Nuclear, Schmuclear!
The trick here is not to treat this, or any other movie, as a docudrama. This is simply a great thriller story, irrespective of any possible technically dubious plot assumptions. I saw the movie when it first came out, but had to leave during the control room lockout scene. I had become so tense that I couldn't breathe and thought I was having a heart attack! After several weeks of tests, it turned out I had Spondilitis in my left shoulder, trapping nerves and causing chest pains. Go figure!
It was a couple of years later that I got to watch the movie all the way through. Still very tense but, happily, no chest pains.
For all those who get too engrossed in the details, I say:
There is real life ... and then there are movies!