 |
| credit: naturenews.com |
The radioactivity released by the melted Fukushima reactors is almost double the amount reported by the Japanese government according to a
new report by the Norwegian Institute of Air Research. The report used data from radiation monitoring stations in Japan and around the world as well as global meteorological data. It focused on two isotopes, ¹³³Xe and ¹³⁷Cs that have different release characteristics and behavior in the atmosphere. Although the radioactive cesium release was only 42% of the Chernobyl disaster (35.8PBq), the radioactive xenon gas release was the largest in history not associated with bomb testing. Nobel xenon gas poses a much less serious health risk to humans or the environment since it is not absorbed. Cesium, with a half-life of thirty years, is absorbed. About 19% of the estimated total fallout was deposited on Japanese soil with most of the rest falling on the North Pacific Ocean. Radioactive cesium releases peaked three to four days after the earthquake and tsunami as shown in the the chart. Contrary to Japanese claims, the spent fuel pool of #4 reactor contributed significantly to the cesium release as did the melting cores of the other damaged reactors. The Norwegian scientists say the latest estimates of radioactive fallout are attributable to the larger data set used in their study. Japanese estimates did not consider the quantities of radioactivity that drifted out over the Pacific Ocean and eventually reached North American and Europe.
