A Japanese blogger obtained an inside information of actual dose from 3/15/2012~5/10/2012 in Fukushima.
This is monitored from this place.
From this data:
1) At the moment of 3/18/2011, the accumulation dose is already over 1 mSv.
2) The peak is 3/16/2011, when reactor 4 exploded.
This information was given out of the crisis management office of Fukushima, but there is no data is uploaded on their webpage.
Iori Mochizuki