Tokyo Radiation Risk Limited Even in Worst Case, U.K. Says
By Kari Lundgren and Joe Carroll - Mar 16, 2011
The risks to human health from Tokyo Electric Power Co.’s damaged Fukushima Daiichi atomic plant are limited to an evacuated area adjacent to the facility, according to the U.K.’s Chief Scientific Officer John Beddington.
“The 20-kilometer (12-mile) exclusion zone that the Japanese have actually imposed is sensible and proportionate,” Beddington said, according to a transcript of a conference call yesterday. “This is very problematic for the area and the immediate vicinity, and one has to have concerns for the people working there. Beyond that 20 or 30 kilometers, it’s really not an issue for health.”
The worst-case scenario would result in an explosion that could send radioactive material about 500 meters in the air for a short period of time, he said. The Fukushima reactor lacks the sort of graphite buffer that burned so intensely during the Chernobyl disaster in 1986 that radioactive plumes jetted into the upper atmosphere as high as 30,000 feet for months, he said.
Workers at the Fukushima facility, damaged after the March 11 earthquake, are struggling to keep the plant’s reactors cool and to control pressure inside the containment vessels. If they fail to do so, pressure would build up inside the reactors and cause the core to melt, Beddington said. As it melts, the material will fall and react with the concrete and other materials on the floor, he said on a call with the British Embassy in Tokyo.
“In this reasonable worst case, you get an explosion,” he said. “Now, that’s really serious, but it’s serious again for the local area. It’s not serious for elsewhere.”
Tokyo is about 240 kilometers southwest of the damaged power plant.
Even if weather patterns carried radioactive material toward Tokyo on the wind and in rain, there would be “absolutely no issue” for city residents, he said. The radioactive pollution would fall out of the sky before it got more than 20 kilometers or 30 kilometers from the damaged reactor, he said.
After the Chernobyl blast, which killed more than 31 workers and firefighters, health problems stemming from direct radiation exposure didn’t extend beyond a 30-kilometer exclusion zone, Hilary Walker, deputy director of emergency preparedness at the U.K. Department of Health, said during the call.
The 4,000 children and adolescents who later developed thyroid cancer did so from eating food and milk contaminated with radioactive iodine, rather than as a result of fallout from the reactor explosion, Walker said.
Japan has a robust food-inspection system that would screen meat, produce, milk and seafood to ensure nothing contaminated by radioactivity reaches store shelves, she said.
“We believe the situation will be very different in Japan where they have extremely well developed plans, and they would be able to ensure that you could not drink contaminated water or eat contaminated food,” Walker said.
Beddington said an expansion of the Fukushima exclusion zone to a 30-kilometer radius would be “well within the sort of parameters that we would think are extremely safe.”
Nick Kent, a physician with the U.K.’s Health Protection Agency, said during the call that there’s no need for anyone who hasn’t been close enough to the plant to inhale radioactive materials to take iodine tablets.