Quick guide on how to find and delete or backup your saved game files, as Not For Broadcast does not offer this option through the game itself.
Finding Your Save Games
Thanks to Nalut on the forums for finding the location.
On Windows, open the Run command (WIN+R) and enter the following:
If you copied and pasted exactly, it should take you to the correct folder. If you typed it in manually, or it doesn't take you to the correct folder, replace %USERPROFILE% with your system profile name; this is what it would be if you were to browse to C:\Users\Profile_Name.
The files listed here will be your saved broadcasts for playback via the Archives. They are saved independently of your save games. You can delete these to delete them from the Archives menu. Once here, open the Profiles folder, and your saved games will be listed.