SpaceX had a lot of the same challenges but the first money making contract - flights to ISS - was only about 5-10 years out. NASA also paid them when they hit certain design milestones toward that contract.
I would think that the best path forward on this would be for the DOE to setup similar milestones w/ large cash rewards. Private companies compete on getting to those milestones with oversight by the appropriate regulatory bodies. Then once through the initial milestones the company could actually build a small scale reactor, make money on it, then build a large scale and really make some money.
Not saying it is going to happen, but that is MORE likely to happen than the DOE building this kind of reactor themselves.
SpaceX also had the advantage of a very wealthy founder willing to pour lots of his own money into the project. This certainly wasn't enough to finance the entire development up until the first ISS flight, but it did allow him to hire a bunch of hotshot engineers right from the get-go, and probably establish a degree of legitimacy that made attracting more funds, government contracts, etc., somewhat easier. I'd wager that if Elon Musk had decided to fund LFTRs instead of rockets, we'd already have a prototype.
I would think that the best path forward on this would be for the DOE to setup similar milestones w/ large cash rewards. Private companies compete on getting to those milestones with oversight by the appropriate regulatory bodies. Then once through the initial milestones the company could actually build a small scale reactor, make money on it, then build a large scale and really make some money.
Not saying it is going to happen, but that is MORE likely to happen than the DOE building this kind of reactor themselves.