Workers exposed to radiation 10,000 times higher than normal
Published 25/03/2011 | 15:57
Concerns over the extent of radioactive contamination in Japan deepened after it emerged that three workers admitted to hospital this week were exposed to radiation levels 10,000 times higher than normal
The news raised fears that the steel and concrete containment around one of the reactors at the crippled Fukushima nuclear power plant could be leaking.
Japan's prime minister, Naoto Kan, made clear that the work to stabilise Fukushima remains on a knife-edge.
"The situation today at the Fukushima Daiichi power plant is still very grave and serious. We must remain vigilant," he said in an evening address to the nation, "We are not in a position where we can be optimistic. We must treat every development with the utmost care."
Japanese officials said further investigations were needed to determine how the three men replacing a cable at the No. 3 reactor were sloshing about in water containing iodine, caesium and cobalt 10,000 times the normal level.
"At present, our monitoring data suggest the (No. 3) reactor retains certain containment functions, but there is a good chance that the reactor has been damaged," said Hidehiko Nishiyama, a spokesman for Japan's nuclear agency.
The possibility of damage to the reactor itself raised fresh concerns and caused some confusion yesterday, although an official later clarified that a leak in the plumbing or the vents was most likely to blame for the elevated radiation levels.
Despite stoppages at No. 3 reactor, some 700 engineers, firefighters and technicians continue to work to stabilise the six reactors at the plant that was badly damaged by the 9.0-magnitude earthquake and subsequent tsunami that struck Japan on March 11.
Two of the reactors are now regarded as safe in what is called a "cold shutdown" but four remain volatile, periodically emitting steam and smoke as work continues to restart the water pumps needed to cool fuel rods inside the reactors.
The three injured workers now brings to 17 the total number of workers exposed to more than 100 millisieverts of radiation at the plant, an annual exposure level considered the lowest at which any increase in cancer risk is evident.
Further afield, the impacts of the radiation leaks continued to be felt as China announced it was joining a growing list of countries banning dairy and aquatic products, vegetables and fruit from five Japanese prefectures near the stricken facility.
"Japan's Fukushima nuclear plant leak accident has already resulted in serious pollution to local food and agricultural products," said China's quarantine agency, adding it would step up surveillance on other products from Japan.
In a separate incident China announced that two Japanese tourists arriving in the eastern city of Wuxi from Tokyo on Wednesday had been found to have levels of radiation that "seriously exceeded standards".
The pair, who lived in an area 200km to 300km from the plant – comfortably outside the 20km exclusion zone – were decontaminated and given iodine pills before being returned to their tour group, a spokesman said.
"We found there were radioactive particles on them and decontaminated them. They were sent back to their tour group," said Liu Yulong, the doctor that treated them, "The (radiation) dosage was not very large and should not harm their health."
Despite reassurances that exposure levels outside the exclusion zone are still only the equivalent of a dental X-ray even when above government safety limits, there was widespread scepticism among the public.
In Tokyo supermarket shelves remained stripped of bottled water on Friday even though radiation levels had returned to within safe limits and the city's governor was shown on television drinking tap water at a municipal purification plant.
Two weeks after the tsunami struck, the official death toll passed 10,000 yesterday with a further 17,500 listed as missing, as rescuers continue to discover bodies, some of which are being interred in mass graves despite Japan's cultural preference for cremation.
Government figures showed 660,000 households still do not have water and more than 209,000 do not have electricity, with damage now estimated at €210bn, making this the most expensive natural disaster on record.