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

Nuclear power and plutonium

  1. Jul 18, 2010 #1
    questiion guys..

    why nuclear power uses diff kind of elements such as plutonium?
    while sun has only two elements two produce energy.

    i ask that question because i am curious on how energy is created trough atom fusion.
    while studying the basic principle of chemical reaction of the SUN, the two main elements that created a huge amount of energy is hydrogen and helium.

    my conclusion is maybe i can create an energy if i do the same as the sun's chemical reaction.
    do you think this could be possible?
  2. jcsd
  3. Jul 18, 2010 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    Fissile isotopes such as U-233, U-235 and Pu-239 release energy (~205 MeV/fission) upon fissioning in response to neutron absorption.

    The sun and most other stars produce energy via fusion, a process in which lighter elements, primarily hydrogen in the form of protons, combine into heavier elements.

    The sun does not produce energy by chemical reactions. The sun is sustained by fusion by virture of the proton-proton cycle, and a little by fusion of protons in the C-N-O cycle.
  4. Jul 18, 2010 #3
    And this happens in the sun because of the huge pressures in its interior caused by gravity.

    There is certainly plenty of research going on into fusion power, but it's very difficult (much more difficult than making an unstable nucleus split) and it remains to be seen if it can be made practical.
  5. Jul 18, 2010 #4
    what if we do make a smaller version of sun?
    i mean if we follow the concept of C-N-O cycle of the sun then we can solve the problem of electricity. because here in our country a few days a go a black out was occured.
    with my simple idea it will change everything.
    actually i've done my first step, by water splitting i've separated hydrogen atom and oxygen. my problem is how to contain the hydrohen atom.

    i've also created my own procedures and collected some materials.

    coz i would like to do some experiments.
  6. Jul 18, 2010 #5


    User Avatar

    Staff: Mentor

    Physicists and engineers have been trying for decades to duplicate the energy production method of the sun in a sustained reaction, so far without success. It is most certainly not a trivial undertaking and there isn't anything you can do on your own that will come anywhere close to it.
  7. Jul 18, 2010 #6
    thank you very much for those who offered their knowledge.
    how ever, i have to continue this and think a possible solution on how to do this idea.
    no one knows.. maybe if i already reach my limitation and my ideas are not working then that would be the time to stop.

    tahnk you very much.
  8. Jul 18, 2010 #7


    User Avatar
    Staff Emeritus
    Science Advisor

    As the_house indicated, the conditions within the sun produce high pressures, well beyond the capability of any man-made engineered material. We simply cannot replicated the conditions within the sun in order to sustain a fusion reaction.

    As Russ indicated, we've been trying to perfect fusion for energy production for several decades now. We don't do proton fusion, but fusion of other hydrogen isotopes, deuterons and tritons, and sometime deuterons with Li nuclei. We can make thermonuclear weapons, but that is not controlled, nor is it practical for energy production.

    An ideal fusion system would produce no neutrons. Beside d + Li6, fusion of p + B11 would be ideal. However, these reactions require high temperatures, and in conjunction with reasonable high nuclear densities, pressure is a problem. The yields are too low to practical with current systems.
  9. Jul 19, 2010 #8
    Producing fusion in the home lab is actually quite easy if one uses a Farnsworth fusor-type device. I've seen it done myself several times, high-school kids are doing it. A friend of mine, Doug Coulter, see: http://www.coultersmithing.com/ has a fusion reactor in his lab.

    The problem with these types of fusion reactors is the efficiencies are very low. If you put 1000 watts of power into the reactor, at best, you get about 1000.0000001 watts of power out, most of the input power is turned into heat. The actual power from fusion is measured in microwatts or less.

    As Russ points out, this isn't "anywhere close" to what is being done in the sun. In a fusor, the fusion ions (deuterium) are accelerated towards each other using a high-voltage (usually 30kV to 50kV or higher) electric field. Some of the ions hit each other with sufficient energy to cause a fusion reaction.

    In the sun, the energy is supplied using heat generated by the pressure of the gravity of the elements in the sun itself. This type of fusion (fusion through heat and pressure) has only been created in very expensive labs with extensive government funding.

    So if you want to duplicate what's being done in the sun, you're best bet is to get a Ph.D and join a big government lab. If you want to experiment with fusion, I suggest looking into electrostatic fusion and Farnsworth Fusors in particular.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook