I'd feel safer sleeping on top a reactor chamber than I would in my own bed. These places are very strict and everything is very tightly controlled.
Even if one of these facilites were the target of an armed assault, it may leave innocents unprotected and dead, but there is a slim possibility of anyone gaining access to an area they could use to do serious damage. These places are like a bunker and are locked down in logical and cellular layouts.
No doubt. Lots of guards with violin cases. I doubt anyone who tried to do something would live very long.
My guess is this is less about sabotage and more about intelligence gathering.