[Big Dave]

Yucca Mountain failed? When was it tried?

The US has extensive reprocessing facilities at Hanford and Oak Ridge. They've been there since the 1940s. Thet quit reprocessing fuel rods because of the coward, Jimmy Carter.

Super Phenix runs - in short bursts. It just does not make electricty any more. It does not make electricity due to a court decision, not because of any problems inherent to the reactor. The cause of the shutdown was not defective hardware but a gullible judge. Now it runs to convert U-238 to Pu-239. It runs about a month at a time then spends a month moving fuel rods and U-238 shielding around in order to maximize yield of fissile material.

The US ran a fast breeder for 25 years without incident. Fast breeders are not run much today because yellowcake is relatively cheap and inthe 90s the US bought up a lot of plutonium from the former Soviet Union, so the US has plenty of MOX fuel.

The idea of Yucca Mountain was never a final repository but rather a "plutonium mine" where reprocessable fuel rods can be stashed until the economics favor reprocessing once again.

As for the depleted uranium, the prevention strategy is clear: Don't mess with the US.

Actually, depleted uranium is just U-238 with zero U-235 in it. Granite statues have a lot of uranium in them.