A Thorium based fast breeder nucear reactor produces much less TRansUranium waste, 0.01% waste products compared to a Uranium-235 fast breeder. The Thorium process has a much higher efficiency of fission than the Uranium process. See the figure below.
Pu = Plutonium, Am = Americum, Cm = Curium, all TRansUraniums, nasty stuff.
With Thorium based Nuclear power, there are no real problems, with traditional U235 power long tern storage is an immense and urgent problem, and has been since the 1960’s. At that time Sweden had a heavy water U-238 nuclear power program going, but abandoned it in favor of traditional U-235 power. U.S. promised to provide the material and take care of the reprocessing and final storage of all nuclear waste at cost if Sweden joined the nuclear proliferation treaty. Reprocessing was to be done in Washington State, and one of the final storage sites mentioned was Yucca Mountain in Nevada, having the ideal Geological properties.
Time goes by and in 1982 – Congress passed the Nuclear Waste Policy Act, requiring the establishment of a deep geologic repository for nuclear waste storage and isolation. Yucca Mountain was high on the list out of of 9 possible sites.
Time goes by, and Congress is still not able to decide on a solution. Meanwhile, TRU’s from spent and reprocessed fuel is piling up in less than ideal locations. Thorium based nuclear power would go a long way to alleviate this problem.