How Nuclear Power Works

When you hear the words "nuclear power," different images may flicker through your mind: concrete coolant towers emitting torrents of steam, a mushroom cloud rising high into the sky or even Homer Simpson asleep at the control panel.

Some peopl­e praise the technology as a low-cost, low-emission alternative to fossil fuels, while others stress the negative impact of nuclear waste and accidents such as Three Mile Island and Chernobyl. There's a lot of discussion out there about nuclear power's role in our lives, but what's going on at the heart of these power plants?As of July 2008, there were more than 430 operating nuclear power plants and, together, they provided about 15 percent of the world's electricity in 2007. Of these 31 countries, some depend more on nuclear power than others. For instance, inFrance about 77 percent of the country's electricity comes from nuclear power [source: NEI]. Lithuania comes in second, with an impressive 65 percent. In the United States, 104 nuclear power plants supply 20 percent of the electricity overall, with some states benefiting more than others.

Despite all the cosmic energy that the word "nuclear" invokes, power plants that depend on atomic energy don't operate that differently from a typical coal-burning power plant. Both heat water into pressurized steam, which drives a turbine generator. The key difference between the two plants is the method of heating the water. While older plants burn fossil fuels, nuclear plants depend on the heat that occurs during nuclear fission, when one atom splits into two.

In this article, we'll examine the process of fission, look at what goes on inside and outside a nuclear power plant and discuss some of the pros and cons of nuclear power.