Document: NUREG-0800
Document ID: b4cff877-ab63-46c3-8140-32e309d767a2
Document Type: srp
Title: EMERGENCY DIESEL ENGINE STARTING SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070571.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.5.6
CFR Part: 
CFR Title: 

Content:
wn condition, and to prevent or mitigate the consequences of accidents. Compliance with the requirements of GDC 2 ensures that emergency ac power will be available to safety- related components in the event of a loss of offsite power resulting from natural phenomena events. 2. GDC 4 requires that SSC important to safety be designed to withstand the dynamic effects of pipe ruptures such as pipe whip and jet impingement, and externally or internally generated missiles. The safety function of the EDESS is to start the emergency diesel engines following a loss of offsite power or as otherwise required by the plant protection circuitry. In order to ensure the availability of emergency ac power, the EDESS must be capable of performing the engine start function under the expected operational and postulated accident conditions for the plant. These conditions include consideration of the dynamic effects of equipment failures such as pipe ruptures and turbine missiles, and events and conditions external to the plant. Compliance with GDC 4 provides assurance that the dynamic effects of equipment failures, and events external to the plant, will not affect the capability of the EDESS to start the emergency diesel engines. 3. GDC 5 prohibits the sharing of SSC important to safety among nuclear power units unless it can be demonstrated that such sharing will not significantly impair their ability to perform their safety functions, including in the event of an accident in one unit, an orderly shutdown and cooldown of the remaining unit. The safety function of the EDESS is to start the emergency diesel engines in the event of a loss of offsite power or as otherwise required by the plant protection circuitry. In order to ensure the availability of emergency ac power to safety-related components, the EDESS must be designed to perform this safety function in each unit regardless of events, failures, and conditions in DRAFT Rev. 3 - April 1996 9.5.6-6 the other unit(s). Compliance with