Nuclear Energy

"The discovery of nuclear chain reactions need not bring about the destruction of mankind any more than did the discovery of matches. We only must do everything in our power to safeguard against its abuse."

 

 - Albert Einstein

 

One of the most mysterious phenomena in the universe is the conversion of mass into energy.  The whole universe is "powered" by this process.  The energy radiated by stars, including the Sun, arises from nuclear reactions (called fusion) deep in their interiors. The release of nuclear energy occurs through the fusion of two light hydrogen nuclei into a heavier nucleus of helium.

 

Until about 1800, the principal fuel on our planet was wood, its energy originating from solar energy stored in plants during their lifetimes. Since the Industrial Revolution, people have depended on fossil fuels—coal, petroleum, and natural gas—also derived from stored solar energy. When a fossil fuel such as coal is burned, atoms of hydrogen and carbon in the coal combine with oxygen atoms in air. Water and carbon dioxide are produced and heat is released.  This amount of energy is typical of chemical reactions resulting from changes in the electronic structure of the atoms. A part of the energy released as heat keeps the adjacent fuel hot enough to keep the reaction going. In a nuclear reaction, however, the energy released is often about 10 million times greater than in a chemical reaction, and the change in mass can easily be measured.

 

Nuclear Energy is released during the splitting (fission) or fusing of atomic nuclei. The energy of any system, whether physical, chemical, or nuclear, is manifested by the system's ability to do work or to release heat or radiation. The total energy in a system is always conserved, but it can be transferred to another system or changed in form. According to the Law of Conservation of Energy, if we add up the total amount of energy in the universe (we can describe energy quantitatively with units such as Joules or kilowatt-hours), the total amount never changes. In other words, energy is neither created nor lost, even though it may be converted from one form to another.  Thus the law of conservation of energy is really the law of conservation of mass-energy.