Check out this power point presentation titled “Routine Releases of Radioactive Materials from U.S. Nuclear Plants,” developed by Dave Lochbaum (Union of Concerned Scientists) in Aug. 2014. It provides a great overview of the atom, sources of radioactive materials, types of radioactive emissions/waste/releases, and more. Though much of the material is specific to Browns Ferry (a nuclear plant in Alabama), the information is quite useful and is certainly relevant to Pilgrim.