[Checkmate] Atmospheric dose in plant area jumps up by 6.4mSv/y for direct radiation from contaminated water

[Decommissioning plan breaking down] Radiation level in plant area jumps up by 6.4mSv/y for direct radiation from contaminated water


On 5/7/2013, Tepco announced the atmospheric dose in Fukushima nuclear plant area is significantly raised by the retained contaminated water.

The highest increasing dose is estimated to be 6.4mSv/y. However, this is the reading on the border of the plant area. It would be higher inside of the plant area.

This is due to be direct radiation from the contaminated water storage facility. Tepco analyzes the main factor would be Bremsstrahlung X ray from Sr-90 (Y-90) in the contaminated water.

It turned out this is one of the reasons why Tepco attempted stocking contaminated water in the underground reservoirs.

Having the contaminated water leaking, Tepco can no longer depend on the underground reservoirs.

They are planning to transfer 15,900 m3 of highly contaminated water to the potential back-up tank called G6, which is above the ground. This tank is estimated to raise the radiation level the most.

However, the tank G6 will not be welded because it’s easier to build according to Tepco.

(cf, [Reservoir Leakage] Tepco not to weld the new emergency tanks of 19,000m3 [URL])

Though Tepco chose the most provisional way to build the safe back-up tank, they haven’t even started building the tanks.

They are still in the process of improving the ground.

Former Fukushima worker Happy11311 commented on Twitter Tepco might be struggling to collect human workers to build it.

(cf, Former Fukushima worker “Shortage of workers is delaying water transfer plan from the leaking reservoirs” [URL 2])

The retained water is likely to contain 1,300 Bq/m3 of Pu-238 and 110 Bq/m3 of Cm-244, but they haven’t even announced when to report how much Pu-238/239/240 leaked from the crippled reservoirs to the environment.

(cf, The leaking reservoirs may contain 1,300 Bq/m3 of Pu-238 and 110 Bq/m3 of Cm-244 [URL 3])

Their decommissioning plan is starting to break down.





Thank you for considering donation !
Monthly donation for the company paypal is also helpful !


Français :

[Checkmate] La dose aérienne dans la centrale monte de 6,4 mSv/an à cause des eaux extrêmement radioactives


[Decommissioning plan breaking down] Radiation level in plant area jumps up by 6.4mSv/y for direct radiation from contaminated water

Le 7 mai 2013, Tepco annonce que la dose aérienne dans la centrale nucléaire de Fukushima a gravement augmenté à cause de l’eau radioactive stockée.

Le record d’augmentation de la dose est estimée à 6,4 mSv/an. Ceci n’est, cependant, que le relevé en bordure de la zone de la centrale. Ce devrait être plus à l’intérieur de la centrale.
C’est provoqué par l’irradiation directe des aires de stockage des eaux extrêmement radioactives. L’analyse de Tepco conclut que le facteur principal doit être le rayonnement X de Bremsstrahlung associé au strontium 90 (Y-90) dans l’eau extrêmement radioactive.
Il se révèle que c’est une des raisons pour lesquelles Tepco a tenté de stocker ces eaux dans les réservoirs enfouis.
Avec les fuites extrêmement radioactives, Tepco ne peut plus compter sur ces réservoirs souterrains.
Ils prévoient de transvaser 15 900 m³ de ces eaux extrêmement radioactives dans la citerne de secours nommée G6 et qui est en surface. On estime que cette citerne portera le niveau de radioactivité au maximum.
La citerne G6 ne sera pas soudée parce que c’est plus facile à monter, selon Tepco. (cf. [Fuites des réservoirs] Tepco n’a pas soudé les nouvelles citernes d’urgence de 19 000 m³)

Bien que Tepco ait choisi le moyen le plus économique pour construire cette citerne de secours, ils n’ont même pas commencé la construction de la citerne. Ils sont toujours en train de stabiliser le sol (qui va la supporter).
L’ancien travailleur de Fukushima Happy11311 a déclaré sur Twitter que Tepco pourrait être en train de se battre pour recruter des travailleurs humains pour la monter. (cf. L’ancien travailleur de Fukushima : La pénurie de travailleurs retarde le transvasement de l’eau des réservoirs qui fuient)
Les eaux stockées devraient contenir 1 300 Bq/m³ de Plutonium 238 et 110 Bq/m³ de Curium 244 mais ils n’ont même pas annoncé quand ils donneront les quantités de Pu 238/239/240 ayant fuit des réservoirs percés dans l’environnement. (cf. Les réservoirs percés pourraient contenir 1 300 Bq/m³ de plutonium 238 et 110 Bq/m³ de curium 244)
Leur plan de démantèlement commence à s’effondrer.


Merci de penser à un don.
Les dons mensuels à la société sont aussi très utiles.

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.


May 2013