Matthew Bunn and Gary Samore just published an op-ed arguing that the program to build a factory that converts excess plutonium from dismantled nuclear weapons into plutonium-uranium mixed oxide fuel for nuclear reactors has become too expensive. Although the two helped to launch the program in the mid-90s, they argue "It is time to stop throwing good money after bad and pursue cheaper alternatives that will serve our national security better" and "whatever we do with this plutonium in the long term, we should move to put it under international monitoring, and commit never again to use it in weapons..."