In 1979, President Carter sent Denton to the Three Mile Island nuclear power plant in Harrisburg, as his personal representative. The arrival of Denton seemed to immediately calm the frayed nerves of public officials and stem the anger of a frustrated press corps. As reporter Steve Liddick of WCMB radio explained to writer Mark Stephens, "Harold Denton was trusted because he looked like a regular, down-to-earth kind of guy. And people wanted someone to believe." It was Denton's task to inform Pennsylvania Governor Dick Thornburgh and the President about the discovery of a possibly explosive hydrogen bubble above the cooling water, at the top of the reactor pressure vessel. The debate over whether the bubble would mix with oxygen and set off an explosion, fueled speculation of a meltdown. At the time of Carter's arrival Sunday morning on 1 April, whether the bubble would explode was still under debate. Denton informed the President of the risk just as he was preparing to enter the plant. "...I briefed the President on this bubble and the possibility of an explosive mixture and tried to give him the two sides that were out there, but we still didn't have single view on that," Denton recalled. Denton has won multiple awards for his contribution at Three Mile Island, including the James N. Landis Medal. In an interview with Dick Thornburgh concerning TMI, Thornburg said, " proved to be a genuine hero with respect to this event. He was a much needed source of information for those of us who had the ultimate responsibility for the safety of the people in the area and the quality of the environment."
Personal life
On 11 July 1959, he married Lucinda Vaden Oliver, and they subsequently had three children. HAROLD R. DENTON Mr. Denton had over 30 years experience in the U.S. Nuclear Regulatory Commission's nuclear safety regulation program. He was the Director of the Office of Nuclear Reactor Regulation for almost a decade. In this position, he was responsible for assuring the safety of all commercial nuclear power reactors, test reactors and research reactors, and was the official authorized by the Atomic Energy Act to issue construction permits and operating licenses. He directed a technical staff of over 500 reactor safety and environmental professionals. Later in his career, he directed the Commission's interactions with Congress, State Governments, the media and other countries. Immediately following the accident at the Three Mile Island nuclear power plant in Harrisburg, Pennsylvania, President Carter appointed Mr. Denton as his personal representative at the TMI site. He subsequently worked closely with Gov. Thornburgh and other public officials. He was the news media spokesman for the federal government during the crisis and directed NRC staff activities to assess and mitigate the consequences. As a nuclear safety expert, he has visited essentially all U.S. power reactors and has traveled extensively to nuclear facilities worldwide. He was in the first group of Americans allowed to visit the Chernobyl site and was instrumental in establishing nuclear safety cooperation with the former USSR. In a ceremony in the Rose Garden at the White House, President Carter presented him with the Presidential Distinguished Executive Award for extraordinary accomplishment and leadership. Mr. Denton issued operating licenses to over forty nuclear power reactors during his career. He often testified before Senate and House committees concerning NRC's positions and activities. Later in his career, he directed the Commission's interactions with Congress, State Governments, foreign countries, the Nuclear Energy Agency, the International Atomic Energy Agency and the media.
He attended North Carolina State College, earning a Bachelor of Science degree in nuclear engineering and did graduate work at the University of Maryland. Before joining the Atomic Energy Commission, he was employed as a reactor physicist by the Dupont Company at the AEC's Savannah River Plant in South Carolina. He was awarded honorary degrees from Gettysburg College, Lebanon Valley College in Pennsylvania and the University of Pennsylvania. Since retiring from the NRC, he has provided advice on nuclear safety matters to a variety of national and international clients, including the US Department of Energy and its National Laboratories, the National Science Foundation, private power companies, and to the Governments of Austria, Japan, Taiwan, and Turkey. He was awarded the James M. Landis Medal by the American Society of Mechanical Engineers for outstanding personal performance related to designing, constructing, and managing the operation of major steam-powered electric stations using nuclear. In December 2011, he participated in a symposium sponsored by the Japanese Society of Mechanical Engineers in Tokyo. This included a visit to several reactor sites damaged by the 11 March earthquake and tsunami where restoration and enhanced safety counter measures are in progress. Denton died at his home in Knoxville, Tennessee from complications of Alzheimer's disease and chronic obstructive pulmonary disease, aged 80.