Fukushima nightmare

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  • November 10, 2013 at 2:19 am #1522
    rashidas
    Participant

    The more I read about the Fukushima nuclear power plants and the thousands of spent fuel rods that need to be removed, the more disturbed I become. Any ideas on what can be done to deal with this situation in a practical way? The estimated clean up costs are astronomical.

    http://www.scientificamerican.com/article.cfm?id=nuclear-waste-lethal-trash-or-renewable-energy-source&page=5

    November 11, 2013 at 10:17 pm #12979
    KeithPickering
    Participant

    In the first place, your link doesn’t discuss Fukushima cleanup at all, which is a separate issue from nuclear waste. In the second place, there are a number of reactor designs than can use spent fuel for fossil-free energy.

    It’s only “waste” if we don’t use it.

    November 11, 2013 at 11:01 pm #12980
    rashidas
    Participant

    The link I added was just a discussion of the pros and cons of recycling spent fuel rods. The real issue is can the spent fuel rods from Fukushima Reactor #4 be removed safely, stored and sent soemwhere else for recycling. If somethings goes wrong nuclear energy will be rejected by public opinion.This will also negatively effect fusion development.

    November 11, 2013 at 11:23 pm #12981
    zapkitty
    Participant

    KeithPickering wrote: In the first place, your link doesn’t discuss Fukushima cleanup at all, which is a separate issue from nuclear waste.

    Er… the spent fuel pool atop Unit #4 is not a Fukushima cleanup issue?

    Hopefully TEPCO will get away with trying to offload it manually but the fact is that if worst comes to worst then it could become an international contamination issue.

    KeithPickering wrote: In the second place, there are a number of reactor designs than can use spent fuel for fossil-free energy. It’s only “waste” if we don’t use it.

    So the first thing we need to do is build more fission reactors?

    I’d suggest that… if the #4 pool survives offloading… that the first thing we do is ensure that all nuclear power plants and any offsite nuclear waste storage facilities de-crowd their remaining spent fuel pools immediately by dry-casking what they can and building new pools as they are needed.

    A pool sitting directly over a reactor is not a good place to store spent fuel.

    November 12, 2013 at 9:49 am #12984
    delt0r
    Participant

    We have a lot of spent once through fuel rods lying around. Most of it is not in dry casket or otherwise so could be used in breeders with reprocess. Right now its about the only way to get its volume and lifetime down to manageable levels. If you add some neutronic fusion to the mix you could have sub critical fission piles that are safer to use to burn this waste.

    Eitherway, we have got this waste and we need to deal with it. A all nuclear is bad don’t do it will not make it go away. Saying there is no problem leave it as is will also no make it go away as TEPCO has found out.

    November 12, 2013 at 7:16 pm #12986
    rashidas
    Participant

    The dangers and costs of nuclear waste materials and spent fuel rods are well documeted:

    http://www.ess.uci.edu/~cdholmes/pubs/dennis2009.pdf

    Many more references can be found on the Internet. FF proponents should be careful to separate themselves from this problem in promoting this technology. To the public fusion sounds like fission – both are nuclear energy in different forms. Just a word to the wise. In the long run we must deal with this issue in a realistic way. Like it or not we are stuck with this problem for generations to come.

    November 14, 2013 at 11:51 pm #12989
    rashidas
    Participant

    Excuse my ignorance but would is it possible to modulate gamma rays in any way? Aneutronic fusion design provides for mitigation of X-rays using “onion” mitigation. Can something similar be done for gamma rays?

    November 15, 2013 at 3:32 am #12990
    zapkitty
    Participant

    rashidas wrote: Excuse my ignorance but would is it possible to modulate gamma rays in any way? Aneutronic fusion design provides for mitigation of X-rays using “onion” mitigation. Can something similar be done for gamma rays?

    I take it that you mean the gamma flux from spent
    fuel rods?

    I don’t believe that the “onion” has much special
    power of shielding beyond the amount of bulk
    material it places in the path of the x-rays.

    As of now the practical solution to gammas is to
    place an appropriate amount of lead or earth or
    water or whatever around the gamma source…

    … if you can.

    November 17, 2013 at 4:11 pm #12991
    zapkitty
    Participant

    First, on Nov 12, TEPCO admitted to the general public that it has already
    kept 3 damaged fuel assemblies in the reactor 4 spent fuel pool (SFP) for
    upwards of 25 years     because TEPCO couldn’t move them to the common
    pool or do much of anything else with them.

    And then, on Nov 16, TEPCO casually mentions that there are actually some
    80 such damaged assemblies known to be stranded in the various reactor
    SFPs… and that some have been stuck in those pools for over 40 years.

    November 18, 2013 at 9:47 pm #12997
    vansig
    Participant

    the damaged assemblies are presently too hot to handle in those areas, both for humans and for robots;
    so they’re stuck there, basically forever. you cant move them, and you cant abandon them to let the water run dry.

    things will remain this way until someone can make a radiation-resistant robot capable of recovery.

    so, how much will that cost? let’s name that tune..

    i could do it if you hand me a cheque for $100M

    anyone with a lower number?

    November 19, 2013 at 1:05 pm #13001
    delt0r
    Participant

    vansig wrote: the damaged assemblies are presently too hot to handle in those areas, both for humans and for robots;

    No they are not. Robots can handle it fine. Electronics when designed with high radiation in mind can handle it fine. In fact the problem with damaged assemblies is active material getting into the cooling water and then delocalization of the radiation. Not an increase in radiation. Waste is not safe to eat or anything. But not some get within 30 feet turn into Godzilla thing either.

    November 20, 2013 at 9:48 pm #13002
    vansig
    Participant

    delt0r wrote:
    Robots can handle it fine. Electronics when designed with high radiation in mind can handle it fine.

    i have no doubt such equipment can exist. but where is it today?

    November 21, 2013 at 6:30 am #13005
    Francisl
    Participant

    There have been some radiation robots working at Fukushima. The ideal robot doesn’t seem to exist yet.

    November 21, 2013 at 9:53 am #13006
    delt0r
    Participant

    Its not even really about bots existing. Its about “can we just leave it safely”. Granted these guys may not have asked that. But its point to consider. Every time you move these things you have a chance of making things worse. Not better. Keeping the pools topped with water is a known quantity.

    November 21, 2013 at 3:46 pm #13007
    Francisl
    Participant

    I have some questions. Is this radioactive waste chemically corrosive? Is the radiation so intense that it destroys the structural integrity of any containers? Are the spent fuel rods and damaged reactors experiencing natural radioactive decay or are sub-critical nuclear chain reactions occurring?

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