A lot of discussion on how simple the loop is vs PWR and BWR systems ignores all the added valves and redundant piping need for maintenance.
We have materials which can resist molten salts, but they will degrade eventually. The rectors as shown on paper are invariably less complex than what's necessary for production.
Not necessarily against LFTRs or anything, but we gotta be honest with each other before going down this 10,000yr road.