Document: NUREG-0800
Document ID: bc7e4c14-0eaa-4591-a506-23d7893f8a00
Document Type: srp
Title: as establishing acceptable guidance for meeting the requirements of this criterion.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070498.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
e unacceptable. The basis for this conclusion is that the required frequent interconnections of the offsite and standby power supplies do not minimize the probability of their coincident loss (General Design CriterionGDC 17), nor can the design be made immune to common failure modes (Section 5.2.1(5) of IEEE Std 308). Further details amplifying the basis for this conclusion are included in Branch Technical Position ICSB 8 (PSB), which sets forth the basis for prohibiting the use of diesel-generator sets for purposes other than emergency standby power supplies. 4. Standby Power Supplies In ensuring that the requirements of General Design CriterionGDC 17 and IEEE Std 308 have been met with regard to the standby power supply diesel-generator sets having sufficient capacity and capability to supply the required distribution system loads, the design bases, design criteria, analyses, description, and implementation as depicted on electrical drawings and functional P&IDs, the diesel generator sets are reviewed to verify that the bases for their selection satisfy the positions of Regulatory Guide 1.9. Specifically, the reviewer first becomes familiar with the purpose and operation of each safety system, including system component arrangement as depicted on functional P&IDs, expected system performance as established in the accident analyses, modes of system operation and their interactions during normal and accident conditions, and interactions between systems. Following this, it is verified that the tabulation of all safety-related loads to be connected to each diesel generator is consistent with the information establishing the safety-related systems and loads and their required redundancy. The characteristics of each load (such as motor horsepower, volt-amp rating, in-rush current, starting volt-amps, and torque), the length of time each load is required, and the basis used to establish the power required for each safety load (such as motor nameplate rating, pump run-out