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Nuclear reactor

  1. Oct 20, 2006 #1

    taylaron

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    now, in simple terms, all a nuclear reactor is a steam engine i know that we use the emitting nutrons to heat up water, which boils, then moves a turbine, but THIS IS SO SIMPLE!!!!
    why, why, why, isnt there a more simple way to convert this neutron into useable energy? a significantly size neuclaer reactor would revolutionize the world. possibly for the worse, but anyways,
    i keep hearing use K.I.S.S. (keep it simple stupd)
    and this is really simple! this idea has been around for at least 100 years. i know that we have exponentially grown in our understanding of science and technology, but why do we stick to this incredibly inefficiant (pollution wize) way of transfering radiant neutrons into heat, then to move a turbine, then back into water....... repeating for ever and ever.
    in my mind this seems rediculously simple.:surprised i think that a more feasable solution is in grasp by now. we need a solution these days to simply convert energy, we've got all sorts of implimintations regarding energy conversion. why can we impliment them into this problem?

    please forgive my spelling and grammar mistakes
     
  2. jcsd
  3. Oct 20, 2006 #2
    The neutrons aren't there so much to create heat as they are to create more fission reactions, with a moderator and control rods to make sure the reactor doesn't go supercritical. It's the energy from the fission reaction that is converted to heat which then heats the water.
     
  4. Oct 20, 2006 #3

    Astronuc

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    Fission of U-235 nucleus produces approximately 200-205 MeV of energy, most of which is manifest in the kinetic energy of two nuclei (fission products), which are produced by the fission, while the rest of the energy is in the form of prompt gammas, decay gammas, beta-particles and fission neutrons. Either two or three neutrons (and sometimes, but rarely, 4), which allow for the continuation of the reaction.

    The fission products and beta particles impart their energy into the ceramic fuel matrix. This heat must then be conducted through the cladding to the coolant. In a boiling water reactor (BWR) the water is boiled and the steam is separated above the core and sent to the turbine. In pressurized water reactors (PWRs), the heat from the fuel is collected by the coolant and transferred to a steam generator (heat exchanger) which passes the heat to another fluid system which produces the steam that get passed to the turbine. (LWR is the generic term for both BWR and PWR type designs).

    The conversion of thermal energy to mechanical energy is constrained by the maximum temperature at the turbine inlet. Generally the steam at an LWR turbine inlet is just about saturated, although there are advanced designs based on superheated (even supercritical) coolant. The downside (and challenge) of superheated/supercritical steam is the increase in erosion/corrosion (i.e. materials degradation) over the life of the plant, as well as potential safety issues associated with higher pressures/temperatures.
     
  5. Oct 20, 2006 #4

    taylaron

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    elaboration of system

    great!
    but isnt there another way to convert all this energy into electricity?
    ...... if there was one it would probably already be in use... so i guess this is a stupid question.

    regarding waist products: i live near a nuclaer power plant and i always hear about contamination of the water. why cant we have a really big container of water to gradually cool down all this water? or at least something to cool it down. to my understanding, all this steam gets shoved through this turbine, then is it re-used? is anything sent to the river? there are steam vents, giant concrete pillars, i forgot what they're called, but if the steam is leaving through there, all that potentially radioactive steam is "venting" into our atmosphere.
    so much for all this talk of clean nuclaer energy.
    if it is being re-used, why is there contamination.
    actually, im over at the Hanford sight so i bet theres alot of explinations for that problem...... it might not be the reactor. i know we have massive ammounts of radioactive waist underground here. some even are leaking and eroding already.... not good....:surprised
    last time i looked, i didnt glow green, so i think im good for now... :tongue2:

    thanks a lot everybody, your helping very much
    pardon my spelling and grammar mistakes
     
  6. Oct 20, 2006 #5

    taylaron

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    if you had a gamma ray laser (for whatever reason)
    if you pointed it at anyting fusible (used in fission) would you potentially have detonated an atomic bomb?
    i know in WWII they used a gamma ray laser on one of the bombs they dropped.
     
  7. Oct 20, 2006 #6

    selfAdjoint

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    Dearly Missed

    Good trick, since the laser hadn't been invented then.
     
  8. Oct 20, 2006 #7

    taylaron

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    interesting.....
     
  9. Oct 20, 2006 #8

    selfAdjoint

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    The laser was invented in 1957 (wiki), WWII ended on August 14, 1945, with the surrender of Japan. The two nuclear bombs were dropped a few days earlier than that.
     
  10. Oct 20, 2006 #9

    Astronuc

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    If you live near the Hanford reservation, then you also live near the Columbia Generating Station, which is a BWR and the plume you see is the vapor from their cooling tower. The cooling tower rejects the waste heat from the plant to the atmosphere, and the water vapor is generally not radioactive.

    The waste heat passes from the primary system through the condenser to the cooling system which rejects heat through the cooling tower. The water on the primary side does contain radioactive corrosion products and some tritium from activated deuterium, which itself come from n-absorption by H. Also, if there is leaking fuel in the core, radioactive gases (isotopes of Kr and Xe) and some volatiles/solubles, e.g. isotopes of Rb, Cs, can make their way to the turbine and condenser. Most of the radioactive corrsion products however are collected on filter demineralizer in both the reactor water cleanup system, which is part of the BWR recirculation system, and the condensate cleanup system.

    In conventional nuclear plants, which are mostly LWRs, the nuclear thermal energy is converted to mechanical energy via the Rankine (steam) thermodynamic cycle. Gas-cooled reactors can use the Brayton cycle, and possibly can be supplemented with a Rankine (steam) cycle.

    As for direct conversion, that has been envisioned with fusion reactors, assuming fusion can be perfected as an economical energy source. In direct conversion, the charged ions and electrons are separated in a magnetic field. The electrons form the electric current on the system and are brought through the load to recombine with the ions, which then become neutral atoms. Easier said than done in practicality for a large energy system.
     
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