I don't understand who's bright idea it was to use water as the primary coolant for a nuclear reactor. IIRC almost every single major nuclear incident has been

I don't understand who's bright idea it was to use water as the primary coolant for a nuclear reactor. IIRC almost every single major nuclear incident has been caused or dramatically exacerbated by having it boil away or cause a steam explosion or mix with the ground water or chemically react with the fuel rods to produce additional heat and hydrogen gas which also explodes. 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_accidents_and_incidents 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. https://en.wikipedia.org/wiki/Lead-cooled_fast_reactor https://en.wikipedia.org/wiki/Lead-cooled_fast_reactor