With the end of the Cold War and break-up of the Soviet Union in the early 1990s, control of surplus nuclear weapons material became an urgent U.S. foreign policy goal. Particular U.S. concern focused on plutonium from Soviet nuclear warheads, which it was feared posed a major nuclear weapons proliferation risk. The United States supported a successful effort to consolidate the storage of Soviet nuclear weapons and materials in Russia, and then began negotiating reductions in weapons material stockpiles. Congress has been closely involved in formulating U.S. policy on surplus plutonium disposition, as well as funding the necessary facilities, operations, and Russian assistance to implement the program. Congressional debate is now focusing on the U.S. program's escalating costs and the Obama Administration's FY2015 proposal to halt construction of plutonium disposition facilities in South Carolina and prepare a new strategy. This book discusses the mixed-oxide fuel fabrication plant and plutonium disposition. It also examines drivers the National Nuclear Security Administration (NNSA) identified for the cost increases of construction projects for plutonium disposition; the extent to which NNSA analysed underlying causes of the cost increases; steps NNSA took to hold construction contractors accountable for their role, if any, in the cost increases; and the extent to which NNSA's most recent estimates met cost- and schedule-estimating best practices.