Homepage Forums Policy Fusion Cleans Up Nuclear Waste from Fission?

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  • #1279

    I saw somewhere that it appears that D-T fusion processes can be used to clean up nuclear waste from current nuclear power plants and nuclear weapons. Cut it by 90% or more.

    If true, and if it’s cost-effective, this would be of very significant interest to federal policymakers, including Congress, and could help accelerate fusion R&D funding.

    First, is this true?

    Second might it be cost-effective?

    Third, has anyone thought about the use of aneutronic fusion to clean up fission-produced nuclear waste, comparing and contrasting aneutronic with D-T for this purpose?

    #11088
    AvatarTulse
    Participant

    As I understand it, aneutronic fusion wouldn’t be much use for cleaning up fission waste, since what you want to do with such waste is transmute the problematic nuclei, which entails a neutron source.

    #11089
    Avatarzapkitty
    Member

    Tulse wrote: As I understand it, aneutronic fusion wouldn’t be much use for cleaning up fission waste, since what you want to do with such waste is transmute the problematic nuclei, which entails a neutron source.

    Nope… neutrons can be generated without a neutronic fusion power source. In fact anyone can generate neutrons. All you need is electricity.

    For the task at hand, transmuting the waste from nuclear fission… artificially “aging” it into safer forms… you’d just need a lot of cheap, safe power.

    … and it’s FF to the rescue again! 🙂

    Aneutronic fusion would actually be both safer and cheaper than neutronic fusion in this task and FF would enable flexibility and portability on top of that.

    Instead of the concatenated expenses and increased hazards of trying to transport and integrate the nuclear fission waste into the fusion fuel process, FF units would power onsite particle accelerators wherever the waste happens to be located.

    So you’d swap the costly neutronic setup of tritium and neutrons and steam and turbines and the extensive modifications to the fusion fuel cycle… for a particle accelerator and on-site waste processing wherever the fission waste happens to be.

    The task must be done with whatever tools we have available. The problem is yet another Sword of Damocles hanging over our heads…

    (passing extraterrestrial: “Errr… quite a blade collection you people have up there on the ceiling…”)

    … but using FF units for the task would be a win-win-win situation.

    #11092
    Avatarzapkitty
    Member

    Mike Weber Goodenow wrote: I saw somewhere that it appears that D-T fusion processes can be used to clean up nuclear waste from current nuclear power plants and nuclear weapons. Cut it by 90% or more.

    If true, and if it’s cost-effective, this would be of very significant interest to federal policymakers, including Congress, and could help accelerate fusion R&D funding.

    First, is this true?

    Second might it be cost-effective?

    Third, has anyone thought about the use of aneutronic fusion to clean up fission-produced nuclear waste, comparing and contrasting aneutronic with D-T for this purpose?

    BTW… did you perhaps mean your topic title to be “Fusion Cleans Up Nuclear Waste from [em]Fission[/em]”…?

    #11093
    AvatarTulse
    Participant

    zapkitty wrote:

    As I understand it, aneutronic fusion wouldn’t be much use for cleaning up fission waste, since what you want to do with such waste is transmute the problematic nuclei, which entails a neutron source.

    Nope… neutrons can be generated without a neutronic fusion power source.

    Right, my point was not that all neutron sources were fusion-based, but that aneutronic fusion is, by definition, [em]not[/em] a neutron source, and neutrons are what is needed.

    In fact anyone can generate neutrons. All you need is electricity.

    Yes, but aneutronic fusion does not have some special advantage in radioactive waste transmutation [em]beyond[/em] producing cheap power. There is nothing [em]inherent[/em] in the aneutronic fusion process that makes it a good way to clean up radioactive waste.

    #11095
    Avatarzapkitty
    Member

    Tulse wrote:

    In fact anyone can generate neutrons. All you need is electricity.

    Yes, but aneutronic fusion does not have some special advantage in radioactive waste transmutation [em]beyond[/em] producing cheap power. There is nothing [em]inherent[/em] in the aneutronic fusion process that makes it a good way to clean up radioactive waste.

    While neutronic fusion… tritium and steam and turbines… makes a waste solution [em]possible[/em] it is not a particularly good solution and it integrates the waste problem into the power system.

    It’s better than nothing, it’s even better than thorium and if neutronic is all we can get we’ll have to take it.

    But if aneutronic fusion is achieved then it becomes the best waste solution hands down. As you say, the pB11 reaction itself can’t do anything about the waste. But as with so many other problems we face a source of really cheap and really safe power makes a better, safer solution not only possible but inevitable.

    Just the savings and safety benefits from not having to integrate the waste into the power supply means that aneutronic would win this one hands down. Again 🙂

    #11097
    Avatarzapkitty
    Member

    … late night thought…

    … and wouldn’t that be an ironic sight? An iconic sight? A decommissioned fission plant at night dotted with a couple of dozen FF units and none of them contributing to the grid. Because they don’t have to, the grid’s taken care of by other FF units elsewhere. A few of the units would be keeping the waste cooled while the rest powered the transmuters, the particle accelerators that “age” the waste into something we and the planet can live with.

    And it will have to go on for decades. At each plant. All that power just to hold the line and clean up the mess…. but aneutronic fusion would give us that power and buy us the time we need. The power and the time to clean up the mess safely and affordably.

    #11098

    Fascinating.

    Yes, I meant fission. I corrected that.

    Thanks.

    #11108
    Avatarvansig
    Member

    Tulse wrote: As I understand it, aneutronic fusion wouldn’t be much use for cleaning up fission waste, since what you want to do with such waste is transmute the problematic nuclei, which entails a neutron source.

    you might be able to do a lot using proton bombardment

    #11109
    Avatarzapkitty
    Member

    vansig wrote: you might be able to do a lot using proton bombardment

    … well, at least in current concepts, protons are what the accelerators are supposed to be accelerating. They are fired into a target just in front of the waste and the spray of neurons spalled off of the target are what actually do the transmuting.

    But currently such plans are hobbled both by energy costs and by proposed fixes that try to recover some of the heat generated during the process as electricity to help power the accelerators.

    And, again, FF shortcuts the vicious cycle: simply power the accelerators and be done with it.

    It will be a big, big project and much engineering will need to be done but that is true of any plan that would actually reduce the waste.

    What aneutronic fusion brings to the table is greatly reduced cost and greatly increased safety from the dual whammy of dirt-cheap power… and not having to make the waste a part of the power system.

    #11173
    Avatardennisp
    Member

    Hmm…do you really need to capture energy from the helium beam and use it to run a big expensive particle accelerator? What if you just let that 3% lightspeed beam of helium nuclei slam directly into the target? Are they going fast enough?

    If so, just do that, while capturing the x-rays as usual to help power the reactor.

    #11180
    Avatarjamesr
    Member

    The other aspect to D-T fusion fission hybrid designs is that you can take a fusion reactor (whether ICF or MCF) that would not be able to achieve nett gain on its own, to a system that with the extra heat of the actinide fission (plus decay heat of fission products) makes a whole system that can generate nett power. However unlike a standard fission reactor it is sub-critical without the fusion neutrons so there is no chance of runaway chain-reaction.

    So it has all the benefits of the accelerator driven sub-critical reactor ( http://www.world-nuclear.org/info/inf35.html ), but swapping the problems of designing a stable, efficient, high current particle accelerator with the problems of laser or magnet design.

    #11181
    Avatarzapkitty
    Member

    jamesr wrote: The other aspect to D-T fusion fission hybrid designs is that you can take a fusion reactor (whether ICF or MCF) that would not be able to achieve nett gain on its own, to a system that with the extra heat of the actinide fission (plus decay heat of fission products) makes a whole system that can generate nett power. However unlike a standard fission reactor it is sub-critical without the fusion neutrons so there is no chance of runaway chain-reaction.

    So it has all the benefits of the accelerator driven sub-critical reactor ( http://www.world-nuclear.org/info/inf35.html ), but swapping the problems of designing a stable, efficient, high current particle accelerator with the problems of laser or magnet design.

    (… pokes head back in…)

    Hmmm…

    Increasing stability in accelerators (uptime) is a point… we’re going to be at this for decades at a bare minimum… but with cheap power just how efficient would the accelerators need to be?

    So would the following comparisons be accurate? Have I skipped something? I tend to favor FF 🙂 but this seems like it would turn out very lopsided to me…

    The costs of FF units, the as-yet undesigned accelerators and handling the (very) hazardous waste on its trips through the accelerators… but it would all happen on-site and external to the power supply.

    versus

    The costs of neutronic fusion, steam handling, turbines and the additional problems and expenses of requiring the integration of the (very) hazardous waste as a part of the power supply… and the question of if using one of the neutronic fusion solutions would mandate prepping the waste for transport, transporting it cross-country and then handling it again for integration into the power supply?

    What have I overlooked? 🙂

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