The Fuel Division of Russian state nuclear corporation Rosatom has manufactured and accepted a unique OS-5 fuel assembly based on mixed nitride uranium-plutonium nuclear fuel with a liquid metal sublayer. Separately, the Mining and Chemical Combine is set to be the location of a MOX fuel plant to supply the BN-1200M fast reactor. The BREST-OD-300 fast reactor is part of Rosatom's Proryv, or Breakthrough, project to enable a closed nuclear fuel cycle. The sodium-cooled BN-series fast reactor plans are part of Rosatom's project to develop fast reactors with a closed fuel cycle whose MOX fuel will be reprocessed and recycled. In addition to the BN-600 reactor at Beloyarsk unit 3, which began operation in 1980, the 789 MWe BN-800 fast at Beloyarsk unit 4 entered commercial operation in October 2016.