Raleigh would have been fine. VA and SC would have heard the explosion but nothing worse. I checked it with a nuclear blast simulator. Even the Tsar Bomba would have killed less than 5% of the population of Raleigh.

"260 times the yield of the Hiroshima bomb" sounds impressive, but most of that energy is wasted heating the nearby air rather than increasing the blast radius. This is why modern nuclear weapons use cluster munitions with smaller yields.