Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Nuclear waste disposal by breakdown

  1. Mar 7, 2009 #1
    since nuclear waste decays due to it emission of radiation why not bombard it with high energy particles so that the particles can react with it and break it down to more stable products?????

    not sure about finer details and thought we should put it out for discusion
     
  2. jcsd
  3. Mar 7, 2009 #2
    I think that's called a breeder reactor.
     
  4. Mar 7, 2009 #3

    Morbius

    User Avatar
    Science Advisor

    Vals509,

    That's EXACTLY what happens if one reprocesses / recycles spent nuclear fuel as the
    French, British, Japanese, Swedes..... do.

    If you reprocess the waste to take out the small amount of fission products, which "poison"
    the reactor; you can put the spent fuel back into the reactor and it gets bombarded with neutrons,
    and the long lived component of the waste, the actinides; are also good fuel and they will fission
    and give you more energy and turn into short-lived fission products.

    Unfortunately, the anti-nukes got Congress to OUTLAW reprocessing / recycling in the USA
    back in 1978. Get Congress to change the law so that the USA can do what the other countries
    that use nuclear power do. You don't see France looking for a Yucca Mountain to hollow out;
    because they don't need to - they have short-lived waste.

    If you are talking as some have suggested in using particles from a nuclear accelerator - you run
    into problems with the number of particles you can accelerate. You would need MILLIONS of amps
    of accelerator current to transmute large amounts of waste. It has been suggested - but it is not
    really practical - especially compared to just recycling the fuel.

    Dr. Gregory Greenman
    Physicist
     
  5. Mar 11, 2009 #4
    why hasn't anyone put reprocessing on the list and proposed it to congress???????
    31 years is an awfully long time for something to be banned and not proposed again
     
    Last edited: Mar 11, 2009
  6. Mar 11, 2009 #5

    Morbius

    User Avatar
    Science Advisor

    Vals509,

    Congress IS advised. However, this is one of those things that Congress is afraid to touch;
    like Social Security.

    There's so much IGNORANCE in the populace about reprocessing / recycling that Congress
    is afraid to reconsider this. They are too afraid of the environmental groups.

    If Congress were to consider shipping spent fuel to a reprocessing plant - the environmentalists
    would be screaming "Mobile Chernobyl" - just like they did about Yucca Mountain.

    If you haven't heard; President Obama has essentially killed the Yucca Mountain project in the
    2010 proposed budget. So we won't be able to reprocess / recycle our spent fuel - and we won't
    have any place to store it either.

    The politics are NOT moving in a good direction for nuclear power.

    Dr. Gregory Greenman
    Physicist
     
  7. Mar 11, 2009 #6

    QuantumPion

    User Avatar
    Science Advisor
    Gold Member

    Are you sure it was a congressional law that prohibited reprocessing? I thought it was an executive order, signed by Carter, rescinded by Reagen, and re-enacted by Clinton.
     
  8. Mar 11, 2009 #7

    Morbius

    User Avatar
    Science Advisor

    QuantumPion,

    YES - POSITIVE!! The name of the law is "The Nuclear NonProliferation Act of 1978"

    There are a bunch of people saying it was an Executive Order - but it is NOT - it is a LAW of
    Congress.

    "Nuclear NonProliferation Act of 1978" Public Law 95-242 [ HR 8638 ] approved 10 March 1978

    Dr. Gregory Greenman
    Physicist
     
  9. Mar 12, 2009 #8
    I hate to be the voice of dissent but the NNPA did not outlaw reprocessing in the US. Here is the link for (most) of the text of the act http://www.nti.org/db/china/engdocs/nnpa1978.htm" [Broken] and it was designed to specifically address the dissemination of nuclear materials to non-nuclear states (i.e., import/export of nuclear fuel and uranium processing technology).
    Another.
    http://www.enotes.com/major-acts-congress/nuclear-non-proliferation-act" [Broken]
    There are a host of other sources out there which also point out that reprocessing is NOT outlawed. It's just too expensive right now. I've had to explain this before and no one has ever provided a link to show that it is outlawed. Specific sources are
    http://www.princeton.edu/~globsec/publications/pdf/Sciencev293n5539.pdf" [Broken]
    http://ftp.fas.org/sgp/crs/nuke/RS22542.pdf" [Broken]
     
    Last edited by a moderator: May 4, 2017
  10. Mar 12, 2009 #9

    Morbius

    User Avatar
    Science Advisor

    daveb,

    As you stated - your link gave the text for MOST of the Act - but NOT ALL!!!

    I have the text of the COMPLETE ACT - including the section that outlaws reprocessing.
    I haven't found an online reference with the complete text.

    Here is a reference courtesy of the Federation of American Scientists:

    http://www.fas.org/blog/ssp/2008/05/nuclear-non-proliferation-act-is-good-policy-30-years-on.php

    Through the NNPA, the U.S. committed to using a “once-through” nuclear fuel cycle which cools and then
    stores spent uranium fuel rods intact with the plutonium and other nuclear wastes that are radioactive
    enough to make theft of the material almost impossible.


    Whether by law or by Executive Order; the nuclear industry is not going to invest in a major facility for
    reprocessing spent fuel when the operation of the facility could be precluded by the results of the next
    election. Witness the West Valley and Barnwell facilities that were built in the '70s for the reprocessing
    of spent fuel; and had to be abandoned during the Carter Administration.

    We can't have the disposition of spent fuel be a political football - the USA has to make choices and make
    decisions and stick with them. In the Nuclear Waste Policy Act of 1982, Congress decreed that spent fuel
    would be dealt with by geologic disposal; and instructed the DOE to study potential sites. In the Nuclear Waste
    Policy Act of 1987, Congress decreed that the repository site would be Yucca Mountain, Nevada.

    Under LAW, the policy of the USA has been that spent nuclear fuel would be disposed of in Yucca Mountain,
    and the Courts have held that this is actually a contract with the US nuclear industry. However, withing the
    last few weeks, the first budget of the Obama Administration has essentially killed the Yucca Mountain project.

    This is akin to the case of the Shoreham Nuclear Power Plant where the then Governor of New York, Mario Cuomo
    was able to essentially "veto" the operation of the plant by appointing PUC members that ruled that LILCO could
    not charge any money for Shoreham electricity.

    We need to decide if we want nuclear power or not. We need to decide whether we want to reprocess / recycle
    our spent nuclear fuel. We need to decide if we are serious about disposing of spent nuclear fuel that we have
    already accumulated in 50+ years.

    So far, these questions are currently all "policy" questions; and policy can swing from one extreme to the other
    depending on the whims of the ballot box. We need to remove these questions from the "policy" realm and encode
    them into LAW.

    We need to decide whether nuclear power, reprocessing / recycling, and spent fuel disposal are going to legal or
    illegal in the US - and not leave those questions to the whims of politicians. The industry isn't going to invest capital
    when the system is as unpredictable as it is now.

    Dr. Gregory Greenman
    Physicist
     
    Last edited by a moderator: May 4, 2017
  11. Mar 13, 2009 #10
    But what is the purpose in killing Yucca? Could it be a move toward IFR style breeders? After all if we are going to use the stuff as fuel it would be a bad idea to glassify it and bury it. Could the IFR process get past the law against enrichment?
     
  12. Mar 16, 2009 #11
    Another approach to nuclear waste disposal was the design project using a powerful proton beam called Accelerator for Transmutation of Waste, or ATW. One design used a multimegawatt proton beam, another used a subcritical reactor confuguration that was made critical by turning on the proton beam to produce extra neutrons. Google "ATW proton" for some papers.
     
  13. Mar 17, 2009 #12

    vanesch

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    You will, in any case, need a repository for waste. What reprocessing and fast neutron spectra can bring you, is that the waste will *mainly* consist of fission products of which *most* have a half life of 30 years or less, which means that they need to be isolated from the biosphere *essentially* for, say, something like 500 years.
    But there *are* a few long-living fission products produced in small amounts, and there *will* be minor actinides and so on in the waste, only much less than with a thermal spectrum and without reprocessing.

    So the BULK of the waste will improve in "quality" if we go to a fast spectrum and do reprocessing, but it will still require at least 500 years of "locking up" and there will always remain impurities for which it is better to keep them locked away as long as we can, and release them as slowly as we can. The nice thing of a fast spectrum is that these are on the level of "impurities" with a fast spectrum and reprocessing, while they are a "serious fraction" with thermal spectrum and once through. But it is impossible in any case to get *entirely* rid of them in any case.

    What this means is that your requirements for the repository can be more relax. The human barriers will be doing most of the work. But not that you can do without (unless you want to keep those waste cylinders in some kind of building on which you will need to keep an eye for several centuries...)

    Now, you can have a fast spectrum in a fast reactor (a breeder say, something like the IFR), but also in subcritical systems such as those ATW facilities under investigation. These systems are pretty much alike concerning the ultimate waste they will produce. I never understood the large advantages an ATW is to have over a fast reactor. Yes, I know, you can burn much larger concentrations of minor actinides in an ATW.
     
  14. Mar 21, 2009 #13
    The link above is clear enough as daveb has indicated, and it does not preclude reprocessing, as it has an "except" clause that only requires the reprocessing facility to comply with IAEA security requirements for weapons useable materials. In light of 911 attacks, this is not unreasonable.

    Also, as others have mentioned, this act of President Carter's, which was a continuation of President Ford's Nonproliferation efforts, could have easily been over turned by the 31 years of Congress since it, if it were such a bad law. We could be reprocessing today as we have had 20 years of Republican presidents since then.

    It is often forgotten that President Carter's administration, led by Admiral Rickover and his core designer Dr. Alvin Radkowsky, reprocessed thorium containing fuel to obtain the bred U233 to fuel the Light Water Breeder Reactor (LWBR) recoring of the first commercial power plant at Shippingport, PA. Unfortunately, its highly successful net breeding of U233 from thorium in a Light Water Reactor (LWR) conclusion was blotted out by the Three Mile Island accident.

    The 'environmentalists' are a convenient scapegoat, but quite frankly, they are not politically powerful enough to enforce a 31 year reprocessing ban. Poor economics killed reprocessing, as GE & Getty Oil, two of the West Valley commercial reprocessing facility's owners, found out. West Valley ended up a Superfund site.

    Reprocessing only extends the uranium resource by ~30%, as plutonium is a lousy reactor fuel and Mixed OXide (MOX) fuel expensive and produces a worse TRU waste than its previous plutonium feed.

    There is an exception to this and it is again Dr. Radkowsky's ingenious "Seed & Blanket Unit" (SBU) design that uses a thorium Blanket that surrounds an enriched uranium or 'reprocessed plutonium' Seed. The construction of the SBU was started during the Clinton Administration as part of the destruction of Russian excess military plutonium in their VVER (their acronym for their Pressurize Water Reactors - PWRs). Testing continues today, albeit on a shoe string, as part of Thorium Power, Inc. and BNL's oversight and sponsorship.

    Here are a few references:
    http://www.thoriumpower.com/default2.asp?nav=technology_solutions&subnav=plutonium"
    http://www.thoriumpower.com/files/Nuclear Future Article.pdf"
    http://www.thoriumpower.com/files/Pu_incinerator.pdf"
     
    Last edited by a moderator: Apr 24, 2017
  15. Mar 21, 2009 #14
    West Valley was abandoned for economic reasons & became a Superfund site. Almost all reprocessing in the world today is being phased out because of its poor economics, and only exists because of huge government subsidies. Here is an excellent paper by Princeton University's Dr. von Hippel on the subject of the failed economics of reprocessing:

    http://www.fissilematerials.org/ipfm/site_down/ipfmresearchreport03.pdf" [Broken]

    If reprocessing was such an excellent approach, why is the EU seriously looking at Molten Salt Reactors (e.g., Russia's MOSART & France's TMSR) and Accelerator based Spallation-Transmutation (e.g., Nobel Laureate Rubbia's "Energy Amplifier")?

    The Reagan Administration passed both of those laws authorizing Yucca Mtn. over the reasonable objections of many who have a fairly good understanding of nuclear waste. Remove the TRUs (TransUranic isotopes of which Pu is the largest TRU fraction), and you remove most of the heat, proliferation, unintentional criticality, and long lived isotopes. Had the Ancient Egyptians buried Spent Fuel 5,000 yrs ago, 87% of the Pu239 (the best bomb material) would remain and due to the shorter half-lives of the other Plutonium isotopes, it would be the excellent bomb grade fissile.

    The problem is MOX is uneconomic without large, continuous government subsidies and the IFR and other fast sodium cooled reactors either make more plutonium or produce an even worse TRU waste problem and are much less safe than LWRs, and far more expensive.

    Dr. Radkowsky's metal fuel rod (the "Seed") reduces the cost of fabrication and can attain the high burnups of Liquid Metal Fast Reactors (LMFRs, LMFBR, IFR, etc.) and High Temperature Gas Reactors (HTGR), or Pebble Bed Reactors (PBRs). However, unlike those reactors, which do not exist in quantity or even in the commercial marketplace, Radkowsky (Thorium Power, Inc.) system is a fairly simple recoring of existing PWRs with the Pu or enriched Uranium Seeds and a Thorium based MOX blanket. The Seed burns up to 150,000 MWd/ton in 3 years and the Blanket burns up to 100,000 MWd/ton in 10 years, both of which are being tested today. Contrast that to today's current 40,000-60,000 MWd/t burnup maximums in today's PWRs & BWRs, or the proposed 100,000 - 150,000 MWd/t of the IFR, LMFR, HTGR, or Pebble Bed.

    Further out, but very achievable, is a Generation IV reactor choice, the Molten Salt Reactor (MSR), a liquid nuclear fuel reactor that Oak Ridge National Laboratory (ORNL) successfully operated 2 MSRs, but President Nixon fired Alvin Weinberg in 1972 because the GOP had selected the LMFRs and did not want a competitor, especially one that was superior, as the MSR was.


    REFs:
    President Nixon firing ORNL's Director Dr. Alvin Weinberg in 1972 --> http://books.google.com/books?id=otQDyt9PeswC&pg=PA198&dq=GOP+LMFBR+President+Nixon's#PPA198,M1"

    My now very old (~1995) web page on MSRs:
    http://home.earthlink.net/~bhoglund/"


    PS: There are those who will say the MSR leaked, had "unresolved materials", and "corrosion" issues, all of which sound reasonable given the dreadful "Molten Salt" name. These accusations are similar to the old, "And when did you stop beating your wife" type accusatory, if unfounded question. Ask them for documentation of these 'problems' & they will not be able to provide them.
     
    Last edited by a moderator: May 4, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Nuclear waste disposal by breakdown
  1. Nuclear waste (Replies: 15)

  2. Nuclear waste. (Replies: 8)

  3. Nuclear waste waste (Replies: 20)

Loading...