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:
abulation of all safety-related loads to be connected to each diesel generator is consistent with the informa- tion 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-ampfs 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 condition, or estimated load under expected flow and pressure) are used to verify the calculations establishing the combined load demand to be connected to each diesel during the "worst" operating condition. In applying this combined load demand to the selection of each diesel 8.3.1-12 Rev. 2 - July 1981 generator capacity, an acceptable design must satisfy Positions 1 and 2 of Regulatory Guide 1.9. To ensure that each diesel generator is capable of starting and accelerating to rated speed all the connected loads in the required sequence and within the minimum time intervals established by the accident analyses, the PSB reviewer examines for each diesel generator.the loading profile curves, voltage and frequency recovering characteristic curves, and the response time of the excitation system to load variations. This examination must verify that the capability of each diesel generator to respond to voltage and frequency variations satisfies Position 5 of Regulatory Guide 1.9. In addition, the adequacy of the circuit design for starting and disconnecting and connecting safety loads from and to each diesel generator is checked. This includes a review of the starting initiating circuits; manual and automatic sequential loading and unloading circuits; interrupting capacity of switchgear, load centers, control centers, and distribution panels- grounding requirements; and electrical protective relaying circuits including their coordination, relay settings, and assigned control power supplies for