MOSCOW, July 15 Specialists from the Russian nuclear industry have successfully completed tests of nuclear fuel that allows nuclear power plant reactors to operate in daily power maneuvering mode, which is important for the energy system, the press service reported management company of the Rosatom fuel division TVEL.
The ability of nuclear power plants, through power maneuvering, to participate in regulating the load of the energy system is now becoming one of the factors of competitiveness of nuclear energy. But for this it is necessary, in particular, to prove the possibility of sustainable operation of nuclear fuel with periodic changes in the power of the reactor plant. 
«Scientists from the scientific and fuel divisions of Rosatom successfully completed the experiment «Maneuver-1″, in which the parameters of nuclear fuel for VVER-1200 reactors were studied in the mode of daily maneuvering of the power of the reactor plant,» the message says.
The tests were carried out in the MIR research reactor at the site of the Dimitrovgrad Research Institute of Nuclear Reactors (NIIAR, part of the Rosatom scientific division) by order of TVEL JSC (the management company of the Rosatom Fuel Division). The object of the study was fuel elements (fuel rods) in various designs. “The test scenario in the research reactor provided a complete simulation of the operation of nuclear fuel in the mode of daily maneuvering of the power of the VVER-1200 power unit in an 18-month fuel cycle,” the report notes. 
The results of the experiment will be used, in particular, to confirm the reliability of nuclear fuel in the daily schedule of carrying a maneuvering load.
Based on the results of reactor tests and post-reactor studies, Russian nuclear fuel has fully confirmed its performance in the daily power maneuvering mode, the press release emphasizes.
«The results of the study confirmed that nuclear fuel produced by Rosatom fully retains its integrity and performance under conditions of multiple rapid changes in the linear power of the fuel element. This is another step towards justifying the operation of Russian high-power reactors in a maneuverable mode. Our industry research on increasing the efficiency of nuclear power generation are of significant interest on the part of foreign operators of nuclear power plants of Russian design. In particular, for VVER-1200 reactors this is a justification for operation in a maneuverable mode, for VVER-1000 reactors it is a justification for operating a power unit at increased power up to 107% of the nominal one,” the senior noted. Vice President for Scientific and Technical Activities of TVEL Alexander Ugryumov, whose words are given in the message. 
In world practice, nuclear power plants, as a rule, are operated in base load mode, and the balance of consumption and demand in the energy system is regulated through highly flexible generation (gas and hydropower), as well as electricity flows. Maneuvering the power of nuclear power units is relevant for individual regional or national energy systems with a high share of nuclear generation (for example, in energy-surplus regions this will help load all generating capacities more evenly).
In some countries where the share of renewable energy is growing, the power of which is not regulated and depends only on the weather, but there is no developed hydro generation or highly maneuverable gas power plants, maneuvering the power of nuclear power plants can be one of the solutions for more effectively balancing the energy system as a whole. Power maneuvering is expected to help improve the flexibility and efficiency of power systems, and ultimately become another factor in the competitiveness of nuclear power.
In 2020-2022, at the advanced Russian VVER-1200 power units of the Novovoronezh and Leningrad NPPs, the power unit operating modes were tested in a daily schedule of carrying a maneuverable load at various power levels. The plans of the Rosenergoatom concern (electric power division of Rosatom) include work to substantiate the possibility of introducing a daily regulation regime at VVER-1200 power units.
