Document: NRC Regulatory Guide
Document ID: 46049842-54a7-40a0-a0cc-ab115059f05e
Document Type: regulatory_guide
Title: Ultimate Heat Sink for Nuclear Power Plants + HISTORY - HISTORY DG-1275 , Proposed Revision 3, published 09/2013 (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1304/ML13043A624.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.27
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Content:
license under 10 CFR Part 50, or an application for a standard design certification, combined license, or standard design approval under 10 CFR Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants” (Ref. 2). Passive light-water reactors have significantly different design bases for the UHS than traditional plants that use active systems. For passive plants, the passive containment cooling system (PCCS) may DG-1275, Page 3 be used as the UHS. This system relies on transferring heat directly from the steel containment vessel to the environment. The guidance provided in this regulatory guide does not apply to passive plants that utilize a PCCS as their UHS. Purpose of Regulatory Guides The NRC issues regulatory guides to describe to the public methods that the staff considers acceptable for use in implementing specific parts of the agency’s regulations, to explain techniques that the staff uses in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations and compliance with them is not required. Paperwork Reduction Act This regulatory guide contains information collection requirements covered by 10 CFR Part 50 and 10 CFR Part 52 that the Office of Management and Budget (OMB) approved under OMB control number 3150-0011 and 3150-0151, respectively. The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number. B. DISCUSSION Reason for Revision This guide is being updated to address revisions in regulations and lessons learned from operating experience since the guide was last revised in January 1976, including system design considerations, natural phenomena and site hazards design criteria, and in-service testing and maintenance considerations. This revised guide contains information applicable to both