"Red Team" report confirms high cost of MOX option for disposal of U.S. excess plutonium

Frank von Hippel

In 2013, when it submitted its proposed budget for fiscal year 2014 to Congress, the Obama Administration declared, that the "current [U.S.] plutonium disposition approach may be unaffordable."

This approach has been, in parallel to Russia, to fabricate at least 34 tons of weapon-grade plutonium (enough for about 10,000 warheads) that has been declared excess for the down-sized U.S. nuclear arsenal into mixed-oxide (MOX, uranium-plutonium) fuel for use in U.S. power reactors. The estimated costs of both constructing and operating the Mixed Oxide Fuel Fabrication Facility (MFFF) that is being built at the Department of Energy's (DOE) Savannah River Site in South Carolina has increased many-fold.

The Administration therefore proposed to freeze construction of the MFFF while it considered alternatives. The Congressional delegation from South Carolina, led by Senator Lindsey Graham, fought back and managed to keep construction moving forward temporarily, albeit at a much reduced rate.

In April 2014, the DOE produced a study of the alternatives and concluded that, even with $5 billion sunk in the MFFF, it would be less costly to dilute the plutonium and dispose of it as waste in the DOE's Waste Isolation Pilot Plant (WIPP) a deep repository under New Mexico. Senator Graham demanded an independent study. The DOE hired the Aerospace Corporation, which did a study that arrived at the same conclusion. Senator Lamar Alexander, chairman of the Senate Appropriations subcommittee, which deals with this part of the DOE budget, requested yet another study to be led by Thom Mason, the Director of Oak Ridge National Laboratory, who, a year earlier had led a study that had devised a strategy that had saved the DOE's similarly over-budget Uranium Processing Facility.

Mason's "Red Team" study of the MOX program was delivered to DOE Secretary Moniz on 13 August 2015 and was obtained by the Union of Concerned Scientists. It comes to the same conclusion as the previous studies but its reasoning is more transparent. It points out that preparing plutonium for disposal is much less costly than for MOX fuel fabrication because costly purification is not necessary. Also, mixing the plutonium with a diluent for disposal is much simpler than the manufacture of tens of millions of high-quality sintered and machined MOX pellets.

The plutonium processing would still take place at the Savannah River Site as well as at Los Alamos where the plutonium-containing weapons pits would be dismantled. With regard to negotiations with New Mexico about expanding the mission of the WIPP facility and with Russia to accept direct disposal, the red team is relatively optimistic. It points out that New Mexico's current governor, Susana Martinez, has declared the Los Alamos National Laboratory and WIPP as "critical assets to our nation's security, our state's economy, and the communities in which they operate." It also pointed out that the U.S. renegotiated the Plutonium Management and Disposition Agreement with Russia in 2010 to allow Russia to use its excess plutonium to fuel breeder reactors instead of light water reactors. (The U.S. had originally volunteered to pay most of the cost for Russia's MOX plant but the plant's cost increased in parallel with the cost of the U.S. MOX plant and the U.S. was unwilling to increase its financial commitment. Thus, Russia's MOX plant was deemed unaffordable before the U.S. MOX plant.)

The Red Team report concludes by urging the Administration and Congress, "Regardless of the DOE chosen path forward, it is vitally important to make a decision as soon as possible and secure consistent funding to prevent further degradation of the Pu Disposition Program."