U.S. Rep. Jeff Duncan and U.S. Secretary of Energy Rick Perry clashed over the future of the embattled Mixed Oxide Fuel Fabrication Facility during a Thursday morning budget hearing.

Duncan, a South Carolina Republican, supports MOX, a currently unfinished facility at the Savannah River Site designed to turn weapons-grade plutonium into fuel for commercial reactors.

Perry, the former governor of Texas, does not support MOX – and neither does President Donald Trump's fiscal year 2019 budget request, the topic of Thursday's U.S. House Energy and Commerce subcommittee hearing.

Duncan told Perry he believes MOX "is absolutely the right facility" to process surplus plutonium housed at SRS.

"We didn't ask for the plutonium to come there," Duncan said, adding that the plutonium was specifically brought to SRS for MOX consumption.

MOX is the result of a 2000s-era nuclear nonproliferation accord with Russia.

At the time, both the U.S. and Russia agreed to dispose of 34 metric tons of plutonium, enough to create thousands of nuclear weapons respectively. In 2010, the agreement, which Duncan and Perry agreed Russia eventually walked away from, was updated to require MOX processing.

MOX, though, is currently 70 percent complete, according to local experts and some of the state's politicians, Republicans U.S. Sen. Lindsey Graham and U.S. Rep. Joe Wilson included.

Construction of MOX was authorized in 2007. Duncan said he would "love" to see MOX funded and completed.

"We've already spent a ton of money down there," the congressman said.

The 2018 omnibus spending bill, approved in March, afforded MOX construction $335 million.

But Trump's fiscal year 2019 budget request allots $220 million for the orderly closure of MOX. Both Trump and former President Barack Obama have tried to mothball the facility.

On Thursday, Perry said MOX is "obscenely over-budget." The secretary said he did not want to rehash prior MOX-related arguments he's had and promised to keep his responses short.

Perry is a fan of dilute-and-dispose, the cheaper and more efficient MOX alternative, according to the National Nuclear Security Administration.

Dilute-and-dispose involves mixing plutonium with inert material and sending it elsewhere, namely the Waste Isolation Pilot Plant in New Mexico.

The fiscal year 2019 budget request assigns $59 million to the pursuit of dilute-and-dispose.

Perry told Duncan dilute-and-dispose abilities at SRS need to be "substantially more robust," adding that the removal of plutonium from South Carolina is "high on" DOE's "priority list."

Duncan seemingly disagreed with Perry's dilute-and-dispose sentiments. Before wrapping up, the congressman asked Perry to sit down with him and discuss the matter further.

"You're on," Perry responded.

Perry toured SRS – he visited MOX specifically – over the course of two days in February.

Colin Demarest is a reporter with Aiken Standard and has been with the newspaper since November 2017. He is a New Jersey native and received his B.A. in Journalism and Mass Communications from the University of South Carolina. Follow him on Twitter: @demarest_colin