tors. These reprocessing technologies can reduce the amount of waste that needs to be managed and increase the amount of energy produced from a given quantity of uranium. However, Moniz and several other speakers at the summit were skeptical about the merits of reprocessing in the near-term future. First, reprocessing technology currently in use can be used in nuclear weapons. Second, Moniz and other speakers argued that the claims for the waste management benefits of reprocessing are exaggerated. John Holdren observed that reprocessing might reduce the volume of waste, but volume is not the constraint on the capacity of a waste repository. The constraint is the amount of heat generated by the waste, and that problem cannot be solved without reactors for reprocessing that are at least 40 to 50 years away. Reprocessing spent fuel makes nuclear energy “more complicated, more expensive, more proliferation prone, and more controversial,” Holdren said. “If you want nuclear energy to be rapidly expandable, and to take a bite out of the climate change problem, you want to make it as cheap as possible, as simple as possible, as proliferation-resistant as possible, and as non-controversial as possible, and that means you don’t want to reprocess any time soon.”
At the same time, all of the speakers agreed that research on reprocessing for the longer term should be intensively explored. “We need to be investing in it,” Holdren said, “but what we don’t need to be doing is deploying reprocessing soon with technologies that are currently available because that will shoot nuclear energy in the foot.” Moniz pointed out that far too little has been invested in advanced nuclear concepts, and “we are paying the price today for that lack of adequate research.” For example, one possible approach would be for a balanced fuel cycle in which conventional reactors in “user” states feed spent fuel into a complex of advanced reactors located in “supplier” states (Figure 6.1). The user states would be assured of nuclear fuel supplies so long as spent fuel is returned to the supplier states. In this way, small nuclear programs could lease their fuel from states with advanced reactors, which would address proliferation concerns while concentrating and reducing the quantities of waste.
The management of spent fuel remains a difficult issue in the United States and around the world. Long-term geological isolation of spent fuel “appears to be scientifically sound in well-chosen sites with good project execution,” Moniz said. Yet a system to dispose of nuclear waste has not yet been implemented anywhere in the world, and whether the designated U.S. site for spent fuel, Yucca Mountain in Nevada, can be licensed remains up in the air.