(4/26/2011) The earthquake and tsunami that ravaged parts of Japan and severely damaged the Fukushima Daiichi nuclear power plant have sparked fears of radiation exposure and a potential meltdown. Here in the United States those realities have renewed the debate over the future of American nuclear power plants -- and have thrust nuclear energy development into the limelight as both America’s answer to its growing electricity needs as well as one of its greatest security threats. In this show excerpt, Dan Rather returns to MIT for a follow up discussion with Dr. Ernie Moniz, Director of the MIT Energy Initiative, on the future of nuclear.