Japan sat on U.S. radiation maps showing immediate fallout from nuclear crisis 19 Jun 2012 The government failed to make use of detailed U.S. maps showing how radiation spread shortly after the Fukushima nuclear crisis began [March 2011], sources familiar with the matter revealed Monday. The sources said the maps were neither publicized nor used to evacuate residents living near the poorly protected Fukushima No. 1 nuclear plant. From March 17 to 19, U.S. military aircraft collected radiation data in an area with a 45-km radius from the plant for the U.S. Department of Energy. The data showed that more than 125 microsieverts of radiation per hour was leaking as far as about 25 km northwest of the plant, meaning residents in the area were being exposed to their annual permissible dose within just eight hours.