Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
Power Technology

Fusion-Fission System Burns Hot Radioactive Waste 432

An anonymous reader writes "A hybrid fission-fusion process has been developed that can be used in some traditional fission reactors to process radioactive waste and reduce the amount of waste produced by 99%. This process uses magnetic bottle techniques developed from fusion research. This seems like the first viable solution to the radioactive waste problem of traditional nuclear reactors. This could be a big breakthrough in the search for environmentally friendly energy sources. Lots of work remains to take the concept to an engineering prototype and then to a production reactor."
This discussion has been archived. No new comments can be posted.

Fusion-Fission System Burns Hot Radioactive Waste

Comments Filter:
  • by SpuriousLogic ( 1183411 ) on Friday January 30, 2009 @11:32AM (#26666687)
    Scientific American just had an article on fast neutron reactors that get around the waste issue and don't create any weapons grade material: http://www.sciam.com/article.cfm?id=smarter-use-of-nuclear-waste&page=1 [sciam.com]
  • by SatanicPuppy ( 611928 ) * <.Satanicpuppy. .at. .gmail.com.> on Friday January 30, 2009 @11:36AM (#26666727) Journal

    I RTFA, but I'm still a bit snowjobbed because it's pretty light on detail.

    It seems like their touting the solution primarily as a way to reduce transuranic waste (sludge). There were no numbers based on how much more or less energy this process would produce.

    It's my understanding that re-enrichment is more about separating undepleted U-235 from depleted U-238, so I have no idea what reducing transuranic sludge would have to do with this. It might increase the (relative) percentage of U-235 enough to keep the fission reaction going, or it might just make the reaction slightly cleaner.

  • by Khaloroma ( 1381853 ) on Friday January 30, 2009 @11:46AM (#26666841)
    For those of you who probably are not familiar with the nuclear industry, let me make a very simple description of how "Nuclear Waste" is classified.<BR><BR>

    Waste falls into three categories:<BR>
    Low Level Waste (LLW)<BR>
    High Level Waste (HLW)<BR>
    Transuranic Waste (TRU)<BR><BR>

    LLW is anything that has been exposed to a reasonably low level of radiation. This is typically things like gloves, towels, suits, etc. and their activity level is usually low enough to store in a temporary facility until the activity level in them dies off enough to be disposed of safely.<BR><BR>

    HLW is primarily spent nuclear fuel that, in places like France, is usually reprocessed, but here it is typically either sent to be disposed of or onto research facilities, disposal, or weapons.<BR><BR>

    TRU waste is what the article has been discussing, which is a big problem. TRU waste comes about as nuclear fuel is fissioned out into various fission products. Obviously these fission products are radioactive and all depend on the type of fuel, but for old LWR/BWRs, there is a significant amount of TRU waste coming out. If what they claim is actually true, then it will be a very big step in the right direction.
  • by Anonymous Coward on Friday January 30, 2009 @12:02PM (#26667083)

    First, they have to get sustainable fusion working, then they can installed the Super-X Divertor to bleed off neutrons to burn fission waste.

    My understanding (which might be incorrect) is the only reason modern fusion reactors are unsustainable is that they don't produce more power than required for operation. That wouldn't be a problem if the fission half of this hybrid reactor has enough output, since the fusion reactor is really there to hit the spent nuclear fuel with neutrons to start secondary reactions that will produce the actual heat. It would be somewhat analogous to an electric ignition on a gas stove, or a pilot light on a central heater.

  • by SatanicPuppy ( 611928 ) * <.Satanicpuppy. .at. .gmail.com.> on Friday January 30, 2009 @12:10PM (#26667169) Journal

    Eviscerate? I think you mean incinerate.

    There are risks to all methods of energy production. There are plenty of other countries who routinely reprocess their waste already, so that scary bomb-grade material you're scared of is already available.

    Our disinclination to do reprocessing, coupled with the irrational nuclear paranoia of a subset of our population saddles us with a massive waste problem, outdated power plants, and a dependence on foreign fossil fuels.

    If we could build fast neutron plants, even, it would reduce our waste output by 99%, with no increase in likelihood of meltdowns.

  • by Ihlosi ( 895663 ) on Friday January 30, 2009 @12:11PM (#26667183)

    If at any point in this process (say you stop it at 50%) the 'waste' is now weapons grade this will never be allowed in the US.

    Producing weapons-grade enrichment (as in "can be used to build nuke") is _frikkin'_ expensive. You don't do that unless you _want_ to build a nuke, since it's a waste of money for any other purpose.

    If it's still 'radioactive' you can still get energy from it. You can refine it, clean it up and shove it back through again.

    Radioactivity is not a criterion for a nuclear fuel used in fusion or fission processes (but due to the mass of the atoms used in the latter, fission fuels are usually also radioactive). Maybe if you want to build a RTG (which isn't fusion or fission), but those are used only in space since they're beaten by pretty much any other power source in terrestrial applications.

    In fact, nuclear waste is way more radioactive than nuclear fuel.

  • by Kupfernigk ( 1190345 ) on Friday January 30, 2009 @12:17PM (#26667277)
    Fast breeder reactors turn out not to be as easy to make safe and reliable as their proponents think. Google for more recent literature. It's a pity, I personally like the idea, but both fast reactors and fuel reprocessing have turned out to be very difficult.
  • The liquid fluoride thorium reactor [theoildrum.com] can burn existing nuclear waste just fine, and it's been available since the 50's.

  • by R2.0 ( 532027 ) on Friday January 30, 2009 @12:25PM (#26667405)

    "Generations ago a single bomb couldn't incinerate millions of people."

    To eviscerate means, literally, to remove the viscera. That's innards in the colloqial.

  • Re:Breeder reactors? (Score:3, Informative)

    by jonored ( 862908 ) on Friday January 30, 2009 @12:27PM (#26667447)

    From what I can tell, this is asserting that breeder reactors can't effectively burn some of the elements that get produced, and this can. If you read carefully, they do mention that they want to do most of the reprocessing in less exotic reactors, and then just take the stuff that those can't effectively burn and "hit them with a sledgehammer", i.e. expose them to a much stronger neutron source, to burn /those/.

  • by JSBiff ( 87824 ) on Friday January 30, 2009 @12:28PM (#26667455) Journal

    "[1st and 2nd generation Thermal] Nuclear power [are] a dead end. No new [1st or 2nd Generation Thermal] nuclear plants have been built in 25 years". . .

    There, fixed it for you. Yes, old reactor designs are a dead end. They are prone to a risk of melt-down (though that risk has been, mostly, successfully managed for the past 30 years; yes, Three Mile Island was a problem, but, keep in mind that even with the TMI incident, the safety features of that reactor design prevented an escape of radiation when the melt-down did occur), they only extract a miniscule amount of the potential energy available in the fuel, and they create waste that "would have to be kept under armed guard forever".

    Nuclear physicists and engineers have continued to do R&D for the past 30 years, and they are proposing *new* ideas. When new ideas are presented, you can't just assume that the same arguments that were valid criticisms of the previous designs continue to be valid for the new designs.

    We have, right now, a Nuclear Waste problem, because of those previous generations of dead-end reactor designs, that must be dealt with. Putting the stuff into storage for 100000 years is not really a solution. The only real solution to the nuclear waste problem is to further process it to make the waste 'safe' and short lived.

    Now, I do not really know if the design proposed in this article is "the solution" or not. Maybe it is. There was also a solution proposed in the 1990s, called the Integral Fast Reactor, which was essentially melt-down proof - not because of systems put in place to prevent a possible melt-down, but because it used a different Nuclear Reaction called a Fast Nuclear reaction, instead of the older Thermal Nuclear reaction, and was such that if the reactor increased in temperature beyond the normal operating temperature, the reaction actually choked itself, sort of like a candle sealed in a glass container. They even successfully tested the design, by purposefully cutting off the cooling to a prototype reactor that the DoE built out in the desert somewhere, and it did, in fact, shut itself down as it is designed to do.

    The IFR design was also based around the concept of using our existing waste stockpiles as *fuel* for the reactor, producing hundreds of times more energy from that fuel, than older 'conventional' reactors do, which should have made it much more economically feasible.

    The reason I mention the Integral Fast Reactor, is that is an example of a new design which I've studied more about than this new fission-fusion hybrid in the article, which demonstrates that the old arguments don't *necessarily* apply to new designs. Every proposal must be studied and evaluated on it's own merits - you can't just make a sweeping statement that Nuclear power is a dead end.

    Unfortunately, the IFR project (which was being conducted by the Department of Energy) was canceled by the Clinton administration because of the same knee-jerk reaction to all Nuclear technology, exhibited by the parent, instead of really considering the IFR design on it's own merits or problems.

    Also, in regards to this new technology, it sounds like they are not necessarily proposing to build new plants, but to 'upgrade' existing plants. If we can upgrade the already built plants in such a way as to reduce our existing waste stockpiles, where is the downside? True, this new design, as with any new design, needs to be thoroughly evaluated and proven, and also compared to other proposals (for example, we should consider if this proposed design is actually superior to the IFR design - if not, we should be restarting the IFR project instead, perhaps) before we role it out to any large scale.

    *Maybe* we should have never gotten into the business of Nuclear Fission, but the fact remains that we have all this waste that we need to do something with. Why not 'burn' it in a new reactor type in such a way that we produce significantly less toxic, shorter lived waste? Environmentalists should be proponents of finding ways to deal with our nuclear waste problem, not object to every single proposal with a blanket statement that nuclear power is a dead end and re-hashing the same old tired arguments regardless of whether or not they apply to the new proposals.

  • by handy_vandal ( 606174 ) on Friday January 30, 2009 @12:36PM (#26667597) Homepage Journal
    President Gerald Ford issued a Presidential directive (October 1976) to indefinitely suspend the commercial reprocessing and recycling of plutonium in the U.S. This was confirmed by President Jimmy Carter in 1977. Link [wikipedia.org].
  • by silas_moeckel ( 234313 ) <{moc.proc-cnimsd} {ta} {salis}> on Friday January 30, 2009 @02:24PM (#26669163) Homepage

    Why? We have had what two failed reactors of note and together they put out far less radioactive anything than coal power plants. You seem to be scared and scared irrational fear has no place in decision making. Would I want to walk into one? No I also would not want to walk into the bottom of a coal power plants smoke stack. Nothing is perfect fission has it's risks but it's the least risky solution that does not involve reductions in living standards. In the modern world that might not seem to bad but having seem the 3rd world they need better living standards and abundant cheap power is part of getting them.

  • by Nyrath the nearly wi ( 517243 ) on Friday January 30, 2009 @03:15PM (#26669945) Homepage

    I RTFA, but I'm still a bit snowjobbed because it's pretty light on detail.

    There are more details at the following links:

    http://nextbigfuture.com/2009/01/university-of-texas-at-austin-proposes.html [nextbigfuture.com]

    http://nextbigfuture.com/2009/01/how-long-until-there-is-capable-fusion.html [nextbigfuture.com]

When you make your mark in the world, watch out for guys with erasers. -- The Wall Street Journal