Russia has completed transfer of all weapon-grade plutonium from the Siberian Chemical Combine in Seversk to the Federal Fissile Material Storage Facility, which is probably the storage in Zheleznogorsk.

The plutonium stored in Seversk as plutonium oxide, is part of the about 18 tonnes of weapon-grade plutonium produced after 1994 (and separated after 1997). About 10 tonnes of plutonium was stored in Seversk.

Under the 1997 U.S.-Russian agreement on plutonium production reactors, this material will not be used for weapon purposes and the United States has the right to inspect the storage facilities that contain that material. All this plutonium was transferred from Seversk by the end of 2014. In April 2015, Seversk hosted a U.S. inspection team that confirmed the removal.