A long time ago, I took a course on nuclear energy for teachers. When time permits, I like to add this topic to my Chemistry or Physical Science classes. Start with The Harnessed Atom. (Here is the teacher’s edition, which has background and answer keys. Here is the website with the presentations.). Let me share some additional resources: RadTown Radiation Exposure, more RadTown Radiation, Average Dose Worksheet, and Nuclear Decay equations.
Most of these resources target Middle Schools students. I find most of the material suitable for high school students. The Harnessed atom resources seem a bit scattered. The Oakridge website has the teacher’s edition, student edition, activities, downloads, and slideshows. Take a look!