Tritium density rose up 17 × in groundwater

On 3/18/2015, Tepco announced they measured Tritium density increased 17 times much as previous reading in groundwater.

2 days after, Tritium density also increased over 8 times much as previous reading in the next boring.


These increases were detected in boring wells in the mountain side of crippled reactors. In one of the boring wells, Tritium density was 200,000 Bq/m3 on 3/10/2015 but it jumped to 3,400,000 Bq/m3 on 3/17/2015. They had not analyzed the sample of this well for one week for some reason.

On 3/20/2015, Tritium density of the next boring well jumped from 300,000 Bq/m3 to 2,500,000 Bq/m3 within just one day.


On 3/10/2015, highly contaminated rain water sank underground in a near tank area. (cf, 750 t of contaminated rainwater leaked to underground / “Bubble came up from the ground” [URL])

However these boring wells are not in the course from this tank area to the sea.

The cause is not identified. Cs-134/137 nor Strontium-90 density have not been analyzed.




Français :

La radioactivité en tritium d’eaux souterraines se multiplie par 17 en une semaine


Le 18 mars 2015, Tepco annonce qu’ils ont relevé une radioactivité en tritium des eaux souterraines 17 fois supérieure aux relevés précédents.
2 jours plus tard, la radioactivité en tritium du forage voisin était plus de 8 fois fois supérieure au relevé précédent.

Ces augmentations ont été relevées dans les puits de forage du côté montagne des réacteurs dévastes. Dans l’un d’eux, la radioactivité en tritium était à 200 000 Bq/m³ le 10 mars 2015 et à 3 400000 Bq/m³ le 17 mars 2015. Ils n’ont pas fait d’analyse d’échantillon de ce forage pendant une semaine.
Le 20 mars 2015, la radioactivité en tritium du forage voisin est montée de 300 000 Bq/m³ à 2 500 000 Bq/m³ en un seul jour.

Le 10 mars 2015, des eaux de pluie extrêmement radioactives s’étaient infiltrées dans le sol de citernes proches de là. (cf. 750 T d’eau de pluie radioactive a fuit en sous-sol / “Des bulles ont jailli du sol”)
Cependant, ces puits de forage ne sont pas sur le trajet allant de la zone des citernes à la mer.
La raison n’en est pas connue. Les radioactivités en Cs-134/137 et en strontium 90 n’ont pas été analysées.

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.


March 2015