Already-grave conditions at the Fukushima Daiichi nuclear plant worsened Sunday with the highest radiation readings yet, compounding both the risks and challenges for workers trying to repair the facility’s cooling system.
Leaked water sampled from one unit Sunday was 100,000 times more radioactive than normal background levels — though the Tokyo Electric Power Co., which operates the plant, first calculated an even higher, erroneous, figure that it didn’t correct for several hours.
Tepco apologized Sunday night when it realized the mistake; it had initially reported radiation levels in the leaked water from the unit 2 reactor as being 10 million times higher than normal, which prompted an evacuation of the building.
After the levels were correctly measured, airborne radioactivity in the unit 2 turbine building still remained so high — 1,000 millisieverts per hour — that a worker there would reach his yearly occupational exposure limit in 15 minutes. A dose of 4,000 to 5,000 millisieverts absorbed fairly rapidly will eventually kill about half of those exposed.
Tests also found increased levels of radioactive cesium, a substance with a longer half-life, the Japanese safety agency said.
“Because these substances originate from nuclear fission, there is a high possibility they originate from the reactor,” said Hidehiko Nishiyama, the agency’s deputy director-general, at a news conference. He said that it was likely that radiation was leaking from the pipes or the suppression chamber, and not directly from the pressure vessel, because water levels and pressure in the vessel were relatively stable.
Meanwhile, plant operator Tokyo Electric Power Co. turned on the lights in the control room of the No. 2 reactor the same day, and was analyzing and trying to remove pools of water containing radioactive materials in the turbine buildings of reactors 1 to 3.
The iodine-131 in the seawater was detected at 8:30 a.m. Friday, about 330 meters south of the plant’s drain outlets. Previously, the highest amount recorded was about 100 times above the permitted level.
If a person drank 500 ml of water containing the newly detected level of contamination, it would be the equivalent of 1 millisievert of radiation, or the average dosage one is exposed to annually, the NISA said.
“It is a substantial amount,” NISA spokesman Hidehiko Nishiyama told a news conference.
But he also stressed there is “no immediate risk to public health,” as the changing tides will dilute the iodine-131, and its half-life, or the amount of time it takes for it to lose half its radioactivity, is only eight days.
Nishiyama said the high concentration was perhaps caused by airborne radiation that contaminated the seawater, or contaminated water from the plant that flowed out to sea.
Tepco said early Saturday that it had detected a radiation reading of 200 millisieverts per hour in a pool of water in the No. 1 reactor’s turbine building on March 18 and failed to notify workers, but later denied that a radiation level that high was found.
“If we had warned them, we may have been able to avoid having workers (at the No. 3 reactor) exposed to radiation,” a Tepco official said.
The amount will be too small to affect humans, the Vienna-based CTBTO said Thursday.
The commission operates a network of monitoring facilities at 63 locations around the world, including Takasaki, Gunma Prefecture.
A senior official at the commission’s monitoring department said figures observed in Takasaki continue to go up and down and the amount of radioactive substances from the Fukushima plant can’t be said to be on the decrease.
Small amounts of radioactive substances were already detected at observation facilities in western California on March 18 and in Iceland on Tuesday, and they are expected to reach European countries in a few days, according to the official.
But Japan’s Nuclear and Industry Safety Agency said it doesn’t expect any impact on other countries, citing data observed so far.
On Thursday, Singapore’s food safety authority said it has found radioactive contaminants in four samples of vegetables from Japan.
The Agri-Food and Veterinary Authority said the contaminants were found in vegetables imported from Chiba and Ehime prefectures, in addition to Tochigi and Ibaraki.
As a result, it said it will suspend food imports from Chiba and Ehime. On Wednesday, the ministry suspended the import of foods such as seafood, meat, milk, fruits and vegetables from Fukushima, Ibaraki, Tochigi and Gunma, the four prefectures worst hit by the March 11 quake and tsunami.
The vegetables found tainted were “mitsuba” Japanese wild parsley from Tochigi, “nanohana” rape seed plant from Chiba, “mizuna” Japanese mustard from Ibaraki and perilla leaf from Ehime.
The government on Monday told Fukushima, Ibaraki, Tochigi and Gunma prefectures to suspend shipping of spinach and kakina, a locally produced leaf vegetable, following the detection of radioactive substances at levels above the provisional limits under the Food Sanitation Law. It also told Fukushima Prefecture to suspend shipping of raw milk for a similar reason. The radioactive substances apparently came from Tokyo Electric Power Co.’s stricken Fukushima No. 1 nuclear power plant. The government the next day called on people to limit consumption of spinach, cabbage and a few other leaf vegetables from Fukushima Prefecture.
Tokyo (CNN) — Despite being urged not to hoard bottled water, residents
of Japan’s capital on Wednesday snapped it up in droves after testing
showed radioactive material in tap water at levels unsafe.
The city’s water agency said the spike was likely caused by problems at
the Fukushima Daiichi nuclear plant, located 240 kilometers (150 miles)
away. Earlier Wednesday, Tokyo government officials advised residents
not to give tap water to infants or use it in formula after tests at a
purification plant detected high levels of radioactive iodine.
Grocery store owner Seiji Sasaki said he noted a sudden increase of
customers. He had 40 cases of water in his store, but they were gone
quickly.
Meanwhile, officials evacuated some workers at the Fukushima plant
Wednesday afternoon as a black plume of smoke billowed above one of the
reactors, plant owner Tokyo Electric Power Co. said. The cause of the
smoke was unclear.
The team of seven workers were planning to inspect gauges and
instrumentation at reactor No. 3, but were unable to determine
conditions in the control room before evacuating, officials with Tokyo
Electric and Japan’s Nuclear and Industrial Safety Agency said.
Workers have been scrambling to cool down fuel rods at the nuclear plant
since a 9.0-magnitude earthquake and massive tsunami on March 11 knocked
out cooling systems.
Some radiation has been released, officials said, but it was unclear
whether radiation levels spiked after the black smoke was spotted
Wednesday. Japan’s nuclear agency said radiation levels near the plant
had not changed, public broadcaster NHK reported.
Alert: Listen very carefully to the narration of this first video clip. ThisJapanese news anchoris referring to exposed spent nuclear fuel rods, and the steam is rising from the pools where those rods are located in at least 4 locations. The USnews media has now moved on to other stories, but this story IS NOT OVER. The danger for clouds of radioactive steam, mixed with weather precipitation, to float over the USAvia the jet stream, in successive waves, over days to come, is not over. Here is the video clip:
Poised for major growth before the earthquake and tsunami in Japan, the U.S. nuclear power industry now faces its greatest PR challenge since the partial meltdown at the Three Mile Island plant in Pennsylvania 32 years ago. In an attempt to allay fears of a catastrophe on American soil, power companies have mounted an aggressive PR campaign — running print ads, sending letters to residents and making frequent media appearances, AdAge.comreports.
Entergy Corp., which owns the Indian Pointnuclear plant about 40 miles north of New York City, is running newspaper ads declaring that the facility was designed with a margin of safety beyond the strongest earthquake anticipated in the region. The plant sits at the intersection of two active seismic zones, and New York Gov. Andrew Cuomo has said he wants it shut down.
Anti-nuclear activists are relying on free media appearances and a letter-writing campaign to push for the shutdown of 23 U.S. reactors, which they say are identical in design to those now releasing radiation in Japan. Adam Mendelsohn, a partner with the PR and crisis management firm Mercury, said that the incident in Japan threatens to undo years of effort by the U.S. nuclear power industry to define nuclear energy as a safe alternative to fossil fuel. — Greg Beaubien
I have discovered at least two groups which are setting up independent radiation measurements around Japan. The groups have no connection to any government agency, TEPCO, or any other agency. This will at least give independent measurements and in my opinion is something very needed in the current serious crisis at the Fukushima Nuclear Power Plant.
The www.rdtn.org website allows people to submit their own radiation readings and maps them alongside official data.
To contribute to the RDTN site people will have to purchase a radiation detection device and the site directs people to four sources of such equipment.
Readings submitted to the site suggest that radiation levels of between 0.178 – 0.678 microsieverts per hour can be detected in and around Onuma Hitachi City that lies south of Fukushima.
Other efforts to pool advice on how to cope with the disaster include new pages on The Global Innovations Commons, a site which compiles out-of-date patents.
We too have been watching events unfold in Japan. We have created this site in an effort to display the reliable data readings as they become available. Although we are careful to evaluate new data sources, we welcome new reliable data from those on the ground in this crisis.
While we hope to gather data via our own website, we recognize the efforts of others out there who are actively seeking and parsing data and making it available for others to use.
We are aware that reliable data is critical, and have carefully chosen partners in supplying information. Our map is populated with data from Pachube andMarian Steinbach. . As more reliable data sources become available, we will consider adding further sources to the site.
We’d like to thank those other sites and individuals who are providing data (for this site and others):
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