As South Carolina's plutonium fines lawsuit transitions to an appeals court, the federal government has indicated the matter could benefit from mediation, despite prior settlement negotiations collapsing and securing a favorable ruling soon after.

In a Sept. 27 court filing, the U.S. government, generally representing the Department of Energy, said mediation might "serve to renew the parties' effort to explore whether the dispute can be resolved." The Palmetto State, though, harshly disagreed, accusing the federal government in its own filing of failing "to engage in good faith settlement discussions."

South Carolina's one-sentence rejection parallels its arguments made in a lower court months prior.

The state first sued the federal government in 2018 in an effort to recover $200 million in fines levied against the Energy Department for failing to remove plutonium from the Savannah River Site, about 30 minutes south of Aiken.

Federal law mandated beginning in 2016 the Energy Department pay South Carolina $1 million for each day – up to 100 days per year – the department did not process plutonium at the never-completed Mixed Oxide Fuel Fabrication Facility or did not get 1 metric ton of the nuclear material out of the state.

The $200 million sought represents the fine total from 2016 and 2017.

In October 2018, following some legal sparring, South Carolina and the federal government announced settlement negotiations had begun.

Those talks unraveled nearly a year later. South Carolina's legal team at the time told a federal claims judge the energy and justice departments were not actively engaged and that the sole counteroffer they received was a "lowball amount," which the state refused. The lawsuit moved forward.

U.S. Federal Claims Judge Margaret M. Sweeney ultimately sided with the federal government, ruling the courts were not the right place for South Carolina to pursue the plutonium fines. Because Congress did not appropriate money for the multimillion-dollar payments, disbursement was not an option, Sweeney said near the end of August in dismissing the case.

S.C. Attorney General Alan Wilson's office promised to appeal the decision shortly after. A notice of appeal was filed Aug. 23.

"The court below erred in failing to order the United States to pay sums owed to the state," reads South Carolina's Sept. 25 docketing statement.

Colin Demarest covers the Savannah River Site, the U.S. Department of Energy, the National Nuclear Security Administration and government in general. Follow him on Twitter: @demarest_colin