No, there were no good enough designs, and after decades of effort they are still elusive: There has been huge amounts of subsidy money poured into breeder reactors and Pu fuel in the west, much later than China Syndrome.

The subsidies have been in the form of the MOX program, PRISM, and other gov funded fuel recycling programs in many countries. The problems remain: weapons grade Pu profileration risk, unviable cost, dearth of demonstrated working large plants due to technical difficulties inherent in the designs, difficulties scaling up to commercial sizes competitive w traditional designs.

Yes, there are many interesting designs on the drawing table, same as it has been for decades...