A Pennsylvania State policeman and plant security guards stand outside the closed front gate to the Metropolitan Edison Nuclear Power Plant on Three Mile Island near Harrisburg, Pa. after the plant was shut down following an accident in the plant in this March 23, 1979 black-and-white photo. A quarter century after the country's worst nuclear accident, the atomic power industry is talking about revival. Yet no one can predict when a new reactor will be built and perceptions about safety, uncertain economics and a new specter _ terrorism _ still haunts the industry. (AP Photo/Paul Vathis)