Nuclear energy is energy inside atoms. When a star explodes, it sends out radioactive material. Millions of years ago, Earth got some of that radioactive material. Now, we mine it for use in nuclear plants (pictured left). A tiny piece of uranium, a radioactive element, can power an entire home for a year! Nuclear energy is potential because it is stored inside atoms. It is nonrenewable because we have only a limited amount of radioactive material. One advantage of using nuclear energy is that a small amount of uranium can supply electricity for many people. It also doesn't produce carbon dioxide and doesn't contribute to global warming. However, it is nonrenewable, so we will run out eventually. It also produces waste that needs to be kept isolated for a long period of time because it can be harmful to people and the environment. Nuclear energy can be extremely dangerous. If something goes wrong that causes the core in the power plant to overheat, a nuclear accident can occur, leaving the land uninhabitable for decades or longer. In 1986, something went wrong at a nuclear power plant in Chernobyl, Ukraine (which used to be part of the Soviet union). Many parts of Russia, Ukraine, and Belarus are still abandoned because of that accident!
This diagram shows an example of a nuclear energy transformation. Uranium was created from supernovae and some of it was trapped when the Earth was formed billions of years ago. We get uranium (nuclear energy) from the ground. Next, we shoot neutrons at the uranium. The uranium atoms split, releasing lots of energy and heat. A water pipe heats up, next to the room where nuclear fission occurs. However, that water has radioactive chemicals in it. Another pipe, free of radioactivity, heats up and creates steam (thermal energy). The steam turns a turbine (mechanical energy) and creates electricity to send to us in power lines (electrical energy). Then we use the energy to do things like charging our phones.