It was a blisteringly hot morning when I reported to Los Alamos National Laboratory (LANL) for nuclear inspector school. The lab is the old home of the Manhattan Project , the secret effort to develop the first nuclear weapons. It sits atop a mesa north of Santa Fe, New Mexico, isolated by geography and security checkpoints.

Credentials checked, I was driven down “Plutonium Corridor,” a main road that passes a building encased in five layers of barbed fencing. It is where they design and maintain nuclear …