If you just dither long enough, someone else in the blogosphere will do it for you!
XKCD, originator of the talismanic internet joke, has developed a chart illustrating radiation levels that seems both accurate and capable of giving some sense of the relative exposures that are relevant to understanding the issues at Fukushima. They’re still hard to grasp, what with the blocks of various colors being such a small part of the next color up.
Also, Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT) is making their radiation readings available online. The graphic on the last page of the readings is a nice complement to XKCD’s boxes. Here's a NYT graphic that seems to get the MEXT data right.
I’ll come back to exposures in another post, but today’s news is that things are stabilizing at the plant. Reactor units 5 and 6 are in cold shutdown. They have external power to provide cooling water from the sea. That’s what the operators are aiming for with all the reactors. The temperatures of their spent fuel pools are going down. The pressure was increasing in reactor 3, which is mostly good news: if the pressure increases, there is probably not a breach in the primary containment. And it looks now like venting will not be necessary. Units 1, 2, and 4 seem to be reasonably stable but still need external power, which is expected to be connected to units 1 and 2 today. (Updates from Tepco and World Nuclear News)
There’s also a new blog - Where are the clouds? - that is tracking the radiation plumes from Fukushima. Check it out. This is much more knowledgeable information than that awful NYT map.