COLUMBIA, S.C. (AP) — Lawmakers are again calling on the Obama administration to keep open a South Carolina facility to process weapons-grade plutonium into commercial reactor fuel.

On Monday, House members including U.S. Reps. Joe Wilson and Jim Clyburn wrote to Energy Secretary Ernest Moniz stressing the importance of the mixed-oxide processing plant. Last week, U.S. Sens. Lindsey Graham and Tim Scott urged President Obama to reconsider his decision to mothball the Savannah River Site project known as MOX.

The facility would help the United States fulfill an agreement with Russia to dispose of at least 34 metric tons apiece of weapons-grade plutonium. Obama has said he wants to stop work on the expensive program while officials evaluate alternative disposal methods.

South Carolina is suing the federal government over that decision.