I believe that's the idea behind the new GenIII+ reactors. However, IANANE.
In the new reactors, there is an emergency(?) secondary circulation system that consists of large amounts of coolant (your good ole' H2O) above steel reactor enclosure. In case of trouble, this water is dumped and bathes the enclosure. There is another steel wall that is being cooled using air coming from outside (gravity driven or what-not). Thus the process goes: reactor rods (HEAT) > primary (radioactive) coolant > reactor containment > secondary/emergency coolant (non-radioactive) > coolant enclosure > moving air > atmosphere. In theory, in case of a situation like the one that happened in Japan, the system should work well enough with little or no extra power needed (if I understood correctly, most of it is actually automated and doesn't even require human intervention). Excess heat that is not removed by air cooling goes away with steam, so you might want to refill the water after few days. This paradoxically leads to less moving elements, control systems, pipes, etc. etc. and significantly reduces the reactor cost too. After you are done, you can just drain the secondary coolant, as it does not become radioactive. I guess it just took someone with enough imagination.
The only problem is, those reactors aren't fully certified yet. But works (and construction) are pending.