Beginning in 2016 Russia has been testing and is now deploying Remix Fuel in which the spent nuclear fuel is put through a process like Pyroprocessing that separates the reactor Grade Plutonium and remaining Uranium from the fission products and fuel cladding. This mixed metal is then combined with a small quantity of medium enriched Uranium with approximately 17% U-235 concentration to make a new combined metal oxide fuel with 1% Reactor Grade plutonium and a U-235 concentration of 4%. These fuel rods are suitable for use in standard PWR reactors as the Plutonium content is no higher than that which exists at the end of cycle in the spent nuclear fuel. As of February 2020 Russia was deploying this fuel in some of their fleet of VVER reactors.