To complicate matters, Russian technical experts never really believed in the standard of burned fuel. For them, a reliable set-up method should alter the isotopic composition of plutonium and transform it into so-called plutonium, which has a high content of Pu-240 isotope. In 2000, Russia agreed that a little plutonium could be removed by immobilization, which does not alter the isotopic composition. But she has always insisted that property should not be the main track. In the end, the options contained in the 2010 version of the PMDA satisfied both parties, although for different reasons – the United States obtained the standards for spent fuel, while Russia got the change in isotopic composition. But while irradiation in a reactor comfortably reaches both, there are options that allow a modification of the isotopic composition without irradiation. For example, the United States might try to mix its weaponized plutonium with reactor materials. The future of the 1987 Medium-Range Forces Treaty (INF) also remains questionable, as the United States and Russia claim that the other violates the agreement. (See ACT, November 2016.) Russia also suspended a 2013 nuclear energy research agreement and a 2010 agreement on the transformation of six Russian research reactors last month.
Many experts were skeptical of the MOX option, not least because it would give a significant boost to the plutonium economy and ultimately lead to a broader acceptance of plutonium by the civil nuclear industry. In addition, it was more expensive and potentially less safe than the immobilization. But Russian experts have insisted that plutonium is a valuable energy resource that should not be eliminated as waste. For example, the plutonium management and implementation agreement (PMDA) signed in 2000 by the United States and Russia provided that most of the excess amounts of plutonium from both countries would be used for the production of irradiated MOX fuel in existing light water reactors. However, the United States has decided to follow the real estate option for some of its plutonium. In 2010, the United States and Russia signed a memorandum to the agreement that allowed Russia to dispose of plutonium with fast neutron reactors, as part of its plan to expand the use of materials in its civil nuclear industry. In the meantime, the United States has committed to continue the moX fuel approach at a plant under construction located on the Department of Energy`s Savannah River site near Aiken, South Carolina. It turns out that plutonium is a very difficult material that can be disposed of.