VIENNA – Diplomats and UN officials are trying to dispel fears of a wider danger from radioactivity spewing from Japan’s crippled nuclear reactors, saying there were no hazards to health outside of the immediate vicinity.
As emergency efforts to reduce the dangers of increased radiation from the crippled plant went into their eighth day, the UN nuclear agency described the situation for the second day in a row as worrying but stable.
Driven by winds over the Pacific Ocean, the radioactive plume released last week from the Fukushima Dai-ichi reached Southern California Friday, heightening concerns that Japan’s nuclear disaster was assuming international proportions.
But in Vienna, diplomats and officials familiar with the situation asserted that there was little to fear outside of the 20 kilometre evacuated zone around the plant.
A diplomat with access to radiation tracking by the UN’s Comprehensive Test Ban Treaty Organisation in Vienna cited readings from a California-based measuring station of the agency as “about a billion times beneath levels that would be health threatening.”
He spoke to The Associated Press on condition of anonymity because the CTBTO does not make its findings public.
Graham Andrew, a senior official of the Vienna-based International Atomic Energy Agency, suggested the diplomat’s comments reflected his own feelings.
“We want to study the data carefully, but one-billionth shows just how far away it is from human danger,” he said. “For members of the public, the dose limit in the air or ingested is 1 milisievert a year and this is 1000 million times less than that.”
Graham said that – after consultation with the IAEA – the International Civil Aviation Organisation found there was no reason to curtail normal international flights and maritime operations to and form Japan and “there is no medical basis for imposing additional measures to protect passengers.”
The CTBTO forecast earlier this week that some radioactivity would reach Southern California by Friday. A CTBTO graphic obtained on Thursday by the AP showed a moving plume reaching the US mainland after racing across the Pacific and swiping the Aleutian Islands.
The comments reflected expectations by IAEA officials and independent experts that radiation levels – which are relatively low outside of the immediate vicinity of the Japanese plant – would dissipate so strongly by the time it reached the US coastline that it would pose no health risk whatsoever to residents.
A presentation on Friday showed radiation levels peaking in Tokyo and other cities in the first days of the disaster at levels officials said were well below risk points before tapering off.
“The rates in Tokyo and other cities … remain far from levels which require action, in other words they are not dangerous to human health,” said Andrew.
While set up to monitor atmospheric nuclear testing, the CTBTO’s worldwide network of stations can detect earthquakes, tsunamis and fallout from nuclear accidents such as the disaster on Japan’s northeastern coast that was set off by a massive earthquake and a devastating tsunami a week ago.
Since then, emergency crews have been trying to restore the Fukushima Dai-ichi nuclear plant’s cooling system and prevent overheated fuel rods from releasing greater doses of radioactivity.
Japanese officials on Friday reclassified the rating of the accident at the plant from Level 4 to Level 5 on a seven-level international scale, putting it on a par with the 1979 Three Mile Island accident.
The International Nuclear Event Scale defines a Level 4 incident as having local consequences and a Level 5 as having wider consequences.
Nuclear experts have been saying for days that Japan was underplaying the severity of the nuclear crisis.
Graham refused to be drawn on that issue, saying severity assessments would be the task of a post-emergency investigation. Describing the situation as “very serious,” he nonetheless noted “no significant worsening” since his last briefing on Thursday – when he used similar terminology.
Things are “moving to a stable, non-changing situation, which is positive,” he said. “You don’t want things that are rapidly changing,” he said.