A really nice and extensive article on many of the uses of nuclear physics appeared on the arXiv this week, written by Anna Hayes of Los Alamos Lab. As well as including the most obvious applications (weapons and power) and perhaps the most widespread, as well as the first, application (medical), it also covers some of the neat uses in areas like geology, where the study of isotopic abundances in things such as groundwater can tell you what it going on far underground. I've yet to read the whole thing yet, but it looks definitely worth bookmarking as a go-to piece whenever you are looking to discuss the range of things nuclear physics is applied to.
The figure attached to this post is from the paper, showing some of the ancient (pre-historic) natural nuclear fission reactors that existed in what is now Gabon, detected by the unusual isotope ratio of the remaining uranium, as well as some fission products. See Anna's paper for more details!