I've been very grateful for my colleague Greg Laden's regular updates of the raw discussions on the Fukushima situation, but it is nice to have a coherent, visual overview, and Nicole Foss has provided another wonderful analysis at The Automatic Earth. It is very hard to synthesize all the information, because there is so much and so many conflicting reports, so it is helpful to have it all pulled together.
On April 17th the same site had the following radiation levels recorded for units 1-3:
Dry Well: 121.4 Sv/hr
Suppression chamber: 97.5 Sv/hr
Dry Well: N/A
Suppression Chamber: 131 Sv/hr
Dry Well: 253.2 Sv/hr
Suppression Chamber: 103.9 Sv/hr
A single dose of about 5Sv would be fatal in about 50% of cases according to the IAEA.
The allowable emergency dose for nuclear workers has been climbing recently. It was originally 100 mSv/yr, was raised to 250 mSv/yr and is now to be raised again, likely to 500mSv/yr.
As I've said before, besides the human and environmental tragedy, what interests me most is how this is both enacted and perceived, and how that shapes our energy future.