Hindsight is always 20/20 , but still.
Looking at the reactor design schematics and given that the rods absolutely need cooling, why on earth did they ever put them at the top of the vessel with the cooling water collecting on the bottom ?
If it was convenience then they're paying one hell of a price for that convenience !
That's simply not fail-safe, it requires pumping just to keep any sort of cooling going.
Putting the cores where even the last remaining water will naturally pool at least gives the emergency option to evacuate a lot of heat by making and venting steam.
Putting the reactor underground and using a simple water column design, it could even have been slightly pressurized by simply pouring on water.
Additionally, any leak below the cores - which now means most of the cooling system - will drain the coolant away from the cores.
So having less of the cooling system below the cores can reduce the chance of that happening.
If I had been asked to design that, I'd basically have inverted it.
Reactor low, coolant above it.
Even with total pump failure, it could have been designed to resort to natural convection flow.