So the vast tract of East Japan has been contaminated with radioactive materials that came out of nuclear fuel rods that were melted down (and through and possibly out), and many areas are more contaminated than the radiation control area of a nuclear power plant which requires strict control and decontamination by nuclear professionals in case of an accident.
So what have the affected municipalities done? Fukushima Prefecture already has a handbook for citizens on how to decontaminate. The national government has promised it will come up with a plan. (It reminds me of "Blackadder" - where Baldrick always say to Blackadder at the very last moment, "I have a cunning plan ..." which is not cunning and usually very bad or useless or both to say the least.)
That national plan may be something like the one that has been apparently released by the Japanese Society of Radiation Safety Management, and it relies on the citizens' effort to locate the high radiation "hot spots" and decontaminate using the household cleaning tools and materials, as if radioactive cesium and strontium and plutonium and cobalt should be no different from dirt and rust.
One great thing about this citizen decon idea is that it won't cost much at all to the national government, other than some support money given to neighborhood associations.
Asahi Shinbun (8/31/2011) reports:
The Japanese Society of Radiation Safety Management has created a manual on how to find "hot spots" in and around one's home and how to decontaminate effectively. The manual shows the locations where radioactive materials tend to accumulate, such as under the rain gutters, and explains the methods of decontamination that do not spread radioactive materials.
[According to the manual,] hot spots are often found at rain gutters, side drains, manholes, locations where there were water puddles, rusted metals, tree stumps and lumber, surface of grass, trees and moss, pile of fallen leaves and dirt.
Cesium tends to adhere to the rain gutters, rusted tin roofs, and roofing tiles with uneven surface. If one sweeps dust and fallen leaves and collect them, the radiation level may jump significantly.
If dead leaves were plowed into the home garden after mid March, one should be aware that radioactive materials may have moved to the plants.
According to the manual, one should use a brush to decontaminate the roof and rain gutters. If the dirt doesn't come off easily, one may wet the surface a little with water with baking soda or with vinegar and scrub. Cleanser is effective on rusty parts.