Figure 5.4: Coal power plants like this one release large amounts of steam and smoke into
the air. ( 5 )
Nuclear Energy
When scientists learned how to split the nucleus of an atom, they released a huge amount of
energy. Scientists and engineers have learned to control this release of energy. The controlled
release of this energy is callednuclear energy. Nuclear power plants use uranium that has
been processed and concentrated in fuel rods (Figure5.5). The uranium atoms are split
apart when they are hit by other extremely tiny particles. These extremely tiny particles
need to be controlled or they would cause a dangerous explosion.
Nuclear power plants use the energy they produce to heat water. Once the water is heated,
the process is a lot like what happens in a coal power plant. The hot water or steam causes a
turbine to spin. When the turbine spins, it makes a generator turn, which in turn produces
electricity.
Many countries around the world use nuclear energy as a source of electricity. For example,
France gets about 80% of its electricity from nuclear energy. In the United States, a little
less than 20% of electricity comes from nuclear energy.
Nuclear energy does not pollute the air. In fact, a nuclear power plant releases nothing
but steam into the air. But nuclear energy does create other environmental problems. The
process of splitting atoms creates a dangerous by-product called radioactive waste. The
radioactive wastes produced by nuclear power plants remain dangerous for thousands or
hundreds of thousands of years. So far, concerns about this waste have kept nuclear energy
from being a larger source of energy in this country. Scientists and engineers are looking for
ways to keep this waste safely away from people.