The nation's nuclear reactors are safe from an airborne terrorist assault ... provided the terrorists use a Boeing 767-400 and keep their speed under 350 mph. A computer engineering model study done by the Electric Power Research Institute, an industry-sponsored consortium, showed the 767, fully loaded with fuel, wouldn't breach the four-foot-thick concrete of a nuke's containment structure at 350 mph. Although there are much larger aircraft both flying and on the drawing board (presumably no more difficult to hijack than their lighter siblings), the 767 was chosen for the study because it best represents commercial aircraft fleets," according to an Associated Press report. The researchers also determined that speeds above 350 mph "would make an aircraft too hard to control at low altitude and a hit on a reactor difficult," said AP's account of the study. Regardless, if such misfortune should become manifest, the study indicated that the containment structure would be somewhat crushed by the impact but "no part of the engine, the fuselage or the wings -- nor the jet fuel -- entered the containment building." The government has thanked the power companies very much for their study but will wait for the results of its own tests before reaching their own conclusions.