You only need Q=1 to have viable fusion fission hybrid reactors that crank out PU239 by the metric tonnes per year. Humans have gotten to Q=1.54 and Q=1 is now just a normal thing.
This was 1979 and we as humans had the tech for fusion hybrids that traitor JCarter ruined not only our reprocessing program without that fusion hybrids are also out of reach.
A hybrid of 3000MWhthr puts out 1800kg of PU239 per year that’s enough for 18 to 20 CANDU reactors yearly fissile fuel needs. No other reactor tech on earth is more efficient in fissile use other than fast reactors with a breed ratio greater than 1. CANDU reactors have a C ratio of .8 for MOX PU based fuels PWRs are sub .6 and a crime against humanity to burn PU in such a waste of energy value.
There are two reasons hybrids never get the spotlight. One they would work today making net energy and fueling a vast fleet of regular reactors. So no grant money gravy train. Second is they make HUGE amounts of PU239 which is also the perfect weapons material a single hybrid would make enough for 180 kg weapons per year every year that scares the politico types. Humans need to get past the nuclear war thing if we are to survive as a species we will need breed reactors or fusion hybrids both make large amounts of PU which is the fuel that never ends there is so much uranium in the crust and oceans it’s inexhaustible at human use scales even with 10+ billion souls.
Remember this is 1979 and tech has moved past by leaps and bounds.
http://large.stanford.edu/publications/coal/references/docs/bethe.pdf
Yes, the ‘NO NUKES’ crowd killed the breeder reactors.
So, why didn’t the Soviets use that technology or the Chi-Coms?.............