MOX facility with Vogtel in the background (copy) (copy) (copy)

The Mixed Oxide Fuel Fabrication Facility, commonly referred to as MOX, at the Savannah River site with the Vogtle nuclear station in the background. The National Nuclear Security Administration delivered an official termination notice on the project on Oct. 10, 2018. File/High Flyer/Provided

Federal officials have revealed that roughly 12 metric tons of surplus plutonium is being stored at the Savannah River Site, answering a nagging question that has long been the subject of speculation and debate.

The disclosure came after the secret figure was recently declassified by the U.S. Department of Energy, a National Nuclear Security Administration official told the Aiken Standard.

It remains unclear how much of this stockpile is weapons-grade plutonium that could be used to make nuclear bombs. Also unknown is how long it will remain at the sprawling plant in the sand hills region of South Carolina.

The stockpile includes plutonium originally destined for a never-finished and now-shuttered facility designed to transform plutonium into commercial reactor fuel. The Mixed Oxide Fuel Fabrication Facility was a key part of the United States’ plan to shrink its aging stockpiles of nuclear weapons before being shut down in October.

More than $7.6 billion in taxpayer money was funneled over a decade on the Aiken County project, which had been marred by delays, cost overruns and millions in questionable spending. Still, the MOX factory needed another $48.8 billion to finish construction.

Also contained in the stockpile is plutonium flagged for an ongoing process known as downblending, which mixes the radioactive element with special inhibiting materials that make it safer for disposal.

This specific stockpile doesn’t include another 34 metric tons of defense plutonium that was designated for disposal at MOX.

Most of that material never reached MOX and is now being held northeast of Amarillo, Texas, at the Pantex Plant, the nation's primary facility for the final assembly, dismantlement and maintenance of nuclear weapons.

In May 2018, U.S. Secretary of Energy Rick Perry told congressional defense committees that the 34 metric tons of defense plutonium would be diluted and then sent to the Waste Isolation Pilot Plant in New Mexico for long-term storage.

This new dilute-and-dispose campaign, still in its infancy, is designed to replace MOX. In fiscal year 2019, Congress authorized design work to support the project. Recently, the NNSA requested funding for the effort.

The disposition project — which both Perry and NNSA chief Lisa Gordon-Hagerty have said is cheaper and more efficient than MOX — is set to begin in 2028, according to a NNSA strategic road map.

Meanwhile, the DOE is required to get 1 metric ton of defense plutonium out of SRS — out of the Palmetto State, more broadly — by 2020. One half-metric ton has already been sent to the Nevada National Security Site, a move later disclosed in federal court documents.

The move to Nevada roiled the state's lawmakers. Nevada Gov. Steve Sisolak has said the clandestine shipments shredded his state’s trust in the Department of Energy.

Perry recently promised U.S. Sen. Catherine Cortez Masto, a Nevada Democrat, the DOE would begin relocating the half-metric ton away from the Nevada site in 2021. The effort will wrap by the end of 2026, Perry said.

The total 1 metric ton slated for removal will ultimately be sent to Los Alamos National Laboratory in New Mexico, according to a July 2018 NNSA study. The plutonium will be used there for the production of plutonium pits, which are nuclear weapon cores.

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Reach Glenn Smith at 843-937-5556. Follow him on Twitter @glennsmith5.

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