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Three Mile Island--failure of science or spin?

An IAP session reviews the 1979 crisis
Andrew C. Kadak
Andrew C. Kadak
Photo / Donna Coveney
The two containment buildings (center) and two of the cooling towers (background) of the Three Mile Island nuclear power plant.
The two containment buildings (center) and two of the cooling towers (background) of the Three Mile Island nuclear power plant.
Photo / DOE

Since 1979, the words "Three Mile Island" have been synonymous with the words "nuclear disaster." But does a careful analysis of the timeline, aftermath and media coverage reveal that the accident at the Three Mile Island Nuclear Generating Station was really a public relations disaster and not a technical failure?

That was the provocative question posed by Andrew Kadak, professor of the practice of nuclear engineering, in his Jan. 22 two-part IAP seminar about five crucial days in March 1979 at the plant near Harrisburg, Pa.

In the morning session of "Three Mile Island--Colossal Failure or Colossal Success?" Kadak concluded there were failures all around--except for the most important aspect: The melted nuclear core was contained and any radiation released was minimal. Thus, the plant design and safety protocols actually worked, despite numerous operator mistakes. Kadak's arguments met with lively opposition, as session participants zeroed in on technical glitches.

Just as lively was the afternoon session on "Three Mile Island Communications--Good, Bad or Ugly?" in which Kadak discussed the role of local reporters, the plant spokesman, members of the Nuclear Regulatory Commission and Pennsylvania Gov. Dick Thornburgh.

"What do you say when people want answers even if you don't have them?" he asked participants.

"You can't handle the truth!" was one humorous response, but the humor underscored the difficulty in explaining technical issues to a media or frightened public that demanded easy, immediate answers

Kadak set the framework for analysis by identifying four aspects of "failure": technical, financial, perception and consequences.

One of the key technical issues in running a nuclear plant is managing heat: radiation decay means that 7 percent of full heat continues even after the plant is "shut down," he explained. The nuclear core has to be covered with water at all times.

On March 28, through a series of errors around 4 a.m.--including a valve that was supposed to close but didn't and a known leak that led operators to conclude high temperatures readings were false--water escaped from the core, which began heating up without a way to remove the heat. Within a matter of minutes, things went from bad to worse as operators continued to believe water was circulating through the core and they had a "bottled-up system."

By 5 a.m. "all hell broke loose," Kadak said. "In my assessment, (operators) had no real idea what was going on … They were not able to deal with all these events at the same time."

By 7 a.m. a site emergency was called; by 7:30 a.m. a general emergency was called, amid concerns that a hydrogen bubble had formed in the core. It had not, Kadak said, although months later cleanup crews were astonished to see how much of the core had actually melted.

Reports that radiation had been released--later found to be inaccurate--led Gov. Thornburgh to order a partial evacuation. A plant spokesman, technically skilled but inexperienced in media relations, gave the impression of a cover-up. Eventually a visit to the plant by then President Jimmy Carter, who had studied nuclear physics, helped calm the public and the cleanup process began. The release of the nuclear accident film "The China Syndrome" 12 days earlier was eerily coincidental.

As a result of the Three Mile Island incident, nuclear plant construction was halted throughout the United States, "killing the nuclear industry for 30 years," Kadak said, and many became convinced nuclear energy was unsafe. Yet Kadak said, despite ominous newspaper photos of (completely safe) steam being released from the plant's cooling towers, radiation was "contained"--the supreme goal of the design. Could that not be considered a success?

Not to Miklos Porkolab, MIT physics professor and director of the Plasma Science and Fusion Center. "I would say they were damn lucky,'' he said. "It reminds me of my Pontiac." That is, everything has failed at one time or another.

Physics graduate student Roark Marsh suggested removing the word "colossal" to make the assessment more accurate. But activist James Williamson, a frequent participant in MIT events, would have none of it, saying that not only did systems fail, but plant operators failed to err on the side of caution and call for an evacuation, even if they were unsure of the risk. "Yes, there was inaccurate information, but who cares?" he said.

But, noted Ian Hutchinson, head of MIT's Department of Nuclear Science and Engineering, evacuations are not without costs--people can be killed in traffic trying to flee.

Other participants said they saw all kind of places where "all systems failed." Some cited lack of user interface; others the lack of fail-safe mechanisms or "redundant sensors to know what's going on," as Joshua A. Stillerman, systems program analyst in the Plasma Science and Fusion Center, put it.

While experts wrongly concluded that hydrogen in the core would form a dangerous bubble (rather than safely recombine with oxygen), "isn't the lesson to imagine things even worse than they can imagine?" Hutchinson asked.

But bottom line: No one was killed in the accident and subsequent studies have turned up no conclusive evidence on health problems. Three Mile Island could have been a huge disaster; because of safety protocols, it was not, Kadak concluded. The real hero, he argued, was Gov. Thornburgh, who took the attitude, "I'm not going to do anything until I get the facts."

A version of this article appeared in MIT Tech Talk on February 7, 2007 (download PDF).

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