An earthquake isn't a black swan event, correct.
An earthquake of that magnitude, creating a Tsunami of that strength, striking in just the wrong place .. is very much a black swan event.
https://www.youtube.com/watch?v=ilFEKSZQv5o
By your 'logic' no dam can be built as they all stand a chance of a direct hit from a meteorite.
Risk-wise the Fukushima nuclear disaster cause less direct and indirect death than many accidents and natural disasers .. including deaths from, say, fertilizer depot explosions, oil rig accidents, etc.
If you can't build a nuclear plant, or a dam, while accounting for expected events, then maybe don't.