Lucid, clear explanation of the Fukushima partial meltdown. Long story short, it was ugly, but a forty-year old reactor at a troubled plant with a spotty maintenance history took two beyond-design-specification disasters in close succession & didn't kill anybody or poison its environs. It sounds like all the radiation casualties will be plant employees.
Frankly, the horrible damage done by the tsunami tearing through the grease, oil, and lubricant-contaminated environs of every port on the Tohoku coast & depositing all of those industrial poisons and toxic wreckage over the once-fruitful coastal plains is the actual environmental disaster to consider in this catastrophe. Those were beautiful fields being submerged under that black, foul hell-tide. They aren't beautiful anymore, and I'm not sure anybody should be eating food grown off of them for the next couple seasons at least.
We need nukes, damnit. The more of them we can build in safe locales (and yes, if nothing else, putting our nuclear power plants in places where we don't have to use design tolerances keyed to survival from a 9.0 earthquake and inundation by a 30-foot tsunami strikes me as *cheaper*, cheaper to build and cheaper to maintain), the better. A modern economy won't be run from power-plants burning unicorn farts and pixy dust, it's either nukes, coal, or gas - and the more of each, the fewer little old ladies get to freeze to death in the depths of winter when it comes down to the limitations. There are bureaucrats in Japan right now, cold-bloodedly plotting rolling blackouts in order to stretch the torn ends of their shredded power infrastructure around the Fukushima-shaped-hole torn in their power net. Redundancy is life.
Explanation link from Rand Simberg; youtube link from the Brickmuppet.