Nuclear reprocessing is a highly-controversial issue; proponents point to the massive reduction in the amount of radioactive waste requiring secure disposal, the utilisation of the remaining uranium and plutonium in the used fuel rods which would otherwise go to waste, and the opportunity to recover valuable fission byproducts such as platinum-group metals and silver, while opponents of reprocessing argue that it delays the switch away from nuclear power and results in massive toxic and radioactive contamination of the reprocessing sites, and that the separation of useable fissile material presents an unjustifiable proliferation risk.