Just an update.

It looks like radiation levels are dropping again. They peaked at around 12,000 mSv yesterday and have dropped back to around 600 mSv and falling as of about 6:10 ET. One article this morning, suggests the increase in radiation was due to a fire in the spent fuel pond for reactor #4, which makes sense.

Rapid drop in levels is a (relatively) good sign that most of the escaping radiation is due to shorter lived isotopes.

-Eric