Tuesday, March 22, 2022

Radioactivity/radioactive material level monitoring points

(Note: The post date is set in the future because that's the only way to keep is on the top of the page. The last update date and time will be here. Last updated Thursday March 24, 2011 10:26 UTC)

We been able to locate, with lots of help, monitoring points where radioactivity/radioactive material levels in the atmosphere are measured. Many of us have been monitoring these levels. Currently there is a mix of English and Japanese information.
We welcome everyone looking at the data to draw their own conclusions. As a group we will be refraining from doing so, just providing links to the sources.
This page is being updated continuously with information. Please add any new links in comments. (Moderated due to the high emotions surrounding this issue right now.)
Note that the data is currently represented in several measurement usnits: sieverts (micro and milli-sieverts have been the most mentioned units in the news), nGy/h, and others. We'll update this page with a simple legend later.
What we we do with this data? We can use it to track those radioactive levels, in some cases even in real time, to see if anything is going on at the Fukushima plants, and how it is affecting the surrounding areae. As mentioned above, we've already been able to spot an incident before it made the news.

Terminology and name clarifications


The Ministry in charge of such data collection in Japan is MEXT, the Ministry of Education, Culture, Sports, Science and Techology (文部科学省).

The name of the affected power plants are Fukushima Daiichi (No.1) and Fukushima Daini (No. 2). They are located in the prefecture of Fukushima (Fukushima-ken). There is also a Fukushima City (Fukushima-shi) in the prefecture (not in 30km radius).

A Japanese prefecture is similar to, but not the same as, a state in the United States.


Radioactivity level data posted by the central government of Japan


This is official central government issued data. Recent data is in Japanese only. Translations are being provided by volunteer students in Japan and worldwide.

Both pages below link to the same documents.


全国の放射能濃度一覧 - Japanese page charting MEXT data


This is a page that allows users to see the data for each prefecture as line graphs.

文科省が公表している情報を元に日本全国の放射能値をグラフ化したページです。非公式。


Japan Radiation Map


Updated every 10 minutes.




Marian Steinbach's efforts to track official MEXT data nationwide


UPDATE: A news shorter download format available on his site which only contains the measures of the recent hour.



Just like the original download, it is uodated every 10 minutes. But it's much smaller in size (only 4 KByte). For comparison, the complete download currently is 2636 KByte, and growing.

So in order to save bandwith and make it faster for you to process Marian strongly recommends to switch download URLs.


A Google Docs spreadsheet initiated by @MarianSteinbach
that is tracking historical data from various locations around the country, where radioactive levels are measured by MEXT


Graphical representation of data by @fleepcom


A page maintained by @fleepcom with continuously updated graphs.


Air Trajectories from the Fukushima Power Plants


Analysis of the air trajectories from the power plants by the Department of Atmospheric Sciences at Texas A & M University. Link


Power plants


Tokai Daini (No. 2) power plant is in Ibaraki, which is the prefecture just south of Fukushima. There's another Ibaraki monitoring point in the source above, but we're also monitoring levels at Tokai no. 2. Unfortunately the data is not presented in tabular form, but we've been monitoring level changes in the charted graph.
Note that levels are higher than what you see elsewhere, but currently well within safe parameters.
Around the time of the 1st incident at the reactor unit 4 at No. 1 Fukushima (the really serious one in terms of radioactive material release) the spike went off the chart. We don't know what the actual numbers are. The highest value that can be displayed on the graph is 2000 nGy/h. Since then the numbers have been slowly and steadily decreasing.

We're also tracking a couple of power plants to the north. Both are operated by the Tohoku power utility, not TEPCO (the Tokyo power company that operates the Fukushima and Ibaraki plants). Only available as a graphic that seems to be continuously updated.
Closest to Fukushima is Onagawa power plant in Miyagi prefecture, and is about 100 km (not exact) north of the Fukushima plants. This one made the news briefly when elevated levels were seen there for an earlier incident. Since then the numbers have been stable.


There's another plant we're tracking way up north, in Aomori. The base levels here have continously been in the low normal range. (I guess they have much cleaner air up in Aomori to start with.) There have been small spikes here around the time of incidents but barely enough to talk about.


Google map of additional points


A Japanese Google Map of both official and unofficial monitoring points. The unofficial ones are basically geiger counters set up by individuals. The official ones are those operated by various authorities.

Control: The famous Hino, Tokyo geiger counter

Finally, there is a geiger counter set up by an individual in Hino, a suburb of Tokyo to the west of Tokyo center. This one has already been discovered by several people. Unlike most of the other geiger counter checkpoints which are just a live streaming video showing the LED monitor (though we are deeply grateful they are made available in any case), this one is generating a handy graph, where we can easily see spikes.
The upper graph is the live one. The bottom one is a static graphic snapshot from last December, to show baseline measures. Note that current levels, even at the severest spike (caused by the initial problem with the containment pool for the used fuel rods at the 4th reactor) it was well within safe levels.


Independent status reports on Fukushima power plants

The official IAEA Facebook page on the Japan earthquake situation, constantly updated.

The original version of this page was here, posted by @makiwi. Copied here with permission.

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