SRS, Plant Vogtle, High Flyer

An aerial view of the Savannah River Site, which is about 30 minutes south of Aiken. In the distance is Plant Vogtle near Waynesboro, Georgia.

About half the price, and still more efficient.

That's the argument officials have made for dilute-and-dispose, the alternative to the canceled Mixed Oxide Fuel Fabrication Facility 30 minutes south of Aiken at the Savannah River Site.

MOX – the product of a 2000s-era pact with Russia, the U.S.'s Cold War ballast and to-this-day adversary – was designed to turn a large cache of defense plutonium into fuel for commercial nuclear reactors. Both international powerhouses had designated metric tons of the metal surplus, enough for hundreds and hundreds of devastating weapons but no longer needed for such pursuits.

The U.S., though, canceled the MOX project in 2018.

Specifically, the U.S. Department of Energy's National Nuclear Security Administration sent project contractors and guarantors termination notices in October of last year, five months after U.S. Secretary of Energy Rick Perry informed Congress he intended to drop the ax and one day after the federal government secured a key win in appeals court.

The MOX project had swollen in terms of price tag; its timeline had ballooned as well. Billions of dollars (and more than a decade of work) had been shoveled onto the MOX fire before it was snuffed.

But what to do with the metric tons of plutonium once destined for MOX, and thus South Carolina? Dilute-and-dispose, the government has pitched.

Dilute-and-dispose, sometimes referred to as downblending, is a plutonium disposition method that involves mixing the metal with other inert material and then sending the batches to the southeast corner of New Mexico.

There, in New Mexico, at a salt mine repository known as the Waste Isolation Pilot Plant, the diluted plutonium would be buried.

The Savannah River Site made more than 1,650 shipments to WIPP through 2014. A few more have been made since it reopened. But that wasn't reworked plutonium. The facility is the nation's only designated repository for transuranic waste: clothing, tools, debris and other items contaminated by radioactive elements.

U.S. Sen. Lindsey Graham, a South Carolina Republican and longtime MOX booster, has described dilute-and-dispose as flimsy, at best.

"It's yet another half-baked idea from DOE that simply has no chance of success," he has said. Officials in New Mexico have also been wary.

But both Perry and the NNSA's administrator, Lisa Gordon-Hagerty, have painted a brighter picture. In certifying the termination of MOX, Perry promised dilute-and-dispose would cost roughly half what MOX would. It's a point he has stuck to. Gordon-Hagerty, too.

"But nonetheless, our plan is to dilute and dispose of 34 metric tons of excess plutonium, and that is our stance, and that will continue to be our stance," she said in a mid-June interview with the Aiken Standard.

Asked if she believes dilute-and-dispose is the cheaper, faster, better path moving forward, she said, "Absolutely."

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