Nuclear disarmament is a good thing. Reducing the weapons stockpiles in the U.S. and Russia has left both countries with large stockpiles of highly-enriched bomb-grade uranium and plutonium. Every terrorist in the world wants to get some, some terrorists are rich, and some 40-year-old nuclear workers in Russia are living hand-to-mouth. It's a dangerous situation.
In 1991, Senators Nunn and Lugar had a good idea. The government-owned U.S. Enrichment Corporation (USEC), which operates enrichment facilities in the U.S. to provide fuel for commercial reactors, would buy a portion of Russia's nuclear stockpile so that it could be burned in U.S. commercial reactors. This is a great idea, and a pretty good summary can be found here. There is a snag, however:
Russia wasn't going to send bomb grade material directly to the U.S., because that would be like actually selling us nuclear weapons. Instead, they mixed the bomb grade stuff with Russian natural uranium, so that the result was 4.4% U-235 -- just right for a commercial reactor. The overall flow of reactor-grade material would have replaced a good chunk of domestic U.S. uranium demand.
Domestic U.S. uranium suppliers didn't like that. Together, the U.S. and Russia have about 2000 metric tons of bomb-grade material, equivalent to 12 times annual world mine production. By the time the U.S. civilian reactors had burned through Russia's half of this stockpile, the domestic U.S. uranium suppliers would be out of business and Russia would end up being the majority uranium supplier to the U.S.
So the deal was that Russia would buy the American natural uranium from the miners that was displaced by the Russian imports. This uranium would be stockpiled in the U.S. in USEC's custody. The U.S. goverment got two commercial reactor operators to promise to buy the Russian uranium eventually. Russia would sell the rest off over sufficient time.
Realistically, it's going to take many decades to work through that stockpile. Now that they've been paid off, the domestic U.S. miners have mostly stopped digging, which will help. Getting this stockpile is yet another good reason to build more nuclear powerplants (though not the strongest, of course).
The notion of U.S. mining interests delaying such an incredibly important piece of national security work so that they could protect their bottom lines still strikes me as... treasonous. But it appears that negotiators at our government have managed to pay off these people, so that we can get on with the business of paying off Russia for the knives held to our throats.