However, we cautioned him that we had low confidence that it was part of a nuclear weapons program, not because there was an alternative explanation that made much sense but simply because our body of knowledge on the other parts needed for such a program (like a reprocessing facility or weaponization work) was pretty thin.

CNN: Obama's Iran problem and the Bush doctrine

Rokkasho has been seen as a facility that will allow Tokyo to reduce radioactive wastes from its nuclear power plants by reprocessing spent nuclear fuel.

WSJ: U.S. Opposes Japan's Nuclear Plan