Just to add to Josh’s post, I have been wondering if any better evidence has come to light that North Korea is capable of producing UF6. I haven’t been following North Korea as closely as I used to, but I once wrote that:

North Korea has indigenous supplies of natural uranium, but whether it can produce uranium hexafluoride is unclear. A former State Department official familiar with North Korea’s nuclear programs told Arms Control Today Feb. 22 that, as of October 2002, there was no evidence that North Korea possessed a facility for producing uranium hexafluoride. North Korea does have a facility for producing uranium tetrafluoride, a uranium compound that is then converted to uranium hexafluoride, that was frozen under the Agreed Framework, the official said.

However, Gary Samore, who headed nonproliferation efforts for the White House during the Clinton administration, said North Korea could “probably start making hex [uranium hexafluoride] fairly quickly,” Nuclear Fuel reported in September 2003.

I wish people would focus on uranium conversion more when they talk about uranium enrichment. Without feedstock, a centrifuge facility can’t enrich a damn thing.