NUCLEAR ENERGY. Big Energy from a Small Source.

   NUCLEAR ENERGY. Big Energy from a Small Source.

Nuclear energy is the energy in the nucleus, or core, of an atom. Atoms are tiny units that make up all matter in the universe, and energy is what holds the nucleus together. There is a huge amount of energy in an atom's dense nucleus. In fact, the power that holds the nucleus together is officially called the "strong force."

Nuclear energy can be used to create electricity, but it must first be released from the atom. In the process of nuclear fission, atoms are split to release that energy.

A nuclear reactor, or power plant, is a series of machines that can control nuclear fission to produce electricity. The fuel that nuclear reactors use to produce nuclear fission is pellets of the element uranium. In a nuclear reactor, atoms of uranium are forced to break apart. As they split, the atoms release tiny particles called fission products. Fission products cause other uranium atoms to split, starting a chain reaction. The energy released from this chain reaction creates heat.

All matter is made up of tiny particles called 'molecules'. In turn, all molecules are made up of even tinier particles called 'atoms'.

The central part of an atom is called a 'nucleus'. When the nucleus splits in two, it produces enormous energy. This breaking apart is called 'nuclear fission'. If two nuclei join and from a bigger nucleus - in a process called 'nuclear fusion' - even more energy is produced.

The nuclear energy released from fission and fusion is called 'radiation'. Radiation - the process of giving off rays - is a powerful spreading of heat, light, sound, or even invisible beams.

One of the first uses of nuclear energy was to build deadly weapons. Atomic bombs built during World War II and dropped on Hiroshima and Nagasaki in Japan largely destroyed those cities and killed many thousands of people. People worldwide now try to make sure that this will never happen again.

Today, however, nuclear energy has many helpful uses. Nuclear power plants produce low-cost electricity. Nuclear energy also fuels submarines. And it has also allowed doctors to see more details inside the body than ever before.

But nuclear energy has its drawbacks. Nuclear energy produces nuclear waste. Living beings exposed to the waste can suffer from radiation poisoning. They may experience damaged blood and organs, effects that can be deadly. And the radiation can remain active for thousands of years wherever nuclear waste is thrown away.

Unfortunately, no country has yet discovered the perfect way to store nuclear waste. But the benefits make it worthwhile to keep trying.