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:
otherwise, the starting air dew point should be controlled to at least 5.5EC (10EF) less than the lowest expected ambient temperature. 9.5.6-6 Revision 3 - March 2007 Technical Rationale The technical rationale for application of these acceptance criteria to the areas of review addressed by this SRP section is discussed in the following paragraphs: 1. GDC 2 requires that SSCs important to safety be designed to withstand the effects of natural phenomena like earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform safety functions. The EDESS safety function is to assure reliable starting of the emergency diesel engine following a loss of offsite power. Compliance with GDC 2 requirements ensures that natural phenomena events will not affect EDESS capability to start the emergency diesel engines. 2. GDC 4 requires that SSCs important to safety be designed to withstand such dynamic effects of pipe ruptures as pipe whip and jet impingement and externally- or internally-generated missiles. The EDESS safety function is to assure reliable starting of the emergency diesel engines following a loss of offsite power. Compliance with GDC 4 provides assurance that the dynamic effects of equipment failures and events outside the plant will not affect EDESS capability to start the emergency diesel engines. 3. GDC 5 prohibits the sharing of SSCs important to safety among nuclear power units unless such sharing can be demonstrated not to impair their ability to perform safety functions, including in an accident in one unit an orderly shutdown and cooldown of the remaining unit. The EDESS safety function is to assure reliable starting of the emergency diesel engines in a loss of offsite power. Compliance with GDC 5 provides assurance that EDESS failures occurring in one unit will not propagate to other units of the site. 4. GDC 17 requires an onsite electric power system for the functioning of SSCs important to safety. GDC 17 requires the