Tuesday, March 13, 2012

Radioactive Materials in Soil May Already Have Reached 30 Centimeters Below Surface, JAEA Says

Japan Atomic Energy Agency's researchers say radioactive materials that remained on the top 5 centimeters of the soil for the first 3 months of the nuclear accident may have already migrated down to as deep as 30 centimeters.

It may be difficult to decontaminate, says the agency who happens to be in charge of the government pilot project to decontaminate within the no-entry zone and planned evacuation zone in Fukushima, using joint ventures by the largest construction companies in Japan. (For more on the confused state of this pilot program, see my post on NY Times article.)

But on the other hand, it's been too late anyway in Fukushima, Miyagi, and areas in Kanto with significant amounts of radioactive fallout (except for Miyagi, whose data is still not disclosed, if it exist), where farmers tilled the land in spring last year to grow vegetables and rice upon encouragement from the government.

From Kyodo News (3/14/2012):

地中30センチにまで浸透か 放射性物質、除染に影響も

Radioactive materials may have migrated to 30 centimeter deep in the soil, may affect decontamination efforts

 東京電力福島第1原発事故で放出され地面に降り積もった放射性物質について、事故から3カ月後の昨年6月にはほとんどが地表から5センチまでの浅い場所にとどまっていたが、1年後の現在では10~30センチの深さまで浸透している可能性があるとの推定を、日本原子力研究開発機構のチームが14日までにまとめた。

Radioactive materials deposited on the ground after the Fukushima I Nuclear Power Plant accident stayed within 5 centimeters from the soil surface in June last year, 3 months after the accident started, says a research team at Japan Atomic Energy Agency. However, the group says there is a possibility that radioactive materials have now migrated to between 10 and 30 centimeters from the surface, one year after the accident.

 雨水がしみ込む際に一緒に運ばれるとみられる。同機構幌延深地層研究ユニット(北海道幌延町)の佐藤治夫研究員は「除染活動が遅れるほど放射性物質は深く移動し、作業の負担を大きくする恐れがある」と警告している。

The team thinks rainwater carries radioactive materials down the soil. Haruo Sato, a researcher in the Horonobe Underground Research Center of JAEA (in Horonobe-cho in Hokkaido) warns, "The longer decontamination takes, the deeper radioactive materials migrate, making the decontamination effort more difficult."

Oops... The government and many researchers have said that radioactive materials remain on the shallow surface of the soil, citing the case of Chernobyl. I guess they didn't realize the warm, rainy climate of Japan was different from Chernobyl. The annual average rainfall in Fukushima is 1,300 to 1,600 millimeters, whereas in Chernobyl it is 300 millimeters.

Looking at blog posts and tweets from last summer, many in Japan were hoping the large amount of rain that Japan gets would wash away the radioactive materials to the rivers and to the sea quickly. Instead, it drove them down the soil, according to JAEA.

9 comments:

Anonymous said...

"However, the group says there is a possibility that radioactive materials have now migrated to between 10 and 30 centimeters from the surface, one year after the accident."

And they think this may have happened, i.e., they couldn't be bothered to dig a few holes and measure?

Anonymous said...

Decontamination is useless in this case, because radioactive emission/fallout is still continuing.

The JP gov also forced Fukushima farmers to till rice paddies and other farmland last year. The farmers, knowing that would further drive contamination deeper, first resisted but gave in, because otherwise they and their community would not get farm subsidiaries. Now thier land and anything grown there are semi-permanent nuclear waste.

You know, it does not require much brain to foresee this outcome.

arevamirpal::laprimavera said...

I don't know what to think about Fukushima farmers. Some say the government forced the farmers with compensation money - that they had to farm and produce radioactive crops to receive compensation.

I don't think it's about the community, because there are farmers who refused to grow anything last year.

Now most of the farmers seem to be doubling down, determined to farm this year and for years to come. And they expect consumers to buy.

Anonymous said...

Please donate, in return a pic of me & my new boyfriend http://fukushima-diary.com/2012/03/settlement-report-31113/

Anonymous said...

Yyyeeewwww! Why should we donate to someone who's been spreading half-truths and lies?

Anonymous said...

No problem as long as we keep laughing, right? I mean the government adviser said so and he wouldn't lie, right? Ha, ha, ha, ha... (repeat chorus ad infinitum)

doitujin said...

i'm kind of unsure what to believe sometimes...
i wonder, is this tweet trustworthy? -> https://twitter.com/#!/sayakaiurani/status/179229948408627200

Anonymous said...

Actually the Chernobyl area gets a bit more than 600 mm of rain per year.

arevamirpal::laprimavera said...

@doitsujin, that people in Tokyo was exposed to radiation is accepted by many as true, after one year. March 15 plume and March 21 rain. That particular person who tweeted, I'm not sure. I know he/she has been quoted and translated into English for some sensational tweets. Doesn't pass my smell test.

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