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Nuclear energy

  1. Mar 20, 2003 #1
    Why do we not use a nuclear fuel instead of uranium that decays into stable elements? Why do we use uranium?
     
  2. jcsd
  3. Mar 20, 2003 #2

    Tom Mattson

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    Which nuclear fuel decays into stable elements?
     
  4. Mar 20, 2003 #3

    chroot

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    All radioactive materials eventually decay into stable products, Tom.

    We use uranium for a couple of reasons:

    1) because it is capable of producing a chain reaction.
    2) because it is relatively abundant on earth.

    - Warren
     
  5. Mar 20, 2003 #4
    As far as i remember uranium eventually decays into Pb, which is quite stable.
     
  6. Mar 20, 2003 #5

    russ_watters

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    Doesn't virtually EVERY radioactive material eventually decay into lead since it is one of the heaviest stable elements?
     
  7. Mar 20, 2003 #6

    Janus

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    It depends upon whether it belongs to the Uranium, Thorium, Actinium or Neptunium series.

    The members of the first three decay to Lead 206, 208 and 207 respectively.

    The Neptunium series decays to bismuth 209 (after passing through Lead 209)

    All three pass through radioactive isotopes of lead on their way to stability. (the uranium series passes through both lead 214 and lead 210).

    This doesn't count the nonseries radionucleides. (such as carbon 14)
     
  8. Mar 20, 2003 #7

    Integral

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    Iron is the element which has no energy to release, through either fission or fusion so will be the ultimate end point of nuclear reactions which release energy. When you consider the nature of the fission process it seems very unlikly that stable isotopes can be the immediate result. It is an environment rich in energetic free neutrons, in order to have stable isotopes each atom would have to complete the process with the unique number of neutrons required to form that element. This is very unlikely, sort of like walking in a rain storm and not getting wet.
     
  9. Mar 20, 2003 #8
    Hm.., I was under the impression uranium is not a natural material. As it was "created" when scientists split the nucleus of plutonium, and the alpha particles (or beta, i haven't studied np in a while) where the uranium?
     
  10. Mar 20, 2003 #9

    chroot

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    Your impression is wrong.
    Generally, in the ground.

    - Warren
     
  11. Mar 20, 2003 #10

    Janus

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    Uranium is found in mine-able concentration in the minerals:
    Pitchblende, uraninite, carnotite, torbernite, tyuyamunite, autunite, uranophane, and brannerite,

    It is also found in varying trace amounts throughout most of the rocks of the crust.
     
  12. Mar 20, 2003 #11

    dav2008

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    Yea, the hard part is refining the abundant U-238 into the U-235 which is used in nuclear bombs.
     
  13. Mar 20, 2003 #12
    However, if you are clever enough you may find some in an underground bunker in Iraq, labeled "For peaceful purposes only"
     
  14. Mar 21, 2003 #13
    I was thinking about eliminating nuclear watse so is there nothing we can use that will do this?
     
  15. Mar 21, 2003 #14
    we could substitute fission with fussion i.e. instead of using uranium we can use H2 and H3 to get energy and He4 + n0.
    according to the quantity burned/gained energy ratio the fussion reactions are more effective.
     
  16. Mar 21, 2003 #15
    So why do we not do this because the main problem with using nuclear energy at the moment is the waste that it produces.
     
  17. Mar 21, 2003 #16

    chroot

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    Fusion is not as easy as fission -- you have to generate huge temperature and confine the reacting gas in a magnetic containment system.

    Fusion is reaching the point where it will be economically feasible. A reactor called DEMO is currently being built that has the express purpose of breaking even economically.

    Fusion does not eliminate the waste problem, however -- the neutrons ejected by the reaction are unaffected by the magnetic containment fields. As a result, they strike the walls and cause the walls to become radioactive. There are still hurdles to overcome in that department.

    - Warren
     
  18. Mar 21, 2003 #17

    FZ+

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    The truth is actually the other way round....
    http://www.fas.org/nuke/intro/nuke/plutonium.htm
     
  19. Mar 23, 2003 #18
    Thanks for real facts

    Thank You Janus for your statement of really true facts of a much-misunderstood area of real matter. Allow me to share with this string my career long labor of sorting all this stuff out.
    1. By scanning the isotopes of the transuranic elements back to Fermium for a contiguous clump of 4 alpha (long-lived) emitters and then skipping Einsteinium to Fermium’s alpha decay daughters, Californium, etc, there is revealed the reality that this 4 isotope contiguousness of the four series you mentioned above is repeated until the Radium contiguum where the Neptunium series isotope was more unstable to beta emission which resulted in that series ending in Bismuth-209.
    2. The interesting thing about the Bismuth series was that there were no “alpha-dams” nor “alpha-super-dams” in that series and therefore all the Bismuth precursor isotopes in nature’s aboriginal 4 element clump had decayed completely to the Bi-209 ultimate daughter in 112 million years after creation. Note that U-238 is a super-dam outside the U-clump that decays by alpha-beta-beta string to U-234 that along with the long ago disappeared U-233 and the “dam”, U-235 and U-236 comprise the contiguous Uranium clump. Thorium-232, which is the daughter of U-236, is a super-dam that is also a member of the Th-clump. Plutonium-242 is a dam in the Pu-clump but Pu-244 is a super-dam.
    3. The series of super-dams includes Curium-250, Pu-244, U-238, Th-232, and Radium-226 and the pattern of 6-nucleon-spacing of these is notable.
    4. If you ever wondered where the Pb-204 isotope came from, remember this: Thallium-203 + a neutron has no other place to go. Cheers, Jim
     
  20. Mar 24, 2003 #19

    pmb

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    Jack asked
    I find that a very confusing question. What exactly do you mean by "nuclear fuel"? Isn't uraniam "nuclear fuel"??

    Pete
     
  21. Mar 24, 2003 #20

    russ_watters

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    Typo, pmb. What he meant to say (i think) is "Why don't we use a different nuclear fuel instead of uranium that decays into stable elements? Why do we use uranium?"
     
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