Associated Press: * 1955: A U.S. government reactor makes Arco, Idaho, the world’s first town electrified by nuclear power. * 1957: The U.S.’ first commercial nuclear power plant becomes operational in Shippingport, Pa. (Nuclear reactors were already in service in the Soviet Union and the United Kingdom). It was retired in 1982. * March 29, 1979: Three Mile Island Unit 2 in Middletown, Pa., melts down. No one was killed or seriously injured that day, but the public relations disaster sets back …