Tepco “Attached a dosimeter on the top of a pole, moved it by a minitruck to measure 25 Sv/h”

Note : If you are from the international mass media, Don’t read this site before taking a contact with me.



Following up this article.. 25 Sv/h from the damaged stack for reactor1 and 2 / Highest reading outside of the buildings [URL]


Because the ambient dose is too high for a worker to survey near the bottom of the stack, Tepco measured it by a dosimeter attached on the top of a pole (12m).

The pole was fixed on a minitruck. By moving the minitruck, they tested the radiation dose of various points.

They assumed there is a part of 25 Sv/h on the stack, but they couldn’t measure it directly.

The moderate technology level implies the various challenges Tepco may encounter through the process of decommission Fukushima plant.

Attached a dosimeter on the top of a pole, moved it by a minitruck to measure 25 Sv/h


2 Attached a dosimeter on the top of a pole, moved it by a minitruck to measure 25 Sv/h






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In short, they make you individual readers pay for this site while they pay nothing, and when they publish the “authorized news”, you pay for the “secondhand news”, which is nothing new for us.
This site is free for the individual readers, but not for corporations.In the world, this site is nearly the only source about Fukushima. I came here alone without any supporting organizations, background or anything. I’m not pleased to be exploited by the corporations that didn’t even properly report about Fukushima when 311 took place.

I demand them to take a contact with me BEFORE reading this site whatever the purpose is.


Français :

Tepco : “Un dosimètre au bout d’une perche déplacée par un petit camion pour relever les 25 Sv/h”
Note : Si vous êtes de la grande presse internationale, ne lisez pas ce site sans avoir préalablement pris contact avec moi.


Article lié : 25 Sv/h sur la cheminée endommagée des réacteurs 1 et 2 : Record des relevés à l’extérieur des bâtiments

Tepco l’a mesuré avec un compteur attaché au bout d’une perche (de 12 m) parce que la dose ambiante est trop élevée pour qu’un travailleur puisse parcourir la base de la cheminée.
La perche a été fixée sur un petit camion. Ils ont relevé la radioactivité en différents points en se déplaçant avec lui.
Ils pensent qu’il y a un endroit à 25 Sv/h sur la cheminée mais ils ne l’ont pas relevé directement.
Ce faible niveau technique explique les différents défis que Tepco peut rencontrer à travers le processus de démantèlement de la centrale de Fukushima.

Attached a dosimeter on the top of a pole, moved it by a minitruck to measure 25 Sv/h

2 Attached a dosimeter on the top of a pole, moved it by a minitruck to measure 25 Sv/h


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En résumé, ils vous font payer à vous, simples lecteurs, ce qu’ils prennent gratuitement dans ce site et lorsqu’ils publient des “nouvelles de première main” vous payez pour des “nouvelles resucées”, qui n’ont rien de nouveau pour nous.
Ce site est gratuit pour les lecteurs individuels, pas pour les sociétés. Ce site est pratiquement la seule source au monde sur Fukushima. Je viens ici seul sans aucun soutien d’organisation quelconque, ni références, ni rien. Je n’apprécie pas de me faire exploiter par ces sociétés qui n’ont même pas été foutues de relater correctement ce qui se passait à Fukushima quand a eu lieu le mois de mars 2011.

Je leur demande de prendre contact avec moi AVANT de lire ce site dans quelque but que ce soit.

  1. 25sv, this is so extremely high. Someone receives deadly radiation amount in only a few seconds at that level.

  2. Don’t be dramatic. A dose of 1 Sv is survivable. So at 25 Sv/h you could hang around for several minutes, without getting a lethal dose. You’d probably get cancer or something later in life, but it’s a long way from getting ‘a lethal dose in seconds’. Staying there for 15mins is probably fatal. So your estimate is about 500 times too dramatic.

  3. Put another way, your chances of surviving 10mins of 25 Sv is a LOT better than your chances of surviving the same 10mins with your head in a bucket of water.

    1. Put yet another way, a Tepco worker would exceed the emergency annual exposure limit (250 mSv) in just 36 seconds, barely long enough to undo a bolt and hand over the spanner to the next guy.

      1. put another way, they can always up the standards again, if the pre fukushima nuclear power workers dose rate became the norm for kids. and that is mild to what the USA declared for evacuation limits, dead for sure in 10 years under it.

  4. Yes, but you can see a bucket of water… sure, there is a difference between seconds and 15 minutes, either way it is still something that is very unhealthy for the natural world. your reference to a bucket of water is a bit juvenile. maybe true, but juvenile..

  5. I would like to say thank you to Fukushima Diary, and Fukushima Watchdogs 311, our families thank you for the information you provide.

  6. Do you rememember the photo of the worker with a SHORT pole standing right at that location measuring radiation? That was seen several weeks ago; and 10 Sv/h was also measured there much earlier in the disaster. Wonder where HE/worker is now? Healthy? Did anyone tell him of the 25 Sv/h he was exposed to? Or is he already aware?

  7. UH..it looked like the worker stood there for enough time to get a good photograph..so minutes at the very least. How much radiation do you think a worker would get if standing within 10 feet of the 25 Sv/h location for five minutes, Niall? Just observing the photograph, the worker had to test in several areas to find the ’10 Sv/h location.” The only reason it was 10..the dosimeter only measured to that range; wonder if the 25 Sv/h is the maximum for THAT dosimeter on the van. Either way, the worker had to walk to and from the high radiation location, put the device in the correct location and pose for a photograph. That would be several minutes I would think….

      1. The worker looks to be on the back side of the smaller pipe, if the configuration is mapped out. From the linked article:
        “This is the 2011 photo of a worker investigating this same area. The bottom bend of the rusty smaller diameter pipe is the location identified today has having 25 seiverts. This same area was dangerously high in 2011. The radiation level found at the base of this stack is potentially lethal.”

      2. The photos do not appear to be of the same location. In the recent photo, 90 degrees anticlockwise (when looking down) from the upwards-bending pipe, the wider downwards-bending pipe has a clear flange with prominent bolts at the point where it meets the stack. In the 2011 photos (with the worker) the flange and bolts are absent, as is the platform structure with diagonal struts beneath the downwards-bending pipe.

        1. The upwards-curving pipe is stained dirty in the 2011 photo but clean in the recent ones. I agree and think the location is not the same.
          Isn’t there two similar stacks, between 1 and 2, and between 3 and 4?

  8. I’ve no idea what the fall-off rate is.. inverse square? Anyone?

    Either way, several minutes there is certainly not good for you. Thats not the point. I get annoyed with people announcing ‘facts’ like several seconds would be lethal, when the bare minimum of knowledge indicates otherwise.

    Do you know for sure that the photographer you refer to was at this exact location? Maybe it was a different stack?

    Didn’t they make similar assumptions at chernobyl regarding the radiation levels? Ie this meter goes up to x rontgen, therefore the level must be x rontgen?
    Looks like no one learned from that lesson…

    1. Yes, inverse square (reduced subtended angle with distance)

      Gamma, XRay, InfraRed and Visible Light Spectrum are similar in that respect, radient energy waves/particles.

      These STRUCTURAL STEEL members are emitting Gamma Radiation, because they were exposed to neutron flux (flow). It is well recognized that the cause of these neutron (beams) is nuclear fission, in this kind of circumstance.

      It happens inside a nuclear reactor all the time and it happens with every atomic explosion.

      These types of hot-spots surround the FDU-3 nuclear reactor explosion, ground zero region. The familiar FDU-3 mushroom cloud represents the 3rd (publicly) known atomic explosion in Japan, following the Hiroshima and Nagasaki bombings by the USA in concluding WWII.

      In my humble opinion, the FDU-3 atomic explosion was an accident. However, reasonable men may come to alternate conclusions. Atomic explosions are really quite simple to create. They do however, make quite a mess.


      Bill Duff

  9. So a radiation meter, tied to a long pole, supported by a string, hanging off the side of a van, is the best level of effort TEPCO can offer ?

    They do not know the location of the melted cores. The groundwater moves with the tide located on the other side of a wall they consider ‘impenetrable.’

    They are putting a huge effort into building tanks to fill with water that will be dumped into the Pacific Ocean.

    I would wonder what the administration of the country is doing, but I have seen the leader explain to the world that radiation can be held back from the sea by a mesh ‘curtain.’

    And our host seems to be the only person working to get this information out to the rest of the world, at great personal cost in both money and quality of life. Thank you, Sir for the Fukushima Diary.

    What will it take to get Japan and the rest of the world to take this problem seriously, and not hope that by ignoring it will make it go away?

  10. “a dose of 1Sv is survivable”. Depends on your definition of survivable. What time period do you mean survivable? Studies in the field of effects of ionizing radiation carried out by experts not paid by Nuclear power companies indicate that 1mSv a year is when the effects start to present. 1Sv in less than hour is 1000x a year dose. LDR effects are not instant death, and cause a large number of both physiological and psychological abnormalities; including depression, aggression and extreme fatigue. Within several years after Chenobyl, hundreds of thousands of exposed citizens died from suicide, depression, alcoholism drug addiction and overdose and AIDS. So to say stupid things like radiation is not harmful because you don’t drop dead instantly is possibly and insult to the 800000 liquidaters, who most had no choice but were conscripted to deal with it. Many thousands are now dead.

  11. Yup.

    If you believe the LNT model a dose of 1mSv in one year will increase your risk of cancer and will reduce your average expected life span by 5 days.

    When I flew back and forth to Japan in November I picked up a dose of around 0.1mSv from cosmic rays which reduced my average life span by 1/2 a day.

    1. DieMost,

      And god-only-knows what you ate/drank/inhaled or had physical contact with and skin-adsorbed.

      Oh and gad-only-cares

      I certainly do not care.

      However, I DO CARE how many innocent Japanese children have been placed at the front of the ‘Cancer Que’, had heart attacks, immunosuppression and all the rest.


      Bill Duff

  12. My family got a good dose from Chernobyl. While no proof, my oldest daughter has thyroid cancer outside the thyroid. Doctors were ‘surprised’..she is so young, and the cancer fingerprint is from radiation. My second daughter is now being treated. One was a teen during Chernybyl, one was a baby. Both had over a year of exposure. AND NO ONE MENTIONED ANY ISSUES! I developed severe arthritis and immune system issues within five years of the exposure. So three out of three, not good for so called low exposures.
    Again, I wonder how the worker is doing. Looking at the mess/trash around the vent stack in the photograph, it would be hard to think it was somewhere else. If somewhere else..WE HAVE PROBLEMS HOUSTON! Because that stack is also mess..so if it is Reactor 5 and 6 or one of the other Nuclear Plants, not good. Interesting to bring up it could be somewhere else, Naill.

  13. The Sievert is an absorbed dosage. So when they state 25 Sv, is that the dosage an unprotected person would receive? If so, the photographed worker with the protective clothes and respirator was protected from a lot of beta radiation at least. If it even was the same location..

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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.


December 2013