Just to set your mind at rest a little:
Oak Ridge is ALSO doing a shedload of research on restarting molten salt fuelled nuclear reactors (The Oak Ridge Experiment) and because MSRs are effectively banned in the USA (you can play with molten salts to your heart's content, but adding anything nuclear to them was explicitly made impossible when Nixon killed off Weinberg's safer mousetrap in 1972(*)), this is about the only way to model the best/safest/most efficient ways of setting up core geometry.
Bear in mind that whilst Thorium LFTR tech is reasonably well understood and not pressurised, the Oak Ridge Experiment used a graphite core - which when push comes to shove is a fire hazard if things go really _really_ wrong. That's highly unlikely in a MSR because you can and do flood the reactor with inert gas if you drain it, but after Chernobyl still a kneejerk response item - and means that less flammable alternatives need to be tested and modelled to provide the necessary criticality.
(*) Standard water moderated nukes are a bloody great steam bomb waiting to go off - Alvin Weinberg invented the water-moderated nuclear reactor for the Nautilus and didn't like his small design being scaled up to Heath-Robinson scales for civil power as he felt it was dangerous, so built a "better mousetrap" in the form of a hotter, much safer, unpressurised reactor.nuclear loop that couldn't burn or contaminate the biosphere. His reward was to be kicked out of the nuclear industry - and the project that Nixon promoted in favour of the MSR (the fast breeder reactor) was a dud.(**)
(**) Bad things to cool or moderate nuclear reactors with:
- water - steam bombs, not hot enough, corrosive and biosphere contamination
- sodium - burns furiously when exposed to air (Monju)
- lead - rots brains (some soviet sub reactors and a few others)
- Helium/CO2/other gases - containment issues