Thorium reactors will be here someday. Lots of good things about them. The waste is bad for a few hundred years instead of 10,000. And Thorium is way easier to find. The only reason we haven’t used them yet is that they are very poor for building weapons grade fissile material.
But these are gonna be a big deal some day.
What’s your source regarding the lack of long-lived fission products?
This hybrid concept actually runs on U-233, which is fissile and can be used for nuclear weapons. Thorium-232 captures a neutron and U-233 is produced.
I recall looking into fusion-fission reactors back in the 1970s.
Not really “new” technology... molten salt/thorium reactor theory has been around for decades. They also have “walk-away” safety. If all operators simply walked away a “plug” melts and all the radioactive material simply drains into an underground chamber and cools to become a non-radioactive blob of slag. Rickover opted for enriched uranium instead of the molten salt technology because you can’t make weapons of molten salt.
Hit thorium for a time period and then rotate that batch out. Chemically separate the non-thorium materials generated by the neutron exposure. The isolated protactinium content will decay to a fissionable uranium isotope. Easy peasy.
That said, this chemical reprocessing of hot materials is one of the difficult points to overcome for a salt based reactor with thorium as the fertile material. We could build a fast neutron version of a molten salt reactor which would burn spent reactor fuel and stored waste for many decades, without need for a thorium breeder.