Radiation In Namie Town, Japan, Almost 2 Years After Fukushima Meltdowns

The pdf of the latest readings of radiation in the areas surrounding the Fukushima Daiichi Nuclear Power Plant (marked with an X on the map inset) may be viewed here.

Namie Town remains the hardest hit with one startling sampling point as high as 21.1 microsieverts/hour, which totals to about 185 millisieverts/year. Normal there is 1 millisievert/year.

Americans typically get about 6 millisieverts/year from all sources environmental, travel- and medical-related. In a long lifetime of 80 years one wouldn't accumulate 500 millisieverts, but in Namie you could have theoretically already come close to that if you had stayed there for the two years since the accident because the levels were much higher in the immediate aftermath. 

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.

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.

Radiation in Namie Town at 34 Millisieverts in Just 25 Days

From March 11 to April 5.

As reported here:

34 millisieverts of radiation had accumulated over that period at one location in Namie Town, about 24 kilometers northwest of the plant. This equates to about 314 millisieverts per year, more than 3 times the permissible level of 100 millisieverts.

The figure of 314 must factor in some estimate of radiation degradation over a year. 34 millisieverts in 25 days is a rate of 1.36 mSv/day, or 496 in a year, not 314. 

The 100 mSv level may be permissible under extreme circumstances, perhaps, but the evacuation standard being used is 20 millisieverts or higher.

Normal average radiation exposure from all sources in the US is 6.2 millisieverts annually. A person living to age 78 would get almost 484 millisieverts in an entire lifetime at that rate. In Namie Town one could conceivably get that same whole lifetime's exposure in a single year.

Nuclear power is safe . . . until it isn't. And then it's unsafe it a big, dirty, relentless and inuring kind of way.

Namie, Japan, Expected to Radiate 300 Millisieverts Within Next Year

According to Kyodo News, here:

For a part of the town of Namie, the government's Nuclear and Industrial Safety Agency has estimated that the dose for one year since the quake would exceed 300 millisieverts.

6 millisieverts per year is average in America from all sources.

The story details the announcement of the evacuation of Namie and other similar hot spots beyond the original 20km evacuation ring.

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.

Radiation in Namie, Japan, Approximately 37.88 Microsieverts Per Hour

As reported here (but you have to do the math of 10 mSv divided by 264 hours times 1000):

On Monday, the [Japanese] government announced that radiation of more than 10 millisieverts had been detected at one location in Namie Town, some 30 kilometers northwest of the plant. The figure is what a person would be exposed to if they stayed outdoors for 11 consecutive days at the location. It is 10 times higher than the 1 millisievert-per-year long-term reference level for humans as recommended by the International Commission on Radiological Protection.

The prefectural government is measuring from Tuesday more than 1,400 institutions in the prefecture outside the 20-kilometer evacuation zone.

If the recommended limit is 1 mSv per year, however, it is utterly misleading to suggest the problem in Namie is 10 times higher than it should be. It is, but only for eleven days. This is comparing 11 day apples with 365 day oranges. The problem is much worse.

The fact is, people are getting almost a millisievert per 24 hour day, 909 microsieverts to be exact, if the radiation has been properly measured. At the levels indicated, people in Namie would get 332 mSv in a year, 332 TIMES normal for a year, if normal is 1.

The reported radiation level of almost 38 microsieverts per hour, if it is accurate, is much lower than prior reports here and here, which were 161 microsieverts per hour around March 21st and 1,400 microsieverts per hour around March 27th.

Radiation at the main gate to Fukushima Daiichi, one kilometer from the reactors, at the latest reading was 121 microsieverts per hour, over three times worse than in Namie.

Radiation in Namie, Japan, Has Risen From 0.161 to 1.4 mSv/hour

According to this report:

The Science Ministry says a reading of 1.4 millisieverts was taken on Wednesday morning in Namie Town northwest of the plant.

We reported the lower level of 0.161 on Monday last, here. The measured increase is dramatic. Just two days later the measurement is over 700 percent higher.

Background radiation plus other routine exposures in America amounts to, on average, 6.2 mSv/year. In Namie, Japan, on Wednesday, one would get that much in just under five hours.

Radiation in Namie, Japan

Kyodo News reports here that radiation levels in Namie (B), 20 km north of the Fukushima Nuclear Plant (A), are 161 microsieverts per hour.

It would take just under 26 days of continuous exposure to such levels to accumulate 100 millisieverts of radiation exposure, and in a year over 1,400 mSv.

Devra Davis for Reuters, here, puts that in its health context:

In terms of cumulative exposure, 100 millisieverts a year is the lowest level at which any increase in cancer risk is clearly evident. A cumulative 1,000 mSv over a lifetime would be expected to cause a fatal cancer many years later in five out of every 100 persons with that kind of exposure.