If you're like most kids, you probably love the many electronic devices you spend time with each day. From smartphones and computers to televisions and video games, the many electronic devices available today provide endless entertainment options.
You can't have electronic devices without one thing: electricity! In many areas, most electricity is generated by burning non-renewable sources of energy called fossil fuels. Because these fossil fuels produce greenhouse gases and will run out one day, scientists have been looking for alternative energy sources for many years.
One form of alternative energy has become popular in many areas of the world, because it does not produce greenhouse gases. Unfortunately, it does produce hazardous wastes and has become synonymous with disasters with names like Fukushima, Chernobyl, and Three Mile Island. What are we talking about? Nuclear energy, of course!
Nuclear power plants work much like their fossil-fuel counterparts. Both heat water to turn it into pressurized steam that will drive a turbine generator, producing electricity. Instead of burning fossil fuels to generate heat, though, nuclear reactors rely on a process called nuclear fission.
To produce nuclear fission inside a reactor, neutrons are fired at the nucleus of a radioactive element called Uranium-235 (U-235). The U-235 nucleus absorbs the neutrons and, in the process, becomes unstable and begins to split immediately, releasing energy that generates tremendous heat.
A little bit of U-235 can go a long way. For example, a pound of highly-enriched U-235 used to power a nuclear submarine would be equal to about a million gallons of gasoline! It's easy to see why scientists would be interested in using a common element like Uranium as an alternative to fossil fuel sources.
Because of the radioactive materials used in nuclear power plants, special safety precautions have to be taken in order to ensure the safety or workers and those who live near the power plant. Nuclear reactors are usually housed in steel containment vessels that are surrounded by multiple solid concrete barriers that could contain radiation in case of a meltdown. Lessons learned from the Three Mile Island, Chernobyl, and Fukushima disasters have enabled the nuclear energy industry to develop even better safeguards for the future.
In addition to the risk of nuclear meltdowns that release radioactivity into the environment, nuclear power plants also produce high-level radioactive waste in the form of spent nuclear fuel. Since it takes tens of thousands of years for this lethal material to decay to safe radioactive levels, it must be carefully stored and monitored in large concrete structures.
Despite its risks, nuclear energy does have many positives that make it an attractive alternative to fossil fuels. For example, nuclear fission yields about a million times more energy per unit weight than fossil fuels. Nuclear power plants also emit minimal amounts of carbon dioxide.
Today, there are over 400 nuclear power reactors generating power in nearly 50 different countries. Some countries, such as France and Lithuania, generate more than 75% of their power using nuclear power plants. In the United States, over 100 nuclear power plants generate nearly 20% of the country's energy.