Japan had one of these liquid sodium cooled reactors. Problem, sodium is highly corrosive and combusts explosively when exposed to air and even more so water. Japan's reactor ate through a pipe, leaked sodium, started a fire.

Molten salt reactors have all the same advantages with none of the disadvantages. The salt though still somewhat corrosive is MUCH less corrosive than sodium AND is not flammable in the event of a leak.

The Canadian Reactors that can BURN Nuclear Waste

Currently, there are two advanced nuclear reactors being developed in New Brunswick, Canada, that can burn nuclear waste to generate electricity. How is that...

^YouTube