[ RadSafe ] Ambient Dose Rates in Fukushima Prefecture

[Joel C.]

It was pointed out to me that ambient levels in the Fukushima Prefecture have been steady at about 0.75 uSv/h @ 1 meter for many months, but recently fell to 0.28 uSv/h.  With patience, you can see the change at:


http://radioactivity.nsr.go.jp/en/list/192/list-1.html

Anyone want to try to explain the decrease?  I guessed snow cover; but the data from 2012 winter are 0.6-0.7 uSv/h.
 

Joel I. Cehn, CHP
Radiation Info
joelc at alum.wpi.edu