TEPCO’s Fukushima Folly

, former director, Nuclear Safety Project | January 20, 2015, 6:00 am EDT
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Fission Stories #180

In early August 2014, the Tokyo Electric Power Company (TEPCO) announced that its latest analysis revealed the meltdown of the Unit 3 reactor at Fukushima Daiichi was worse than previously estimated.

(Source: Mazeo-Creative Commons)

(Source: Mazeo-Creative Commons)

Recall children’s books with dots and numbers? Children connect the dots to reveal pictures of clowns and puppies and spaceships and such.

TEPCO is essentially painting pictures using very few dots with no numbers. They keep running computer studies that put numbers almost randomly on the few dots they have to see what picture emerges. “Lo and behold” to quote a professor I had in college, different pictures emerge.

TEPCO doesn’t know when the Unit 3 core damage began

Or how much of the reactor core was damaged.

Or how and when the damaged core relocated after melting.

Or how, when, and where the molten burned through the reactor pressure vessel.

Or how it moved after it fell onto the containment’s concrete floor.

And they don’t know how much water, if any, was on the containment floor when the molten core joined it.

TEPCO fills in these information gaps with guesses. And they keep revising their results because they keep revising their guesses.

Our Takeaway

I choose not to play rate-a-guess. It would take me away from helping my nephew finish his connect-the-dots drawing. Only seven numbers remain to be connected. While it resembles a race car now, it might yet turn out to be a giraffe. Or maybe even a kitten.

Before I decide which TEPCO picture I most prefer, they are going to have to fetch more dots and put real numbers on as many of them as possible.

At some point in the next few years, TEPCO will maneuver a robot into the reactor area. That will reveal what the former reactor core looks like now. This information won’t answer all the questions, but it’ll number several more dots to support a meaningful analysis of what happened when.

Until then, TEPCO is just keeping their computer jockeys busy. They could get results of similar value using Ouija boards—and it would reduce their carbon footprint.


“Fission Stories” is a weekly feature by Dave Lochbaum. For more information on nuclear power safety, see the nuclear safety section of UCS’s website and our interactive map, the Nuclear Power Information Tracker.

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  • Richard Solomon

    At the risk of sounding like a ‘conspiracy theorist,’ I must wonder if TEPCO is simply not telling the whole truth about the events and current status at Fukushima. It has a long history of withholding information until a later date at which time it then comes out with more of the story after apologizing. In Japan, a CEO or high level government official can often bow and apologize for some terrible mistakes and still keep his/her job. The government has left TEPCO in charge of the clean up so it has an intermediary which the people can blame for the mess rather than the government itself. Meanwhile, the Japanese taxpayer is still left holding the bag financially to pay for the cleanup efforts. For PM Abe to have told the Olympic steering committee that things are ‘under control’ at Fukushima ranks right up there with ‘there is a tooth fairy!’

  • jharragi

    In a similar way, the nuclear industry claims that only a handful of deaths resulted from the Chernobyl accident where the actual death toll may range in the hundreds of thousands. While it is usually impossible to link individual deaths, birth defects and diseases to the event, statistically the numbers can (and have) been determined. It is obvious why the industry does not want to connect the dots. They not want an accurate picture, and actively generate misinformation regarding the risks of radiation and the toxic chemicals that emit it.

    Also at some point Fukushima will likely be recognized as the worst nuclear disaster to date. Because the location of the core is ‘unknown’, huge spikes of radiation being measured in groundwater and the ever increasing ‘estimates’ of radiological releases to date, I’m leaning toward Fukushima’s trumping of Chernobyl – maybe I’m better at connecting dots than Tepco and the nuclear industry. The picture also reveals that many other reactors around the world are not as safe as they should be…

    • xoviat

      There is no way that Fukushima could be worse than Chernobyl. The entirety of the core escaped the containment in Chernobyl while only a few percentage points of the core escaped in Fukushima. It is simply impossible that a much smaller release that travels over an area that is much less populated can cause more damage. Indeed, Chernobyl is virtually certain not to cause more than 100,000 full-life deaths while Fukushima is virtually certain not to cause more than 1,000 full-life deaths. The full-life deaths from Japan’s nuclear shutdown may be higher than the full-life deaths from Fukushima!

      • jharragi

        I suppose you are founding your ‘virtual certainty’ on the shifting sand that Tepco presents as facts? The estimates of releases continue to change – that is grow. This continues to happen despite a continual effort by the nuclear industry, government (s) and their agencies, and a media that is subservient to corporate owners to downplay the risks and their consequences.

        The cores location is uncertain. It may have burrowed 50% through the concrete ‘containment’ or 99% and counting. We can’t say how bad it is yet, if it is going to reach or how exactly it will interact with the groundwater if it does. We know the Japanese were extremely fortunate that the wind was not blowing toward the south during the worst parts of the disaster. That was certainly good luck – but hardly a good argument to base nuclear safety upon. The only real certainty is that that debacle is not yet over…

        • xoviat

          I suppose you are founding your ‘virtual certainty’ on the shifting sand that Tepco presents as facts?

          I am not. I am basing it on the solid facts of Chernobyl combined with conservative assumptions of what happened at Fukushima.

          We know the Japanese were extremely fortunate that the wind was not blowing toward the south during the worst parts of the disaster. That was certainly good luck – but hardly a good argument to base nuclear safety upon.

          You are correct. The weather conditions were very lucky. However, you seem to be basing the severity of Fukushima on what could have happened rather than what happened.

  • dinkydave

    Dave, in “Fukushima, the Story of a Nuclear Disaster” to which you contributed, it was pointed out that the fancy computer codes to predict meltdowns didn’t actually work as expected. So, what we have is three reactor cores which we don’t really know what happened, where they are or what they are doing. Spikes in radiation in ground water is really scary. Shut ’em all down, work on decon and long term disposable. While our home world is still fit for human habitation.