Cs-134/137 density in retaining water of Reactor 1 basement jumped over 16 times much as March

According to Tepco, Cesium-134/137 density rapidly increased in retaining contaminated water of Reactor 1 basement.

The water is assumed to be the mixture of coolant water and groundwater.


On 6/26/2015, Tepco published the report on contamination level of the retaining water in Reactor 1 and Reactor 2 basement. The sample was collected on 5/14/2015. From this report, Cs-134/137 density was 21,300,000,000 Bq/m3.

The previous report published on 3/17/2015 reads the density as 1,280,000,000 Bq/m3.


The ratio of Cs-134/137 wasn’t significantly changed, however the detailed situation of Reactor 1 basement has not been published.







Français :

La radioactivité en Cs 134/137 des eaux des fondations du réacteur 1 multipliées de plus de 16 fois depuis mars


Selon Tepco, la radioactivité en césium 134/137 a rapidement augmenté dans les eaux extrêmement radioactives retenues dans les fondations du réacteur 1.
Le liquide est supposé être un mélange de liquide de refroidissement et d’eaux souterraines.

Le 26 juin 2015, Tepco a publié un rapport sur les niveaux de radioactivité des eaux retenues dans les fondations des réacteurs 1 et 2. Les échantillons sont du 14 mai 2015. Selon ce rapport, la radioactivité en Cs 134/137 est de 21 300 000 000 (21,3 milliards de) Bq/m³.
Le rapport précédent, du 17 mars 2015, parle d’une radioactivité de 1 280 000 000 (1,28 milliards de )Bq/m³.

La proportion Cs 134/137 n’a pas significativement changé, néanmoins la situation précise dans les fondations du réacteur 1 n’a pas été publié.


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.


June 2015