Three Mile Island anniversary: the lesson the nuclear industry refuses to learn

Before Fukushima and before Chernobyl, the world got its first nuclear-power scare  –  the one at Three Mile Island 35 years ago Saturday that is indelibly etched in global consciousness and the one that remains an impediment to a nuclear renaissance.

On March 28, 1979, the alarm began – and in some corners, it has never ceased.

Around 4 a.m., a valve malfunctioned and Unit 2 suffered a loss of primary coolant, which caused a partial core meltdown. By 7 a.m., Harrisburg, just a few miles upriver, and  the surrounding Pennsylvania countryside were awaking to a panic about a "hydrogen bubble" that could explode.

For five frightful days, area residents were kept on edge as the facility’s owner, Metropolitan Edison, made reassuring comments only to backtrack later with more dire news. Areas as far as 300 miles away from Harrisburg were advised they might need to evacuate. Even Pennsylvania's governor complained that he was unable to get answers.  

“People in central Pennsylvania were frightened – appropriately so, partly because the situation looked genuinely alarming and partly because the information coming out of MetEd was so contradictory,” says Peter Sandman, a New York-based  expert on crisis management who covered the crisis for the Columbia Journalism Review.

The reality is that hydrogen in the core could not explode; rather, it would safely combine with oxygen. And while radiation was released from the plant, the public was not endangered – all confirmed after endless environmental investigations and legal challenges. Despite the melting of about one-third of the fuel core, the reactor vessel contained the damage.

The nuclear disasters at Chernobyl in 1986 and Fukushima in 2011 were far more dangerous. Nevertheless, the specter of Three Mile Island still haunts the US nuclear industry, despite the lessons it has learned in the intervening 35 years.

Today's nuclear plants are far more efficient. Their safety record, even including Three Mile Island, has been good. And there is now a strong global emphasis on reducing greenhouse gas emissions – something that nuclear power can deliver at a scale and cost that wind and solar cannot match. 

As a result, four reactors at two plants in Georgia and South Carolina are under construction, which are supposed to herald the industry's revival.

But other nations are at the forefront of the nuclear push today: China, Korea, the UAE, Saudi Arabia, and the United Kingdom. China has 20 nuclear plants today and 28 more under construction – 40 percent of all projected new nuclear units, says the World Nuclear Association. The UK has approved the construction of two reactors at Hinkley Point that will provide 7 percent of the UK’s electricity.

Surprisingly, the nuclear industry worldwide has not learned the most basic lesson of Three Mile Island – to get accurate information to the public in a timely manner. The Soviet Union's inherent secrecy prevented disclosure in the Chernobyl disaster. Japan’s TEPCO failed in the Fukushima crisis. “TEPCO mishandled communications in ways reminiscent of Three Mile Island,” Mr. Sandman says.

Even in the US, secrecy continues to undermine the industry's credibility. This past June, when Southern California Edison announced it would shutter its San Onofre Generating Station because of a small radiation leak, the utility maintained that it only learned of the seepage in 2012 during routine maintenance.

But letters subsequently surfaced that proved that the nuclear operator had been expressing concerns to its vendor, Mitsubishi Heavy Industries, over uncommon vibrations and the possibility of radiation leaks since 2004. That helped erode the utility’s credibility with the public and the regulators, prompting the utility to close the plant and prepare it for decommissioning.