A significant amount of radiation has been released to the atmosphere from this site since the beginning of the crisis. Two of the main health hazards from the radioactive gases that have been released are from iodine-131 (I-131) and cesium-137 (Cs-137). One analysis estimated that roughly 20% of the I-131 and up to 50% of the Cs-137 released in the Chernobyl accident was released from Fukushima to the atmosphere within the first few days of the accident.
Very high radiation levels are being detected at some points many kilometers away from Fukushima, outside of the evacuation zone, although there is no clear picture at this point because the locations of the readings are not publicly available and there has not been a systematic survey.
As the radiation is carried by winds across the ocean, it spreads out and becomes diluted. While trace amounts have been detected in the US, these amounts have been much lower than the natural background levels of radiation that people are constantly exposed to, and are not a serious health hazard.
A partial meltdown of fuel rods in the No. 2 reactor probably caused a jump in the readings, Japan Chief Cabinet Secretary Yukio Edano said.
Plutonium-239, a byproduct of fission used in nuclear weapons, was found in soil samples taken on the plant site March 21 and March 22, Tokyo Electric said in a statement today.
| Press Release (Mar 28,2011) Detection of radioactive material in the soil in Fukushima Daiichi Nuclear Power Station |
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On March 28th 2011, as part of monitoring activity of the surrounding environment, we conducted analysis of plutonium contained in the soil collected on March 21st and 22nd at the 5 spots in Fukushima Daiichi Nuclear Power Station. As a result, plutonium 238, 239 and 240 were detected as shown in the attachment. We will continue the radionuclide analysis contained in the soil. ‹Results of the analysis› -Plutonium was detected in the soil of Fukushima Daiichi Nuclear Power Station. -The density of detected plutonium is equivalent to the fallout observed in Japan when the atmospheric nuclear test was conducted in the past. -The detected plutonium from two samples out of five may be the direct result of the recent incident, considering their activity ratio of the plutonium isotopes. -The density of detected plutonium is equivalent to the density in the soil under normal environmental conditions and therefore poses no major impact on human health. TEPCO strengthens environment monitoring inside the station and surrounding areas. -We will conduct analysis of the three additional soil samples. |
| Wind direction JAPAN http://www.weather-report.jp/com/home/kishomap/fusoku/japan.html | ||
