Nuclear Energy

Nuclear energy produces electricity through a process called fission. In 1956, the first commercial nuclear power plant opened in England. In the United States, as of 2008, there were 104nuclear reactors producing about 20 percent of the country's electricity needs.Nuclear energy doesn't produce greenhouse gases , and no pollution is released into the air. Compared to coal or other fossil fuels, the emissions from nuclear power plants are very clean. Some people say we should build more power plants to reduce greenhouse gases pollution. However, the waste from nuclear energy stays dangerously radioactive for thousands of years.
Other than fission, there is another kind of nuclear energy is fusion. This is the energy that powers the sun and stars. However, scientists cannot yet control the process on earth. If scientists could learn how to create and control fusion, it could become an energy source that is clean and would never run out.

Nuclear Fission

Everything is made up of tiny atoms. Atoms are made up of protons, neutrons and electrons. Some elements, like helium are small, composed of only one proton. Some are large. Uranium, the heaviest element in nature, has 92 protons.
Because uranium is so heavy, the atoms break apart easily. This is why uranium is used as a fuel in nuclear reactors. Fisson happens when a neutron crashes into a uranium atoms and spilt it. The neutrons from that atoms then crash into other atoms, and so on. When huge numbers of neutrons are crashing into atoms, it is called a chain reaction. A chain reaction produces heat.
At the centre of the nuclear power plant is reactor, where fission takes place. Inside the reactor is a supply of uranium, called the core. If the uranium reactor were left on its own, the chain reaction would get out of control. It would became so hot that that the reactor would melt, and then it would pass through the floor. Dangerous radiation would escape in the air. This would be a terrible disaster called the meltdown. To prevent this, scientist have used cooling rods or control rod, that are lowered into the nuclear reactor. This keep the reactor from getting too hot,and control the change reactions.