Document: NUREG-0800
Document ID: 8e754440-b70e-4b8a-9816-b4a64b631220
Document Type: srp
Title: Initial – February 2012
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1136/ML113640138.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
CFR Part: 
CFR Title: 

Content:
if severe weather conditions are anticipated. • The system load dispatcher will be contacted once per day to ensure no significant grid perturbations (high grid loading unable to withstand a single contingency of line or generation outage) are expected during the extended AOT. • Component testing or maintenance of safety systems and important non safety equipment in the offsite power systems that can increase the likelihood of a plant transient (unit trip) or LOOP will be avoided. In addition, no discretionary switchyard maintenance will be performed. • TS required systems, subsystems, trains, components, and devices that depend on the remaining power sources will be verified to be operable and positive measures will be provided to preclude subsequent testing or maintenance activities on these systems, subsystems, trains, components, and devices. • Steam-driven emergency feed water pump(s) in case of PWR units, and Reactor Core Isolation Cooling and High Pressure Coolant Injection systems in case of BWR units, will 8-8-6 Initial - February 2012 be controlled as “protected equipment.” In summary, in light of the recent experiences in grid outages, it is the staff’s position that the availability of an additional power source is a condition for approval of the extended EDG or offsite power AOT. Therefore, a supplemental power source must be available when extending the current AOT allowed by the plant TS for a single inoperable EDG or offsite power source up to 14 days provided the extended AOT is also supported by a risk-informed evaluation. License amendments requesting an extended EDG or offsite power AOT without a risk-informed evaluation must include adequate justification for the requested AOT based solely on deterministic criteria. Licensees requesting an extension of the onsite or offsite AOT should either install permanently, or make available on a temporary basis, a supplemental AC source capable of powering the inoperable onsite or offsite