Such high priority tech!! How promising are expectations after 70 odd years no progress?

Experimental at Oak Ridge in 1950s and 60s – MSR program closed down in the early 1970, after which research stagnated in the United States.[15][16] Today, the ARE and the MSRE remain the only molten salt reactors ever operated.

https://en.m.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor