Stress and fracture analyses of nuclear power plant LP turbine rotor discs

Fracture phenomenon has been reported on blades, rotors, connections and ro tor discs of LP turbines of nuclear power plants, which is caused by fatigu e, stress corrosion and erosion. In this study, as a tool of reliability ev aluation, a number of stress and fracture analyses were performed on the de fected area under various operating conditions using the finite element met hod. Possible defects on key-way and rotor disc were assumed to be two-dime nsional cracks and centrifugal force, temperature distribution and shrink-f it effect were included as external loads. From stress analysis results, st ress intensity factors were obtained and these values can be utilized to ev aluate reliability and predict remaining lifetime of the turbine discs.