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:
ithout operator action, following a loss of both onsite and offsite ac power sources. Consequently, passive reactor designs meet the requirements of 10 CFR 50.63 for 72 hours. Meeting the requirements of 10 CFR 50.63 provides assurance that the nuclear power plant can be able to withstand or cope with, and recover from a station blackout and will ensure that core cooling and appropriate containment integrity are maintained. 8. 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) 8.2-14 Revision 4 - March 2007 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 EDG, a battery, a steam-driven pump, or an alternate ac power source). III. REVIEW PROCEDURES The reviewer will select material from the procedures described below, as may be appropriate for a particular case. These review procedures are based on the identified SRP acceptance criteria. For deviations from these acceptance criteria, the staff should review the applicant’s evaluation of how the proposed alternatives