TOKYO—Speaking to a visiting committee of American experts, a Tokyo Electric Power Company (TEPCO) official conceded that the root causes of the Fukushima nuclear disaster stemmed from a lack of humility in anticipating the full effects of natural disasters and a reluctance to share internal concerns about nuclear power risks with regulators and the public. Company officials feared such openness would "make people worry about the safety" of nuclear power, he said.
The disclosures were part of a presentation to a committee of the U.S. National Academy of Sciences (NAS) and the National Research Council tasked with identifying the lessons that American nuclear power plant operators should learn from last year's Fukushima nuclear power plant accident. The NAS group was on the first day of a weeklong fact-finding trip to Japan that will include visits to the devastated Fukushima Daiichi Nuclear Power Plant as well as other nuclear facilities that withstood the March 2011 earthquake and tsunami that precipitated the crisis. The committee comprises 22 experts from various disciplines. NAS emphasizes that the committee's brief calls for it to develop recommendations for "improving the safety and security of nuclear plants in the United States."
The committee has already held two previous meetings in Washington, D.C. In Tokyo, it is being briefed on the conclusions of the several Japanese committees that have studied the Fukushima disaster. It will also hear details about nuclear power plant operator training and the hydrogen explosions that ripped through the Fukushima buildings.
Today, the group heard from Kiyoshi Kurokawa, a prominent Japanese physician and scientist who headed an investigating committee authorized by Japan's legislature that concluded the accident was a manmade disaster. Akira Kawano, TEPCO's general manager, then presented numerous details on improvements the company is making to its other nuclear power plants in light of its Fukushima experience. These include increasing the height of tsunami walls and upgrading emergency equipment, plans, and training. Kawano also presented the findings of internal investigations into what he called the root causes of the disaster. "TEPCO did not have sufficient humility to consider [the full impact] of natural disasters," he said. He explained that TEPCO had never sought the advice of outside experts who might have helped improve disaster planning.
Another root cause of the disaster, Kawano said, was that TEPCO "did not face the regulatory body and the public squarely" in sharing internal concerns about the ability of critical power plant equipment to withstand a disaster. The company "worried that [such disclosures] would make the public worry about the safety" of nuclear power, he said.
"I want TEPCO to make this presentation to the Japanese public," said Hiroyuki Yoshikawa, an engineer and former president of University of Tokyo who in the wake of the disaster has pondered the scientific community's responsibility for the disaster.
The first day "was a good start," said Norman Neureiter, chair of the NAS committee who is also senior adviser to the Center for Science Diplomacy of AAAS (publisher of ScienceInsider). The committee plans to issue its report in early 2014.