Fukushima fears 'are inflated'

The International Atomic Energy Agency's deputy director, Denis Flory, supports the Japanese assessment that Fukushima is significantly less catastrophic than the 1986 disaster in the former Soviet Union.

"The Fukushima accident and Chernobyl are very different," he said. "Chernobyl happened when the reactor had power, it was a huge explosion, vapour, power explosion, and then you had a huge graphite fire."

Mr Flory echoed Japan's comments that the Fukushima radiation releases had been less than one-tenth of the total released at Chernobyl.

The re-rating of the Fukushima crisis to the highest level on the international INES scale -- a category 7 -- has sparked global concern about its impact.

Japan had previously judged the incident to be a category 5, and the dramatic upgrading of its severity amid new estimates of the amount of radioactivity released caused alarm in some quarters.

Chief Cabinet Secretary Yukio Edano refused to say whether any foreign governments had expressed concerns about the re-rating. However, he said Japan had taken precautions on the basis of the worst-case scenario and the upgrading did not mean they were deficient. The confusion was heightened by the fact the INES scale effectively does not cater for the clear distinction between a disaster such as Chernobyl and the Fukushima crisis.

Japan's latest estimates put the amount of material released into the air at Fukushima at 370 terabecquerels of iodine 131 equivalent, about 7 per cent of the estimated 5200 terabecquerels released at Chernobyl.

The limitations of the INES scale, and the juxtaposition of the severity upgrade with Prime Minister Naoto Kan's comments that things were improving at the plant, fostered an atmosphere of confusion.

Timing issues aside, Mr Kan's comments about gradual improvement were correct and the re-rating of the incident was based almost wholly on radiation releases that occurred in the first week of the crisis.

Still, the Chernobyl linkage appeared to rattle some governments. Immediately after the change, The Philippines initiated charter flights to evacuate about 2000 Filipinos living within 100km of the plant. Australia's Department of Foreign Affairs and Trade updated its travel advice on Japan to reflect the re-rating, but described it as a "technical adjustment" that nuclear regulator ARPANSA said would not change the radiological health risk in Tokyo from its "low" level.

The US nuclear regulator said it was not surprised by the re-rating but backed Japan's handling of the crisis. Russia's atomic energy body, Rosatom, said the re-rating was "exaggerated" and the incident had not exceeded level 5. France's nuclear agency backed the view that Fukushima would not become another Chernobyl.

Radiation confusion has also been causing problems for evacuees from within the exclusion zone around the plant.

Reports have emerged that these people were being turned away from evacuation centres because of unfounded fears they might contaminate others.

Fukushima evacuees were being asked for local government-issued "radiation-free" certificates before being allowed to enter centres, Japanese media reports said.

Critics said the measures were discriminatory and reminiscent of the stigma that was applied to survivors of the Hiroshima and Nagasaki blasts.

But those running evacuation centres said the certificates were necessary for the peace of mind of others inside the centres.

The recovery in Japan from the disaster continues to gather momentum. Sendai Airport yesterday reopened, a month after it was swamped by the tsunami.

At the Fukushima Daiichi plant, the pumping of highly radioactive water from the basement of the No 2 reactor into a storage tank continued, despite a new magnitude-5.8 quake that shook the region.

The economic impact of the disaster was reinforced yesterday when the Cabinet Office downgraded its economic assessment for the first time in six months. The nascent recovery was "a thing of the past", it said.