25 Février 2012
February 26, 2012
The government has announced the latest radiation readings from areas in the no-entry zone and the expanded evacuation zone around the crippled Fukushima No. 1 nuclear power plant.
Based on this rough data, the government is scheduled to reorganize the 20-kilometer no-entry zone around the nuclear plant and the expanded evacuation zone into three zones.
One of the three zones to be set up is a zone where residency is prohibited for an extended period. This zone has estimated annual radiation exposure levels of more than 50 millisieverts--or more than 9.5 microsieverts per hour--and stretches mainly northwest from the plant in Fukushima Prefecture, according to the latest data.
The information was released Friday by the Education, Culture, Sports, Science and Technology Ministry, the Cabinet Office's nuclear accident evacuees life support team and the Land, Infrastructure, Transport and Tourism Ministry. The readings were measured during flights over the area.
February 25, 2012
TOKYO (Kyodo) -- High levels of radiation have been detected in municipalities in evacuation zones around the crippled Fukushima Daiichi nuclear power plant, with the highest reading of 470 millisieverts per year recorded in one town, a midterm report on an Environment Ministry survey showed Friday.
A survey conducted between Nov. 7 and Jan. 16 showed that the annual readings topped 50 millisieverts -- a level deemed uninhabitable under a proposed new classification -- in many spots north-northwest of the plant that was crippled by the March 2011 earthquake and tsunami.
The highest level of 470 millisieverts was logged at a spot in Futaba, northwest of the plant, while the lowest level of 5.8 millisieverts was detected in another part of the same town, the survey said.
The results were similar to those in an earlier survey by the ministry of science using airplanes.
The Environment Ministry plans to compile a final report on the survey by the end of March so the government can use the data to reclassify a no-go zone and evacuation zone near the plant into three categories in April.
The three categories are an uninhabitable area with annual radiation levels of 50 millisieverts or more, an area with levels between 20 and 50 millisieverts where residents would be restricted, and another area with levels below 20 millisieverts where residents would be allowed to return in stages.
The transport ministry has decided to reduce the no-fly zone over Fukushima Prefecture from a 20-kilometer radius of the Fukushima plant to 3-km radius based on the survey conducted by the science ministry earlier in February, effective from midnight Friday.
The highest radiation level was 12 microsieverts per hour at an altitude of 150 meters. The transport ministry determined that the smaller no-fly zone will not undermine safety as estimated radiation exposure at that altitude during 1,000 hours of flying per year would be less than 20 millisieverts, the level set by the government for designating an evacuation zone, it said.
Meanwhile, the Environment Ministry also said that high levels of radioactive cesium have been detected in ash and firewood in eight prefectures in the Tohoku and Kanto regions, with the highest reading of 240,000 becquerels per kilogram measured in ash from a household in Minamisoma, Fukushima Prefecture.
In a survey conducted on ash and firewood from 65 households, 163,000 becquerels of cesium was also detected in ash from a household in Kawamata in Fukushima. At two households in the prefecture, firewood from around the houses had been collected and used for boiling bathwater.
Waste with radiation levels exceeding 100,000 becquerels needs to be kept in a disposal site with its walls and base sealed with reinforced concrete to keep out rainwater, and only waste with radiation levels of 8,000 becquerels or below can be disposed of like normal waste.
More than 8,000 becquerels of cesium was detected in ash from 13 households -- three in Iwate, one in Miyagi, eight in Fukushima and one in Ibaraki prefectures -- while up to 1,460 becquerels was detected in firewood, the ministry said.