The accident at Chernobyl was predicted at the Atomic Energy conference
in Vienna in 1956, but the Russians elected to ignore the warning.

The accident at Fukashima should have been anticipated and could have
been avoided by building the plants on the West Japan coast.
The plants did not fail but were flooded.
The plate divide is not far east of Japan.

The third accident in the US was just a straight out failure of the
plant and is the only true accident, or rather design failure.

So two failures should not have happened if humans took into account
geography in one case and human pride in the other.
Those two failure scenarios could have been prevented by review
at the planning stage.