But, when does the bad stuff start happening?
The sim does not tell when fire erupts and lava spawns...
And where do you place the Uran cells?
Edit: 2 of the coolant cells melt after a short while.
Fixed the missing Uranium. And the cells shouldn't be melting, the entire layout should be heat neutral. I jump started it like so...
...and removed Uranium rods when the coolant got too hot, so no melting. Like i said, a bit of managing at the start but it'll get to 9000 fast and stay there. At least until the cells are done cooking.
And if Dezuman is right, which i think he is, with the 4 chambers, you'd need to get to about 12k heat for anything to go really bad.