To be fair Chernobyl was designed what, 15 years after the invention of nuclear technology? Even discounting all the politicial and management control problems, the engineering and scientific knowledge of nuclear reactor design was still in its infancy. Imagine if we judged the safety of automobiles on pre-Model-T cars. Or steam boilers and engines on the first 20 yearrs of their invention.

What's the worst accident involving a Model T, maybe a dozen dead? Early steam boilers aren't going to be much worse either. Nuclear accidents are essentially unlimited in size. Nothing else can do that kind of country-sized - let alone it being permanent.

Chernobyl showed the potential impact. Fukushima showed that even several decades down the line things can still rapidly run out of control. All the knowledge and experience in the world isn't going to save you when something unexpected happens and things are just waiting to spiral out of control.