[Porsche-O-Phile]

Reading a summary of the TMI situation from 1979 - apparently the standard heat output in the core right after the scram (emergency shutdown) was 160 megawatts, an hour later it was down to 30 megawatts and after three hours was down to 20 megawatts. The point is, yes, the output of heat drops pretty quickly but you're dealing with HUGE amounts of it. Even 20 MW of heat is a LOT if there's not way to cool it or bleed it off.

Also consider that with these water cooled reactors, I believe the cooling water temps in the core flirt regularly with the critical point of H2O which is in the 700-ish degree range. Above that, I doubt you'd get any cooling benefit at all and you'd get a cascading effect until you could get the inlet cooling water temperature below that level...

Kind of a beast to control when things go south, but not impossible.