Yes, I'm well aware of that (minored in nuclear science while getting my PhD in chemistry). But the reaction characteristics of the two isotopes are different, and 233 is NOT the isotope used in U-Pu "burner" and/or "breeder" reactors reactors. That is 235. And for an article that claims to be authoritative, that mistake is NOT one that should have been made.
Yes, many mistakes in the article - some pretty funny.
A LFTR needs U-233 to start the reaction, as I understand it. Then Thorium decay cycle maintains the reaction with a minimum of resulting actinides. Not really a burner fast neutron reactor.
The TE IMSR looks like it will use Uranium decay cycle, so more actinides. Good for burning “spent” fuel is the thinking I suppose.
U233- more neutrons available for fuel breeding.