Document: NUREG-0800
Document ID: ed02b850-92b8-49b0-bb93-6c21528c5133
Document Type: srp
Title: EMERGENCY DIESEL ENGINE STARTING SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550034.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.5.6
CFR Part: 
CFR Title: 

Content:
to its operation. The essential EDESS portions necessary to shut down the reactor down safely or to mitigate the consequences of an accident are designed to seismic Category I and Quality Group C. The staff concludes that the EDESS design is acceptable and meets the requirements of GDCs 2, 4, 5, and 17. This conclusion is based on the following findings: 1. The applicant has met the requirements of GDC 2, "Design Bases for Protection Against Natural Phenomena," for the ability of structures housing the EDESS and the system itself to withstand the effects of natural phenomena like earthquakes, tornadoes, hurricanes, and floods and GDC 4, "Environmental and Dynamic Effects Design Bases," for the ability 9.5.6-9 Revision 3 - March 2007 of structures housing the system and the system to withstand the effects of externally- and internally-generated missiles, pipe whip, and jet impingement forces of pipe breaks. The EDESS is housed in a seismic Category I structure which protects it from the effects of tornados, tornado missiles, turbine missiles, and floods. This protection meets the positions of RGs 1.115, "Protection Against Low-Trajectory Turbine Missiles," Position C.1, and 1.117, "Tornado Design Classification," Appendix Position 13. 2. The applicant has met the requirements of GDC 5, "Sharing of Structures, Systems and Components," for the ability of shared systems and components important to safety to perform required safety functions. Each unit of the plant has its own emergency diesel generators with an EDESS not shared between other diesel generators. 3. The applicant has met the requirements of GDC 17, "Electric Power Systems," for the ability of the air starting system to meet independence and redundancy criteria. Each EDESS is independent and physically separated from the other system serving the redundant diesel generator. A single failure in any one of the systems will affect only its own diesel generator. Each of the starting systems can crank a cold