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:
enforced by a formal contract or other means and include notification requirements to inform the NPP when the grid is stressed to the point where a trip of the NPP would result in inadequate post-trip switchyard voltages (less than the design basis voltage) for either actual grid conditions or potential (i.e., anticipatory contingency) grid conditions within any predetermined time limits. Additionally, the reviewer may perform independent calculations using the electronic copy of the model of the onsite distribution system provided by the applicant to ensure that each offsite power circuit has sufficient capacity and capability to provide power to the safety loads. See Section 8.3 for details. The reviewer should also review the description of the analysis tool used by the TSO to determine, in real time, the impact that the loss or unavailability of various transmission system elements will have on the condition of the transmission system to ensure that adequate post-trip voltages are available at the switchyard. The true capability of the offsite source cannot necessarily be verified through direct readings of plant switchyard or safety bus voltages. Recent operating experience (Reference 43) has shown that analyses of the surrounding grid and plant conditions, based on accurate and timely transmission system data, are needed to evaluate all possible contingencies at a given time. The reviewer should verify that adequate status information, communications, analytical resources, and procedures are provided to determine that the plant is operating within the offsite power grid operability limits required by GDC 17 and the plant’s TS. The information and guidance provided in NRC generic communications (Reference 21), industry standards (Reference 50), and other NRC documents (e.g., References 22, 24, 25, 29, 30, and 43) are useful in the review of the adequacy and reliability of the plant’s interface with the offsite power grid and communication with offsite