Proven Methods to Repair and Extend the Life of Low Pressure Turbine Rotors

Much of the world’s Steam Turbine Generator fleet was commissioned well over 40 years ago. These turbine generator sets have had many in-service issues leading to poor reliability and in some cases, requiring full turbine and generator replacements. On the turbine side, most issues, as documented by EPRI surveys, have been related to the low pressure turbines. Discovery of issues during planned shutdown inspections such as rotor shaft cracking, stress corrosion cracking (SCC) of dovetails, and blade reliability concerns can be addressed without the costly replacement of the full rotor/blade components. This paper will review and provide actual case studies of methods to repair and extend the life of these components.