Japan 'Underestimated' Tsunami Nuclear Risk

Japan underestimated the risk of tsunamis to its coastal nuclear power plants, a British-led UN safety team has concluded.

The report also said Japan needs to closely monitor public and workers' health after the crisis at the Fukushima nuclear plant, as a result of the world's worst nuclear disaster since Chernobyl.

The report, from an International Atomic Energy Agency(IAEA) team, was led by Britain's top nuclear safety official Mike Weightman.

It highlighted some of the well-documented weaknesses that contributed to the crisis at the Fukushima facility, 150 miles north of Tokyo.

The plant was hit by a massive earthquake and then a tsunami in quick succession on March 11.

Fukushima was swamped by the huge tsunami waves

Among the criticisms was a failure to plan for a tsunami that would overrun the 19ft break wall at Fukushima and knock out back-up electric generators to four reactors.

This occurred despite multiple forecasts from a government agency and operator Tokyo Electric Power company's own scientists that such a risk was looming.

The IAEA team said Japan's crisis offered several lessons for the nuclear industry globally, including that plant operators should regularly review the risks of natural disasters.

It also recommended that "hardened" emergency response centres should be established to deal with accidents.

"The tsunami hazard for several sites was underestimated," the report's three-page summary said.

Local residents were put at risk by nuclear radiation

"Nuclear plant designers and operators should appropriately evaluate and provide protection against the risks of all natural hazards."

Goshi Hosono, an aide to Prime Minister Naoto Kan, accepted the report, marking the first step in an effort by Japanese officials to show that the lessons learned from Fukushima can be applied to make its remaining reactors safe.

Hosono said the government would need to review its nuclear regulatory framework.

The IAEA team will submit its findings to a ministerial conference on nuclear safety in Vienna from June 20-24.

"We had a playbook, but it didn't work," said Tatsujiro Suzuki, a nuclear expert and vice chairman of Japan's Atomic Energy Commission.