I remember getting semi-private, and slightly off-the-official-track tour of a nuclear power plant by my Dad. His company was involved in servicing the plant during an outage. It was open for organized public tours during that time (an idea that just seems bonkers now). My brothers and I got to see that part, and even a little bit more.
I was pre-teen at the time and unfortunately he has passed. I really wish I could get more details from him on this and other stories.