The wires this morning are buzzing with new developments at the Fukushima One Nuclear Power Station. Two new extraordinarily readings of radiation have been found outside of reactors. The levels are so high that anyone simply walking by could be killed (details and links below). I’m not quite sure what to think yet. It seems most likely that this is evidence of loss of containment back in March, during the most intense week of the accident. However, I cannot tell whether (a) the person in this picture will likely be dead within two weeks (TEPCO says no), (b) this is evidence of new containment failures (seems unlikely), (c) there will be several more astounding finds of high radiation in unexpected places on site (nearly certain?), (d) there has been no effort to look for radiation leaks yet (more below) and/or (e) there has been a systematic underreporting of the onsite radiation dangers.
(a) Will the man in this picture die in the next two weeks? If the caption on the photograph is to be believed, then the answer is, “maybe, maybe not.” He is holding a radiation monitor mounted on a boom. The boom appears to be three times his height. Assume he is two meters tall (a conservative assumption). Then he is standing approximately six meters from a radiation source of at least 10 Sieverts per hour. (According to TEPCO, the monitor cannot register levels above 10 Sieverts per hour and was maxed out.) Radiation like this goes in all directions, and decreases in intensity inversely proportional to the distance. 10 Sv/ hour divided by 36 yields an approximate dose of 280 mSv / hour. The man is not walking away. Let’s say he stood there for 1 minute or less; now the dose he received would be something like 4-5 mSv total. TEPCO reports that the workers who found the new hot spot received only 4 mSv. That is not a dangerous dose, but I have to say that this appears to be either extremely lucky or a lie. The photographer took this picture, why? Because they photograph everything they do? No, more likely because this was an extraordinary finding that was being documented. It takes time to recognize and document an extraordinary moment. As I have posted before, most of the thousands of workers TEPCO has cycled through are not particularly well-trained (some working at the site were homeless before the earthquake/tsunami, trying to make ends meet by taking short-term, dangerous contract work at the nuclear power station). I would be really surprised if the man in the photo stood there for only 1 minute. Assume it was 20 minutes. Also, I doubt that he is six meters away from the source. More likely, he was something like 3 meters away. Finally, the monitor maxed out at 10 Sv / hour. We have no idea how much stronger the actual source is. What if it were 4 times stronger? If those assumptions were correct, then the exposure would have been 4 x 4 x 20 times greater, or 1.5 Sv. At this level of gamma exposure, recovery would be expected (with treatment). If he stood there for an hour, death would be expected (even with treatment). So, probably he will live but I have a very hard time accepting the TEPCO estimate which implies he hustled away from the scene in the photo after about a minute. It could be true! However, TEPCO also acknowledges that this finding of the highest levels of radiation onsite since the earthquake are at “a level that could lead to incapacitation or death after just several seconds of exposure.”
(b) Immediately after this announcement, a second announcement of a stupendously high radiation reading where it shouldn’t be was made: 5 Sv/hour inside reactor building one, just adjacent to the area in the photograph linked above. It seems likely that upon finding the first stupendously high reading, they are tracking down just where the pipes that contain whatever is bad lead to. Is it likely that there are new containment failures? Radiation is really easy to measure. To think that thousands of workers over nearly five months have failed to notice these stupendous levels beggars belief. However, it is also really very difficult to come up with any scenario that is moving the radioactive stuff that is in the pipes around those same five months later. Most likely: the company knew these were problem areas and is just getting around to measuring them. They are probably really shocked at just how high the levels are…
(c) Which is why I’m betting that we’ll be hearing about a lot more very bad radiation leaks in the coming weeks. There were three meltdowns on site, after all. There are still known to be daily, uncontrolled releases of radiation into the environment. The site is large and was seriously damaged by the tsunami and earthquake and explosions. If there is some kind of radioactive inventory in one section of piping, I’m willing to bet good money that we’ll be hearing about more rather than less. The only “good” part of this news is that this is all on-site trouble. These shockingly high levels of radiation mainly mean trouble for the people cleaning up rather than new trouble for the general population of Japan.
(d) Returning to the strengths of these radiation sources for a moment…I just cannot understand how these problems eluded detection for five months. The proposition is simply hard to comprehend. These are levels that one expects to find inside the containment, where humans are not expected to go for 5-10 years. These are levels that would trip any reasonably sensitive monitor on site, of which there are undoubtedly many. The only explanation I can come up with is based on really severe triage. I.e., the continuing dangers of hydrogen explosions from radiolysis-induced H sources inside the containment, further core melting, management of more than 100,000 tonnes of water highly contaminated with radioactive elements, etc, etc, etc, have meant that there has not been time before now to survey the site at a very basic level. If you haven’t realized how bad the situation at Fukushima is before now, these announcements should make it pretty clear. Discovering a 10 Sv/hour source of radiation outside all the reactor buildings nearly five months after the earthquake is truly astounding. Looking ahead to the looming 10th anniversary for an analogy, it would be something like finding out that there was a fifth plane years later.
(e) It is clear from the foregoing that there has been a systematic underreporting of the radiation dangers faced by the workers at Fukushima One. As the gravity of today’s announcements sinks in, the associated further loss of confidence in TEPCO and in the Japanese government will be tangible. People will legitimately ask what else is not being reported. That is a big part of what makes a nuclear accident different. Even if the health risks have been managed well, events like this severely and appropriately erode citizens’ trust in government and big business. Questions about the food supply are already taking their toll in Japan. Something like this makes the possibility of further catastrophe seem less unlikely. Further catastrophe is less likely every day, but perception trumps reality when reality is abstract.