LINDA WERTHEIMER, host:
For weeks the world has been anxiously watching every development in Japan's nuclear crisis.
RENEE MONTAGNE, host:
Thirty-two years ago, international attention was on an American reactor going through partial core meltdown. The nuclear accident at Three Mile Island was the worst in U.S. history, and it was a major setback for nuclear power here.
WERTHEIMER: But NPR's Joel Rose reports that industry leaders say the accident taught them critical lessons about safety and crisis management.
JOEL ROSE: It was nothing as dramatic as an earthquake or tsunami that triggered the accident at Three Mile Island Nuclear Generating Station, about 10 miles south of Harrisburg, Pennsylvania.
Mr. SAM WALKER (Historian): A valve stuck open. A valve didn't close as it was supposed to and as a result coolant ran out of the core.
ROSE: Sam Walker is the former historian of the Nuclear Regulatory Commission and the author of a book about the Three Mile Island accident.
Mr. WALKER: It was a minor breakdown that was compounded by operator error. What they could see was that something was wrong. And they could see it because alarms were sounding, lights were flashing. It was clear that something was wrong. But it wasn't clear exactly what was wrong.
ROSE: That confusion extended beyond the control room. At first, the utility that operated the plant, Metropolitan Edison, insisted this was a minor accident with no release of harmful radioactivity.
But by the afternoon of March 28th, Pennsylvania Lieutenant Governor Bill Scranton was telling reporters that wasn't exactly true.
(Soundbite of archival audio)
Lieutenant Governor BILL SCRANTON (Republican, Pennsylvania): The situation is more complex than the company first led us to believe. There has been a release of radioactivity into the environment.
ROSE: When the crisis ended five days later, relatively small amounts of radiation had escaped from the plant. No one was even injured. But the accident at Three Mile Island had a huge impact on the industry. Not a single nuclear plant has been ordered and built in the U.S. in the 32 years since the accident. And historian Sam Walker says it led to tougher safety standards for nuclear plants.
Mr. WALKER: Well, the most important changes were what were called human factors. That was the lesson that was most obvious, was one, you had to improve operator training, you had to give the operators the knowledge and the tools that they needed to be able to deal with a situation like they faced on the morning of March 28, 1979.
ROSE: Today, every nuclear power plant is required to build a replica of its control room for training purposes.
Mr. RALPH DESANTIS (Communications Manager, Three Mile Island): It's real. It's as real as it can be. Very much like a cockpit simulator for airline pilots, the training's very realistic.
ROSE: Ralph DeSantis is communications manager at Three Mile Island. While Unit 2 has been shuttered since the accident, Unit 1 at the plant reopened in the mid-1980s under new management. DeSantis says better training is only one lesson the industry learned from the accident.
Mr. DESANTIS: We're very open in saying that at the time of the accident, the utility here at TMI did a bad job of communicating to the public about what was going on, and that led to some of the fear that existed.
ROSE: But for some, that fear never went away.
Mr. ERIC EPSTEIN: So it's a real-time system essentially. And I'll show you how it works.
ROSE: Eric Epstein has turned the basement of his house in Harrisburg into a monitoring station, where he collects independent readings of radiation levels around Three Mile Island. Epstein doesn't trust the plant's operators or the government to share sensitive information in a crisis.
Mr. EPSTEIN: When you're living through a nuclear accident and don't know what the outcome is going to be, it's a nightmare that you never wake up from. So you know, those are shadows that chase you forever.
ROSE: Those shadows are still chasing the U.S. nuclear industry too. Polls show that Americans are divided over whether to build more nuclear power plants. And that was before the disaster in Japan.
Joel Rose, NPR News.
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