The USA is expanding its nuclear fuel production capacity with up to three new enrichment plants likely to begin operation before 2020. Currently, almost all the uranium used in US commercial reactors is imported, with about half of it coming from Russian weapons-grade uranium downblended to low enriched uranium in Russia. After reaching a peak in 1980, domestic mining now accounts for only 5% of the fuel used in US reactors. Between 1977 and 2005, government policy did not allow reprocessing of used fuel for commercial reactors. Recent legislation, however, calls for stepped-up R&D in advanced fuel technology and advanced reactors to recover the energy value of used fuel and reduce the volume of nuclear waste.