Looking at human history, the assumption that some state power will always be able to manage it seems rather naive. There have been long stretches of feudalism, warfare, and all-out anarchy and indeed the current relatively stable forms of government are not the norm historically. If all it takes to cause a nuclear meltdown is a brief lapse in order or relative peace, then that doesn’t strike me as very anti-fragile.
Furthermore, nuclear power requires and perpetuates government control over things in a way that say, solar energy, doesn’t. Whether that’s a good thing or not depends on your political persuasion, of course.
That said, one could probably also make the opposite argument that nuclear power would lead to more incentives for peace and stability, in the same way that arguments for Mutually-Assured-Destruction argue that nuclear weapons prevent warfare.