system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is nuclear energy so safe? How would someone avoid a nuclear disaster in case of an earthquake?
gpt
Modern reactors are very safe, because the physics that's going on inside them is pretty well understood.  Sure, things can go wrong, but things can go wrong with other sorts of power plants.  When something goes wrong, you shut the reactor off and wait.

The TEPCO plant at Fukushima was quite old, and all the cooling and backup power generation was underground, precisely to protect it from earthquakes.  Alas, it turned out bad when there was a tsunami.

Should the tsunami risk have been considered? Of course.  This plant was not safely designed, and it wouldn't be approved today.  Modern GenIV nuclear plants have to be passively safe, even with no power input, they don't malfunction.  Alas, anti-nuclear activists are greatly slowing deployment of nuclear plants in hopes that hydrogen fusion will be the power source of the future.  There isn't ever going to be enough "green energy" to run the entire Earth at a desirable standard of living.  Nuclear is a key component in addressing climate change.