Gov’s investigation committee gave up identifying the burst of reactor2, “need international help”


Government’s nuclear accident investigation committee is to conclude that they can’t identify the route and cause of the burst in reactor2 because of the time restriction and technical limitation in their final report planned to be published on 7/23/2012.
Reactor2 is thought to have bursted the biggest amount of radioactive material on 3/15/2011 without explosion.

Tepco analyzed that PCV was damaged around 7:20 of 3/15/2011, when the vessel pressure decreased drastically.
On the other hand, government’s investigation committee is to report it was from 13:30 to 18:00 of 3/14/2011, when the vessel pressure decreased gradually. Because their analysis result about reactor1 and 3 contradicts with Tepco as well, they are going to point out that the assumption of Tepco is probably not based on the facts in their final report.

However, they could not investigate detailed cause of reactor2 burst because the radiation level is too high even 1 year and 4 months later than the accident.

Prof. Okamoto from Tokyo University graduate school commented, Tepco has just started the robot survey in reactor2, there is no enough information to investigate the cause, it is important to invite experts from around the world not only within Japan to continue survey.


Gov's accident investigation committee gave up identifying the burst of reactor2, "needs international help"



  1. FUKUSHIMA DIARY FR – La commission d’enquête du gouvernement abandonne sur l’explosion du réacteur 2 : “Assistance internationale requise”.
    Par Mochizuki, le 13 juillet 2012.

    Dans son rapport final à paraître le 23 juillet 2021, la commission d’enquête du gouvernement sur l’accident nucléaire va conclure qu’elle ne peut identifier ni la cause, ni la manière par lesquelles le réacteur 2 a explosé, à cause de leur manque de temps et de compétences techniques. On pense que l’explosion du réacteur 2 est celle qui a libéré le plus de radioactivité le 15 mars, et sans explosion.

    Tepco a trouvé que le PCV (enceinte de confinement primaire) a été endommagé le 15 mars 2011 vers 7:20, lorsque la pression de l’enceinte a diminué de façon drastique.
    D’un autre côté, la commission gouvernementale va publier que c’est entre 13:30 et 18:00 ce 15 mars 2011, lorsque la pression de l’enceinte s’est progressivement effondrée. Parce que leurs résultats d’analyse des réacteurs 1 et 3 sont également en contradiction avec ceux de Tepco, ils vont montrer dans leur rapport final que les affirmations de Tepco ne sont probablement pas basées sur des faits.

    Toutefois, ils ne peuvent pas enquêter pour trouver la cause précise ayant amené à l’explosion du réacteur 2 parce que le niveau de radioactivité est encore trop élevé, un an et 4 mois après l’accident.

    Le Pr. Okamoto de l’Université de Tokyo commente : Tepco a juste commencé les explorations robotisées dans le réacteur 2, il n’y a pas assez d’information pour enquêter sur la cause et pour continuer les investigations il est important d’inviter des experts du monde entier et non pas seulement du Japon.

    (copie d’écran NHK)

    Source :

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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.


July 2012