Radioactivity level spikes 6,500 times at Fukushima well

If definitely already does, and I think there is a systematic under-appreciation of just how catastrophic Fukushima could become if there is an additional criticality if not a series of them, it is truely an order of magnitude bigger of a concern than Chernobly ever was. The upper band for relocation might be in the tens of millions instead of hundreds of thousands:

"a newly stated concern is the proximity of melted fuel in relation to the Tokyo aquifer that extends under the plant. If and when the corium reaches the Tokyo aquifer, serious and expedient discussions will have to take place about evacuating 40 million people from the greater metropolitan area"

Of course this is a 'worst case' but given that the likelihood of a perfect mitigation is so extremely rare planners need to be at least considering this at a non-zero probability, which is more than a bit frightening.

More here:

http://rt.com/news/fukushima-apocalypse-fuel-removal-598/