7,230,000 Bq/m3 of all β nuclide leaked from drain to the sea / “Contamination level suddenly jumped up”

Related to this article.. Tritium density reached the highest level at 3 bypass wells [URL]


On 2/22/2015, Tepco announced the radiation level suddenly jumped up in the plant area drain to let it flow to the sea.

According to Tepco, 2 radiation monitors detected the rapid increase of all β nuclide density (to include Strontium-90) around 10:00AM.

The indicated radiation level was 5,050,000 〜 5,630,000 Bq/m3.

It made Tepco check the potential leakage of the contaminated water tanks upstream and contaminated water transferring system, but they did not shut down the drain outlet for nearly 3 hours for some reason.

Extremely high level of all β nuclide was detected from seawater near the outlet, which was 3,000,000 Bq/m3. The contaminated water flowed to the sea.


The highest density detected by the monitor was 7,230,000 Bq/m3, which was 10 〜 100 times much as usual.


After all, Tepco found no leakage from contaminated water related facility upstream. There is a possibility that highly contaminated groundwater moved and flowed to the drain.

Currently they are collecting the water from drain by vacuum truck.









Français :

Une radioactivité β de 7,23 millions de Bq/m³ s’est écoulée en mer par une évacuation : “La radioactivité est brutalement montée”


Article lié : La radioactivité en tritium passe des records dans 3 puits de dérivation

Le 22 février 2015, Tepco annonce que la radioactivité a brusquement augmenté dans une évacuation qui s’écoule dans la mer.

Selon Tepco, 2 moniteurs de radioactivité ont détecté une augmentation rapide de la radioactivité β (dont le strontium-90) vers 10:00 AM. Le niveau de radioactivité indiqué était entre 5,05 et 5,63 millions de Bq/m³.

Ça a amené Tepco à vérifier les fuites potentielles en amont sur les citernes à eaux extrêmement radioactives et sur leur système de transvasement mais ils ont laissé le déversoir ouvert pendant 3 heures.
Une radioactivité β extrêmement élevée avait été relevée en mer près de ce déversoir, 3 millions de Bq/m³. Des eaux extrêmement radioactives se sont écoulées en mer.

Le record de radioactivité détecté par le moniteur a été de 7,23 millions de Bq/m³, ce qui est entre 10 et 100 fois plus que d’habitude.

Au final, Tepco n’a pas trouvé de fuite dans les équipements en amont. Il se peut que des eaux souterraines extrêmement radioactives soient remontées puis se soient écoulées par l’évacuation.

Ils récupèrent actuellement les eaux de l’évacuation avec un camion-pompe.


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.


February 2015