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Solution for nuclear waste?

  1. Apr 3, 2007 #1
    This may seem extremely stupid, but what if we did the following:

    1. Grinded up nuclear waste.

    2. Mixed it with tonnes and tonnes of radio-inactive earth.

    3. Put it back where we mined the uranium in the first place.

    I understand that most of nuclear waste is just uranium, the remainder is more active radioactive isotopes like cesium and iodine.

    So how would the area be any more radioactive than before the uranium ore was mined, especially after the more active elements had decayed to reasonable levels?

    A problem I see is the chemical toxicity/affects, not related to radiation, of some of the compounds/elements within the spent fuel.
  2. jcsd
  3. Apr 3, 2007 #2


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    Spent fuel is more than just uranium and isotopes of Cs and I.

    There is a spectrum of radionuclides, many of which are short-lived, which decay in hours, days, weeks, months, years. Every 10 half-lives, the specific activity decreases by 3 orders of magnitude (~1000, or actually a factor of 210=1024). So in 30 half-lives, the activity has decreased by a factor of 1 billion, which great for most isotopes.

    However, there are a few isotops that have half-lives of 100's or 1000's of years. Those must be kept immobile for millenia or 10's of millenia, and hence the challenge.

    Then consider the matter of groundwater penetration, dissolution and consequent transport.

    If one were to grind the waste - then one would likely have to calcine and vitrify it, i.e. convert it to a relatively impermeable state, and then surround it with something entirely inert.

    The French do this with the waste from the reprocessing plant, i.e. after they remove the uranium, plutonium and most of the transuranics beyond Pu, in order to reuse/recycle the U, Pu and TU.
  4. Apr 3, 2007 #3


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    Yes - the largest percentage component of nuclear waste is the U-238 that was also the
    largest component of the fresh fuel.

    As Astronuc points out; there's more than just Cesium and Iodine in the nuclear waste;
    there's a whole spectrum of nuclides.

    However, they do fall into two classes; fission products and transuranics [actinides].

    The transuranics [actinide] are those that are heavier than Uranium. Some also have long
    half-lives; like Pu-239 with a half-life of 24,000 years. However, these materials can
    also be used as fuel. They should be recycled back to the reactors as fuel. The USA
    is also considering building "actinide burner" reactors, fast reactors that are particularly
    adept at transmuting actinides to shorter lived nuclides.

    The other class are fission products. They have short half-lives, so they are very
    radioactive at first. However, that radioactivity dies down more quickly than the
    actinides. In a relatively short time, these nuclides decay to activities that are
    less than the original uranium that was dug up. You don't need to dilute them;
    just wait long enough.

    Nuclear waste disposal isn't so much a technical problem as it is a political problem in
    the USA. There have been plans for nuclear waste disposal for as long as the USA has
    had nuclear reactors.

    It's just portrayed in the popular press as this overarching technical problem that nobody
    knows how to solve. The problem is basically a political one - not a technical one.

    Dr. Gregory Greenman
  5. Apr 4, 2007 #4

    Andrew Mason

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    While there is no doubt a large political problem, there are technical problems as well. For example, the metal containers for the radioactive material break down over time due to the presence of corrosive elements in the waste.

    My own view is that it is a terrible waste to dispose of material that is in limited supply and which contains a huge amount of potentially useable energy (when the nuclear technology is developed to use it safely and securely). Just store it for another 60 years. Then we will be mining the waste instead of opening new low-grade uranium mines and dumping thousands of tonnes of chemically processed tailings in huge tailings pits.

  6. Apr 4, 2007 #5


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    I'm afraid that's INCORRECT!!! This issue has been studied extensively and modeled
    via computers and extensive accelerated laboratory testing:



    The tests also have shown that the canister metals have extremely high resistance to all forms
    of localized corrosion and stress corrosion cracking in environments relevant to the repository.
    Also, no appreciable differences have been noted in corrosion rates obtained from the various
    water compositions and temperatures. The testing results support Livermore’s models for
    long-term prediction of the waste packages’ performance and strongly confirm the selection of
    Alloy 22 for the outer canister.

    Scientists at LLNL and other national labs involved in the Yucca Mountain Project
    reported to then Secretary of Energy Bill Richardson that the development of the
    Yucca Mountain project should proceed.

    Corrosion of the metal containers is not expected untll LONG after the radioactivity
    of the waste has decayed below levels at which the uranium ore was originally dug
    from the ground, if the USA were to reprocess / recycle nuclear waste. The waste
    containers now are being developed with lifetimes of over 10,000 years. If the USA
    were to recylce / reprocess nuclear waste; such that only the fission products needed
    to be buried; those decay to radioactivity levels lower than the original uranium in only
    a few hundered years - NOT the 10,000. So the current 10,000 year metal containers
    provide a very significant safety margin.

    Additionally, the waste is locked in a matrix of borosilicate glass; the metal container is
    just an additional layer of defense against migration of the waste; not the only defense.

    Dr. Gregory Greenman
    Last edited: Apr 4, 2007
  7. Apr 4, 2007 #6

    Andrew Mason

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    I agree that if the waste is first reprocessed to remove fission products and plutonium, there would be no problem at all. But that is not currently the plan. Unless the plutonium and higher actinides are removed, I think that the waste has to be stored for much longer than 10,000 years (Pu having a half life of 24000 years).

  8. Apr 4, 2007 #7


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    Even if the USA doesn't change its plans on reprocessing; the latest results on
    accelerated corrosion tests show that these alloys will be fine for storage of even
    long-lived actinides like Pu-239:


    "Based upon measurements of corrosion rates of passive metals, the waste
    packages remain intact with no penetrations due to corrosion for durations of
    10,000's and even 100,000's of years."

    Dr. Gregory Greenman
    Last edited: Apr 4, 2007
  9. Apr 26, 2007 #8


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    Reprocessing creates it's own problems in the shape of huge amounts of low level radioactive waste. France and Britain who took on reprocessing to get plutonium to build bombs dump most of the LLW their process generates into the sea.

    Personally before any more reprocessing plants are built I'd like to see responsible proposals for how LLW is going to be managed and using the sea as a giant dustbin doesn't come under the heading of responsible.
    Last edited: Apr 26, 2007
  10. Apr 26, 2007 #9
    Well, if the U.S. is looking into Yucca Mountain for spent fuel, I can't see why we'd need to find another place for low level waste.

    I heard from one of my professors that at current rates, Yucca Mountain would last 30 years before being filled up. If we reprocess the waste, it would last 300 years.
  11. Apr 26, 2007 #10


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    Reprocessing generates far more radioactive waste than it eliminates.

    The actual figures for LLW produced through reprocessing and the LLW produced through the once through cycle are ~8,000 m3/GWe-yr (cubic meters per Gigawatt electricity-year) of low level waste for reprocessing compared with ~500 m3/GWe-yr LLW produced through the once through cycle.

    It is a complete fallacy that reprocessing eliminates waste. The reality is it does the complete opposite!

    On a related topic people seem to get hung up on materials such as plutonium which have very long half-lives but the real danger to people comes from radioactive material with half lives comparable to human lifespans. The reason plutonium has such a long half-life is because it isn't very radioactive and so not very deadly. Picking up a block of plutonium will do you no harm at all whereas materials such as C-60 have much shorter half-lives (a little over 5 years) but are correspondingly far more deadly. Close exposure to 1 gram of C-60 for a few minutes is enough to kill you.

    However if it is the long half life elements that concern you then you only need to look at some of the waste these plants are pumping into the ocean such as I-129 with a half life of 16 milllion years! And instead of the discharge of this element decreasing over time with better technology and filtraton systems in the case of Sellafield it has actually increased 10 fold since 1970.


    America made a very sensible decision when it decided not to go down the reprocessing route.
    Last edited: Apr 26, 2007
  12. Apr 26, 2007 #11


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    I'm afraid this is 100% WRONG!!!

    Reprocessing is a chemical separation; so it CAN'T create any additional

    About 94% of the nuclear waste is U-238 that has not undergone any type of neutron
    capture and transmutation.

    This U-238 is no more radioactive than the day it was dug out of the ground.

    Reprocessing nuclear waste REDUCES the amount of material to be disposed of.
    It takes material out of the waste stream that DOES NOT need to be treated as
    high level waste.

    The anti-nuclear crowd has been propagating the MYTH that reprocessing increases
    the amount of waste for a long time. Unfortunately, you fell for it.

    Dr. Gregory Greenman
  13. Apr 26, 2007 #12
    That site seems like anti-nuclear propoganda effort. Also, I tend not to trust sources that cite economic benefits/problems as the first case against reprocessing. How can they call themselves enviromentalists if they're worried about the economy? One or the other in my opnion.

    I wonder what makes up that 7956 cubic meters of "liquid discharges" that they say in included in the figure. Maybe something like water?
  14. Apr 26, 2007 #13


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    In any case, it CAN'T BE MORE - haven't the IDIOT anti-nukes ever heard of the
    conservation of mass?

    As I stated in my response to Art; a chemical process like reprocessing can't make
    ANY additional radioactivity; ONLY the reactor can do that.

    The IDIOT anti-nukes are evidently counting the U-238 as LLW [ low level waste ]. The
    U-238 IS mildly radioactive due to its half-life of 4.5 Billion years. However, the
    radioactivity of the U-238 has NOTHING to do with the operation of the reactor.

    The untransmuted U-238 was slightly radioactive when it was dug out of the ground, and
    slightly radioactive when it went into the reactor, and slightly radioactive when it came out
    of the reactor.

    However, the untransmuted U-238 is no more radioactive than when it was dug out of the
    ground - so nobody should be upset if you just PUT IT BACK the way you FOUND IT!!!

    It's just another example of the lack of scruples of the anti-nukes; specious arguments
    like this abound from them. However, a well-informed public that is well-versed in the
    sciences, a service that this forum provides; will not be gullible enough to fall for it.

    Dr. Gregory Greenman
  15. Apr 26, 2007 #14


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    Morbius it is you who are WRONG!!!

    The post I responded to was in relation to the VOLUME of radioactive material and as my post clearly shows the data I provided was in relation to the VOLUME of radioactive waste!!!!!!!!
  16. Apr 26, 2007 #15


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    Are you being serious re the part I bolded?? Are you seriously suggesting U-238 ore is not dangerous to health. As someone who works in the industry you have to be aware that a study in 1980 showed that 50%! Yes, that's right! 1 in every 2 miners who had dug out uranium ore for America's nuclear program in the 50s and 60s died of lung cancer.
    Last edited: Apr 26, 2007
  17. Apr 26, 2007 #16


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    Did you look at the title of the second source I provided? It's a report commissioned by the European Parliament!!!

    Here's a further extract from the same report showing the practical implications of Sellafields dumping policy;

    And as regards risk to humans
    Is this an acceptable risk to you?

    And if I apear to be a little ticked off over Sellafield it's because I live in Ireland and the British were kind enough to build their reprocessing plant on their east coast so that in the event of an accident the prevailing winds would blow the contamination over to us as happened in 1957. Plus of course we can't / won't eat sea food from the irish Sea as it is so heavily polluted with radiation.
    Last edited: Apr 26, 2007
  18. Apr 26, 2007 #17


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    WRONG!!!! WRONG!!! WRONG!!!!

    You are taking stuff OUT of the waste stream that doesn't need to be there.
    It doesn't matter whether you are measuring by mass or measuring by volume;
    if you are REMOVING material from the waste stream - you are REDUCING
    the amount of waste.

    If you take 95% of the MASS of the waste away, because it really isn't any more
    radioactive than when you put it into the reactor; you also reduce the VOLUME
    significantly too.

    Here's a statistic for you. If you use nuclear power to generate all the electricity that
    a family of 4 uses in 20 years with a once-through fuel-cycle - then the volume of waste
    that must be disposed of [ prorated for this family ]; fits in a shoe-box.

    if you reprocess; then the same electricity can be generated yielding a volume of waste
    that fits in a "shot-glass" or "pill-bottle".

    The plain facts are that 95% of the mass / volume of nuclear waste is stuff that is NOT
    really radioactive waste. If you remove it; you reduce BOTH mass and volume.

    I've argued this with many anti-nukes before. It all comes about because of a
    misunderstanding of the science on their part. The anti-nukes think that if you
    expose the reagents, the chemicals one uses to scavenge the uranium from the
    waste, that the exposure of these reagents to the gamma and beta radiation from
    the nuclear waste, that the reagents then become radioactive themselves and
    contribute to the volume or mass of the waste.

    That is just plain UNTRUE!!!! Just because a material is exposed to gamma or
    beta radiation, doesn't make it radioactive. That's why I stated that reprocessing
    is a chemical process, not a nuclear process. Chemistry doesn't
    alter the nucleus of the atom, which is what one needs to do to make it radioactive.
    More stupidity and ignorance on the part of the anti-nukes.

    That 50% of uranium miners died statistic is BOGUS too!! Yes uranium miners in
    the '50s and '60s did experience higher radiation exposure; but that 50% died as a
    result has been debunked. Quit reading junk from the anti-nukes, and read what
    good scientists like from Lawrence Berkeley Lab have to say:


    Uranium miners of the '50s and '60s also turned out to be heavy smokers,
    as compared to the general population.

    Besides mining practices in the '50s and '60s pale compared to what is being
    done NOW - and THAT'S what matters for the future.

    Don't let the IDIOT anti-nukes make a fool of you,. THINK about it.

    Dr. Gregory Greenman
    Last edited: Apr 27, 2007
  19. Apr 26, 2007 #18


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    For Heaven's sake, put your THINKING CAP ON!!

    U-238 is an alpha radiation emitter. Alpha particles outside the body can't
    even penetrate the dead layer of skin. So as long as you don't breathe or
    injest U-238; it can't hurt you.

    When uranium is mined, the miners are grinding the rock face of the tunnel
    exposing new surfaces. That creates air-borne dust. Even if you put water
    sprays on to keep down the dust, the newly formed surfaces also release
    radioactive gases that are daughter products of uranium.

    However, when we go to put the U-238 back into an existing tunnel; we
    don't need to grind new tunnel. The U-238 can be in any form we want;
    metal, ceramic oxide... The point is - it WON'T be air-borne.

    Encase the U-238 in a sealed metal box if you like. Drop it off in the tunnel,
    and when you are through; backfill it. Who cares if the metal box survives.
    If it breaks down after 1000 years; that will just mean that for 1000 years,
    it had a steel isolation box that it wouldn't have had if it had never been
    mined in the first place.

    Dr. Gregory Greenman
    Last edited: Apr 26, 2007
  20. Apr 26, 2007 #19


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    NO - that decision has been decried by the National Academy of Science and
    Engineering as a BIG MISTAKE!!!!

    The USA's BEST scientists disagree with it.

    The founder of Greenpeace, Dr. Patrick Moore; endorses nuclear power:


    Dr. Gregory Greenman
    Last edited: Apr 27, 2007
  21. Apr 26, 2007 #20


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    Who cares who commissioned it!!! Who DID the study? WISE-Paris,
    an anti-nuclear group. Hardly what I would call authoritative.

    How can one make a judgment; they didn't quantify the risk.

    They hypothesize an accident. What is the risk - the PROBABILITY
    of the hypothesized accident? Is the risk a million to one, a billion to one...?

    Suppose we have 500 people in a 747 airliner. If all the engines quit, then
    the plane will crash and all 500 people will be killed. Is that an acceptable
    risk for you?

    Don't you see how scientifically SHODDY such a statement is? People fly in
    747 airliners all the time, because the probablility of that event happening is
    next to nil.

    So is the hypothesized release from Sellafield.

    You just got "snookered" by anti-nuclear propaganda.

    Keep believing in this tripe, and you will have your anti-nuclear merit badge in no time.

    Dr. Gregory Greenman
    Last edited: Apr 27, 2007
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