The sunflowers that the ministry had planted in Iitate in May had absorbed around 52 becquerels of cesium per kilogram, according to the ministry. Even if sunflowers worth 10 kilograms were grown per square meter of farmland, only about 1/2000th of cesium in the soil could be absorbed, the ministry said. The topsoil removal method, on the other hand, proved to be highly effective, with radioactive cesium in the soil plunging from 10,370 becquerels to 2,599 becquerels per kilogram after three to four centimeters of the topsoil was scraped off. The method becomes even more effective when the topsoil is hardened by pharmacological agents before being removed, or when the topsoil was taken away all together with grass roots. Both methods could reduce levels of cesium by 82 to 97 percent.
Sending all of my love to Boston after a day of sadness and confusion and not knowing what to say. I just don't understand. http://www.politicalforum.com/groups/taylor-swift-13/
At some point, "do nothing" becomes the preferred way of handling the radioactivity. There aren't any areas there, outside the immediate plant, that are unsafe for humans to live in. It's not safe to eat crops and livestock from the contiminated zones, due to bioaccumulation of radionucleides, but simply living there is no problem. There are other places on the planet with higher natural levels of radiation, where people live without any adverse health effects.
So, you do nothing, other than ban agriculture there. With a 30 year half-life for the caesium-137 and strontium-90, doing nothing for 60 years has the same effect (75% reduction) as scraping the topsoil from hundreds of square miles and finding a disposal site for it. (That is, spreading it around and raising radioactive dust clouds). The sunflowers pull radiation out so slowly that natural radioactive decay would be removing radioactivity much faster than the sunflowers.