SEOUL, South Korea — Japan did not properly protect its nuclear plants against tsunami threats prior to the March 11 disaster that caused radiation to spew from the Fukushima Dai ichi plant, a preliminary report released Wednesday by international nuclear experts concluded.
“The tsunami hazard for several sites was underestimated,” according to a three-page summary released by a United Nations nuclear safety team probing the aftermath of a magnitude-9.0 earthquake that triggered a nearly 50-foot-high wall of water, deluging the plant.
That miscalculation led to meltdowns in three of the facility’s six reactors, which caused the release of harmful radioactive isotopes into the air, soil and seawater. The emergency prompted the evacuation of more than 80,000 residents.
The report by the International Atomic Energy Agency — compiled by nuclear experts from a dozen nations, including the U.S., France, Russia and China — blamed the tsunami for causing power outages that quickly caused the disaster to spiral out of control.
Although characterizing Japan’s response to the disaster as “exemplary,” the report called for nuclear plant designers and operators to better coordinate safety preparations at more than a dozen atomic power plants operating nationwide.
Investigators also urged regulatory officials to better monitor the effect that prolonged radiation exposure might have on both the general public and nuclear workers at the crippled plant, located 150 miles north of Tokyo. The full report is scheduled for release this month.
