U.S. plutonium disposition program: Uncertainties of the MOX route

The FY2012 budget request for the National Nuclear Security Administration shows that disposition of weapons-grade plutonium as MOX fuel in power reactors remains one of the largest items in the Defense Nuclear Nonproliferation program. NNSA asked for $645,721,000 for the Fissile Materials Disposition related activities (60 percent of this money - $385,172,000 - would go to the MOX Fuel Fabrication Facility at the Savannah River Site). The FY2012 request is about 10 percent smaller than the previous year request for these activities, but the MOX related expenses would still account for a quarter of the $2.5 billion ($2,549,492) that NNSA requested for its Defense Nuclear Nonproliferation program.

The direction of the U.S. plutonium disposition program has raised a number of security concerns. In addition to absorbing a large part of the funds allocated for nuclear nonproliferation, the program is likely to increase proliferation risks by supporting development of the plutonium economy. In FY2010, NNSA has reached an agreement with the Tennessee Valley Authority (TVA) "to evaluate the irradiation of MOX Fuel in up to 5 TVA reactors" (NNSA FY2012 Budget Request, p. 379). It has also been encouraging other utilities to enter the MOX irradiation program. This effort was partly a response to the decision of Duke Energy to abandon testing of MOX assemblies in its Catawba Unit 1 reactor and pull out of the program.

DOE documents obtained by Friends of the Earth in February 2011 show that Energy Northwest is "formally evaluating the potential use of MOX fuel" in its Columbia Generating Station reactor. According to Tom Clements of Friends of the Earth, the plan developed by Energy Northwest and DoE calls for irradiation of 10 to 20 fuel pins fabricated by Pacific Northwest National Laboratory would begin in 2013 or 2015. This would be followed by the use of up to eight "lead use assemblies" (LUAs) around 2019. NNSA expects that MFFF will produce the first eight fuel assemblies "a part of the facility hot start-up plan" (Budget Request, p. 400). Clements estimates that the assemblies would have to be tested in the reactor for three or more two-year fuel irradiation cycles, so the use of MOX fuel would not begin until at least 2025. Use of MOX fuel assemblies in TVA Browns Ferry BWRs would also begin no earlier than 2025, assuming NRC licenses for use of the material are secured. The FY2012 budget request apparently to include funds for these activities - the irradiation part of the plutonium disposition program includes money for "qualification of MOX fuel designs for pressurized water reactors and boiling water reactors from multiple fuel suppliers, and execution of fuel supply agreements with TVA and potentially other utilities" (Budget Request, p. 380).

Given the time required to license the fuel, there is a real possibility that the $5 billion MOX plant could sit idle during multi-year irradiation tests of MOX in BWRs. The two PWR reactors at TVA's Sequoyah nuclear plant might not be able to use all fuel produced by MFFF and further NRC-licensed testing of "lead test assemblies" will also be needed to certify MOX use in PWRs. The Sequoyah reactors also might participate in the DoE Tritium Readiness program, which may complicate the use of MOX fuel in these reactors. In January 2011 TVA and Areva signed a letter of intent regarding potential use of MOX produced at MFFF in TVA reactors. The letter, obtained by Friends of the Earth, shows that TVA has not yet made a strong commitment to MOX and that little progress has been made towards NRC-licensing of MOX use by TVA.

Among the factors that might contribute to the reluctance of U.S. utilities to enter into the plutonium disposition program are concerns about reliability of MOX fuel supply.

(with contribution from Tom Clements)