In doing so, he closed the books on a 1993 agreement that allowed Russia to sell 500 megatons of enriched uranium — the equivalent of about 20,000 nuclear warheads. The program converted the uranium for use in commercial nuclear power plants and, more importantly, ensured that the weapons-grade material stayed out of the hands of terrorists.
But civil lawsuits against Russia had threatened to tie up the sales, leading Presidents Clinton and Obama to invoke the National Emergencies Act to block Russian assets and shield them from creditors.
Those payments were completed in December, 2013. White House officials would not say why the emergency remained in place for more than a year after that.
"With the successful conversion of 500 metric tons of highly enriched uranium extracted from