Depleted Uranium is not waste from nuclear reactors, it’s waste from nuclear fuel production through uranium enrichment. It’s very pure U₂₃₈, the uranium isotope you end up with after you extract all the easily fissionable U₂₃₅ from natural uranium, which is a mixture of different isotopes, with U₂₃₈ being the most abundant.

A good part of the waste from reactors can’t be used for manufacturing anything useful, if it could, it would be. Nuclear fuel reprocessing does extract the materials useful for further use from spent fuel, but that’s small amounts, and creates a fair bit of extra waste itself, because the processes involve a whole lot of complicated and interesting physics and chemistry. The majority of the spent fuel assemblies (materials turned radioactive from Neutron flux, Fission products) are good for nothing (unless you want to make spicy paper weights which remotely* taste like metal) and will be anything from mildly to highly radioactive, some of them will be for tens of thousands of years.

* remotely as in “from a distance”