Аннотация:Measures directed to increases of power application coefficient (PAC) should be taken to increase NPP operation efficiency. Apart from PAC increase the cycle of reactor operation prolonged, as compared to the rated one, provides for reduction of expenses for substitutional power at power unit shutdown for refuelling. Fuel cycles calculated for 12, 18 and 24 months meet seasonal variations in power consumption, as far as they enable to conduct refuelling and preventive maintenance in summer and autumn when power consumption is minimal one. Main characteristics of refuelling rated conditions, fuel cycle with ≈1÷5 annually reloading quantity of all fuel assemblies, 4-year fuel cycle, as well as, two fuel cycles with increased power generation between reloadings, are presented. One power unit with VVER-400 during its operation time (30 years) is shown to have opportunity to generate additionally about 3 billion kWh due to intensification of main equipment operation.