The radiation dose limit of Fukushima schools and kindergartens is 3.8 μSv/h / MEXT “Unrealistically low”

MEXT (Ministry of Education, Culture, Sports, Science and Technology) allows Fukushima schools to use the school facilities if the atmospheric dose is lower than 3.8 μSv/h.


MEXT states the annual dose would be 20 mSv on the unrealistically strict assumption that a child spends 8 hours on a schoolyard and 16 hours inside of the building when the atmospheric dose is 3.8 μSv/h. (1 mSv = 1,000 μSv) 20 mSv / y is the maximum dose within the safety range that ICRP defines.

ICRP advises that the artificial exposure (except for the natural exposure and medical exposure) dose for ordinary people should not exceed 1 mSv per year, which is based on the study of Hiroshima / Nagasaki atomic bomb victims. This 20 mSv / y is 20 times much as this dose limit. Additionally, ICRP regulates the annual average dose of arbitrary 5 years should not exceed 20 mSv / y in case of occupationally exposed personnel.


This “20 mSv / y rule” is applied for kindergarten, elementary school, junior high school and high school in Fukushima prefecture.

It was made in April of 2011. In July of 2011, MEXT re-announced that they try to keep the annual dose lower than 1 mSv / y as ICRP advises, however they add “this is only the desired value. They won’t limit the outdoor activities if it’s lower than 20 mSv / y.”.


Downplay it in the beginning, and quietly add more information so nobody notices it. All for not letting the cattle escape. This is their strategy.


Français :

La radioactivité maximale des écoles et garderies de Fukushima fixée à 3,8 μSv/h / Le MEXT : “trop irréaliste”


Le MEXT (Ministère de l’Éducation, de la Culture, des Sports, des Sciences et Technologies) n’autorise les écoles de Fukushima à ouvrir que si la radioactivité ambiante est inférieure à 3,8 μSv/h.

Le MEXT affirme que cette dose annuelle devrait être de 20 mSv sur la stricte hypothèse irréaliste qu’un enfant passe 8 heures dans la  cour de l’école et 16 à l’intérieur de ses bâtiments alors qu’elle est de 3,8 μSv/h  (1 mSv = 1 000 μSv). 20 mSv / an, c’ est la dose maximale à l’intérieur de l’intervalle de sécurité défini par l’ICRP.

L’ICRP conseille une dose d’exposition artificielle (naturelle et médicale exclues) des gens ordinaires n’excédant pas  1 mSv par an, ceci sur la base des études faites sur les victimes des bombes d’Hiroshima et Nagasaki. Ces 20 mSv/an sont 20 fois plus violents que la dose maximale admissible. De plus, l’ICRP fixe le maximum admissible de dose moyenne annuelle sur 5 ans arbitraires pour les personnels des professions exposées à 20 mSv/an.

Cette “loi des 20 mSv/an” est appliquée aux garderies, écoles primaires, secondaires et lycées de la préfecture de Fukushima.
Elle a été promulguée en avril 2011. Le MEXT avait re-déclaré en juillet 2011 qu’ils allaient essayer de maintenir la dose annuelle en dessous des 1 mSv/an comme recommandé par l’ICRP, néanmoins, ils ajoutaient “ce n’est qu’une valeur souhaitée. On ne limitera pas les activités d’extérieur si la dose est en-dessous des 20 mSv/an”.

Le minimiser au début et ajouter tranquillement de nouvelles information pour que personne ne le remarque. Tout pour que le troupeau ne s’échappe pas. C’est leur stratégie.

  1. So now it is okay for Japanese children to be exposed to 165% of the annual dose limit prescribed for US radiation workers. This is in addition the risk from hot particles, which are lying in schoolyard gutters, gathering on desks and shoelaces, blowing in the wind.

    This is filicide on an industrial scale.

  2. Rather obviously, the PARENTS, Grandparents, extended families, friends and neighbors of these children are unarmed, cowardly SERFS.

    This particular on-going exposure rate, is cumulatively added to all the preceding internal and external nuclear fallout exposures.

    Freemen would reasonably use pitchforks and other available means to summarily execute anyone threatening their children in this fashion.

    Allowing such evil persons to live, represents a sad, death of honor. In My Humble Personal Opinion (IMHPO).

  3. This number is an atmospheric dose.

    No doubt the official testing procedure is to measure directly after a rainstorm, as far from any buildings or trees as possible, with a preference given to raised ground, and hard impermeable surfaces that drain quickly are preferred.

    We are now more than 3 years past the event. There should be nothing manmade to detect in atmospheric testing. Anything above airborne background radiation levels from 5 years ago, should be considered unacceptably high.

    As mentioned above the problems are with the soil that is played in and the trees that are climbed, and the berries that are found. Bringing schools and kindergartens to 3.8 μSv/h is not “unrealistically low.” Difficult, expensive, and time consuming to achieve, yes, but it is not unrealistically low.

    Such issues are just a part of cheap, clean, and ‘safe’ nuclear power.

  4. Spring has sprung

    Pollen, Spores, sap and certain seeds carry radioactive fallout from the soil back into the air and general environment.

    So also: thermals, dust devils, storms, wind-spouts, tornadoes and gusting winds carry radioactive fallout back into the ambient atmosphere.

    It happens every year at Chernobyl and Fukushima.

    Nothing new or unexpected, though errors are always possible.

  5. Noting that 3.8 μSv/h equates to 33.31 mSv per year, if i have that calculated correctly.
    That seems unrealistically high, not low.

    Maybe it is MEXT that is unrealistically high (on something hallucinogenic).

    Would it not be prudent if to err, to err on the side of caution?
    Parents likely shouldn’t trust their children to the likes of those Fockers. I wouldn’t, though that is my humble opinion.

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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.


April 2014