A nuclear power generating station operates on the same principle
as a conventional fossil-fueled (oil or coal) power plant, except that
the heat generation is provided by nuclear fission rather than combustion.
The heat liberated in either process (fission or the combustion of fossil
fuel) is used to convert water into steam. The steam enters a turbine which
is connected to a generator that produces electric current for commercial
A byproduct of the fission process is the production of radioactive
gases in the fuel. These are called fission gases. Nuclear particles (neutrons)
are also absorbed by the water coolant and structural materials producing
radioactive activation products. A typical power reactor may experience
a small number of pinhole leaks in the fuel over its operating life. Radioactive
gases may escape the fuel rod through these leaks and enter the water coolant.
As a result, radioactive fission gases are present to some extent in the
water coolant of the reactor at all times.
Fission is a nuclear process in which a
heavy nucleus splits into two smaller nuclei. A fission reaction was used
in the first atomic bomb and is still used in nuclear reactors.
Fission reactions can produce any combination
of lighter nuclei so long as the number of protons and neutrons in the
products sum up to those in the initial fissioning nucleus. As with fusion,
a great amount of energy can be released in fission because for heavy nuclei,
the summed masses of the lighter product nuclei is less than the mass of
the fissioning nucleus.
Fission occurs because of the electrostatic
repulsion created by the large number of positively charged protons contained
in a heavy nucleus. Two smaller nuclei have less internal electrostatic
repulsion than one larger nucleus. So, once the larger nucleus can overcome
the strong nuclear force which holds it together, it can fission. Fission
can be seen as a "tug-of-war" between the strong attractive nuclear force
and the repulsive electrostatic force. In fission reactions, electrostatic
Fission is a process that has been occurring
in the universe for billions of years. As mentioned above, we have not
only used fission to produce energy for nuclear bombs, but we also use
fission peacefully everyday to produce energy in nuclear power plants.
Interestingly, although the first man-made nuclear reactor was produced
only about fifty years ago, the Earth operated a natural fission reactor
in a uranium deposit in West Africa about two billion years ago!
E=mc2, This is Einstein's famous formula
that we all know and love, but it is also the basis for understanding
fusion. Einstien theorized that mass can be converted into energy. We
are already using fission in Nuclear Power Plants. The key is to bring
fusion into the picture. While Fission is splitting an atom, Fusion is
fusing or joining atoms.
Fission is already used comercially, usually with
uranium since it is the most heavy atom that can be found in mass quantity.
Fusion however has only been tested in a laboratory. Fusion uses lighter
atoms like hydrogen.
Fusion reactions occur naturally in stars, like
the sun. Only a few of those are pracitical for use on earth. These involve
different forms (isotopes) of hydrogen. The three forms are hydrogen,
and tritium. In any form (isotope) of hydrogen there is only one proton.
Hydrogen has no neutrons, deuterium has one neuton, and tritium has two
neutrons. No matter what form hydrogen has one electron to balance the
Conditions for Fusion
The nucleus of an atom is positive and so they
normally repel each other (Remember: oposites attract). The higher the
temperature the faster the atoms move. The atoms must be moving fast enough
to overcome their natural repulsion and collide.
The difficulty is heating the atoms high enough
and long enough so that they will collide while still producing more energy
than was needed to do the heating.
The temperature required to fuse a deuterium-tritium
fuel must be heated to 100 million degrees Celsius (°C). That is more
than 6 times hotter than the interior of the sun(estimated at 15 million
°C). As High as these temperatures are, it is still possible to reach