Document: NUREG-0800
Document ID: 97120913-d26f-4324-ab62-22f3f5b73925
Document Type: srp
Title: and 8.3.2.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600410.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
if these use a common transmission tower, transformer, or a breaker in a remote switchyard or substation. The station layout and the grid system layout drawings are reviewed to determine that all the above events were included in the analysis. Branch Technical Position 8-6, industry standards (e.g., References 46 & 48), and, for COL applications, Regulatory Guide 1.206 (Section C.I.8.2.2) provide further information for the reviewer regarding stability studies of offsite power systems. 8.2-17 Revision 4 - March 2007 The reviewer verifies that the grid stability analysis considers the effect of grid events on the adequacy of offsite grid voltage available at the plant switchyard. Operating experience has shown that a variety of factors, such as, power flow through the transmission grid, reactive power capacity, the plant voltage and frequency protective schemes and setpoints, and weather or temperature conditions in the region can all affect grid voltage levels and overall stability. Branch Technical Position 8-6 and References 21, 25, 29, 30, and 43 provide information for the reviewer regarding degraded transmission grid voltage and the effects of grid events on grid voltage at the plant switchyard. The applicant should include in the grid stability analysis the consideration of failure modes that could result in ac frequency variations exceeding the maximum rate of change determined in the accident analysis for loss of reactor coolant flow. Failure modes that could produce abnormal frequency events and the plant frequency protection schemes are reviewed. Abnormal frequency operating experience from the assessment of grid transient events (Reference 43) and industry standards (Reference 54) provide further information on abnormal frequency considerations at nuclear power plants. Passive reactor designs incorporate passive safety-related systems for core cooling and containment integrity and therefore, do not depend on the electric power grid connection and grid