The reactor itself doesn't even need to be capable of utilizing the degraded fuel. Other reactors in other locations could be built to utilize the degraded fuel and receive it from the primary reactors at a reduced cost, free, or even have the primary sources pay the secondary reactors to take it.
There could be a series of reactors that utilize lower and lower grades of fuel until it no longer makes economic and environmental sense to further "burn" the fuel, at which point it finally gets stored at a much less radioactive state, or gets processed to remove the fissile material from the non-fissile material. Isn't it easier to get fissile material from used rods than to dig it out of the ground?
MODS- can we have post #27 on put in a different thread, perhaps this one:
https://ecomodder.com/forum/showthre...ide-36723.html