Tokyo (CNN) -- The Japanese government halted the sale of all food from farms near a tsunami-affected nuclear plant Saturday after abnormally high levels of radiation were found in milk and spinach.
The news of food contamination came as emergency workers scrambled to curb a nuclear crisis sparked by last week's monster earthquake and tsunami.
Crews came closer to restoring electricity needed to power up failed cooling systems in stricken reactors at the Fukishima Daiichi nuclear plant and an unmanned contraption was able to spray seawater continuously to cool down an overheating spent nuclear fuel pool.
Chief Cabinet Secretary Yukio Edano said levels of radiation exceeding safety limits stipulated by Japanese law were found in some samples of spinach and milk from the Fukushima and Ibaraki prefectures but authorities said the radioactive iodine-contaminated food posed little risk.
Tainted milk was found 30 kilometers from the plant and spinach was collected as far as 100 kilometers (65 miles) to the south, almost half way to Tokyo.
"Though radioactive iodine has a short half-life of about eight days and decays naturally within a matter of weeks, there is a short-term risk to human health if radioactive iodine in food is absorbed into the human body," warned the International Atomic Energy Agency.
A person who consumed the tainted food continuously for a year would take in the same amount of radiation as a single CT scan, Edano said. That's about 7 millisieverts or double what an average person in an industrialized country is exposed to in a year, according to the U.S. Food and Drug Administration.
At the Fukushima Daiichi nuclear plant that is responsible for the contamination, emergency crews connected electric cables needed to power up cooling systems in the six stricken reactors rendered inoperable after the tsunami.
Officials with plant owner Tokyo Electric and Power Company told CNN that electric cables have been successfully connected but the company still has to conduct safety and stability checks on the circuit before throwing the switch.
The company said workers hope to fully restore a stable power supply by day's end to the plant's Numbers 1, 2, 5 and 6 reactors. The plan is to get power up and running Sunday for the Numbers 3 and 4 reactors.
The cooling systems are essential to keep temperatures low, curb the further emission of radioactive material and, in a worst case scenario, prevent a full nuclear meltdown. A meltdown could occurs when nuclear fuel rods get so hot that they melt the steel and concrete structure containing them, spilling out into the air and water with potentially deadly results.
Meanwhile, authorities set up a new system to spray seawater continuously on the Number 3 reactor's overheating spent nuclear fuel pool.
A Tokyo fire department official said an unmanned contraption began operating around 2 p.m. Saturday and can spray water for up to seven hours at a time. Previously, firefighters, soldiers and electric company workers had manually done the same in brief intervals to avoid prolonged radiation exposure.
The water, pumped from a nearby port and then funneled to the system, is being directed at the Number 3 reactor's spent fuel pool in order to cool it and prevent the emission of more radioactive material into the atmosphere.
"We believe the situation has been stabilized, though much remains to be seen," said Edano, adding that authorities are also looking into spraying the Number 4 reactor and its spent fuel pool as well.
Also Saturday, a Tokyo Electric official said three holes apiece have been drilled in the ceilings of the Numbers 5 and 6 units in order to alleviate pressure. A hydrogen gas buildup had previously contributed to explosions at the Numbers 1, 2 and 3 reactors.
A water pump, powered by a second diesel generator, began circulating water in the Number 6 units spent fuel pool shortly after 5 a.m. Saturday, according to a news release from Japanese Prime Minister Naoto Kan's office.
Graham Andrew, a special assistant to the IAEA director, noted Friday that efforts to use seawater to cool overheated spent nuclear fuel pools -- both by pumping in seawater, as well as in the case of Unit 3 in which water has come from the ground -- in and around the Numbers 1, 2 and 3 reactors appear to be working.
While each of those reactors have damage to their fuel cores, Andrew said they appear to be relatively stable for now. Japanese authorities reported temperatures lower than 100 degrees Celsius (212 Fahrenheit) inside the reacters, lower than had been expected.
Beyond Saturday's food safety announcement, there have been few indications of any immediate fallout from the nuclear crisis.
Airborne radiation levels around Japan have shown no signs of spiking drastically, according to measurements posted online Saturday by the nation's education and science ministry.
Most readings showed detectable but relatively small amounts of radiation. Even the two top readings in Mito (in Ibaraki prefecture) and Utsonomiya (in Toshigi prefecture) are well below what's considered dangerous to humans and had fallen in recent days.
Still, no one has said that authorities are in the clear. In fact, authorities acknowledged Friday that the situation is far more serious than they'd originally estimated.
"We sincerely apologize ... for causing such a great concern and nuisance," said a statement from Masataka Shimizu, the president of Tokyo Electric.
And the company's managing director, Akio Komori, broke down in a tears after leaving a news conference in Fukushima at which exposure levels were discussed.
This came shortly after Japan's nuclear and industrial safety agency raised its rating for the crisis' severity (specifically, at the Numbers 2 and 3 reactors) from a Level 4 to a Level 5 -- putting it on par with the 1979 accident at Pennsylvania's Three Mile Island plant, the worst nuclear accident in U.S. history.
According to the International Nuclear Events Scale, a level 5 indicates the likelihood of a release of radioactive material, several deaths from radiation and severe damage to a reactor core. Each step on the scale indicates an increase of 10 times the severity of the step below it, the International Atomic Energy Agency says.
The Chernobyl nuclear accident in the former Soviet Union rated a 7, the highest level on the scale, while Japan's other nuclear crisis -- a 1999 accident at Tokaimura in which workers died after being exposed to radiation -- rated a 4.
But the rating change was not due to new problems at the plant, said Hidehiko Nishiyama, deputy head of the nuclear safety agency.
Rather, it came after Japanese authorities got a better assessment of what had happened, partly based on images showing damage to fuel rods and other structures inside certain reactor buildings.
IAEA Director General Yukiya Amano cautioned against reading too much into the raised assessment, saying it is too early to make a full assessment.
Yet Peter Bradford, a member of the U.S. Nuclear Regulatory Commission when the Three Mile Island incident occurred, said the Fukushima Daiichi crisis is worse than the partial meltdown of a single reactor at the Pennsylvania plant.
"In terms of severity, this accident left Three Mile Island in the rear-view mirror several days ago," he said.
Tokyo Electric has more than doubled the radiation threshold for those on-site trying to avert a further crisis.
The company said those at the Fukushima Daiichi plant can now be exposed to 250 millisieverts of radiation before they must leave the area, up from its previous standard of 100 millisieverts.
People are naturally exposed to about 3 millisieverts of radiation a year. The International Commission on Radiological Protection recommends no more than 50 millisieverts exposure in a given year for nuclear rescue and recovery workers. It offers no restriction in a crisis when "the benefit to others clearly outweighs the rescuer's risk."
A Tokyo Electric official said Saturday afternoon that the new standard applies to the several hundred people -- power company employees as well as soldiers, firefighters and others -- now on the site.
http://edition.cnn.com/2011/WORLD/asiapcf/03/19/japan.nuclear.reactors/index.html
The news of food contamination came as emergency workers scrambled to curb a nuclear crisis sparked by last week's monster earthquake and tsunami.
Crews came closer to restoring electricity needed to power up failed cooling systems in stricken reactors at the Fukishima Daiichi nuclear plant and an unmanned contraption was able to spray seawater continuously to cool down an overheating spent nuclear fuel pool.
Chief Cabinet Secretary Yukio Edano said levels of radiation exceeding safety limits stipulated by Japanese law were found in some samples of spinach and milk from the Fukushima and Ibaraki prefectures but authorities said the radioactive iodine-contaminated food posed little risk.
Tainted milk was found 30 kilometers from the plant and spinach was collected as far as 100 kilometers (65 miles) to the south, almost half way to Tokyo.
"Though radioactive iodine has a short half-life of about eight days and decays naturally within a matter of weeks, there is a short-term risk to human health if radioactive iodine in food is absorbed into the human body," warned the International Atomic Energy Agency.
A person who consumed the tainted food continuously for a year would take in the same amount of radiation as a single CT scan, Edano said. That's about 7 millisieverts or double what an average person in an industrialized country is exposed to in a year, according to the U.S. Food and Drug Administration.
At the Fukushima Daiichi nuclear plant that is responsible for the contamination, emergency crews connected electric cables needed to power up cooling systems in the six stricken reactors rendered inoperable after the tsunami.
Officials with plant owner Tokyo Electric and Power Company told CNN that electric cables have been successfully connected but the company still has to conduct safety and stability checks on the circuit before throwing the switch.
The company said workers hope to fully restore a stable power supply by day's end to the plant's Numbers 1, 2, 5 and 6 reactors. The plan is to get power up and running Sunday for the Numbers 3 and 4 reactors.
The cooling systems are essential to keep temperatures low, curb the further emission of radioactive material and, in a worst case scenario, prevent a full nuclear meltdown. A meltdown could occurs when nuclear fuel rods get so hot that they melt the steel and concrete structure containing them, spilling out into the air and water with potentially deadly results.
Meanwhile, authorities set up a new system to spray seawater continuously on the Number 3 reactor's overheating spent nuclear fuel pool.
A Tokyo fire department official said an unmanned contraption began operating around 2 p.m. Saturday and can spray water for up to seven hours at a time. Previously, firefighters, soldiers and electric company workers had manually done the same in brief intervals to avoid prolonged radiation exposure.
The water, pumped from a nearby port and then funneled to the system, is being directed at the Number 3 reactor's spent fuel pool in order to cool it and prevent the emission of more radioactive material into the atmosphere.
"We believe the situation has been stabilized, though much remains to be seen," said Edano, adding that authorities are also looking into spraying the Number 4 reactor and its spent fuel pool as well.
Also Saturday, a Tokyo Electric official said three holes apiece have been drilled in the ceilings of the Numbers 5 and 6 units in order to alleviate pressure. A hydrogen gas buildup had previously contributed to explosions at the Numbers 1, 2 and 3 reactors.
A water pump, powered by a second diesel generator, began circulating water in the Number 6 units spent fuel pool shortly after 5 a.m. Saturday, according to a news release from Japanese Prime Minister Naoto Kan's office.
Graham Andrew, a special assistant to the IAEA director, noted Friday that efforts to use seawater to cool overheated spent nuclear fuel pools -- both by pumping in seawater, as well as in the case of Unit 3 in which water has come from the ground -- in and around the Numbers 1, 2 and 3 reactors appear to be working.
While each of those reactors have damage to their fuel cores, Andrew said they appear to be relatively stable for now. Japanese authorities reported temperatures lower than 100 degrees Celsius (212 Fahrenheit) inside the reacters, lower than had been expected.
Beyond Saturday's food safety announcement, there have been few indications of any immediate fallout from the nuclear crisis.
Airborne radiation levels around Japan have shown no signs of spiking drastically, according to measurements posted online Saturday by the nation's education and science ministry.
Most readings showed detectable but relatively small amounts of radiation. Even the two top readings in Mito (in Ibaraki prefecture) and Utsonomiya (in Toshigi prefecture) are well below what's considered dangerous to humans and had fallen in recent days.
Still, no one has said that authorities are in the clear. In fact, authorities acknowledged Friday that the situation is far more serious than they'd originally estimated.
"We sincerely apologize ... for causing such a great concern and nuisance," said a statement from Masataka Shimizu, the president of Tokyo Electric.
And the company's managing director, Akio Komori, broke down in a tears after leaving a news conference in Fukushima at which exposure levels were discussed.
This came shortly after Japan's nuclear and industrial safety agency raised its rating for the crisis' severity (specifically, at the Numbers 2 and 3 reactors) from a Level 4 to a Level 5 -- putting it on par with the 1979 accident at Pennsylvania's Three Mile Island plant, the worst nuclear accident in U.S. history.
According to the International Nuclear Events Scale, a level 5 indicates the likelihood of a release of radioactive material, several deaths from radiation and severe damage to a reactor core. Each step on the scale indicates an increase of 10 times the severity of the step below it, the International Atomic Energy Agency says.
The Chernobyl nuclear accident in the former Soviet Union rated a 7, the highest level on the scale, while Japan's other nuclear crisis -- a 1999 accident at Tokaimura in which workers died after being exposed to radiation -- rated a 4.
But the rating change was not due to new problems at the plant, said Hidehiko Nishiyama, deputy head of the nuclear safety agency.
Rather, it came after Japanese authorities got a better assessment of what had happened, partly based on images showing damage to fuel rods and other structures inside certain reactor buildings.
IAEA Director General Yukiya Amano cautioned against reading too much into the raised assessment, saying it is too early to make a full assessment.
Yet Peter Bradford, a member of the U.S. Nuclear Regulatory Commission when the Three Mile Island incident occurred, said the Fukushima Daiichi crisis is worse than the partial meltdown of a single reactor at the Pennsylvania plant.
"In terms of severity, this accident left Three Mile Island in the rear-view mirror several days ago," he said.
Tokyo Electric has more than doubled the radiation threshold for those on-site trying to avert a further crisis.
The company said those at the Fukushima Daiichi plant can now be exposed to 250 millisieverts of radiation before they must leave the area, up from its previous standard of 100 millisieverts.
People are naturally exposed to about 3 millisieverts of radiation a year. The International Commission on Radiological Protection recommends no more than 50 millisieverts exposure in a given year for nuclear rescue and recovery workers. It offers no restriction in a crisis when "the benefit to others clearly outweighs the rescuer's risk."
A Tokyo Electric official said Saturday afternoon that the new standard applies to the several hundred people -- power company employees as well as soldiers, firefighters and others -- now on the site.
http://edition.cnn.com/2011/WORLD/asiapcf/03/19/japan.nuclear.reactors/index.html
Comments