A government body conducted analyses on the damage tsunamis of various scales would inflict on a nuclear power plant, according to documents made public yesterday, adding to allegations that Japan and its largest utility failed to heed warnings.
The latest revelation, reported by the Mainichi Shimbun, emerged as the government prepares to help Tokyo Electric Power Co (TEPCO) compensate victims of the crisis at the tsunami-crippled nuclear Fukushma Dai-ichi nuclear power plant.
The government and TEPCO have repeatedly described the combination of the magnitude 9.0 earthquake and the ensuing 15m tsunami on March 11 as beyond expectations.
An institution affiliated with the Japanese Ministry of Economy, Trade and Industry, however, analyzed the dangers of tsunamis ranging from 3m to 23m in a report originally published in December.
“Our analysis shows that a tsunami of a certain height [some 7m in the absence of a seawall and some 15m if one were present] or higher would have almost a 100 percent chance of damaging the reactor core...,” the Japan Nuclear Energy Safety Organization said in the report.
“We presume a tsunami of at least 7 meters would destroy the functions of a seawater pump and that of at least 15 meters would destroy outside equipment such as an electrical transformer,” it said.
The government and TEPCO have explained that the Fukushima plant that leaked radiation following the disaster was designed to handle roughly a 6m wall of water.
Engineers are still struggling to bring the plant north of Tokyo under control two months after the disaster. More than 15,000 people were killed in the disaster and about 9,500 are still missing.