After Alarmingly High Radiation Levels Detected, What Are the Facts in Fukushima?

Six years ago, three nuclear reactors were crippled in Fukushima, Japan, when a tsunami knocked out power to the cooling units, and flooded the generators mistakenly kept at sea level. What was termed a cultural disaster caused a nuclear meltdown and over 70,000 nuclear refugees have still not been able to return home.

It is widely accepted in Fukushima that there is a perception gap between the reality of the problem, and what media outlets, both reputable and fake, have claimed the problem to be. So when recent reports came out that radiation in Fukushima was rising, I began to do my homework to discern what was really happening and what was “fake news.”

Recently Tokyo Electric Power Company (TEPCO) began sending robotic cameras into the primary containment vessels (PCV) that house the damaged reactors. However, due to extremely high levels of radiation, the robots keep breaking. Within the last two weeks, two cameras have broken—including the one on a scouting mission for the robot meant to locate the radioactive fuel.

According to TEPCO, “The previous highest radiation level was about 73 Sv/h measured in March 2012, so we designed cameras and robots to tolerate that level of radiation (about 100 Sv/h) for 10 hours for the investigation this time. The estimation of radiation levels (as high as about 530 Sv/h at a certain point) was more than we expected, but based on the findings, we proceed with further steps with some modification, necessary, to investigate inside the Unit 2 PCV with the Scorpion robot.”

There has been no change to radiation levels outside of the PCV, the power company added. “Extra precautions have been taken to prevent leaks of radiation during the investigation. The penetration pipe through the PCV wall is tightly shielded, and the work area is pressurized so that air only moves from the outside into the PCV and not the reverse.”

To find out more, I contacted Safecast, a citizen science network that bills itself as neither pro-, nor anti-nuclear. Safecast’s team of volunteers have developed the bGeigie handheld radiation monitor, that anyone can buy on and construct with suggested instructions available online. So far over 350 users have contributed 41 million readings, using around a thousand fixed, mobile, and crowd-sourced devices.

Here is what Azby Brown, Safecast’s lead researcher, has to say in an interview.

Let’s recap. TEPCO sent in a robot, it captured pictures before frying, and they stitched the photos together and found the hole. Inside the hole are extremely high levels of radiation, higher then ever measured before. They believe this is THE hole, created by melting radioactive material.

The first step in TEPCO’s recent investigations deep inside Unit 2’s reactor was to insert a camera on a long telescoping pole through an existing maintenance opening. It was not a robot. It captured striking images of what appear to be melted metal spattered on floor decking and other elements inside. They also detected a hole in the steel floor decking about 1m by 1m [about 10 square feet]. They were not able to actually see a hole in the steel reactor pressure vessel (RPV) above, but the working assumption is that the hole in the decking was caused by molten core material mixed with steel falling through.

 This grating inside Daiichi Unit 2 was likely melted by falling fuel debris (TEPCO photo). Click image to enlarge.

This grating inside Daiichi Unit 2 was likely melted by falling fuel debris (TEPCO photo). Click image to enlarge.

Also, it seems likely that the material spattered around is a similar mix of core and steel, but some will have to be removed and tested to be sure, and TEPCO is cautiously waiting to until they’ve done that to confirm.

A few days after the telescoping-arm investigation, a small-tracked cleaning robot with a high-pressure water nozzle and a scraper was inserted.  This operated for 2 hours before the radiation had degraded the camera too much to continue. Neither the telescoping unit nor the cleaning robot had an actual radiation detector, and radiation levels were inferred from camera noise and degradation of the cameras. TEPCO’s first announcement was that radiation levels were estimated to be as high as 530 Sv/hour; the succeeding estimate was over 600 Sv/hr. Either would be fatal to a human after a few minutes’ exposure.

Finally, on Feburary 16, Tepco inserted a second robot into the reactor. This one is called the “Scorpion” because it has a folding “tail” containing powerful lighting and a camera. It operated well for about 30 minutes before becoming immobile, but was able to obtain about 6 hours of video images as well as better radiation measurements, which showed maximum levels of about 210 SV/hr. While this is lower then the previous estimates, it is also considered more accurate and within an order of magnitude. It would also be fatal to humans after a few minutes’ exposure.

What does this mean for the cleanup of the disaster? is this a breakthrough or a setback? 

These investigations are essential, and the fact that they’ve been fairly successful so far is a step forward. At the same time, the high radiation levels are sobering, and may mean that the timeline for removing the melted fuel and decommissioning the reactors will be longer than hoped.

Why does the world’s media claim a spike in the radiation, but Safecast is telling people that perhaps it’s not as bad as it seems. What makes you sure of this?

There’s no simple answer for why the findings were misrepresented in the media. TEPCO probably should have stated more clearly that they were measuring these high-radiation areas for the first time, not that radiation levels were rising. Some media posted alarming headlines about rising radiation levels, but their stories were actually pretty factual. Other media have a business model that uses “clickbait” and alarmism intentionally, regardless of fact. This time all these factored into the misreporting.  Safecast has a network of real-time radiation sensors in Fukushima, including several within a few kilometers of the Daiichi plant. None of these have showed a spike in radiation, and no other official or independent monitoring has either.

Where are these high levels coming form?

Highly radioactive molten fuel almost certainly dropped to the 7m [23-foot] thick concrete floor of the reactor building beneath the RPV in March 2011. TEPCO believes that it is now covered by about 30cm [a foot] of water, which is being constantly purified and recirculated. It seems to be a very safe presumption that high radiation levels are from this core material, which has likely solidified.

Is the radiation contained? From where is the radiation still leaking? 

It’s not fully contained, in that some of the recirculated cooling water, which becomes contaminated by contact with the core material, leaks out of the building, presumably through cracks in the basement walls of the reactor. Lots of measures have been taken to try to contain and minimize this, but none have been fully successful yet. Many of the steps being taken now are to prepare for locating and closing these leaks. This will be several years in the future at best, however.

Why has it taken so long to reach this hole? How do you imagine it can be dealt with finally and totally to decommission the plant. 

In order to insert the telescoping arm and the robot, human workers need to have access to the maintenance opening. That area has high radiation as well — though not as high as inside the reactor. It took TEPCO much longer than initially estimated to decontaminate these areas sufficiently to allow the workers to perform their tasks with minimal risk. TEPCO and its partners have suggested several approaches for removing the melted fuel and dismantling the building, all of which rely heavily on developing new remotely operated and robotic technology. Again, this process will take decades.

Why is third-party citizen science reporting more believable than government information? 

We believe that groups like Safecast can function independently of either pro-nuclear or anti-nuclear bias, which government agencies in Japan and abroad have not been able to fully free themselves from. Certainly governments are perceived by many as biased even when their information holds up. Our model depends on citizens themselves taking measurements and reporting them, so they can have full confidence in their data and in the system itself. We think our model can be widely adopted in other areas as well, from environment to food safety to supply chains. They key is the openness of the entire system.

In the era of fake news and misinformation, what can people do to verify these results for themselves? 

There’s no substitute for doing the homework, becoming technically and media-literate, and informing oneself. Radiation issues are largely scientific, but as we’ve seen in the current political situation in the U.S., other issues are ripe for abuse and manipulation as well. We encourage people everywhere to be skeptical and to become skilled at fact-checking. This is only possible with adequate education.

As far as radiation and Fukushima are concerned, it’s usually pretty obvious when a website is distorting or manipulating information. But we’ve seen good journalists fall prey to bad info as well.

Safecast is always available to answer questions from the public as objectively as possible. Readers should feel free to contact us at As far as we’re concerned, there’s no such thing as a dumb question!


 Ari Beser is the author of the book ‘The Nuclear Family‘ and director of the documentary ‘Hibakusha‘. He used his Fulbright-National Geographic Digital Storytelling Fellowship (2015-2016) to give voice to the hundreds of thousands of people directly affected by nuclear technology today. He is the grandson of Lt. Jacob Beser, the only U.S. serviceman aboard both B-29s that dropped atomic bombs on Japan during World War II.


  1. David Dunning White
    March 26, 7:49 am

    We simply do not learn……All investment should be in clean renewable energies such as solar wind and water ……
    It doesn’t take a PhD to understand this…..
    Instead governments subsidise Nuclear and fracking ….
    This is literally insane ……

  2. John Mecca
    United States
    March 22, 11:40 pm


  3. Guest
    March 19, 10:25 pm

    Furkushima will never ‘be “contained” or cleaned up in our life time
    It will destroy the Pacific ocean ground water is impossible to stop

    Japan is running out of room to store the waste including uniforms masks and safety wear for hundreds of workers EVERYDAY stored in TRASH BAGS

    Water contaminated is stored in giant vessels that are filling up now Japan is thinking about diluting the water and releasing it into the OCEAN

    Furkuashima is underrated it is more serious and more of a complicated problem then anyone will ever bother to tell you no expert no Harvard degree specialist can deny that this is a problem for hundreds of years to come.

    We just don’t Learn

    We didn’t learn after world war 2
    We didn’t learn after Chernobyl
    And we sure didn’t learn after fukushima

    Nuclear energy is not an option it never should have even been considered.

    Albert Einstein regrets writting that letter to FDR I wonder if he would regret it even more if he seen what we have done with nuclear physics today.

  4. silas augustine
    March 13, 1:20 am

    If Tepco and the IAEA were truthful they would be honest with the public and confess they the Nuclear Industry is in unchartered waters. Japans parliment has already threatened its citizens not to be truthful about what is happening there. Japan is threatening its former Fukashima residents to return to Fukashima or lose their subsidies. The problem is that Tepco says it will take 40 years to clean up the sites and to fix the damage? Really? Radioactive water continues, radiation levels are off the charts and still the games in Japan and the world continues. No one knows what will happen next, and if the truth be told which it isn’t at the present time, and the whole world is watching and monitoring the on-going effects of six (6) years of a continuing Nuclear Meltdown in three (3) Nuclear Reactors. Another problem no in the media is talking about is the seismic activity right there in Japan and in the ocean which sits on the most active Fault Zone on top of the Ring Of Fire. So the meltdown is near or on the plate . Truly a freightening thought that another earthquake may be the all that end’s all.

  5. Andy Smith
    Dundee Scotland
    March 1, 4:51 am

    I would like to know this source of the foot of water that is being constantly purified and recirculated… How is the water being purified?… And then recirculating something that has been in contact with the rods in the reactor will that not cause further degradation?… And is this the possible source of pollution of the Pacific ocean? Is this a danger of becoming a world event? And why are there not more experts from the global society involved? what I am suggesting is that the experts working around Chernobal are relocated…to offer their experiences in dealing with this highly unstable situation….

  6. JAYoung
    February 27, 10:16 am

    One should consider just the financial consequences of Fukushima, setting aside for a moment the health effects of three lost reactor cores plus whatever spent fuel remains unaccounted for at the site.
    TEPCO’s loss of assets at the site alone meant is was bankrupt the moment the tsunami wave hit and has become a ward of the state, with Japan’s taxpayers picking up the tab now and into the uncertain future.
    The cleanup efforts, at a cost of many millions of dollars a day, are expected to continue 50 years. The technology needed to perform the work does not exist, and will require more investment. All this expense generates not one watt of electric power for the Japanese economy. There will be political consequences.
    Yet the work must be performed, as Japan’s largest island and the world’s largest city will remain under a threat that they may become unihablitable if Fukushima is left to fester over the decades ahead. Another earthquake that might shatter the hundreds of storage tanks at the site would reset the cleanup back to zero.
    True, the news media has moved on to other stories, returning only to report the frightening news that nothing has been achieved and the situation is growing worse.

  7. KramLafup
    February 27, 12:09 am

    I’ll fix it. Now where did I put my keys?

  8. Phillip Munyororo
    February 26, 5:31 pm

    Let’s hope no earthquake will hit Fukushima in the coming days.

  9. Terry
    Whidbey Island, WA
    February 25, 6:04 pm

    Yep! All of you self proclaimed geniuses did a great job refuting everything in the article with the typical brand of conspiracy theory responses, and a hysterical fear on the level of some of the finest paranoid schizophrenics on the planet. Because, you know, the people who wrote this article and others like it, have some secret agenda that will result in some huge benefit to them for making things up about Fukushima. What a crock you people are. Are you also afraid of Muslims, and Mexican, and small dogs, and clowns.And in review, not one of you posted a source to substantiate your information. Any of you ever heard the phrase “in God we trust. All others, bring data”. And if you do post a link…if it’s an obvious clickbait site….we are going to confirm your stupidity. Post your email and I’ll send you a roll of aluminum haberdashery raw materials.

  10. Floridun
    United States
    February 25, 2:07 pm

    Technically if it melts through the bottom of the plant, as soon as it hits ground water it blasts into the atmosphere and sends out clouds of radioactivity.

  11. Floridun
    United States
    February 25, 1:37 pm

    On its way to the core of the earth.
    China Syndrome.

  12. Douglas M. Fabish
    Ozone perimeter
    February 25, 1:15 pm

    I guess I didn’t make it passed moderation the first time so I’m trying again – anyone got any ideas about where the missing 350 tons of enriched uranium might be? I read an article awhile back, of an interview with the designer of Fukushima. He said he believes all of the uranium escaped containment within hours of the power failure. Are we allowed to discuss this?

  13. Douglas M. Fabish
    February 25, 12:50 pm

    My father was a Fulbright scholar.

  14. Douglas M. Fabish
    Ozone perimeter
    February 25, 12:48 pm

    Any ideas about where the missing 350 tons of enriched uranium might be?

  15. Richard Hoon
    February 25, 10:51 am

    Use the same weapon used on the WTC Compound {all seven buildings} which pulverized carbon based materials into fine dustings. It may require a longer dosage,but even the Safes were were particlized….Just building WTC1 required 40 stories of materail 200’X200′ to create a 120 story builing which was reduced to “1” story less materails,120,000Tonnes steel and concrete reduced to dust in mere minutes,now thats Energy. Fire Away

  16. Floridun
    United States
    February 25, 5:03 am

    Georgia, you are correct. China Syndrom in at least one reactor probably more. As if that’s not bad enough reactor #4 is fueled with plutonium. Half life on this stuff is many millions of years.
    Why didn’t the whole world become involved as David Nolan mentioned? To realize we all share the same small planet, with every country doing whatever it could, possibly bringing the world together as one could have been the evolution of mankind. Instead we chose to let mankind die.

  17. Kevin Leider
    United States
    February 24, 5:38 pm

    Reactor 3…..There is no reactor 3! It exploded, along with it’s MOX Plutonium fuel. 1 & 2 are killing the Pacific, and eventually all the World’s Oceans. #3 gets the rest of the planet with aerosolized uranium and bucky balls! The single greatest threat to our planet, species, and life, and we get 6 years of lies, inaction, and 0 accountability!

  18. Steven Schoenbach
    United States
    February 24, 1:09 pm

    Just supposing that cleaning up the reactors is determined to be beyond our capabilities, and sealing it in concrete (as at Chernobyl) is to be done. At present, water is poured over the reactors to cool them. Would this be possible after sealing, and if not, what would be the consequences of letting the heat rise unchecked? How was this problem attacked in Chernobyl, or are the circumstances different?

  19. Jason paczay
    February 24, 9:07 am

    I hear a lot of complaints and scepticism, I don’t hear a viable solution, nor am I sort enough to see one. I also don’t think the tree is a person or group of people who can * solve* this problem, after 6 years all we’re seeing is damage control and I hate to think it but that is all we are going to see… there was a meltdown on the other side of the planet if those results are any indication and on a so much smaller scale, arm yourself with knowledge

  20. David L Nolan
    United States
    February 24, 7:38 am

    The half life of this type of radioactive material is about 25000 years. Radiation levels are up. Hundreds of thousands of tons of water is flowing into the Pacific. This has cumulative effects of contamination on the ecosystem. Plankton absorbs it and it moves up the food chain. In effect this accident will kill off the Pacific over time. But let’s put our heads in the sand and say that this is only Japan’s problem and ignore what’s happening. We’re allowing the worst ecological nightmare to continue on with out intervention on a global level. It has to be contained. The investment will be massive. Coffer dams should be installed around the site to prevent ground water contamination. These precautions should have been started along time ago. But it cost serious money. The Japanese government either doesn’t have the means or is trying to down play the severity of the situation. This site will be radioactive virtually forever.

  21. Azby Brown
    February 23, 11:23 pm

    You’re right that without actually getting inside the reactor and measuring, all estimates of radiation levels there will have a high level of uncertainty. That said, I don’t recall ever seeing any actual estimates from TEPCO about radiation levels in the areas where they expect the core material to be. Since this interview was done, I’ve read some informed commentary that suggests that the very high doserate material detected in these investigations might be core material lodged in pipes above where the robots and other devices were, not from the bulk of the melted fuel below. Regardless, more time-consuming measurements will need to be done before anyone has a good idea of the real situation.

  22. Azby Brown
    February 23, 11:22 pm

    Charles Jannuzi:

    Correct, it is not possible for the cooling water system to function as designed. Instead, TEPCO is using some intact elements together with new piping to flood the reactor buildings. The water pools at the bottom of the buildings where the melted fuel is believed to be. Then it is pumped back out. Overall, you could compare the process to a swimming pool that continually has water added at one end, and pumped out at the other. The purification system removing radionuclides has actually become very sophisticated and effective. Keeping the swimming pool analogy in mind, clean water is constantly mixed in with contaminated water, but eventually all the water will be recirculated.

  23. Azby Brown
    February 23, 11:21 pm


    Using air pressure to control air flow is very common in many industrial and other applications. An area is sealed, pumps are used to increase the air pressure there, when an opening is made to a normal-air pressure area, air will only flow from the high-pressure area to the lower pressure area.

    Initial reports said that it stopped moving after 30 mins, but that the cameras continued to operate.

  24. Azby Brown
    February 23, 11:20 pm

    Safecast publishes a yearly report summarizing what research is showing regarding the Daiichi plant itself, the environment (including the ocean), food, health, and the situation for evacuees. You might be interested in reading it; it’s a free download. The 2017 edition should be available by the end of March. Here’s the link for the 2016 edition:

    This is a lengthy and detailed report by 11 researchers who examine many aspects of Fukushima-related ocean contamination. It’s a bit technical, but a very good source of scientifically-verified information:

    Fukushima Daiichi–Derived Radionuclides in the Ocean: Transport, Fate, and Impacts
    Annual Review of Marine Science, Jan. 2017

  25. Douglas M. Fabish
    February 23, 11:03 pm

    We are toast.

  26. Georgia
    February 23, 8:31 pm

    Are you kidding me? There was no safe shutdown, there is no positive air pressure when there is a 10 ft2 hole in the bottom of the containment vessel, and the 23 foot thick concrete floor that is cracked and leaking over 10,000 gallons per day into the ocean is not contained either. The only control anyone has mentioned is that some of the water was being pumped out and stored on site. Pray for these Fukushima workers and scientists. Pray for them to find a way to retrieve this toxic melted morass of radioactive materials. It may be thousands of pounds. Rods were also dropped from storage in the reactor that was not in service. This situation is still untenable. It is apparent there is no measure to tell exactly how high the radioactivity is in the melted hole. The fact that groundwater was also contaminated indicates the melted fuel has melted through the 23 feet of concrete, and is still headed downward. How far is our Earth’s core? Agree with above comments!

  27. Kimberly V. Davis
    United States
    February 23, 6:33 pm

    I’ve been following the groundwater issue since 2013. Radioactivity that destroys alloy and synthetic resin robots, is not good for the marine ecosystem and food web. Our epidemiology study design is made for human health – reasonably – but I’m not worried about Californians and their salmon (no offense to Californians). They’re using cesium as an indicator pollutant – meaning, cheap and easy to monitor. Sr-90 accretes in kelp, bones, and the exoskeletons of macroinvertebrates like crabs. Those creatures migrate even more than the ocean current modeling shows. Plutonium is heavy, and has likely sunk to the sediment around the destroyed plant, being taken up by bottom feeders and into the marine food web.

  28. Douglas C Linsenmann
    United States
    February 23, 3:48 pm

    Purified and recirculated ???

  29. Luke
    North East USA
    February 23, 12:24 pm

    Nice comments here, Thank god everyone is waking up to this, its just horrible. NO MORE NUKE PLANTS, we are smarter than this old tech

  30. Martin Miron
    United States
    February 23, 11:51 am

    Two things come to mind. How can you have air go in but not back out? How can the Scorpion operate for 30 minutes and produce six hours of video? Let’s not even get into earthquake probability of the Olympics.

  31. Dallas Snell
    United States
    February 23, 9:54 am

    Its sad to say but I believe they will never stop radiation from leaking into the ocean. This is forever as we humans describe it. Reactor 3 will be much worse than 2 or 1.

  32. Jaybob
    February 23, 9:07 am

    when you think engineers should know about the quaky situation with tsunamis in Japan and still build that near the ocean… them engineers shoudl be presented to the firing range for stupidity.

  33. Charles Jannuzi
    Fukui, Japan
    February 23, 8:08 am

    Please explain how, once the fuel is out of the pressure vessel, and melted down to the bottom of the structure, they can maintain a water cooling circuit on it? That part of the reactor IS NOT DESIGNED for that. If you think they are capturing and purifying all the water going in and out of the place, I would suggest you need to think a bit more about things.

  34. jimmy cavil
    February 23, 7:19 am

    fucishima was a place

  35. John
    February 23, 2:19 am

    There is one small but important detail missing from your story and from the other reporting I have read about this: the previous value for the radiation level of 73 Sv/hr was measured 5 years ago. If the source of this radiation is a mix of normally decaying nuclear fuel and construction material, the radiation at this previous measurement spot should have gone down by at least an order of magnitude, so down to 5 Sv/hr or so. Now finding, in about the same area, a radiation level which is 100 times higher is highly surprising, to say the least. Tepco clearly did not anticipate this when they specified the radiation hardness of the robots. If Tepco cannot even predict the correct order of magnitude of the radiation level inside the containment vessel, how sure can we be about their statement that the reactor is in cold shutdown and that everything is safe? If you don’t know things you cannot be in control of them.