Disposition of surplus weapons plutonium in the United States and Russia is an urgent non-proliferation goal. However, the current course of favoring conversion of surplus plutonium into MOX fuel raises serious proliferation and safety concerns. The use of MOX fuel for disposition would establish the infrastructure of facilities and financial interests for a long-term plutonium economy and hence pose additional proliferation risks.

It was hoped that if the United States agreed to MOX use, Russia would agree not to reprocess MOX spent fuel or to use facilities built for disposition of surplus weapons plutonium for commercial purposes. These hopes have not been realized. Instead, in the name of disposition, the US seems not only to be relinquishing its decades-old policy of not using plutonium in commercial reactors, but aiding and abetting Russian plans to build a plutonium economy.

The Joint US/Russian Plutonium Disposition Study, which was signed by the Science Advisors to Presidents Clinton and Yeltsin (see main article), demonstrates this US acquiescence: "To facilitate the objective of disposition as rapidly as practical, if the reactor option is pursued, the resulting material should not be reprocessed and recycled at least until current excess stockpiles of separated plutonium are eliminated. Once that is complete, final decisions can be taken as to whether the intensely radioactive plutonium-bearing materials resulting from the reactor option should go directly to geologic disposal, as the U.S. prefers; or should eventually be reprocessed to recover separated plutonium, the current preference for Russia."¹ Later, the report is even more explicit: "..Russia will ultimately recycle any plutonium left in the [MOX spent] fuel." And, "the U.S. objective of plutonium disposition" appears to be satisfied if MOX spent fuel "is stored for several decades before reprocessing."²

It is not very relevant whether MOX spent fuel is reprocessed now or in a few decades. So long as the infrastructure for MOX fuel production and reprocessing is created and maintained, there will be plenty of other spent fuel to reprocess and plenty of surplus plutonium to occupy MOX fuel fabrication plants in the meantime. Furthermore, if Russia reprocesses MOX spent fuel, then the idea that MOX fuel use would lock up surplus plutonium in a highly radioactive matrix so that it cannot again be used in weapons will have been defeated. While the Russian government may not want to use reactor-grade plutonium in weapons, some non-nuclear governments or terrorist organizations may be willing to pay a high price for this weapons-usable material. Further, the use of weapons-grade plutonium in fast breeder reactors may not degrade its isotopic composition significantly. In fact, breeder reactors, when operated with uranium blankets, can be used to upgrade reactor-grade plutonium into weapons-grade. The main limitation will likely continue to be money for the reactors and reprocessing plants.

The joint report also notes that "there is some uncertainty as to whether the cost of decommissioning of [MOX] facilities built primarily for electricity production [in Russia] should be assigned to the plutonium disposition mission since these facilities are likely to be used by a civilian plutonium program once the plutonium disposition campaign is complete."³ A MOX fabrication facility, if used for commercial purposes after military plutonium disposition is completed, would provide a crucial link that is currently missing in Russia's plans for a plutonium economy.

Thus, the net result of the plutonium disposition program will have been for the United States to subsidize the very thing that it should be against: an infrastructure for a plutonium economy in Russia. Interestingly, and perhaps not coincidentally, a similar infrastructure would be created in the United States since a MOX plant would be built and since the U.S. appears increasingly reluctant to shut down its decades-old military reprocessing plants at the Savannah River Site in South Carolina.

In return, the U.S. would gain a few decades before Russian MOX spent fuel is reprocessed and, one hopes, the full cooperation of Russia on materials accounting. But so far, unlike the United States, Russia has made no declarations of surplus materials, and even more important, no declarations of total military and commercial weapons-usable materials production.

Even the modest goals of the current US MOX disposition program are unlikely to be realized in a timely way. Plutonium disposition using MOX will take at least three decades in Russia and probably about that in the United States. In the meantime, much plutonium will be stored in weapons-usable form. It may take far longer because many people in the United States and Russia oppose the use of MOX fuel, given its potential role in the establishment of a plutonium economy. Intense controversy has been manifest in the media and at the grassroots since the United States declared last December that it would include the MOX option in its disposition plans. In Russia, there has been consistent public opposition (outside the nuclear cities) to the construction of plutonium-processing facilities since 1989. That opposition continues today. Construction of both the BN-800 fast breeder reactor and the RT-2 reprocessing plant were stopped in the late 1980s and early 1990s due to local objections, and a lack of money.

Russia does need a great deal of financial help in securing its weapon-usable materials and putting surplus plutonium into non-weapons form, far more than the United States is now providing. And the United States stands to derive immense security benefits from Russia's actions by providing greater aid. But potential US aid in the creation of a plutonium infrastructure in Russia would be counterproductive for the very same reasons that such expenditures should be avoided in the United States itself.

The US and Russian governments should decide now to vitrify their plutonium and store the resulting glass logs, since Russia does not want to dispose plutonium-bearing materials as waste. One of the gains of the negotiations so far has been that Russia has agreed at least to consider the immobilization option. Vitrification followed by secure storage would be a safer, faster, and cheaper way to address the urgent short-term security goal of putting surplus plutonium into non-weapons-usable form and to gain the time needed to arrive at sound agreements on long-term plutonium security issues.