[Olog-hai]

But nobody has demonstrated how transmutation of Th-232 into U-233 is economically viable or even “safer”, particularly with U-232 contamination still being a problem with its high gamma ray output.

[Hiddigeigei]

"But nobody has demonstrated how transmutation of Th-232 into U-233 is economically viable or even “safer”, particularly with U-232 contamination still being a problem with its high gamma ray output."
A number of nations are in the process of developing Thorium based power right now. WikipediA (https://en.wikipedia.org/wiki/Thorium-based_nuclear_power) has a rather extensive artticle on its history and the many countries in the planning stage of building power stations.