Tuesday, March 27, 2012

Radioactive Fallout in Futaba-machi, Fukushima in January 2012: 19,120 MBq/Square Kilometer

The Ministry of Education and Science released the data on radioactive fallout by prefecture in January 2012, on March 23.

For Fukushima Prefecture, it is measured in Futaba-machi, where Fukushima I Nuclear Power Plant is located. The measurement for the month of January, 2012 was:

Cs-134: 8,020 Mbq (megabecquerels)/km2
Cs-137: 11,100 MBq/km2
Total cesium: 19,120 MBq/km2

The measurement in Fukushima in Futaba-machi started in September 2011. From September to November, the numbers were in 4 digits. The fallout amount jumped in December, as you see in the table below (created from the data at MEXT website):

There was a similar jump, albeit much smaller, in the fallout measured in Fukushima City starting December 2011. The increase in Fukushima City has been attributed to winds blowing the dusts. (FYI, here's the latest fallout data for Fukushima City.)

West of Shizuoka, it's all ND. Miyagi is supposed to have started measuring the fallout in March this year.

From MEXT announcement on March 23, 2012, "Reading of environmental radioactivity level by prefecture (Fallout)(January, 2012)"

Prefecture City Fallout#
I-131 Cs-134 Cs-137 Other detected nuclides
1 Hokkaido Sapporo ND ND ND

2 Aomori Aomori ND ND ND

3 Iwate Morioka ND 1.6 2.0

4 Miyagi - - -

5 Akita Akita ND 0.069 0.086

6 Yamagata Yamagata ND 3.0 3.9

7 Fukushima Futaba ND 8020 11100

8 Ibaraki Hitachinaka ND 15 18

9 Tochigi Utsunomiya ND 16 20

10 Gunma Maebashi ND 3.3 4.1

11 Saitama Saitama ND 7.6 9.8

12 Chiba Ichihara ND 7.1 11

13 Tokyo Shinjuku ND 8.9 11

14 Kanagawa Chigasaki ND 2.6 3.2

15 Niigata Niigata ND 0.084 0.087

16 Toyama Imizu ND ND ND

17 Ishikawa Kanazawa ND 0.068 0.090

18 Fukui Fukui ND ND ND

19 Yamanashi Kofu ND 0.41 0.54

20 Nagano Nagano ND 1.3 1.6

21 Gifu Kakamigahara ND ND ND

22 Shizuoka Shizuoka ND 0.34 0.51

23 Aichi Nagoya ND ND ND

24 Mie Yokkaichi ND ND ND

25 Shiga Otsu ND ND ND

26 Kyoto Kyoto ND ND ND

27 Osaka Osaka ND ND ND

28 Hyogo Kobe ND ND ND

29 Nara Nara ND ND ND

30 Wakayama Wakayama ND ND ND

31 Tottori Touhaku ND ND ND

32 Shimane Matsue ND ND ND

33 Okayama Okayama ND ND ND

34 Hiroshima Hiroshima ND ND ND

35 Yamaguchi Yamaguchi ND ND ND

36 Tokushima Myozai ND ND ND

37 Kagawa Takamatsu ND ND ND

38 Ehime Matsuyama ND ND ND

39 Kochi Kochi ND ND ND

40 Fukuoka Dazaifu ND ND ND

41 Saga Saga ND ND ND

42 Nagasaki Omura ND ND ND

43 Kumamoto Uto ND ND ND

44 Oita Oita ND ND ND

45 Miyazaki Miyazaki ND ND ND

46 Kagoshima Kagoshima ND ND ND

47 Okinawa Uruma ND ND ND


Anonymous said...

Does this mean people have to evacuate Tokyo?
I didn't see any special buses.

Anonymous said...

Wow, I wonder what are the other detected nuclides? Mega refers to "million" so we are looking at about 20 million becs per sq km in Tokyo so that's about 2 becs per sq meter per month of accumulation. If this goes on for awhile (400 - 800 years) pretty soon the soil throughout the region will exceed government limits of 5000 becs per kg for agriculture. Time to get on the bus.

Anonymous said...



accuracy : Hashizume Bun, the 80-year-old author of "The Day the Sun Fell: I was 14 years old in Hiroshima",was less than 1.5 kilometers from the hypocenter of the explosion.


Chibaguy said...

How is Japan to survive with ambulances running 24/7 (I do not like this phrase)? I cannot go a single day in Chiba nor Tokyo without hearing the sirens all the time. Not one single day. I wish someone had stats on this. People, watch what you eat!

elbows said...

To make better sense of radiation data, especially that which comes out months after the data is collected, we need to keep a better track on weather conditions. Not just the wind direction, but whether it has snowed or rained in a particular place on a particular date.

For example it seems that Tokyo would have received much worse contamination early in the crisis if it had been raining there when the plume arrived, but this was one piece of luck that helped at a time when there was no shortage of bad luck and incompetence.

Anonymous said...

According to the latest from rt.com:

"Radiation blowback: 10 times lethal level registered at Fukushima".

Has anyone background to this report?

Anonymous said...

@anon at 1:15PM, I suggest you read the article not just headline before posting a comment. It's about inside the Containment Vessel of Reactor 2.

Atomfritz said...

@ elbows
Raining down actually is bad...
My cousin was riding home on her bike in Spring 1986 when the highest-radioactive rain from Chernobyl poured over her. (The area where our family lived is the second-most radioactive area in Germany after the Bavarian Forest)
Her child, born 5 years later, got cancer with 16.

I think the weather's main influence is in the time the major releases happen. Just remembering the weather planning for nuclear testing at the NTS. If the wind directed towards California, no testing was conducted. If the weather headed toward Mormon-inhabitated Utah, testing was given green light.

Actually the Utah mormons are in special interest of long-term radiation effect studies, as in this group some common carcinogens like alcohol, nicotine etc aren't much of a co-factor.

But, in long term it's the main climate. Dust is carried over long distances in the dry seasons.
At this point of view it could potentially have actually made some sense having the peasants plow down the upper layer of soil.
But why wasn't then the zone and the highest-contaminated northwestern corridor plowed, where agriculture got forbidden?

Anonymous said...

@anon 1:50pm
It is Mega(=million) Bq per square kilometer, which is equal to Bq per square meter as one square kilometer is one million square meters.
e.g. Shinjuku: Cs-134: ND Cs-137: 8.9 Bq/sqm Other: 11 Bq/sqm

Anonymous said...

Y: 1 MBq/km^2 = 1 10^6 Bq/(1000 m)^2 = 10^6 Bq/(10^3)^2 m^2 = 1 Bq/m^2

Anonymous said...

It is not that bad, translates into 19kBq/sqm.

It is similar to what Southern Bavaria in Germany received following the Chernobyl accident. People are still living there and don't have any health effects. The only restriction is that you don't collect wild mushrooms there anymore, and cannot hunt for wild boars - their meat is too contaminated.

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