Document: NUREG-0800
Document ID: d9e9d0a9-6390-4154-94dc-7d5e6d8145cd
Document Type: srp
Title: A-C POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350489.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
e testing of components and a replacement plan as specified in subsection 1I. e. The repair and maintenance procedures provide for a final equipment check and test procedures provide for returning the diesel engine to automatic standby service and under the control of the control room operator. f. Operating experience at certain nuclear power plants which have two cycle turbocharged diesel engines manufactured by the Electromotive Division (EMD) of General Motors driving emergency generators have experienced a significant number of turbocharger mechanical gear drive failures occurring as the result of running the emergency diesel generators at no load or light load conditions for extended periods. When this equipment is operated under no load conditions insufficient exhaust gas volume is generated to operate the turbocharger; as a result the turbocharger is driven mechanically from a gear drive in order to supply enough combustion air to the engine to maintain rated speed. The turbocharger and mechanical drive gear normally supplied with these engines are not designed for standby service encountered in nuclear power plant application where the equipment may be called upon to operate at no load or light load condition and full rated speed for a prolonged 8.3.1-15 Rev. 2 - July 1981 period, where no load speeds for the engine and generator are much lower than full load speeds. The locomotive turbocharger diesel hardly ever runs at full speed except at full load. EMD has developed heavy duty turbo charger mechanical drive gear assemblies for installation on their diesel engines. EMD diesel engines drives proposed for driving emergency generators for nuclear power plants should be provided with heavy duty turbocharger mechanical drive gear assembly as recommended by the manufacturer. The reviewer verifies that the EMD diesel engine is provided a heavy duty turbocharger mechanical gear drive assembly to assure optimum availability of the emergency generators on demand.