I Understand there was at least one tech in the containment who took a while to remove. Not sure about releases, though.
Yup. The one standing on top of the containment vessel. The building pretty much contained all the radiation. The reactor also was in a remote area and was subsequently cleaned up.
FYI, I got to sit on the rim of a university reactor with only water between myself and the core. Turned out the lights in the reactor room and cranked it up to a few megawatts. I got to see the blue glow of the reactor core with my own eyes. It lit the room up. :-)