560566 ) on Monday September 24, 2012 @04:31PM (#41442297)

    Back in the 1990s this was developed at Los Alamos and a few other accelerator centers. it's not new or unique to belgium.
    http://www.lanl.gov/orgs/pa/science21/ATW.html [lanl.gov]

    http://www.world-nuclear.org/sym/1999/venneri.htm [world-nuclear.org]

    • Re: (Score:3, Insightful)

      by radtea ( 464814 )

      Back in the 1990s this was developed at Los Alamos and a few other accelerator centers. it's not new or unique to belgium.

      But because it's a technological solution to a political problem, it's a wheel that will keep being reinvented and everyone who ignored it the previous time will be surprised by it the subsequent time.

      The dialog goes like this:

      Anti-nukes: "Nuclear power is unsafe. We must ban it!"

      Engineer: "Look, I have found a way to make nuclear power safer than coal!"

      Anti-nukes: "That would be terr

    • by quax ( 19371 )

      What's new and unique to Belgium is that they are embarking on constructing the industrial scale MYRRHA reactor. Don't know of any other accelerator driven reactor project of this scale. TFA contains links to a presentation with the detailed blueprints for this machine.

  • Depending on how big the accelerator has to be, I wonder if this could be used for making smaller reactors, perhaps using thorium instead of uranium as fuel. With the permanent moratorium in place since Carter, this would allow nuclear energy to be useful in the US, and since the reactors are smaller and can be QA-ed at a factory before hitting a site, it means that problems have a greater chance of being caught before the thing goes live.

    Subcritical fission isn't just useful for getting rid of fuel, it wo

    • by quax ( 19371 )

      TFA links to a science paper of how this design could work with Thorium.

  • Thorium reactors? (Score:4, Insightful)

    by kheldan ( 1460303 ) on Monday September 24, 2012 @04:38PM (#41442381) Journal
    I keep hearing about thorium reactors. What I've read of it seems to indicate it'd be much safer and cheaper to operate than what we've been using. I really haven't read about any downside to these. Anyone care to fill me in on why we aren't using them?
    • Re:Thorium reactors? (Score:5, Informative)

      by Que_Ball ( 44131 ) on Monday September 24, 2012 @04:47PM (#41442529)

      Primary reason is the many billions of dollars of development needed to figure it all out.

      There is no design for a "working commercial thorium reactors". It's all just bits and pieces of theory, and experimental reactors that only answered some of the questions.

      It's a possible technology, just not an actual technology. Kind of like the guy at NASA who recently got into the news for a pen and paper proposal of how warp speed might be possible. We are still a long way from building interstellar spaceships. Just like we are long way from building a Thorium salt reactor that works and is economically viable.

      • There is no design for a "working commercial thorium reactors". It's all just bits and pieces of theory, and experimental reactors that only answered some of the questions.

        This is not true — CANDU reactors can burn thorium in a number of fuel configurations, and they have been around for decades. That none are operating commercially on a thorium fuel cycle is, I believe, primarily due to a combination of regulation and infrastructure considerations.

        Next generation thorium reactors will be great, but we already have the technology to use thorium. We just don't.

        • by quax ( 19371 )

          CANDU is another example for a reactor design that while not sub-critical is much safer than most other designs due to its ability to use natural uranium. The latter obviously does not have a tendency to spontaneously sustain a fission reaction. (Although in nature this apparently occurred at least once in earths history in Africa [wikipedia.org]).

    • Capitalism and the fact Thorium does not produce products which can be weaponized.

      I guess it sort of made sense at the time.

      • Hmm. Capitalism kind of operates on the idea of profitability, so if you can make an argument that a Thorium reactor will be profitable (even a 10% return on investment), people will listen. If you can argue that it's more profitable that a Uranium-based reactor, even more people will listen.

        No one, in their right mind, slights someone who will arguably make them a little richer at the end of the day. None of us are wealthy enough that that isn't a problem.

    • by sjames ( 1099 )

      Uranium reactors were developed first because we (the U.S.) needed bomb grade material. Thorium reactors cannot provide that.

    • by erice ( 13380 )

      I keep hearing about thorium reactors. What I've read of it seems to indicate it'd be much safer and cheaper to operate than what we've been using. I really haven't read about any downside to these. Anyone care to fill me in on why we aren't using them?

      1) They are more complex than Uranium reactors we use now. The fuel is cheaper but fuel is not a major contributor to the cost of running a nuclear power plant.
      2) They are inherently breeder reactors and that raises concerns about nuclear proliferation. U-232 contamination makes it actually rather difficult to use a Thorium reactor to make bomb material but not everyone is satisfied that is it difficult enough.
      3) U-232 contamination also makes normal operation more difficult too. U-232 is an intense gam

      • by vlm ( 69642 )

        They are inherently breeder reactors and that raises concerns about nuclear proliferation. U-232 contamination makes it actually rather difficult to use a Thorium reactor to make bomb material

        Close but wrong. All you need to make Pu is some U (no big deal) and some excess neutrons laying around for the U to soak up... like from a Th reactor.

        A Th reactor can cook above delayed critical (obviously, otherwise how does it power up?, think about it). So you have a convenient controllable source of excess of neutrons laying around, and its no great technical achievement to shove a U target in there to soak up the excess neutrons thus making yummy Pu.

        You have a really awkward situation of trying to p

        • The U232 makes it deadly to handle therefore extremely difficult and unlikely to use for machining into something usable as a weapon. I'd never say someone couldn't but there are likely easier ways of getting U. Anyway, If you have a LFTR reactor, you already have a bunch of U in the core. The U232 is bred in the blanket later of a LFTR reactor, filtered out through fluorination and pumped back into the core for fuel.

          A Th reactor can cook above delayed critical (obviously, otherwise how does it power up?

          A LFTR starts with a core of U (I believe it is U235) in the Berylium Fluoride - That i

      • Very good summary of the arguments against Thorium, but your first point can be put more succinctly:

        1) They are more complex than Uranium reactors we use now. The fuel is cheaper but fuel is not a major contributor to the cost of running a nuclear power plant.

        1) There is no economic advantage to Thorium reactors.

        And make no mistake: the main factor holding back nuclear all over the developed world is not safety issues, public opinion, waste management or proliferation, but cost.

      • by quax ( 19371 )

        If you read the TFA it links to a paper that discusses Thorium use in an accelerator driven reactor. I guess in a sense this is a breeder but the Thorium fuel cycle only requires Plutonium to achieve criticality. Don't see a need for it in this kind of sub-critical design.

        Plutonium management really is a matter of political will, one can also argue that Thorium can be used to constrain Plutonium as this paper does (PDF) [iaea.org].

        • by erice ( 13380 )

          If you read the TFA it links to a paper that discusses Thorium use in an accelerator driven reactor. I guess in a sense this is a breeder but the Thorium fuel cycle only requires Plutonium to achieve criticality. Don't see a need for it in this kind of sub-critical design.

          The conventional Thorium fuel cycle does not require plutonium at all. It just requires some fissile material to start the process. Enriched uranium is the conventional choice.

          However, any Thorium reactor is a breeder. Fissile Uranium-230 is bred from non-fissile thorium and Uranium-230 is just as good of a bomb material as plutonium. That is, if you can can remove the U-232, which is a bit of a trick.

          Using the particle accelerator removes the need for an enriched U-235 to start the reactor. That is u

          • by quax ( 19371 )

            Thanks for the correction with regards to the plutonium. Indeed any fissile material will do.

    • You could watch "LFTR remix 2011" but since google/YouTube is down where you live:

      -Banks don't like unknowns. A commercial-grade LFTR reactor has never been built. If it did they would know how long it would take for the reactor to make $.
      -Current regulations only cover WW2-tech reactors. Anything else is a gray zone. So, no permits, etc.
      -Current nuclear industry is a monopolistic cash-cow. They don't want to end the 25-year, sole source supply contracts for solid fuel.(You can't buy fuel pellets on special

      • -LFTR could kill the coal and the oil well business. so...

        Wah.
        Coal and oil aren't going to last forever, or much longer for that matter. Wouldn't it be nice, for once, if humans would actually change something before it became a life-or-death situation?

        • The United States has enough proven reserves of coal to last for several hundred years at our current rate of consumption. Even then we don't really run out, it just gets progressively more expensive to extract.

          Given that gasoline can be made out of coal, even if the middle east went dry tomorrow we wouldn't really be out of oil, we'd just be out of cheap oil...
  • by Que_Ball ( 44131 ) on Monday September 24, 2012 @04:40PM (#41442419)

    Yes. Spent fuel has always been considered a long term asset by the nuclear industry. People in that industry believe that as mining the raw ore becomes more expensive and the technology for reprocessing the spent fuel becomes better it starts to become a more valuable source of future fuel.

    The industry would be very different if the governments did not push the technology towards weapons production. The reactor designs we have are all old and they are designed in a way that facilitates the production of plutonium. If the research into other reactor and fuel designs that did not have as many dangerous byproducts were pursued it would be a safer industry today.

    The most promising alternative is and was to use Thorium fuelled reactors instead of uranium. There is the potential for far safer reactor designs and far less hazardous waste when using that type of fuel. The USA took a relatively short look at this but then they stopped since they could not also produce weapons from these reactors and at the time it was all about the bomb. But from what I have read they will likely become a technology that becomes more interesting over time as it's capable of using depleted uranium along with the Thorium as a way to use up that spent fuel that's hanging around.

    It should be obvious though there are significant challenges to getting the theory into a practical design. All those research reactor projects back in the 50's that gave engineers and scientists the knowledge to build the current reactors would need similar efforts to develop the technology for these alternative fuels and reprocessing technologies. It's starting to happen but in China and India where they have not lost their love for nuclear power yet.

    • by vlm ( 69642 )

      starts to become a more valuable source of future fuel.

      To expand on that, non-nuke people think fuel is burned up and there's just a tiny percentage of ash remaining, like coal plants.

      Nukes work differently. Usually the fuel rods have to support themselves... what fraction of atoms in a chunk of "stuff" can you screw up and its still recognizably a chunk of "stuff"? AKA "burnup" or "burnup ratio". Well it turns out "a percent or so" is the most you can do before mechanical properties get all weird. More with some chemistries and designs, less with others.

      Im

    • not even slightly true.

      nuclear regulation became ridiculous precisely because of non proliferation.

      the weapons focused designs are almost all but decommissioned (one of them decommissioned itself spectacularly in 1986...). the UK still has a few running. their distinguishing feature is the ability to hot-swap fuel while keeping it running. you can't do that with a PWR or BWR - you fuel it all in one go, you leave it a couple of years (viable pu239 production takes a couple of weeks, not years. if you le

      • (granted, the fuel cycle infrastructure can certainly be used to enrich uranium beyond the small amount needed for commercial reactors).

    • Actually, the liquid fluoride thorium reactor (LFTR) could actually make a huge contribution to getting rid of nuclear waste.

      Why? Because spent uranium reactor fuel rods and even plutonium from dismantled nuclear weapons could be reprocessed into a form that could be used in an LFTR by dissolving the reprocessed nuclear material in molten sodium fluoride salts. And after this fuel is used up, the final radioactive waste is very small in amount and only has a half-life of under 300 years, which means very ch

  • by Gordonjcp ( 186804 ) on Monday September 24, 2012 @04:44PM (#41442467) Homepage

    ... there's just stuff you haven't configured your second fast-breeder reactor to run on yet.

    • Yeah, sure until you have stripped everything down as far as will go and are left with a cloud of hydrogen gas... oh. I see. Clever.

      • Yeah, you get that hydrogen and fuse it into helium, thus preventing us running out of helium like we're always hearing about.

  • The "transmutation" of nuclear waste into harmless substances, sounds too good to be true? That's because it is. This paper takes a more critical look at the theory: www.laka.org/docu/boeken/pdf/6-01-5-56-25.pdf

    "Transmutation of all long-lived radionuclides into short lived ones to a degree sufficient to obviate the need for a geologic repository is practically impossible. In particular, the transmutation of separated uranium, which constitutes about 94 percent of the weight of light water reactor spent fu

    • If they (the referenced paper, which I flipped through) are saying that you need to transmute the U-238 to a short-lived isotope to make it safe, they are nuts. U-238 has a half-life of 4.5 billion years and so is not very radioactive, it is what primarily comes out of the ground. If the industry were to just mine the natural uranium, take out the U-235 for reactors then put the leftover U-238 back into the ground (or dump it in the sea which already has a lot of natural uranium) then the final result is

    • by quax ( 19371 )

      As another commenter pointed out transmuting U238 is kind of pointless. The Minor Actinides is specifically what they are after (this becomes clear if you look at the linked papers and presentation in TFA).

    • by Prune ( 557140 ) on Monday September 24, 2012 @09:26PM (#41445155)

      Shame on you for posting a "paper" that is published by a politically driven organization (IEER) and not any recognized academic journal.

  • Ive always heard of particle accelerators as enormous power hogs. Is this really an effective means of generating net power? If neutrons can be generated efficiently, couldn't you also use this to generate power by directly fissioning U-238? (I.e., not breading plutonium)

  • Anyone seen the Firehose lately?

    It appears to have been removed.

    Anyone?

  • While I think this would be great to deal with the waste that already exists, I think for budgeting 200 years is longer than anyone is willing to think anyways, so it won't make much of a difference to the financial viability.
  • by Animats ( 122034 ) on Monday September 24, 2012 @05:19PM (#41442913) Homepage

    This has been talked up for a decade or two, but needs cost and capacity numbers.

    There's also the painful fact that every reactor design that had anything mechanically non-trivial inside the reactor has been a flop. There have been two German pebble-bed reactors, both of which had pebble jams serious enough to cause major accidents with significant radiation leaks. Tsinghua University in China has one that's worked for a while, and that design is being scaled up. The Rongcheng Shidaowan Nuclear Power Plant, with two pebble-bed reactors, is under construction now. Completion in 2015. Maybe they can make it work. We won't really know until there are a few hundred reactor-years on that technology.

    High temperature, gas-cooled reactors have been tried, but were troublesome. The only big one was Fort. St. Vrain, which had a lot of troubles with auxiliary equipment and corrosion. It only ran 10 years. No big safety issues, though; just high maintenance costs.

    • by quax ( 19371 )

      An accelerator beam I would not consider a mechanical system. No moving parts.

      At any rate these research reactors are build to determine technological feasibility, are they not?

  • by KonoWatakushi ( 910213 ) on Monday September 24, 2012 @07:57PM (#41444455)

    Is Nuclear Waste Really Waste? [youtube.com] The short answer, is "hell no"; while there is a very small part of spent fuel which could actually be considered waste, the vast bulk of it is a goldmine of energy and a source of other highly valuable fission products.

    It is totally silly to talk of "waste treatment" or "destruction"--this is just another way of doing fission. It is equally silly to talk about destroying enormously vast reserves of energy, just because our antiquated reactors are terribly inefficient and make a mess of the partially burned fuel. It does not have to be that way, and modern molten salt reactors like LFTR [wikipedia.org] burn the fuel so completely that there is barely any waste left at all.

    We need to take another look at spent fuel. Aside from burying it, which merely delays the problem, the only way to rid ourselves of it is by fissioning it. There are many ways of doing so, but the best would be to harness the energy contained within in safe and inexpensive LFTRs. Such reactors are capable of providing not only for our electrical needs, but also the production of liquid fuels, as well as process heat for water desalination, foundries, fertilizer, concrete, and more.

    Certainly, fissile material like U235 and Pu239 should be disposed of, but it should be done so in a manner which maximizes its value, and fast reactors or other waste eaters are terrible in this respect. LFTRs require much less fissile material to start up, and if we were to use the fissile in this way, we could ramp up their production very quickly, and eliminate it just the same. Only this way would be safer, simpler, more efficient, and vastly cheaper.

  • We should burn sweet, sweet coal instead and have No Consequences.

  • I have an antique bowl that's more radioactive than fuel glass...

  • Nuclear has the lowest deaths per terawatt-hours produced than any other significant energy production method, by a couple orders of magnitude: http://www-958.ibm.com/software/data/cognos/manyeyes/visualizations/deaths-per-twh-by-energy-sources [ibm.com] (and yes, the figure includes all nuclear power accidents). Note that even hydro is far, far worse. Here's another, more striking, visualization: http://transitionvoice.com/wp-content/uploads/2011/03/death-rate-per-watts-Seth-Godin.jpg [transitionvoice.com]
  • by Anonymous Coward

    Search for stuff on ADSR's (accelerator driven subcritical reactor). Or the Energy Amplifier, which is patented by a CERN guy. The basic idea is (insert car analogy) a turbocharger. You have a barely subcritical reactor that by geometry of the tanks/reactor (if using molten fuels, which is a good thing by the way) can't go critical. You have a freeze plug in the tank bottom, so if it overheats, the thing drains the fuel into multiple dump tanks, which by geometry, prevent it from being critical. Now, you ha

  • The original version of "Blowups Happen" by R.A. Heinlein centered around an accelerator driven subcritical reactor, the only way that Heinlein thought that a reactor could be made controllable at the time the story was originally written - the story was written before the discovery of delayed neutrons from fission.

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