Russian scientists have started reactor testing of nuclear fuel with 5% enriched Uranium-235 and a new type of neutron absorber (Erbium) for VVER reactors. The purpose of the experiment is to enhance the efficiency of nuclear power plants. At present, the main fleet of nuclear commercial reactors worldwide is running on nuclear fuel with of less than 5%, which now meets international standards for capacity reactor fuel (except for fast reactors, small-scale NPPs, and research reactors).