U.S. Rep. Joe Wilson, R-S.C., has led a bipartisan letter sent to the Committee on Appropriations Subcommittee on Energy and Water Development this week, requesting the committee support continued construction of the Mixed Oxide Fuel Fabrication Facility at the Savannah River Site.

The letter dated March 11 requests funding at the “House passed fiscal year 2016 level” of $345 million.

“The MOX facility is nearly 70 percent complete, according to the U.S. government-certified earned value management system process,” the letter reads. “The project is essential to the United States nuclear nonproliferation goals and to uphold the Plutonium Management and Disposition Agreement in 2000 with the Russian Federation.”

The 70 percent completion number has previously been disputed by Department of Energy officials, according to a previous Aiken Standard article.

Wilson, whose district includes Aiken County, signed the letter along with U.S. Reps. Jeff Duncan, Trey Gowdy and Tom Rice – all South Carolina Republicans.

U.S. Rep. Jim Clyburn, D-S.C., also signed the letter, along with Republican Georgia congressmen Reps. Jody Hice, Barry Loudermilk, Rob Woodall and Rick Allen.

The letter states President Barack Obama’s budget request for fiscal year 2017 “irresponsibly proposes to terminate construction of the MOX facility,” referencing the administration’s proposal to shift to a dilute and disposal method known as downblending.

Obama’s budget proposal calls for the termination of the MOX project and around $270 million would be allocated to begin shutting down the Savannah River Site MOX facility.

Obama has proposed using a downblending method that would dilute plutonium and dispose of it at the Waste Isolation Pilot Plant, or WIPP, in Carlsbad, New Mexico. The administration believes switching to the downblending option would be cheaper and faster.

Several South Carolina legislators have opposed the alternative.

The congressmen’s letter states the alternative “continues to include numerous technical, legal, regulatory and political challenges that the Department of Energy has failed to address adequately.”

“The MOX facility remains the only path forward to dispose of our nation’s stockpile of weapons grade plutonium,” it states.

The facility is part of the MOX program, the nation’s current pathway to meet an agreement with Russia that states each nation must dispose of 34 metric tons of weapons-grade plutonium.

The letter is also calling for language to be included in the fiscal year 2017 Energy and Water Appropriations bill that prevents termination of the facility.

It comes days after U.S. Sen. Lindsey Graham, R-S.C., questioned U.S. Energy Secretary Ernest Moniz on MOX at a U.S. Senate Appropriations Subcommittee on Energy and Water Development hearing. Chairman and U.S. Sen. Lamar Alexander, R-Tenn., suggested that more time was needed to discuss the project and funding.

Graham said at the hearing $5 billion has been spent on the project so far.

Christina Cleveland is a general assignment reporter at the Aiken Standard. Follow her on Twitter @ChristinaNCleve.