I haven't had time to read all of the info, but I get the impression that this is still a pressurized water reactor, just on a smaller scale. It will fail in pretty much the same way as current reactors like Fukushima and Chernobyl. I believe that the point is that the pool provides an extra level of failsafe against coolant loss, and additionally that the substantially smaller size of the core limits the amount of heat build-up in a meltdown.