Mechanics of the Nuclear Chain Reaction

• Certain heavier elements, like uranium, are unstable due to their size and the ratio of protons to neutrons in their nuclei. In a nuclear chain reaction a free neutron introduced to a mass of fissionable material, like uranium or plutonium, strikes one of the large atomic nuclei and imparts sufficient energy that this nucleus splits into two smaller atoms and releases multiple neutrons. These neutrons in turn strike other nuclei and sustain the process. This is known as a nuclear chain reaction. Each splitting of an atom releases large amounts of energy, which gives a nuclear chain reaction its incredible power and makes it a useful power source.
  
  

Control of a Nuclear Chain Reaction

• If the process of neutron generation is allowed to proceed without outside interference, sufficient energy will be released to cause a catastrophic destabilization of the entire mass of fissionable material present. This usually results in an explosion of potentially staggering magnitude. Nuclear explosions are effectively uncontrolled chain reactions that release vast amounts of energy in a very short amount of time. However, it is possible to control the rate of neutron production and thereby the rate of the nuclear chain reaction by introducing a neutron absorbing material, like boron, to the reaction. This material removes free electrons from the reaction, resulting in a nuclear chain reaction that is self-sustaining but that doesn't cause an explosion.
  
  

Use of a Controlled Nuclear Chain Reaction

• A controlled nuclear chain reaction is at the heart of a nuclear power plant. A quantity of fissionable material is at the core of the plant, and its fission is carefully controlled by inserting neutron absorbing-control rods into the core. The nuclear chain reaction is maintained to produce a constant and manageable flow of heat energy. This heat is picked up by water pumped over the reactor core that turns to steam. This steam is then channeled to a turbine that produces electrical current. By this process a nuclear chain reaction is utilized to produce power in a form fit for human consumption.
  
  

Future Uses of Nuclear Chain Reactions

• Nuclear power has been used since the 1940s to generate power and is likely to continue to do so in the future. Nuclear power is extremely efficient in terms of energy produced per pound of fuel consumed, and nuclear power provides a significant percentage of the electrical power generated worldwide. However, the initiation of a nuclear chain reaction is inherently dangerous. If control is lost, the reaction can go out of control and the reactor can overheat, melting through the core containment and coming into contact with the environment. Radioactive isotopes are produced by nuclear chain reactions, and so any contact between a nuclear chain reaction and the outside environment is extremely dangerous. Accidents at Chernobyl, Three Mile Island and Fukushima have highlighted the dangers of nuclear chain reactions and contribute to a debate over the future use of nuclear power.