Exactly. Mainly, the current nuclear power industry, i.e. Areva, Westinghouse and GE make all their money on the fabrication fo fuel rod assemblies. They tried to make thorium fuel rods work in Indian Point Unit 1, but the layout of the rod bundles was tough to optimize to allow fertile material to become fissile and cycle correctly to be efficient at heating up the primary coolant.

Add this to all the regulatory hurdles and the big three nuke companies see no reason to pursue such a financial risk.