Environment & Energy
In reply to the discussion: Snowstorm shuts down expensive nearly useless solar plant in Massachusetts. [View all]Art_from_Ark
(27,247 posts)than anyone else in this forum--
If the levels within the 20km/12-mile zone were so benign, the Japanese government would not hesitate to let people back in. Really. Residents have been clamoring to get back to their homes, but most places within that zone are still multiples of what the natural radiation levels used to be.
For example, here, about 500 feet above sea level 100 miles south of the Dai-ichi complex, the natural radiation level is about 0.09 to 0.1 microsievert per hour. Converted into millisieverts per year (the usual unit used for Denver), that would be approximately 0.7-0.8 millisievert, compared to 10 millisieverts of radon as an annual dose in Denver. However, this map and accompanying graph, which were compiled from February 2013 data, show that there are many hotspots in Fukushima that have much higher radiation levels than Denver (shown with red or darker squares in the map). The hottest spot is the Ottozawa district of Okuma Town, which is still registering more than 30 microsieverts per hour-- which is more than 300 times higher than the ambient radiation level in my city, and more than 26 times higher than the annual dose in Denver.
http://new.atmc.jp/pref.cgi?p=07