nuclear power

Nuclear Power


Contents of Entire Course


Ionizing Radiation
Examples of Radiation Risk
Nuclear Energy Fission
Fusion of Hydrogen to make Helium
Environmental Effects of Various Energy Sources - Comparison
Chernobyl, Ukraine
Radioactive Waste Repositories
Links

adapted to HTML from lecture notes of Prof. Stephen A. Nelson Tulane University

Ionizing Radiation

  • Ionizing Radiation is radiation that ionizes (or removes electrons from) material that it passes through.
  • Examples of Ionizing Radiation include:
  • Neutrons - Have high enough energy to be able to knock electrons off of nearby atoms.
  • Alpha particles - Helium atoms with no electrons.
  • Beta Particles - Electrons
  • Gamma rays - Very high energy radiation.
  • X-Rays - Another high-energy radiation, the main source of which is medical equipment.
  • Cosmic rays - Photons and alpha particles. The earth is being constantly bombarded with this type of radiation; the average person is hit by around a hundred cosmic rays a second
  • Radioactivity is natural; we have been bombarded by ionizing radiation from Uranium (U), Potassium (K), and Thorium(Th) as well as by cosmic rays all our lives.
  • Billions of years ago when life first started there was much more natural radiation than at present. Life has evolved with natural ionizing radiation. Some maintain that without the natural radiation which causes genetic mutations, evolution would not be possible.


  • Average Relative Radiation Exposure of Humans 
    Source  Relative Exposure (%) 
    Cosmic rays  24 
    Terrestrial (U,K,Th)  32 
    Medical (X-rays)  40 
    Nuclear fallout 
    Misc. nuclear plants, waste 
    TOTAL  100 
     

    Ionizing Radiation 
    Dose (mSv)  Effect 
    5,000  Lethal
    1,000 to 2,000  Vomiting, fatigue, increased rate of abortion 
    within first 2 months, temporary sterility in males 
    500  Physiological damage 
    50  Maximum allowed for nuclear employees per year 
    1.0-2.5  Natural background 
     

    Dosage  Effect 
    Extremely high dose  burns and damage to brains, die within 48 hours 
    Lower Doses  Diarrhea, bleeding and hair loss 
    Increased susceptibility to infection 
    Cancer 
    Lowest (Natural) Dose  Genetic mutation (some argue that this is necessary for evolution) 
     

    Examples of Radiation Risk

    Nuclear Energy Fission

    In a reactor U-235 or Pu-239 undergoes fission. As can be seen, the two types of plants are basically the same...the only real difference is in the method of heat generation. In Australia there is one nuclear facility which produces medical isotopes. In the U.S., as of 1988 there were 110 operable nuclear power plants, 1 in construction and 10 for which construction permits had been granted. None of the new plants were completed and put into energy production.

    Fusion of Hydrogen to make Helium

    In this reaction a tritium nucleus (hydrogen 3) is combined with a deuterium nucleus (hydrogen 2) (fused) to create a helium 4 nucleus. This reaction releases energy and neutrons.


    Environmental Effects of Various Energy Sources - Comparison
    Chernobyl, Ukraine  

    Radioactive Waste Repositories
    (examples from U.S.A.)
      
    Links