For those who care: Current Fukishima headlines....

[kristopher]

16. Here is another - this study explains why we need to be concerned

Last edited Sat May 26, 2012, 12:07 AM - Edit history (1)

Tomography of the 2011 Iwaki earthquake (M 7.0) and Fukushima nuclear power plant area
[font size="1.5"]P. Tong1,2, D. Zhao1, and D. Yang2 1Department of Geophysics, Tohoku University, Sendai 980-8578, Japan
2Department of Mathematical Sciences, Tsinghua University, Beijing, China
Correspondence to: P. Tong, D. Zhao Published: 14 February 2012
Solid Earth, 3, 43–51, 2012 [/font]

Abstract.
High-resolution tomographic images of the crust and upper mantle in and around the area of the 2011 Iwaki earthquake (M 7.0) and the Fukushima nuclear power plant are determined by inverting a large number of high-quality arrival times with both the finite-frequency and ray tomography methods. The Iwaki earthquake and its aftershocks mainly occurred in a boundary zone with strong variations in seismic velocity and Poisson’s ratio. Prominent low-velocity and high Poisson’s ratio zones are revealed under the Iwaki source area and the Fukushima nuclear power plant, which may reflect fluids released from the dehydration of the subducting Pacific slab under Northeast Japan. The 2011 Tohoku-oki earthquake (Mw 9.0) caused static stress transfer in the overriding Okhotsk plate, resulting in the seismicity in the Iwaki source area that significantly increased immediately following the Tohoku-oki mainshock. Our results suggest that the Iwaki earthquake was triggered by the ascending fluids from the Pacific slab dehydration and the stress variation induced by the Tohoku-oki mainshock. The similar structures under the Iwaki source area and the Fukushima nuclear power plant suggest that the security of the nuclear power plant site should be strengthened to withstand potential large earthquakes in the future.

Download study here: http://www.solid-earth.net/3/43/2012/se-3-43-2012.pdf

Also, some claim that aftershocks of 3-11-11 in "nearby" Hamadori demonstrate that the structure of Building 4, housing fresh fuel containing plutonium, is proof that there is no need to worry. This is the Iwaki earth event referred to in the paper above. Clearly the authors of this paper disagree with the assessment of "some".
It is worth downloading the paper for the graphics if nothing else.

At the link below is another interesting map (topographic) showing the stresses from the quake.