John McCarthy, Stanford University Professor Emeritus, wrote these facts on Elementary Nuclear Physics over 17 years ago and they are still applicable. We are using them because he presents the science of nuclear physics and nuclear power in a clear, easily understood manner.
If you want an excellent explanation of why some atoms split and give off energy while others have to be bashed together to emit energy, click this Fission and Fusion video from the Cassiopeia Project.
Here is a YouTube video explaining the operation of a nuclear power plant. It was prepared by the United Arab Emirates to promote Nuclear Power. Even a major oil producing state knows that their petroleum resources are limited. This video is an example of other countries farsighted thinking about energy, something the United States has been grossly lacking. How Nuclear Energy Works.
While we are on the topic of other countries rational outlook on nuclear you might want to inspect nuclearinfo.net. This website was developed by a group of Physicists from the School of Physics at the University of Melbourne in Australia.