I understand the idea of wanting to make something as strong as possible, but I don't understand the idea that we can just make something stand up to a particular strength of earthquake/hurricane/disaster. Maybe that 7.5 was the best they could do. Maybe the idea should be phrased, "it can withstand X disaster" rather than "was designed to withstand X" because the later implies we could take the design further. There's about 175 times more energy released in a 9.0 earthquake compared to the 7.5 these were rated for. While I imagine it's not a one to one scale, making something 175 times tougher isn't just something we can will into existence.
I guess it just goes back to Cobra's point because we might not actually be able to build a nuclear plant that can survive such a disaster. If the plant is designed to contain the radiation should it fail to sruvive, I sort of think that nuclear power could still be worth it. Then the trick is to see if things are actually being contained at a reasonable level which is pretty hard to do right now for all of us just able to read news stories.
One thing I've had hammered into my head over the past couple of weeks is that radiation is a term that tends to be scarier than the results. I visited a neutron source to do an experiment last week and to use the facility I had to receive a quick training on radiation. Apparently, the "legal" limit at a lot of places is just barely above the an amount that is measurable beyond the normal background radiation that is coming from everything else around you, meaning not very much. I was told that generally working at the facility, even for periods of a weeks and moving through areas marked as high radiation, will expose me to less radiation than I would receive had I flown across the country. The limits are designed not with the idea of not exposing people to tolerable limits, but the idea that people are batshit crazy about radiation and any is considered bad. If you can design a facility that creates a beam of neutrons to expose people to almost no radiation, that's a good thing. The point is, there's a lot of wiggleroom between experiencing elevated levels of ration and experiencing toxic levels and when radiation is simply detected it doesn't automatically mean things have gone to hell. I don't have a good sense of just how elevated the radiation is in areas around the plants, but part of me tends to think that heavy precautions are being taken over what may still be relatively acceptable levels. That's not a bad thing either while things are still hairy over there. But some radiation doesn't mean the land is no longer usable.
Of course, I have really meager knowledge on the subject and am talking more with the hope that terrible things won't happen. I just know that everything gets really dramatic when nuclear power is involved, to the point of exaggeration on both sides. It's hard for me to accept that it's either as bad as many places are saying or even as good as others are.