Local peasants get in, take some pretty glowing things back home, apply the stuff as makeup, and die horrible deaths. When the family tries to bury their daughter in the town cemetery, the rest of the town marches in protest.
Clearly, the lesson is that we should stop building... hospitals.
Like just go through this list and count the number of times water was a good chunk of the problem.
https://en.wikipedia.org/wiki/Nuclear_and_radiation_accident...
There are multiple options that don't have this issue. For instance, if you use liquid lead the thing can sit around indefinitely with no active cooling. In fact you have the opposite problem, you need to keep heating the lead to prevent the whole reactor pool from freezing.
This isn't true with all liquid metal reactors though. Liquid sodium reactors have flammable radioactive coolant, and a coolant breach could be environmentally disastrous.
The current gigawatt-scale plants (AP1000, Hualong One, etc.) can cool without external water for 72 hours, after which a meltdown occurs. NuScale plans to run their reactors at the bottom of a pool, with enough water to passively transition to air cooling over the course of a month. (There are a bunch of proposed reactor designs with similar safety characteristics, but I know more about NuScale because they've been in the news lately.)
I'm not against building plants with a 72-hour buffer for now, due to the pressing need for low-carbon energy, but we should really focus our future resources on passive self-cooling designs that we can safely copy-paste across the planet on a massive scale.