Revalidation Program for Nuclear Standby Diesel Generators

This paper describes the program which Duke Power Company carried out to revalidate the diesel engines used in diesel generators for nuclear standby service at Unit 1 of the Catawba Nuclear Station. This program included: (1) Performance of extended operation tests to accumulate about 10 million stress cycles on parts (2) Thorough extensive engine disassemblies and inspections. (3) Participation in the TDI diesel Owners Group (4) Completion of regulatory requirements (5) Completion of enhanced Return to Service Tests The diesels operated satisfactorily during the tests, and only relatively minor conditions were noted during the test and inspections, with one exception. This exception was that cracks were detected in the piston skirts. The piston skirts have been replaced with improved design skirts. The diesels have been fully revalidated for their intended service, and have been declared operable.