Document: NUREG-0800
Document ID: 81256f55-72dd-4777-9472-f373c71c4554
Document Type: srp
Title: AC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550065.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
rements of 10 CFR 50.63 if it can establish and maintain safe shutdown conditions for the specified duration of the station blackout event, without operator action, following a loss of both onsite and offsite ac power sources. Detailed reviews to verify the that evolutionary and passive ALWR design applications satisfy the requirements of 10 CFR 50.63 are covered in SRP Section 8.4, "Station Blackout." Meeting the requirements of 10 CFR 50.63 provides assurance that the nuclear power plant will be able to withstand or cope with, and recover from, an SBO and will ensure that core cooling and appropriate containment integrity are maintained. 9. 10 CFR 50.65 (a)(4) requires that licensees assess and manage the increase in risk that may result from proposed maintenance activities before performing the maintenance activities. Grid stability and offsite power availability are examples of emergent conditions that may result in the need for action prior to the conduct of the assessment or that could change the conditions of a previously performed assessment. Accordingly, licensees should perform grid reliability evaluations as part of the maintenance risk assessment before performing “grid-risk-sensitive” maintenance activities (such as surveillances, post-maintenance testing, and preventive and corrective maintenance). Such activities are those which could increase risk under existing or imminent degraded grid reliability conditions, including (1) conditions that could increase the likelihood of a plant trip, (2) conditions that could increase the likelihood of a LOOP or SBO, and (3) conditions that could have an impact on the plant’s ability to cope with a LOOP or SBO, such as out-of-service risk-significant equipment (for example, an emergency diesel generator (EDG), a battery, a steam-driven pump, or an AAC power source). III. REVIEW PROCEDURES The primary objective in the review of the ac power system is to determine that this system satisfies the acceptance