It's a reactor. If you haven't got somewhere good to put it, with lots of cooling water, it will break down just a quickly as any other. It will still make mess.- Just different sorts of mess.
What always makes me wonder about these new designs is this- If they are so good, why does no one want to build them? Why muddle along with existing designs? It's not as if the current designs are perfect, but no one seems willing to say- We're going to put our shirt on this new type.
There's natural conservatism, and there's people who clearly don't believe everything that the engineers tell them about how great this new idea is.