 It is difficult for plants to measure within even tens of kilograms, because making measurements at that accuracy is very time-consuming; consequently, it is likely that smaller amounts of plutonium could be stolen without detection.Additionally, reprocessing is more expensive when compared with spent fuel storage.One study by the Boston Consulting Group estimated that reprocessing is six percent more expensive than spent fuel storage while another study by the Kennedy School of Government stated that reprocessing is 100 percent more expensive.