Russia has suspended a 15-year-old agreement with the US under which each country was to dispose of 34 metric tons of plutonium. The Kremlin blames deteriorating bilateral relations and the Obama administration’s intention to scrap the mixed oxide (MOX) fuel fabrication facility that is under construction at the Department of Energy’s Savannah River Site in South Carolina.

On 3 October Russian president Vladimir Putin submitted to the Duma a measure formally suspending the 2000 pact. A Kremlin statement pointed to US interference in Ukraine, economic sanctions imposed by the US in the wake of Russia’s annexation of the Crimea, and a buildup of NATO forces in nations bordering Russia “resulting in a fundamental change in strategic stability” between the two superpowers.

The statement also said the US had yet to consult with Russia over its plan to change what had been the mutually agreed disposition route: conversion of the surplus plutonium into MOX fuel, which is suitable for nuclear power plants but not nuclear weapons. US officials have long acknowledged that they would need Russian approval to implement DOE’s alternative approach of diluting the plutonium with an inert material for burial at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. But Putin told reporters in April that the dilute-and-dispose method was unacceptable because the plutonium could be retrieved from the mixture and used for weapons.

The K Area Complex at the Savannah River Site in South Carolina handles and stores the country’s excess plutonium. Credit: US Department of Energy

A spokesperson for DOE’s National Nuclear Security Administration (NNSA) says the US “remains fully committed to verifiably disposing of our surplus plutonium, and is disappointed with Russia’s unilateral decision.” The Russian action “only reinforces the Administration’s intent to pursue the already proven dilute-and-dispose approach, which will save tens of billions of dollars.”

In September DOE released a new estimate that placed the cost to finish building the MOX facility at $17.1 billion, with a completion date of 2048. Two months earlier, project contractor CB&I AREVA MOX Services produced an estimate of $10 billion and set completion for 2029. DOE assumed annual funding of $350 million—close to the $345 million appropriated in fiscal year 2016; with unconstrained funding requiring in excess of $1 billion per year for four years, the plant could be built for $11.8 billion and completed in seven years. Some $4.6 billion, near the original 2007 estimated cost for completion, has been spent to date, the agency reported.

The NNSA spokesperson said the estimated lifetime cost, including operating expenses, for the MOX fuel approach is more than $50 billion. Although a life-cycle cost estimate for the dilute-and-dispose approach is still in development, a 2015 review team chaired by Oak Ridge National Laboratory director Thom Mason estimated annual costs of the program at about $400 million annually, compared to $700 million–$800 million for the MOX fuel path.

Existing facilities at the Savannah River Site can be used to dilute and package the plutonium. Officials at the site announced last month that they will begin processing 6 tons of plutonium oxide that isn’t covered under the Russia–US agreement. Mixing the plutonium with the classified inert material known as stardust will render the plutonium unusable for weapons, the department says. The NNSA spokesperson acknowledged that SRS facilities would need to be expanded to fully implement the dilute-and-dispose program.

The Obama administration’s plan to abandon the MOX plant has been steadfastly opposed by South Carolina legislators, and construction has continued since the administration first proposed alternative approaches in 2013. In February the state sued DOE, claiming the agency had failed to meet the terms of an agreement specifying that 1 ton of plutonium be removed from the state by 1 January 2016. The lawsuit seeks up to $100 million in fines.

But DOE is unable to ship diluted plutonium, which it considers transuranic waste, to WIPP for permanent disposal. The repository has been closed for repairs since February 2014, when an improperly packaged waste container exploded and contaminated the underground facility. The department plans to reopen WIPP in the next several months, but the facility won’t be able to accept waste at full capacity for several years.

Senator Lindsey Graham (R-SC), who has led the congressional effort to keep the MOX plant alive, had frequently cited the need to honor the now-suspended agreement with Russia. In a statement, Graham blamed “gross incompetency of this administration [for leaving] the fate of 34 metric tons of Russian weapons grade plutonium in doubt.” He said that the “deliberate assault on the MOX program and South Carolina” by Obama and DOE “needs to stop immediately. As it is, our next president will inherit a mess.”