[monocasa]

We've had that tech for decades, it's what France's infrastructure is built on.

The US doesn't like it because you end up with plutonium doing that. It's contrary to their geopolitical/non-proliferation goals if we start using it because we simultaneously want fairly arbitrary foreign states to use nuclear power (so they don't feel as compelled to start wars over energy), and we don't want arbitrary states having the ability to create nuclear weapons. So pretending that reprocessing fuel isn't the best way to approach long term nuclear power generation is what the DoE/DoD/DoS are stuck on, even domestically.