A confidential study by the U.S. Energy Department has concluded that completing a controversial nuclear fuel factory in South Carolina may cost billions of dollars more than the department has previously promised, according to government officials and industry sources briefed on its results.

The study, conducted for Energy Secretary Ernest Moniz, also found that finishing and then operating the factory to help get rid of Cold War-era plutonium as part of a nonproliferation arrangement with Russia would likely cost a total of $25 billion to $30 billion on top of the $4 billion spent on its construction so far, the sources said.

That amount is so high, the officials said, that Barack Obama’s administration is leaning toward embracing what one described as “some other option” for dealing with the 34 tons of weapons plutonium that the so-called Mixed Oxide (MOX) Fuel Fabrication Facility at Savannah River was supposed to help eliminate. The problem is that walking away from the plant won’t be easy, politically or diplomatically.

Cost Overruns in Plutonium Conversion Plant