Cesium fallout spikes every 40 days


Cesium concentration and fallout in Fukushima go higher than average every 40 days regardless of the wind direction.
Prof. Watanabe from Fukushima university analyzed the data to publish at Meteorological society of Japan on 5/29/2012.
The data is about cesium fallout from March 2011 to April 2012, detected at environmental radioactivity monitoring center of Japan.

The trend has been very clear especially since January of 2012.
In the daily conference of 5/31/2012, Tepco stated they are not going to corporate with the researcher to figure out the mechanism.


↓ Tepco’s daily conference. 19:50 ~

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(2012年5月29日20時44分 読売新聞)


  1. Not sure whether you mean that the cesium increases every forty days, and then falls again, only to rise forty days later; or whether you mean that in a time frame of forty days, one sees an increasing trend, and that the cesium is always increasing – and does not fall back to where it was before.

    Your first meaning is implied by the last sentence, where one is left wondering about the mechanism of the observed phenomenom.

    1. agreed , language difficulties sometimes, if he means the average is creeping up slowly each 40 days thats showing that the continual loss of containment is continuing to raise the level of cesium in the area greater than is disperses, which is logical . a cyclical up down shows intentional releases to the environment with rapid dispersal , which sounds to me a little less probable if we were talking about anyone but Tepco in charge here

    2. FYI:
      The Japanese version says that the figures are falling but have a spike (roughly) every 40 days.

      Professor Watanabe says “We don’t know whether there are localised concentrations (of radioactivity material) which are moving around, or whether the atmospheric motion has the effect of causing accumulations of radioactivity material”

      The Japanese version does not mention “the daily conference of 5/31/2012”

      I’d like to see the graph and interpret the data for myself.

  2. FUKUSHIMA DIARY – Les retombées de césium augmentent tous les 40 jours
    Par Mochizuki le 31 mai 2012

    Les concentrations et retombées de césium à Fukushima augmentent plus vite qu’en moyenne tous les 40 jours sans tenir compte de la direction du vent.
    Le pr Watanabe de l’Université de Fukushima a analysé le 29 mai 2012 les données à publier par la Meteorological society of Japan.
    Ces données portent sur les retombées de césium de mars 2011 à avril 2012 détectées au centre de surveillance de la radioactivité dans l’environnement du Japon.

    Cette tendance a été très claire, en particulier depuis janvier 2012.
    Dans sa conférence de presse quotidienne du 31 mai 2012, Tepco affirme qu’ils ne vont pas s’associer avec les chercheurs pour en trouver la raison.

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This website updates the latest news about the Fukushima nuclear plant and also archives the past news from 2011. Because it's always updated and added live, articles, categories and the tags are not necessarily fitted in the latest format.
I am the writer of this website. About page remains in 2014. This is because my memory about 311 was clearer than now, 2023, and I think it can have a historical value. Now I'm living in Romania with 3 cats as an independent data scientist.
Actually, nothing has progressed in the plant since 2011. We still don't even know what is going on inside. They must keep cooling the crippled reactors by water, but additionally groundwater keeps flowing into the reactor buildings from the broken parts. This is why highly contaminated water is always produced more than it can circulate. Tepco is planning to officially discharge this water to the Pacific but Tritium is still remaining in it. They dilute this with seawater so that it is legally safe, but scientifically the same amount of radioactive tritium is contained. They say it is safe to discharge, but none of them have drunk it.


May 2012