Monday, April 18, 2011

#Fukushima I Nuke Plant: Nuclear Safety Commission Sitting on Over 2,000 Radiation Dispersion Estimates

From Kyodo News English (4/18/2011):

The Nuclear Safety Commission of Japan has released only two computer-simulated estimates of radioactive substance dispersal since the nuclear accident at the Fukushima Daiichi power plant, although more than 2,000 of them were made, sources familiar with the matter said Monday.

The estimates were made using the Nuclear Safety Technology Center's networked computer system known as SPEEDI, or system sor prediction of environmental emergency dose information, developed and operated with a budget of about 12.8 billion yen.

The government commission released the two estimates on March 23 and April 11, including accumulated exposure to a radiation dose of more than 1 millisievert even outside a radius of 30 kilometers from the Fukushima plant that was crippled by the March 11 earthquake and tsunami.

The same news in Kyodo Japanese gives a bit more details:

The Nuclear Safety Technology Center in Tokyo, who runs SPEEDI, says it has been running the simulations taking into consideration the wind directions, rain, and amount of radioactive materials released. The Center has been making the 3-hour dispersion predictions ever since the accident happened. There are over 2,000 dispersion simulation charts drawn up so far.

The reason why the Nuclear Safety Commission hasn't disclosed the simulation results is that there's not enough data on the amount of radioactive materials released. "Simulations are different from the actual dispersions, and that would lead to misunderstanding," says the Commission. However, some of the simulation charts were similar to the actual dispersions.

風向、降雨といった気象や放射性物質の放出量など、さまざまな 仮定の条件に基づいた試算を繰り返している。ほかにも事故直後から1時間ごとに、その時点で放射性物質が1ベクレル放出されたと仮定して3時間後の拡散を 予測。これまでに作成した拡散試算図は、2千枚以上になるという。

 安全委は、試算図を公表しない理由について「放射性物質の放出量データが乏しい。試算図は実際の拡散状況と異なり、誤解を招きかねない」と説明するが、未公表の試算図の中には、実際の拡散と近似した傾向を示すものもあった。

Shoot these people. They are more keen on covering their behind and staying in good grace with their benefactor the government than warning their fellow citizens.

4 comments:

netudiant said...

A good but not very detailed daily plume update is here:
http://www.zamg.ac.at/wetter/fukushima/

This is based on estimates from the Comprehensive Test Ban Treaty monitoring network.
The issue will become much more acute now that the weather is shifting to a summer pattern, with inland winds and rain. Fortunately, the Fukushima emissions mostly blew out to sea thus far. Hopefully the reactors have cooled enough for the summer emissions to be manageable, else a lot of Honshu will be impacted.

Robbie 001 said...

"One of the worst factors of the Fukushima crisis is clarity of information – and the distinct lack of it since the quake first hit. The people behind RDTN say to hell with the government and TEPCO – let citizens report radiation.

The idea has yet to crack from its Kickstarter egg ($US9700 out of $US33,000), but its ambitions are pretty huge. The RDTN (radiation!) team wants to distribute 600 geiger counters to ordinary citizens to fill in the pretty massive data holes about how much radiation has made its way across Japan.

http://www.gizmodo.com.au/2011/04/rdtn-project-wants-to-arm-japan-with-geiger-counters/

arevamirpal::laprimavera said...

@netudiant, thanks. I've been posting that map on my Japanese blog. The plume has been all over Japan already. Fukushima, Ibaraki, Chiba, Saitama, part of Tokyo are constantly under the plume. Summer will be on-shore wind on Fukushima, and that's bad news.

Anonymous said...

netudiant wrote:
> A good but not very detailed daily plume update is here:
> http://www.zamg.ac.at/wetter/fukushima/

The zamg.ac.at simulations are just that, simulations. As such, only persons without a shred of critical thinking would consider them to contain information that has enough value to be worth acting upon.

Consider the latest animated GIF movie published by ZAMG:
http://www.zamg.ac.at/pict/wetter/sonderwetter/fuku/20110419_I-131_FUKU.gif

That simulation indicates that on Friday April 22, at 00:00 UTC, that is, 09:00 Japanese time, a plume of radiation with "AREA D" dose rate will cover most of the Fukushima and Miyagi prefectures.
As that "AREA D" plume is predicted to almost reach 40 degrees of latitude, the city of Sendai will be well within it: according to Google Maps, Sendai's central railway station's latitude is about 38 degrees and 15 minutes.

ZAMG's dose rate mapping are as follows:

AREA A: maximum dose rate 0.3 microSieverts/hour
AREA B: maximum dose rate 3 microSieverts/hour
AREA C: maximum dose rate 30 microSieverts/hour
AREA D: maximum dose rate 300 microSieverts/hour
AREA E: maximum dose rate 3000 microSieverts/hour

It so happens that staff members at the Cyclotron / Radioisotope center of Tohoku University, located in Sendai, are monitoring the radiation doses on the University's campus. The publication of these values is officially sanctioned by Tohoku University. The relevant web page is:
http://www.bureau.tohoku.ac.jp/anzen/monitoring/

It is important to note here that ZAMG's simulation values have NEVER had any semblance of reality compared with the actual radiation values measured by various independent, non-governmental groups — e.g. Universities — in various regions of Japan (Kyushu, Kansai, Tokyo, Tohoku etc.)

Two staff members of Tohoku University have also started making their own, non-official measurements independently of the Radioisotope center. Their unofficial, unsanctioned results are not published via a tohoku.ac.jp web server, and are hosted by Google:
https://spreadsheets.google.com/spreadsheet/pub?hl=ja&key=0AqCNir5ySiBLdGc5eW8wcDUyRG9scHBvUTVaV0V4Znc&hl=ja&gid=2

The International Atomic Energy Agency has also sent specialized staff to monitor radiation levels in various locations in Japan.
Their daily radiaiton measurement updates can be accessed from IAEA's top page:
http://www.iaea.org/

So, a little Googling immediately brings up measurements done by three competent teams:
1) Tohoku University Radioisotope Center
2) two Tohoku University staff members with specialized knowledge in radioactive materials
3) The IAEA inspectors.

AS ZAMG'S FUKUSHIMA SIMULATION RESULTS HAVE, UP TO NOW, NEVER HAD ANY SEMBLANCE OF REALITY, I AM QUITE CERTAIN THAT THE MEASUREMENTS THAT WILL BE DONE BY THESE THREE TEAMS ON FRIDAY APRIL 22 AT AROUND 09:00 AM JAPANESE TIME WILL BE MUCH LOWER THAN THE "AREA D" (30~300 microSieverts/hour) ESIMATE PUBLISHED BY ZAMG.

In fact, I'm pretty sure the actual measurements in Sendai will be at least one, and probably two orders of magnitude lower than the values predicted by ZAMG's simulation, and that they'll thus lie between 0.3 and 3 microSieverts/hour.

Anyway, wait until Friday April 22, 09:00 Japanese time, access the URLs above, and compare the results. The values measured by these three teams will probably all be pretty similar, and consistent with each other, as they've always been.

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