I remember this large facility with security checkpoints and plenty radiation checkpoints, people walking around slowly in white coats with clipboards checking instruments, wearing radiation badges, and I remember this deep weird blue pool you could see stuff down at the bottom, and then going downstairs, there were people maneuvering these long robot arms to move stuff looking through this thick glass window, sort of like this
Then we went outside and seen these huge cooling towers and I remember my dad explaining briefly how it all worked and the backup to backup systems if the system went wild - and it never did, probably because of the safety designs, procedures and people training.
One last cool thing for a kid, while outside we walked to this outhouse facility where a colleague took a flower leaf, dipped in it liquid nitrogen and then dropped it on cement, shattering in so many pieces!
Mind blowing for a kid, now a flexible, soft leaf we all know about, a second later changing consistency and breaking like china. I'd say if more kids got similar tours, we'd have lots more science people