The man who calmed fears after Three Mile Island accident
Once-obscure federal regulator was hailed as hero for his leadership during nuclear crisis
At 3:55 a.m. on March 28, 1979, people living near the Three Mile Island nuclear power plant about a dozen miles from Harrisburg, Pa., were awakened by a loud roar that “shook the windows, the whole house,” in the words of one resident.
Within hours, alarm sirens sounded inside the facility, as workers struggled to understand what was happening. Harold Denton, the country’s leading authority on nuclear safety, was summoned from a meeting at Nuclear Regulatory Commission (NRC) headquarters and told that a “relatively serious sort of event” had occurred.
Denton, a once-obscure federal regulator who went on to be hailed as a hero for his calm leadership and technical mastery during the most serious nuclearpower accident in the country’s history, died Feb.13 at his home in Knoxville, Tenn. He was 80.
He had complications from Alzheimer’s disease and chronic obstructive pulmonary disease, said his wife, Lucinda Denton.
Denton had been an inspector of nuclear reactors for 15 years before he became director of the federal Office of Nuclear Reactor Regulation in1978. Just one week before the Three Mile Island emergency, he happened to watch The China Syndrome, a Hollywood movie about an accident at a nuclear power plant. When a technician, played by Jack Lemmon in the film, looked at a gauge, Denton casually remarked to his wife, “That’s a faulty reading.”
As the real-world emergency unfolded at Three Mile Island, there was confusion about the accident and its potential risk. State officials and executives from the utility company, Metropolitan Edison, offered little guidance.
“I live a mile from the plant,” one reporter asked. “What are you going to be doing to protect my family?”
Telephone lines were overburdened, making com- munications between Three Mile Island and Washington difficult. NRC chairman Joseph Hendrie said he and Pennsylvania Gov. Richard Thornburgh were “operating almost totally in the blind. His information is ambiguous, mine is nonexistent.”
Thornburgh recommended that everyone within 10 miles (16 kilometres) of the nuclear facility stay indoors.
CBS News anchor Walter Cronkite described the events at Three Mile Island as “the first step in a nuclear nightmare.”
The danger was real: increased radiation levels had been measured in the atmosphere, and temperatures inside the reactor were abnormally high. News reports speculated on several apocalyptic scenarios, including the possibility that an explosion could rip through concrete walls four feet thick. The most serious risk was a meltdown, in which the reactor’s superheated core could burn through the building’s base and burrow into the earth.
Denton was monitoring events from NRC’s headquarters, but President Jimmy Carter said a federal official should be at the scene to take charge. On March 30, two days after the initial accident, Denton flew to Three Mile Island in a White House helicopter.
He found the power plant to be in “absolute chaos,” he told the Washington Post at the time. He brought in as many as 100 scientists to examine the facility, and a special phone line was installed, connecting Denton directly to the White House. His son drove to Harrisburg with a suitcase containing extra clothes and a toothbrush.
During his first day, Denton learned that, in a colossal blunder, radiation had been released from an auxiliary building. A large hydrogen bubble in the building that contained the reactor was in danger of exploding.
Moreover, water pumps intended to cool the reactor’s fuel rods had been turned off, and a relief valve was locked in the open position, which allowed steam to escape. As a result, the 36,000 uranium fuel rods in the reactor’s core overheated, and as many as half were damaged beyond repair.
As the face of the federal government at Three Mile Island, he made it clear that the utility company answered to him.
“Since I’m the director of the office of nuclear reactors,” Denton said at the time, “I can issue, modify or suspend licenses. So I never had any doubt that if I didn’t like the way they were running it, I could issue an order on the spot.”
His news conferences were carried on national television, and the public found his technical expertise and folksy demeanour reassuring. He gave the president a tour of the facility, calming public fear.
Within days, the hydrogen bubble dissipated, the reactor began to cool and the danger passed. There were no injuries at Three Mile Island, but the accident led to reforms and slowed the construction of nuclear power plants for decades.
Denton spent almost three weeks at Three Mile Island. The accident was the result of compounded human errors — pumps turned off, valves left open, instrument readings wrongly interpreted — but the regulations Denton helped put in place kept it from being even worse.
“I suspect it was a little bit because of our actions and maybe a bit of serendipity,” he told the Post in 1979. “A little bit of luck and little bit of forethought.”