Nuclear update 2011-03-18

By | March 17, 2011
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Despite the crazy, panicked reporting about people fleeing Tokyo, the latest information I can find (from the Wall Street Journal, citing the Tokyo Metropolitan Government) states that radiation there has been steadily dropping; now down to 0.05 microsieverts/hr, one 16th of the level reported on Tuesday. Apparently this is within the normal range of radiation received in the city (from 0.028 to 0.079 μSv/hr), demonstrating as disingenuous claims that Tuesday’s level of 0.809 μSv/hr was ’24 times above normal’.

This fits in with the plume model I previously linked to, where the plume briefly passed over Tokyo in response to short term winds from the NE.

It’s hard to say what will happen if they are unable to put in place adequate cooling for the fuel at the plant – certainly, there’d be the leakage of radioactive material and though most of it would be carried out to sea, there to cause us angst about seafood for years to come, there would always be the chance that some of it would be brought back to land by variations in the prevailing wind. The question, of course, is what magnitude this would be. I’ve got opinions on what’s likely to happen and what the risks are*, but I’m going to keep them to myself and stick to reporting facts so people can decide for themselves.

There’s plenty of good reading out there, if you want to skip the hype:

  • MIT’s Nuclear Science & Engineering blog gets into the science & engineering of what’s going on.
  • The International Atomic Energy Agency (a branch of the UN, not an industry body) issues periodic releases summarizing efforts and the current status of the plant.
  • Japan’s nuclear regulatory agency, NISA issues more detailed releases, focused on specific actions and technical details. These are potentially the best information I can find, but they require a lot more technical knowledge to interpret.
  • Various reputable news sources have good independent reporting as well as interviews with scientists answering common questions. I’d suggest checking out the New York Times, the BBC, and the Asahi Shimbun. The Asahi is particularly interesting, because it’s a Japanese language paper translated into English, and is thus insulated from the massive cross-pollination of news from western sources.

Bottom line: This is a highly complex and confusing situation, with a lot of false information. Don’t just trust your local paper, as they’re probably re-printing something of dubious quality from the AP or Reuters.

Update:
I’ve found another source worth mentioning – Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT), who are putting out a list of radiation readings across all of Japan about twice daily. The list is in Japanese, but the numbers are readable and there’s a handy table allowing you to translate place names to English. Visit

Readings are presented in microsieverts / hr, with dates presented in Japanese format – 3月16日 means 16 March.