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.
Fukushima is a BWR design using water moderator, closed with a lid bolted on a flange. It uses two pumps. Chernobyl is a RBMK design with graphite moderator and a highly positive void coefficient.
This reactor is a much smaller PWR with a double containment and natural circulation, without these failure modes.
In a standard commercial pwr the containment building is a steel shell surrounding the entire system, then there is a void of varying width then that large cement building that you can see when driving by. That building is called the shield building.
