It was not, repeat not, 9 at Fukushima. I can't find the power dissipation map anywhere, but with (bad) luck it was somewhere sixish (?).
Nowdays TEPCO is probably saying that the tsunami was ove 30 meters high when it hit the pwoer plant, with way it has been raising since the catastrophe...
But the main point is, that after the earthquake and tsunami, the damn energy generators were running for over an hour. So they were not damaged by the events. They failed on their own! Like huge diesel engines that have been neglected for a long time -- they start, in short order burn trough their piston rings and die.
Everything happened because a power plant was left without power! That's what nuclear engineers call safe nowadays?
Come on, guys, fezz up: if a reactor is left without cooling for any* reason for a relatively short time (years, if we look at the spent fuel rods), it will be a bad thing. Any kind of reactor. They are not 'safe', and never will be. Admit that, and we can start discussing the future of nuclear power.
Like the pebble bed fiasco, or the travelling wave wet dream.
Btw, did you know what the quake-tsunami double blow did to Japan's wind power farms? Nothing. They're now madly milling electricity out of the thin air to cover all the nuclear that disappeared from the grid...