Document: NUREG-0800
Document ID: f9d2d9cb-1d13-407e-ad7a-523fff64de06
Document Type: srp
Title: DC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1007/ML100740391.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.2
CFR Part: 
CFR Title: 

Content:
r meeting the requirements of this criterion. Meeting the requirements of GDC 50 provides assurance that a LOCA will not cause a containment structure, including its electrical penetrations, to exceed the design leakage rate, thus limiting the consequences of a LOCA. 8. Compliance with 10 CFR 50.63 requires that each light-water-cooled nuclear power plant be able to withstand and recover from an SBO of specified duration. As required by 10 CFR 50.63, electrical systems must be of sufficient capacity and capability to ensure that the core is cooled and that appropriate containment integrity is maintained in the event of an SBO. The capacity of any onsite dc sources required for SBO response must be verified as adequate to address the worst-case SBO load profile and specified duration. For new advanced light-water reactor applications that use passive safety systems (such as the AP1000) and do not include a spare, full-capacity alternate ac power source for coping with an SBO, the reviewer should ensure that (a) all safety-related functions can be performed without relying on ac power for 72 hours after the initiating event, and (b) the applicant has implemented an RTNSS process that conforms to Chapter C.IV.10 of RG 1.206. For COL applicants who reference a certified design, that certification addresses the implementation of the RTNSS process. RG 1.155 and SRP Section 8.4 describe guidance acceptable to the staff for meeting the requirements of 10 CFR 50.63. Meeting the requirements of 10 CFR 50.63 provides assurance that nuclear power plants will be able to withstand or cope with, and recover from, an SBO by providing capability for maintaining core cooling and an appropriate level of containment integrity. III. REVIEW PROCEDURES The primary objective in the review of the dc power system is to determine whether this system satisfies the acceptance criteria in Subsection II and will perform its design functions during normal plant operations, anticipated operational