In the peer-reviewed Philosophical Transactions A of the Royal Society, researchers Costas Synolakis of the USC Viterbi School of Engineering and Utku Kânoğlu of the Middle East Technical University in Turkey distilled thousands of pages of government and industry reports and hundreds of news stories, focusing on the run-up to the Fukushima Daiichi disaster in 2011. They found that “arrogance and ignorance,” design flaws, regulatory failures and improper hazard analyses doomed the coastal nuclear power plant even before the tsunami hit.
Synolakis and Kânoğlu report that the Tokyo Electric Power Co. (TEPCO), which ran the plant, first reduced the height of the coastal cliffs where the plant was built, underestimated potential tsunami heights, relied on its own internal faulty data and incomplete modeling and ignored warnings from Japanese scientists that larger tsunamis were possible.
Prior to the disaster, TEPCO estimated that the maximum possible rise in water level at Fukushima Daiichi was 6.1 meters — a number that appears to have been based on low-resolution studies of earthquakes of magnitude 7.5, even though up to magnitude 8.6 quakes have been recorded along the same coast where the plant is located.
This is also despite the fact that TEPCO did two sets of calculations in 2008 based on datasets from different sources, each of which suggested that tsunami heights could top 8.4 meters — possibly reaching above 10 meters.
Additionally, the 2010 Chilean earthquake (magnitude 8.8) should have been a wake-up call to TEPCO, said Synolakis, who described it as the “last chance to avoid the accident.” TEPCO conducted a new safety assessment of Fukushima Daiichi but used 5.7 meters as the maximum possible height of a tsunami, against the published recommendations of some of its own scientists. TEPCO concluded in November 2010 that they had “assessed and confirmed the safety of the nuclear plants,” presenting its findings at a nuclear engineering conference in Japan.