I don't understand what you're trying to say here. Reprocessed fuel does not imply that we're now fissioning U-238. That takes place in a completely different energy regime (fast fission vs. thermal). Light Water Reactors and fast reactors operate differently, with different fuels. LWRs in commercial operation use slightly enriched U-235. There is no fissioning of U-238 other than the very small amount of spontaneous fission which is negligible compared to contributions from thermal fission in an LWR. The Six Factor formula governs criticality reactions, and these terms differ for both reactor types. The nuclear cross sections are fundamentally different between these energy regimes.

Reprocessed fuel is what it implies, recycled processed LWR fuel, stripped of the fission products that built up as the fuel underwent burnup in the core. If this were some sort of pretend activity then I guess the entire reprocessing back end of the nuclear fuel industry is fake.

I don't appreciate the personal attacks, so if you have nothing constructive to say, good day to you sir slash madam.