The problem is we don't know if it's a real floating box design. I have tried to find out information about Fukushima I foundation type but hasn't been able to find it. Anybody else luckier? Just because there is a thick bottom concrete doesn't make it a floating box. If it's a floating box design then all of the bottom concrete is a supporting structure. To build it like this is expensive. If it's not a floating box then there are weaker parts and stronger parts in the bottom concrete. Another interesting thing is do they have http://en.wikipedia.org/wiki/Base_isolation" [Broken]. I guess the simplest/cheapest design would be this: there are footings that support the weight of the building and then there are beams to transfer weight from one footing to another if there happened to be a landslide underneath one footing. These are interesting things to study on their own. I think we have to separate two things here. The first thing is a crack which is directly created by a fault line. I have an impression that these cracks rarely cut through hard rocks in Fukushima area although now this has happened: The second thing is the shaking of the ground itself. When the ground is shaking the weaker soil on top of the hard rock could (or could not) amplify the shaking. How much this has happened in the Fukushima area is again an interesting thing itself. I agree. And the radioactive levels of seawater have been decreasing so we know there should be no big leaks from polluted groundwater into the sea. This would suggest that deeper groundwater is perhaps not that polluted at all. As far as I see it, there are larger issues concerned. At one point there was a news report where TEPCO said it cannot deny the possibility that in the number #3 reactor some major damage could have been done by the earthquake itself (I think it was a piping system). It will take many years until they will finally conclude did the earthquake itself cause any major problem. And who is going to study it? TEPCO itself or some independent research team? (I hope the latter and I hope also not just an IAEA team.) If at the end they would conclude that the earthquake itself actually did cause some major damage they would also start to find reasons behind it. One thing is of course that ground acceleration numbers were above design parameters. But at this point they could also question if the whole plant has been built in a proper place / in a proper manner (soil amplification & foundation type etc). The soil amplification studying as a branch of science is quite young, AFAIK, at least when it concerns the actual maps over different areas. Perhaps the theories are older. For instance: do they have soil amplification maps all over Japan? When I studied a little bit soil amplification maps from the U.S. I noticed some of them were made only quite recently. Like this one was presented in 2002, perhaps made a couple of years earlier: http://gsa.confex.com/gsa/2002NC/finalprogram/abstract_31500.htm So even if we don't know how is it going to proceed it is still an interesting thing to study. How well are the soil amplification aspects understood all over the world? What kind of foundation types are they using when they are not building on a top of granite/other hard rock? Should a proper soil amplification study be required in the future when building in seismic areas? How about existing NPP:s, should we force them to make soil amplification studies if none exists for that area? These are interesting questions and I think one can study it a little further without speculating. Like: What kind of foundation type do they really have in Fukushima? Do they have soil amplification maps all over Japan?