U.S. aircraft carrier exposed to radiation
Experts debate wind-borne peril to U.S.
By William J. Broad
New York Times
Updated: 03/13/2011 11:56:30 PM CDT
The Pentagon was expected to announce that the aircraft carrier Ronald Reagan, which is sailing in the Pacific, passed through a radioactive cloud from stricken nuclear reactors in Japan, causing crew members on deck to receive a month's worth of radiation in about an hour, government officials said Sunday.
The officials added that American helicopters flying missions about 60 miles north of the damaged reactors became coated with particulate radiation that had to be washed off.
There was no indication any of the military personnel had experienced ill effects from the exposure. (Everyone is exposed to a small amount of natural background radiation.)
But the episodes showed that the prevailing winds were picking up radioactive material from crippled reactors in northeastern Japan. Ever since an earthquake struck Japan on Friday, authorities worldwide have been laying plans to determine what, if any, danger radioactive plumes could pose to people.
Blogs were churning with alarm. But officials insisted that unless the quake-damaged nuclear plants deteriorated into full meltdown, any radiation that reached the United States would be too weak to do any harm.
Washington had "hypothetical plots" for worst-case plume dispersal within hours of the start of the crisis, a senior official said Sunday. The aim, the official added, was "more to help Japan" than the United States, since few experts foresaw high levels of radiation reaching the West Coast.
For now, the prevailing winds over Japan were blowing eastward across the Pacific. If they continue to do so, international stations for radioactive tracking at Wake or Midway Islands might detect radiation later this week, said Annika Thunborg, a spokeswoman for an arm of the United Nations in Vienna that monitors the planet for spikes in radioactivity.
"At this point, we have not picked up anything" in detectors midway between Japan and Hawaii, Thunborg said in an interview on Sunday.
On Sunday, the Nuclear Regulatory Commission said it expected no "harmful levels of radioactivity" to move on the winds to Hawaii, Alaska or the West Coast from the reactors in Japan.
But some private nuclear experts urged caution.
"We're all worrying about it," said Robert Alvarez, a nuclear expert who, from 1993 to 1999, was a policy adviser to the secretary of energy.
"It's going to be important," he added, "for the Japanese and U.S. authorities to inform the public about the nature of the plumes and any need for precautionary measures."
The plume issue has arisen before. In 1986, radiation spewing from the Chernobyl disaster in Ukraine reached the West Coast in 10 days.
Since then, scientists have refined their abilities to monitor such atmospheric releases.
With the Japanese crisis, apprehension has also soared.
"Concern has been raised about a massive radioactive cloud escaping and sweeping over the West Coast," said a blog, recommending whole grains and health foods for fighting radiation poisoning.
On another blog, someone asked, "Should I take iodine now?" That referred to pills that can prevent poisoning from the atmospheric release of iodine-131, a radioactive byproduct of nuclear plants that the Japanese authorities have identified as escaping into the atmosphere.
