This isn't a sodium cooled reactor, in this case the molten salt is the fuel itself, not the coolant. Plus there is probably no sodium involved but instead a fl

This isn't a sodium cooled reactor, in this case the molten salt is the fuel itself, not the coolant. Plus there is probably no sodium involved but instead a fluoridated nuclear fuel such as thorium or uranium. Also this is a sub-critical experiment so pretty much all they have to do is turn it off if it overheats. The best part of a molten salt fueled reactor is that in case of heat runaway the fuel would melt plugs and drain into separate containers. Essentially a meltdown would only require replacement of the plugs and refueling of the reactor to make it operational again.