Primary coolant: molten salt or liquid metal.
Mark Pawelek

Once we setup an industrial scale pebble (molten salt cooled) or solid fuel assembly (liquid metal cooled) manufacturing unit, we will be locked-in to that particular technology for 2 generations.

Solid fuels can crack (TRISO-pebbles) or melt (solid fuel assemblies) if all the cooling pumps fail, and most importantly, much of the fuel is still left unburnt when solid fuel is removed from the reactor.

I hope we will choose wisely between Solid fuel or Fluid fuel and prevent a technology lock-ins, so that power-reactor technology will have progress similar to that of semiconductors.