Some are saying that a couple of these Tornadoes may have been the strongest we have ever seen here in modern times. If so, then our nuclear plants were not built to withstand them.
OK, you could have a point there. We have, in recent times, been able to generate a lot more data on twisters than we’ve had to make designs from in the past.
Again, there’s a bias for data that we have recently. We’ve certainly had some ferocious twisters in the past, but we didn’t have the level of analysis on the results of those storms we have today.
I would add, however, of all the threats a plant operator has to design for, flooding is the worst. You could have a twister make a mess of the switchyard and infrastructure at a plant and be able to get back to some semblance of normal operation much faster than with flooding.
With a tsunami, you not only have flooding, you have vast, vast quantities of wreckage pushed inland into areas people never thought to protect. Just getting new equipment into Fukushima was no doubt a week-long process. Take a look at more of the pictures of the mountains of stuff piled up along the roadways there. All that had to be moved out of the way before you could get heavy equipment into the coast.
With a twister, that level of damage is fairly localized, and there’s not a huge amount of water left laying around to complicate things.