We really need somebody rich to decide to build a thorium reactor. That seems to be the only way we get things done now in the US. The companies that build reactors in the US are unlikely to enter a new design era because of their patents, etc. But I would be perfectly happy with an Indian or Chinese design. India in particular has a great incentive to mass produce them because it needs so much energy to modernize and it has lots of thorium and not much uranium. There is really no reason for a thorium-reactor-race. A decent design that was inexpensive to build and walk-away reliable would benefit everybody on Earth.
They can be drop-in modules that power companies can buy and put right to work. Get out of this one-up 10 year nuclear power plant design and custom build cycle. Just think: One standard design approved by the NRC in advance. Power companies with existing hot water reactors could just buy modules to truck to the site and start to replace the energy output of the hot water reactors as they age out.