Authorities have battled to prevent radioactive contaminants from escaping the six-reactor Fukushima Daiichi facility following a March 11 earthquake and tsunami that left more than 20,000 people dead or missing in Japan. Radiation releases on a level not seen since the 1986 Chernobyl disaster forced the evacuation of about 80,000 residents from the 12-mile ring exclusion zone.
An increasing number of radiation-tainted "hot spots" have been located at greater distances from the site, according to Bloomberg.
Helicopters will be used to check for radiation in 22 prefectures, up from assessments of the six prefectures nearest to the facility. The move follows the identification this week of contaminated detritus 125 miles from the site, a distance that is more than twice what is allowed by law.
"The government should have expanded the monitoring area by helicopters much earlier to ease concerns among the public," according to Tetsuo Ito, who leads the Atomic Energy Research Insitute at Kinki University in Osaka.
The Japanese Health, Labor and Welfare Ministry is also preparing to examine food from roughly 100 communities in 14 prefectures, an agency official said.
The government since June has not issued any specific data on how much radiation has been emitted by the plant (Inajima/Okada, Bloomberg, Aug. 24).
One specialist told lawmakers in July that the amount of radioactive material released from the Fukushima plant is about 30 times greater than the quanity produced by the U.S. atomic bomb that was dropped on Hiroshima during World War II, the Japan Times reported.
"It means a signficantly large amount of radioactive material was released compared with the atomic bomb," according to University of Tokyo systems biological and medicine professor Tatsuhiko Kodama (Jun Hongo, Japan Times, Aug. 24).
The New York Times reported on Sunday that Japan might declare parts of the 12-mile exclusion zone around the nuclear plant uninhabitable for decades.
One specialist said the government's cap on maximum yearly contact with radioactive contaminants should be increased from the anticipated 1 millisievert to as high as 5 millisieverts, Kyodo News reported. That would be more reasonable in allowing citizens to return to their homes, according to Shunichi Tanaka, one-time head of the Japan Atomic Energy Commission.
"Past experience of decontamination has shown it would be very difficult to reduce annual radiation exposure to 1 millisievert," Tanaka said during a commission session.
A recent government assessment indicated that annual exposure levels at 15 of 50 specific locations within the exclusion ring would be presently in excess of 100 millisieverts (Kyodo News/Mainichi Daily News, Aug. 24).
Meanwhile, a tentative plan calls for the International Atomic Energy Agency over three years to conduct one or more safety checks in all countries that have atomic energy facilities, Reuters reported. The proposal is intended to head off disasters similar to the situation in Japan.
"The robust implementation of this action plan with full transparency will be of utmost importance and will represent a significant step forward in strengthening nuclear safety," according to the plan, which has not been finalized.
Some states have pushed for tougher regulations, while others have said the safety issue should remain under the purview of nations' governments, according to Reuters.
"This is middle ground," one European envoy said. "It is still not the most ambitious of documents."
The IAEA Board of Governors could consider the safety proposal when it meets next month (Fredrik Dahl, Reuters, Aug. 23).
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