The Federal Aviation Administration is really determined not let air-traffic controllers take naps. In yet another agreement on fatigue recommendations following several incidents of controllers falling asleep on the job, the FAA said controllers will be allowed to listen to the radio and read appropriate printed material during the graveyard shift. They still won't be able to take naps on their breaks, and are expected to be “be available for recall at all times.” However, if they're too tired to work, the new rules allow them to request a leave of absence.
Read it at CNN