Tepco reported radiation level of Reactor 2 suddenly dropped just after Reactor 4 blasted during 311

Following up this article.. [Photo]Tepco admitted Reactor2, 3 directly released radioactive material to the air by 3.15.11/100Sv/h in PCV [URL]


On 12/17/2015, Tepco announced that they observed a sudden decrease in radiation level of Reactor 2 after 311 took place. The fact is mentioned in one of their reports titled “unidentified accident analysis”.

In this report, Tepco states the explosion at Reactor 4 occurred at 6:14 AM of 3/15/2011 (JST) and the sudden drop of the radiation level in Reactor 2 was observed from 6:20 AM to 6:25 AM of the same day.

They add, “There is a possibility that these two occasions might be related to each other, but the exact reason is not identified yet”.

During the issued period of only 5 minutes, the radiation level dropped from 62.7 Sv/h to 43.0 Sv/h in Reactor 2’s PCV.






Français :

Tepco rapporte que, en mars 2011, la radioactivité du réacteur 2 a brusquement diminué juste après l’explosion du réacteur 4


Article lié : [Photos] Tepco reconnaît que vers le 15 mars 2011 les réacteurs 2 et 3 ont relâché leur radioactivité (100Sv/h) directement dans l’atmosphère

Le 17 décembre 2015, Tepco avait déclaré avoir observé une diminution soudaine de la radioactivité du réacteur 2 après le 11-3. Le fait est mentionné dans un de leurs rapports sous le titre “Unidentified accident analysis“.

Dans ce rapport, Tepco affirme que, le 15 mars 2011, l’explosion à 06:14 (JST) du réacteur 4 a été suivie de 06:20 à 06:25 ce même jour par une baisse de la radioactivité dans le réacteur 2.
Ils ajoutent “Il est possible que ces deux évènements soient liés mais la cause exacte n’en est pas encore déterminée”.
Dans la PCV (Enceinte de confinement primaire) du réacteur 2 et pendant ce laps de temps de 5 minutes seulement, le niveau de la radioactivité est descendu de 62,7  à 43,0 Sv/h.


About this site

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.


December 2015