Actually, no they didn't.

http://en.wikipedia.org/wiki/Fukushima_Daiichi_Nuclear_Power...

Yes, all systems fail. Fukushima was hit by a magnitude 9.0 earthquake and a 10m tsunami, which is about the worst environment imaginable and it almost survived intact. Most newer technologies would have been unaffected, or at least shut down into a safe state.

And yes, you can come up with nightmare scenarios for every technology. Fukushima experienced one in a dilapidated state and just about came through unscathed. Add in another 30 or 40 years of science and engineering and the chances of a nuclear disaster effectively become zero.

Compared with the pollution and deaths associated with coal, I know which side I'd rather be on.