TOKYO, Japan—International nuclear inspectors have criticized the operator of the Fukushima Daiichi nuclear plant for failing to prepare for a tsunami of the size that slammed into the facility on March 11, sparking the world’s worst nuclear crisis since Chernobyl.
In a preliminary report issued on Wednesday, inspectors from the International Atomic Energy Agency (IAEA) said Tokyo Electric Power (Tepco) had underestimated the risk of a giant tsunami, and urged authorities to closely monitor the health of plant workers and members of the public.
The team, led by Britain’s chief nuclear safety official, Mike Weightman, said lack of preparedness had contributed to the crisis at Fukushima, where workers are still trying to restore cooling systems to reactors, three of which suffered meltdowns soon after they were struck by a magnitude 9.0 earthquake and 14-meter tsunami.
Weightman dismissed speculation that the earthquake had caused substantial damage before the tsunami arrived. “In terms of the cause it is clear — the direct cause was a tsunami, associated with an earthquake, of tremendous size,” he told reporters.
The three-page report said Tepco had failed to heed warnings by government experts and its own scientists of the possibility of waves big enough to breach the plant’s 5.7-meter protective wall. “We had a playbook, but it didn’t work,” said Tatsujiro Suzuki, the vice chairman of Japan’s Atomic Energy Commission.
The IAEA report said: “The tsunami hazard for several sites was underestimated. Nuclear plant designers and operators should appropriately evaluate and provide protection against the risks of all natural hazards.”
The inspectors said the global nuclear industry should regularly review the risks posed by natural disasters and “harden” its ability to respond to emergencies.
They said “simple, effective [and] robust equipment should be available [at all nuclear plants] to restore essential safety functions in a timely way for severe accident conditions.”
Despite the criticism, Tepco will have been encouraged by the IAEA’s appraisal of its post-disaster response. “The response on the site by dedicated, determined and expert staff, under extremely arduous conditions has been exemplary and resulted in the best approach to securing safety given the exceptional circumstances,” it said.
The team delivered its report to the prime minister, Naoto Kan, who was expected to face a no-confidence motion in parliament later on Wednesday, over what some regard as his poor handling of the nuclear crisis. Voting on the motion will take place on Thursday. Kan is expected to survive, unless the main opposition party can persuade enough rebels in his own party to vote for the motion.
The IAEA inspectors will present their findings at a meeting of member-state ministers in Vienna later this month.
The need to improve their ability to withstand earthquakes and tsunamis could lead to more nuclear plant closures in Japan while they undergo maintenance work. In the worst-case scenario, all of Japan’s 54 reactors could be closed by the middle of next year, according to some reports, removing almost a third of the country’s power generation and raising the possibility of long-term power rationing.
The IAEA inspectors urged Japan to step up efforts to monitor the health of Fukushima workers and people living nearby. The accident has forced more than 80,000 people living near the plant to evacuate their homes, while concern is rising over the effects of accumulated radiation on the health of those living in the wider Fukushima region.
While it described the evacuation and attempts to protect the public as “impressive and extremely well-organized,” the team said “a suitable and timely follow-up program on public and worker exposures, and health monitoring would be beneficial.”