This post is more an appeal for info than anything useful in itself. But I’ll probably update it if I get anything. Fukushima refers. My question, in the context of the area around Fukushima that is contaminated by radioactivity, is
In response, M points me to radioactivity.mext.go.jp/en/distribution map around FukushimaNPP/; here for example is July 2011 (take care to do what I didn’t, and scroll down to the integrated dose map. But unfortunately I don’t know how that compares to radiation levels in Cornwall. I made brief pathetic efforts on google to find out, but then gave up and wrote this. Over to you.
[Ah, hold on, I've just realised something. Thinking forwards, we don't care about the integrated dose from the start, if we're worrying about what will be uninhabitable in the future. What we care about is the area that will settle, in say 6 months time, to a value that will be bad, then -W]