It is conceptually easy to contemplate mass evacuation of 70,000 people but a big decision politically. This problem was sort of in the middle of “have to address now” and “let’s kick the can down the road”. The Japanese were looking for more consensus, as usual.
It’s a big job doing a real radiological survey over such an area. My own point of view is that where you have several million becquerels per square meter of caesium 134 and 137 you should evacuate everyone under 30 or 40 years of age until you can fence off areas contaminated at about 200,000 becquerels per square meter or more. 20 millisieverts per year won’t hurt anyone who knows what they are doing. For instance, don’t eat the dirt. Wear a dust mask. Keep your skin clean. Don’t eat food grown in the area. It is OK to feed animals contaminated food and eat them but don’t eat anything but muscle and maybe fat. This should be fine but should be monitored as needed.
There was an April survey of dust samples at Fukushima province elementary schools.
Results are in Becq/m3.
Most readings are ‘not detected’ or 3000 or so.
There are a 10,000 and 16,000. It seems to me even those could be remedied by, carefully, running a garden tiller over the land.