ATOMIC ENERGY 4 Binding Energy 4 Fission and Fusion 4 Nuclear Reactors 4 Electrical Generation

BINDING ENERGY The amount of energy required to remove a single proton or neutron from an atomic nucleus varies with the mass of the nucleus. The graph of this relationship is called the binding energy curve.

FISSION and FUSION

 Nuclear energy can be released in two different ways: by fission (splitting) of a heavy nucleus, or by fusion (combining) of two light nuclei.  In both cases energy is released because the products have a higher binding energy than the reactants.  Fusion reactions are difficult to maintain because the nuclei repel each other, but unlike fission reactions, fusion does not create radioactive products.

CHAIN REACTION

NUCLEAR POWER PLANT The Palo Verde Nuclear Power Facility in Arizona, like other nuclear power plants, was built to harness nuclear energy for controlled use by humans. Nuclear power is a controversial energy source: it is inexpensive and creates no air pollution, but the radioactivity released during accidents at nuclear power plants has environmental damage.

NUCLEAR REACTOR

4 A nuclear reactor is a unit constructed to enclose all the equipment and material necessary to produce and control the process of nuclear fission. 4 Compounds of uranium are also used as fuel. 4 The second essential part of a nuclear reactor is the moderator material. It must be relatively light in mass and must not absorb neutrons. Fast neutrons, produced by fission, are slowed by a series of collisions with the nuclei of the moderator atoms. 4 One other essential part of the reactor is the coolant. The main coolant is a liquid or gas that is pumped or blown through the reactor core to remove heat given off mainly by the fuel.

FUSION REACTOR In 1993 scientists at the Tokamak Fusion Test Reactor, at Princeton University, produced a controlled fusion reaction, during which the temperature in the reactor surpassed three times that of the core of the sun. In a tokamak reactor, massive magnets confine hydrogen plasma under extremely high temperatures and pressures, forcing the hydrogen nuclei to fuse.

From Reactor to Electricity 4 A reactor produces heat. Once the heat is made, it makes little difference whether the heat comes coal, gas, oil, or wood. 4 The heat is used to produce steam which spins a turbine which drives a generator, making electricity.