Radiation From Fukushima Accident Revised Up In New Report

CNN.com reports here:

Japan's largest utility said Thursday that more radiation than previously thought was released into the atmosphere in March 2011, in the days after the nuclear disaster that followed an earthquake and tsunami. TEPCO (Tokyo Electric Power Co.) estimates about 900,000 terabecquerels of radioactive materials were released between March 12 and March 31, according to Japan's Kyodo news agency. ... In one town in the Fukushima area, the estimated thyroid doses to infants are within a dose band of 100 to 200 millisieverts (mSv), the preliminary report said. This level of radiation exposure could be associated with an increased likelihood of developing cancer. However, in the rest of Japan, the estimated thyroid doses are within a dose band of 1 to 10 mSv, the report said. Outside the country, the estimated thyroid doses are less than 0.01 mSv, and are usually far below this very low level, it said.

PBS.org had a fuller report here, comparing the accident's severity to Chernobyl and assessing the health consequences of the radiation releases:

Tokyo Electric, the plant’s operator, said on Thursday that reactor meltdowns at the Fukushima Daiichi plant released approximately 900,000 terabecquerels of radioactive substances into the air in the immediate aftermath of the March 2011 accident. By comparison, approximately 5.2 million terabecquerels of total radiation were emitted in the 1986 Chernobyl disaster. ... In terms of the accident’s health implications, the World Health Organization said on Wednesday that the amount of radiation released fell below cancer-causing levels in nearly all of Japan. Outside of “no-go zones” in Fukushima prefecture, residents were exposed to radiation levels between 1 millisievert and 10 millisieverts, the W.H.O. said. The annual average amount of exposure from naturally occurring background radiation is 2.4 mSv globally, according to the report ... . Cumulative exposure to 100 mSv is generally thought to raise a person’s risk of cancer death by 0.5 percent.

Reuters.com reports here that Namie and Iitate were the two towns hardest hit:

In a preliminary report, independent experts said that people in two locations in Fukushima prefecture may have received a radiation dose of 10-50 millisieverts (mSv) in the year after the accident at the power station operated by TEPCO. ... The areas estimated to have received the highest doses of radiation were Namie town in Futaba county and Iitate village in Soma county, northwest of the stricken plant, the report said. Infants in Namie were thought to have received thyroid radiation doses of 100-200 mSv, it added. The thyroid is the most exposed organ as radioactive iodine concentrates there and children are deemed especially vulnerable.

Follow the labels at the end of this post for this blog's reporting on the accident from the beginning.

Radiation Hotspots South of Iitate Japan in Namie Range from 11-20 Microsieverts/Hr

Measurements in Iitate, Japan, are much lower by comparison at 2.6 microsieverts per hour, but are still far above normal of 0.11 per hour.

Latest Fukushima Map Shows Four Radiation Hotspots NW of Nuke Plants

As shown on today's map from mext.go.jp/ here, air measurements continue to show values from 15 to 31 microsieverts per hour northwest of the crippled nuclear plants on the coast at four locations beyond the 20 km evacuation zone:

For comparison, note that Iitate, Japan, continues to post values quite a bit lower in the vicinity of 2.6 microsieverts per hour, but that normal values should be more like 0.11 in all areas.

Fukushima International Association Stops Reporting Iitate Radiation Figures

The air measurement of radiation in Iitate, Japan, which remains stubbornly high compared to other areas at 2.59 microsieverts per hour, was routinely published here at the English version of the Association's website through September 9, 2011:

As of September 10th, Iitate has been de-listed from the report, along with three other reporting points:

Radiation in Iitate, Japan, Today Measures 2.53 Micro Sieverts Per Hour

As reported here.

That rate of exposure is 3.5 times higher than is typical in America from all sources on an annualized basis.

Fukushima Prefecture Residents Have Absorbed 3.2 MilliSieverts Between March and May

According to this story.

The total is over 3 times the annual limit, in just 2 months, while Americans typically get 6.2 millisieverts per year from natural background radiation, air travel, and medical diagnostic scans.

Levels of radiation in the air in Fukushima have declined steadily, but concentrations of radiation in soil and water have contaminated food which residents are urged to avoid.

Residents of Iitate and Kawamata had their food and urine tested in the study.

Radiation in Iitate, Japan, is Down to 2.69 Microsieverts Per Hour

Per the June 8th report of environmental radiation in the districts of Fukushima Prefecture, here.

The reading remains the highest of the 13 reporting locations and is roughly 24 times normal for the area.

Radiation in Iitate, Japan, at 3.09 Microsieverts Per Hour as of May 25

As reported here, 39 km northwest of the Fukushima Nuclear Power Station 1.

Normal for the area would be more like 0.11 microsieverts per hour.

The long term repercussions of a nuclear accident such as this have faded from the news, but they are real, on-going, extremely difficult to mitigate, and costly.

Cheap, safe production of such electricity is cheap and safe until it isn't.

Radiation at Iitate, Japan, Down to 3.22 MicroSieverts/Hour

As reported here.

Iitate Japan Radiation Down to 3.29 MicroSieverts Per Hour

As reported here.

Radiation in Iitate is Down to 3.88 Microsieverts Per Hour

As measured April 20th at 9:00 AM Japan time and reported here.

New Radiation Totals For Namie, Iitate and Minamisoma

Per the story here, for the three week period starting March 23 and ending April 15:

Namie: 17 millisieverts;

Iitate: almost 10 millisieverts;

Minamisoma: 0.5 millisievert.

Annual exposures in the range of 1 millisievert are considered normal.

Iitate Radiation is 5.26 Microsieverts Per Hour, Fukushima Main Gate is 70.0

Per the latest information available right now.

Radiation in Iitate Japan is 5.38 Microsieverts Per Hour

At 9:00 AM on the 15th, Japan time.

Japan Expands Evacuation Zone Due To Expected Annual Radiation of 20 Millisieverts

A month after the accident at Fukushima, the future is clear: there will be radiation problems 20 to 30 km around the nuclear plant for the foreseeable future.

So NHK World, here:

[A]nnual exposure in the zone is expected to be above 20 millisieverts. The worldwide average exposure from the natural environment is 2.4 millisieverts.

The expanded zone includes Katsurao Village, Namie Town, Iitate Village and some parts of Kawamata Town and Minami Soma City.

Was it worth it, Tokyo?

Namie, Japan, Radiation 14 Millisieverts in 17 Days, In Iitate 8 Millisieverts

The source is believed to be cesium, with a very long half-life (a generation) compared to radioactive iodine (a week).

An American gets on average 6.2 millisieverts in a year from all sources. Japanese set the threshold for natural sources at 1 millisievert.

NHK World has the story here:

Since March 23rd, the ministry has been measuring radiation levels in 15 locations more than 20 kilometers away from the crippled Fukushima Daiichi nuclear power plant.

At one location, in Namie Town about 30 kilometers northwest of the plant, 14,480 microsieverts of radiation had accumulated over the 17-day period to Sunday.

8,440 microsieverts of radiation were observed in Iitate Village.

In another location in Namie, the amount reached 6,430 microsieverts.

People would be exposed to this accumulated amount of radiation if they had stayed outdoors throughout the entire period.

5 Radiation Monitoring Posts 20-30 Km From Fukushima Daiichi Over 10 MicroSv/Hr

One radiation post, #83 near the 20 km ring northwest of the reactors, continues to register the highest reading of all the monitoring posts: 58.5 microsieverts/hour.

A little farther out, four others, #s 33, 32, 31 and 79 near the 30 km ring, register 19.5, 27.8, 11.4 and 14.8 microsieverts per hour respectively.

The main gate to the reactor complex is about 108 microsieverts per hour, while Iitate is just over 6 microsieverts per hour.

These values would all need to come down to 0.11425 microsievert per hour just to mirror normal, natural conditions under which a person gets 1.0 millisievert per year. Just a handful of locations even come close.

For the following map and values, go here:

Fleep.com/earthquake Has The Most Comprehensive Fukushima Accident Radiation Data

Here is a sample, graphing the differences between the histories of the radiation levels measured at the two gates to the reactor facility, compared with the main building of the complex itself, from March 24th until April 1st:

Note that the radiation in the main building is still close to a full millisievert per hour (1000 microsieverts). You would absorb there in just 6 hours what the average American absorbs in a year.

Radiation in the most sensitive areas of the reactors themselves, and the turbine buildings, has been reported as high as 1000 millisieverts per hour, even now. Expressed in full sieverts, an hour of such exposure equals 1 sievert. 8 of those will kill you very quickly.

When it comes to radiation, distance away is your friend: first the main building, then the main gate, then anyplace else, even Iitate.

Radiation Level in Iitate, Japan, Down to 6.65 Microsieverts/Hour

As of 2:00 PM, Japan time, April 3, 2011 according to the Main Disaster Office of Fukushima Prefecture (here):

The level is down from 12.1 microsieverts per hour, reported here on March 21.

Radiation Report About Iitate, Japan, Had to Be Wrong

Nothing illustrates the incredibility of some of the radiation reports about Japan in the popular press than the case of Iitate, Japan.

Today The Wall Street Journal is reporting here that the radiation level at the main gate to the Fukushima Daiichi Nuclear Plant is 144 microsieverts per hour. Inside the grounds of the plant, high level readings have been reported in reactor and/or turbine buildings all the way between 200, 300, and 400 millisieverts per hour on the lower end to as much as 1000 millisieverts per hour or more at the higher end, readings worlds away from microsieverts per hour (1 millisievert per hour is the same as 1000 microsieverts per hour).

The main gate is exactly one kilometer distant from the reactors, while the west gate is just slightly farther out.

This means that despite the catastrophe unfolding at the water's edge, a kilometer away the radiation levels drop dramatically. It doesn't mean they are safe, but the decline is dramatic with distance. 

Compare that observation with the report by Kyodo News (which we detailed here) in which the spokesman for the Japanese Nuclear and Industrial Safety Agency is quoted as saying radiation levels in Iitate, Japan, 25 to 30 miles away, were at 25 millisieverts per day, or 1.04 millisieverts per hour, if one spent a maximum of eight hours outdoors. In microsieverts per hour, that would have to be 1,040.

The following map (source) of today's conditions shows that that statement must be in error, and wildly so:

All the readings in the affected area displayed here are measured in microsieverts, and very low measurements are reported.

There is only one line of contamination running northwest of the reactors where there are reports of relatively higher readings, the highest of which is around 70 microsieverts per hour, still much lower than at the main gate to Fukushima, and nowhere even remotely in the vicinity of 1,000 microsieverts per hour.