Cs-134/137 density in retained water of Fukushima underground spiked 4000 times higher than last year

(Photo ; Reactor 4 just after 311 took place. Photo was released on 9/11/2012.)


On 12/9/2015, Tepco announced Cs-134/137 density significantly jumped up in the retained water of basement floor since last year.

The sample was the contaminated water retained in the South of Reactor 4. It was kept in the part called connection duct among the buildings.

From the sample collected on 12/3/2015, they detected 92,000,000 Bq/m3 of Cs-134 and 390,000,000 Bq/m3 of Cs-137. One year ago, it was 27,000 Bq/m3 (Cs-134) and 94,000 Bq/m3 (Cs-137). The density became 3,983 times higher than last year.

Tepco states they don’t think it has leaked to the outside of the duct. However, the reason of this increase is not identified. It is assumed that 420 t of contaminated water is retained in this duct.






Français :

La radioactivité en Cs-134/137 des eaux souterraines retenues à Fukushima 4000 fois supérieure à l’an dernier


(Photo : Le réacteur 4 juste après le 11-3. Photo publiée le 11 septembre 2012.)


Le 9 décembre 2015, Tepco a annoncé que la radioactivité en césium 134/137 des eaux retenues dans les fondations a gravement augmenté depuis l’an dernier.

L’échantillon était constitué d’eau prise au sud du réacteur 4. Il a été prélevé à l’endroit appelé canalisation de connexion entre les bâtiments.
Ils ont relevé 92 000 000 (92 millions) Bq/m³ de Cs-134 et 390 000 000 (390 millions) Bq/m³ de Cs-137 dans leur échantillon du 3 décembre 2015. Il y a un an c’était 27 000 Bq/m³ (Cs-134) et 94 000 Bq/m³ (Cs-137). La radioactivité a augmenté 3 983 fois depuis l’an dernier.
Tepco précise qu’ils ne pensent pas qu’il y ait eu des fuites à l’extérieur de la canalisation. Néanmoins, la raison de cette augmentation est inconnue. Ils pensent qu’il y a 420 tonnes d’eau contaminée retenue dans cette canalisation.


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