Research of the Possibility of Operating a NPP Turbine Without a Stage of Damaged Blades

The reliability of nuclear power plants is a strategically important task. In case of damage to the blades of one of the stages, the possibility of further operation of the turbine needs to be justified. The paper considers the high-pressure cylinder of the K-1000-60/3000 turbine in the original design version and without the 5th stage blades of both turbine flows. A model of one-dimensional steam flow in the flowing part of a high-pressure cylinder was developed. The study of thermodynamic and kinematic parameters of the flow revealed insignificant differences in the operating conditions of the first three stages of the turbine and more significant for the 4th and 5th stages. A large decrease in the internal power of the turbine high-pressure cylinder by 15% was observed. A model of thermal and stress–strain state was developed for a high-pressure turbine rotor at typical operating conditions. A shift in the region of maximum stresses from the 5th pressure stage to the 4th and a general decrease in the level of stresses for all operating conditions were observed. The service life indicators of the rotor and the resistance of the base metal to fatigue damage accumulation were investigated. A general improvement in the turbine's service life was noted. In particular, the individual rotor service lifetime increases by 11.6%.