COLUMBIA, S.C. — It would take nearly eight years to remove one metric ton of plutonium from South Carolina as promised under longstanding agreements, using a proposed alternative method, according to the federal government.

The Department of Energy included that information in court documents filed this month as part of a federal lawsuit with the state. In the Aug. 11 filing, the government said that the process known as downblending would take until the end of the 2025 fiscal year for a single metric ton. Under previous agreements, one metric ton of plutonium was supposed to be gone by 2016.

South Carolina is suing the federal government over an unfinished mixed-oxide fuel plant at the Savannah River Site, a sprawling former nuclear weapons plant along the South Carolina-Georgia border. That facility is billions over budget, a situation Energy Department officials blame on design and construction mistakes and escalating supply costs.

The state says the government owes it millions in fines. A federal judge has already said the U.S. Court of Federal Claims is a better venue to sort out the money issues but also ordered both sides to agree on a court-enforceable removal schedule. Earlier this month, South Carolina filed a separate lawsuit over $100 million in fines, an amount it says it’s due since the federal government has failed to remove the plutonium from the state, as previous agreements required it to do by Jan. 1, 2016.

U.S. District Judge Michelle Childs has also ruled the state can’t challenge the constitutionality of the federal government’s failure to keep its promises regarding the partially built facility, which was intended to turn 34 tons of weapons-grade plutonium — enough to arm 17,000 warheads — into nuclear-reactor fuel as part of a non-proliferation agreement with Russia.

Following the lead of the Obama administration, the Trump administration has proposed mothballing the fuel project and pursuing an alternative method known as downblending — a process that involves mixing the plutonium with another material to stabilize it — then storing it at a repository, like one in New Mexico.

Since the United States lacks a designated long-term storage site for high-level radioactive waste, tons of unwanted plutonium have accumulated at the site, including at least 7 tons intended for the mixed-oxide fuel facility. Other nuclear waste is stabilized in glass canisters, which remain at the site.


Kinnard can be reached at http://twitter.com/MegKinnardAP. Read more of her work at http://bigstory.ap.org/content/meg-kinnard/