Ok, I would like to see this nuclear plant that denies humans access to it.
My example was fictional, but in the fiction, once the computer complex was built, control of the reactor, and complex security, was handed over to the computer, with the thought that the computer would not be subject to human failings. Once activated, no guards, no one to override the systems, which were designed to protect from outside attack. No one counted on the computer misinterpreting its instructions to insure its own survival at all costs, by killing friend and foe alike.