Anarchism

All reactors are subject to overheat leading to meltdown when suddenly shutdown. They become massive energy vampires, requiring huge cooling power (and manpower) for up to 2 years after to avoid that.

What are the odds that a "social collapse" (war, plague, disaster, etc) leaves some with no workers and no external juice? Not if, when! Meltdowns will occur, some will breach containment. Only fools light an unextinguishable fire that kills them if they ever stop feeding it.

While reactor designs are "safe": this requires that they follow protocols, which often means unplanned downtime. Given the social pressures for energy, it seems that reactor operators will sometimes disobey shutdown requirements. Corruption is real in all societies. With reactors it absolutely includes a non-zero catastrophe chance. Again not if, when!

Reactors are safe, for a pre-designed lifespan. Often 50 years. To decommission properly is massively expensive and takes years of labour, and requires a replacement plant. Are operators actually squirreling away the funds to have this all saved up 50 years later (by "overcharging" now)? Or are the future governments just gonna keep patching a pig... not if, when!

What kind of containment system will work for 10s of thousands of years? What does that cost, or even look like?

https://www.damninteresting.com/this-place-is-not-a-place-of-honor/