Effects In Tokyo Area

Everybody has concerns and fears about what is going on in Fukushima, not because we know the worst scenario may come true, but because we have no idea what the worst scenario is going to be like. We all are at a loss between unclear government's words and massive media hype.

This page is intended to provide decent information to people in Tokyo, especially foreigners who are left uninformed / misinformed about what's going on and what's the latest status. No intention to give you optimistic/pessimistic view. Please make your own decision based on your own thinking.  I just want each of you to stay cool knowing that you can reach to the fact if necessary.

This page is to give you a big picture of the latest status in terms of radioactive levels.

<How far you are>

This s a map roughly indicates the distance from the plants in question.

If you live in Tokyo, you are about 200-250km away from the plants.

http://4.bp.blogspot.com/-Rs5XPVkAC2U/TXuOqCs-L6I/AAAAAAAAAJc/rUv3jrrgVJ4/s1600/9dd863d106538b8d.jpg

 

<The radiation level around Tokyo at the moment>

Here's the list of the monitors that you can check:

  • These monitors are operated by Ibaraki Prefecture to watch the plants that TEPCO operates around there. Located between Tokyo and Fukushima, approximately at 100km distance from the Fukushima Plants. Possibly due to the damage from the quake, half of the machines are not working, but you can still grab a big picture. Just fyi, the fourth column indicates the wind speed at that point.

http://www.houshasen-pref-ibaraki.jp/present/result01.html

 

  • This is a monitor operated by Yokohama City - Yokohama locates in 30km distance from Tokyo. (south west of Tokyo) Some data are missing due to scheduled black-out from Mar 15.

http://www.city.yokohama.lg.jp/kankyo/saigai/  

 

  • This guy, apparently on personal basis, shows his geiger counter on-line (located in Hino City, awest Tokyo). The above one is the latest graph, while the latter shows that in Dec 2010 for comparison.

http://park18.wakwak.com/~weather/geiger_index.html

* There's a note saying: "a few minutes before 9 am on 17th Mar, unusual spike was observed. This is because my computer had been temporality overloaded for 14 minutes, and recorded the accumulated data after 14 mins of temporal freeze. The average level should be: 142 counts / 14 mins = 10.14 cpm/min (normal level). Sorry for any confusion if caused"

 

  • Here's another nationwide version run by the government. From the top row to the bottom, that says: Hokkaido, Aoyama, Miyagi (not working), Fukushima (not working), Ibaraki, Kanagawa, and goes down to south west. Tokyo is between Ibaraki and Kanagawa, so you can check the two numbers.

http://www.bousai.ne.jp/vis/index.php

 

  • These are monitors surrounding the Onagawa Nuclear Plant that was cooled down already, about 100 km north of Fukushima.The level is relatively high, and the Tohoku-Epco (different enterprise from TEPCO) explains it should be coming from anywhere else, implying the effect from Fukushuma Plant. (Anemovane is not working.)

http://www.tohoku-epco.co.jp/electr/genshi/onagawa/mp.html

 

  • Tokyo Metropolitan Government is said to have started their own monitoring. Any updates on this will be reflected here.

 

* By the way, 1,000nGy ~ 1,000 nSv = 1 micro Sv (thanks Dan for pointing out)

   In accurate definition, 1 SV = 1 * N * Q * Gy = (approx) 1 * Gy

   N = 1 for Human (could be lower, depending on the organ)

   Q = 1 for gamma-ray that are considered as the principal immediate threat for now. (could be higher for other types of ray)

   Source: http://en.wikipedia.org/wiki/Sievert  

 

<How it possibly changes in the near future>

It is considered that the radiation level in outside of Fukushima is largely affected by:

1. The source: release of radioactive materials from the Fukushima Plants

2. Aerodynamics: the wind direction

 

1. Radioactives from Fukushima Plants

Vapor including a little amount of radioactive materials has been and scheduled to released for several times - but you never know how much radioactive materials are released in the environment. The best possible thing we can do is again, to assess the radiation level around the Fukushima Plants. We have to rely on the TEPCO monitors on this.

The latest issues (as of 6:00 am, Mar 14) from Fukushima I (Daiichi)

http://www.tepco.co.jp/cc/press/betu11_j/images/110314e.pdf

The latest issues  (as of 8:00 am, Mar 14) from Fukushima II (Daini)

http://www.tepco.co.jp/cc/press/betu11_j/images/110314f.pdf

The 3rd columns explains where it was monitored from MP-1 to MP-8, and 正門 (main gate), and the 4th one is the Gamma-ray strength, 5th is neutron ray strength, the rest is about local wind. As for Fukushima II, only MP-4 is available.

These data is updated on the press release page on TEPCO site (only in Japanese)

http://www.tepco.co.jp/cc/press/index11-j.html

 

2. Wind direction and velocity

Again, there are missing data in the tohoku area due to the quake.

South Tohoku (centered around Fukushima)

http://www.jma.go.jp/jp/amedas/205.html?elementCode=1

Kanto (Greater Tokyo Area)

http://www.jma.go.jp/jp/amedas/206.html?elementCode=1

Wind direciton at the 700hPa & 850hPa Sphare (roughly about 3,000 & 1,500m above sea level, respectively)

http://n-kishou.com/ee/exp/exp01.html?cd=aupq78&cat=e1

 

Simulated wind effect by German Newspaper

http://www.spiegel.de/wissenschaft/natur/bild-750835-191816.html

 

I put here as many sources as I can so as that you can cross-check. I don't think the government or TEPCO bias on the fact itself, but I agree there are suspicions and skepticism about their transparency and diligence when it comes to negative facts.

Lastly let us think of the firemen, policemen, armies and plant workers at the Fukushima Plants who are having a very hard time to avoid the catastrophe, risking their own lives to defend the rest of the country. I'd also like to express deep sympathy for those who are still waiting for help in Tohoku.

 

最終更新:2011年03月17日 10:30