You've taken liberties with the descriptions. I've worked on anti-aircraft guided missiles in engineering development and test. I'm not a nuclear engineer (though I have an unfulfilled ambition to get a degree in the field), but I have read the texts for nuclear engineering. I am an aeronautical engineer by training and application. I helped to design advanced weapons, so that would be at the front end of the weapon life cycle. I was a system designer, which led me into many areas.