Reprocessing was banned in the US for a few years. Carter banned it, Reagan lifted the ban. But reprocessing didn't pick up again because it's economically absurd. The plutonium separated from spent fuel has negative value -- it costs more to produce fuel rods containing it than you save in enriched uranium.
Reprocessing may have made sense in a world where enrichment was expensive, uranium resources becoming limited, and fast reactors practical. We do not live in a world with any of those properties. Enrichment prices crashed with gas centrifuges; uranium resources are ample; and fast reactors have turned out to be difficult to make competitive even with thermal nuclear reactors.
Reprocessing may have made sense in a world where enrichment was expensive, uranium resources becoming limited, and fast reactors practical. We do not live in a world with any of those properties. Enrichment prices crashed with gas centrifuges; uranium resources are ample; and fast reactors have turned out to be difficult to make competitive even with thermal nuclear reactors.