Japan feared 'demonic chain reaction' at reactor, report says A new report vividly portrays the Japanese government's fears in the first hours and days after the March 11, 2011, tsunami overran a coastal nuclear power plant, including concerns that officials might have to evacuate Tokyo. The government was afraid that a "demonic chain reaction" would ensue after the meltdown at the Fukushima Daiichi nuclear power plant, even as it assured the public that all was under control, according to the report by the Rebuild Japan Initiative Foundation, a private policy group. At one point, advisors to then-Prime Minister Naoto Kan began referring to a worst-case scenario that would not only force the evacuation of tens of millions of Tokyo residents, but could also cause widespread environmental damage across Japan, the report says. At the same time, Kan's staff continued to assure the Japanese public and the international community that the situation was under control. When the nuclear plant was struck by a wall of water after an earthquake hit northeastern Japan on the afternoon of March 11, Kan ordered workers to remain at the devastated facility, fearing that thousands of spent fuel rods stored at a damaged reactor would melt and spew radiation after a hydrogen explosion at an adjacent reactor, the report says. Kan, who was forced to resign in September amid criticism that he had mishandled the crisis, flew over the damaged plant by helicopter on the morning of March 12, a move critics say slowed the response to the disaster. The six-month investigation by the foundation involved 30 independent researchers, academics, lawyers and journalists. To reach its findings, the review panel interviewed more than 300 government officials and nuclear regulators, including Kan, to piece together a timeline of the tense hours after Japan's worst environmental disaster. The report, scheduled for publication this week, was released early to several media organizations. The foundation team is one of several conducting independent reviews of how the government responded to the crisis. Although the Fukushima disaster did not prompt the evacuation of Tokyo, it spewed radioactivity into the atmosphere, leading to the displacement of about 80,000 residents near the plant, many of whom have yet to return. Engineers stemmed further damage by pumping seawater into the plant's ailing reactors and spent fuel pools. As the nation prepares to mark the anniversary of the disaster next month, officials say it may take decades to conduct a proper cleanup. During a recent tour, plant officials told reporters that minimizing the release of additional radioactivity is a day-to-day job. An earthquake or tsunami like the ones seen a year ago could be a source of trouble for these [cooling] systems. But we are currently reinforcing the spent fuel pool and making the sea walls higher against tsunamis," Takeshi Takahashi, the plant's manager, told reporters. Government spokesman Yukio Edano on Tuesday told reporters in Tokyo that he had disclosed all information available in the hours after the disaster. I shared all information. Back then, I was not in a position where I, as someone who is not an expert, could irresponsibly speak about my own personal impressions and my sense of crisis," he said at a news conference. I conveyed assessments and decisions of the government, government agencies and experts.