A US sailor
, either enlisted or commissioned officer, who has successfully finished the US Navy
nuclear power pipeline and is qualified to operate the nuclear
power plants aboard aircraft carriers or submarines.
Prospective nukes are subjected to intense scrutiny and higher standards of behavior and technical knowledge than your standard sailor. They are the elite of the elites.
Nukes often advance quickly through the ranks due to the amount and intensity of training they are subjected to while as a student.
Nuke school is widely considered to be one of the toughest schools offered in the military.