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
CFR Part: 
CFR Title: 

Content:
he U.S. Nuclear Regulatory Commission (NRC) that nuclear power plant facility licensees and applicants can use to establish ultimate heat sink (UHS) features of plant systems required by NRC rules and regulations. Applicable Rules and Regulations General Design Criterion (GDC) 1, “Quality Standards and Records,” in Appendix A, “General Design Criteria for Nuclear Power Plants,” to Title 10 of the Code of Federal Regulations, Part 50, “Domestic Licensing of Production and Utilization Facilities (10 CFR Part 50) (Ref. 1) requires in part, that structures, systems, and components (SSCs) important to safety shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Where generally recognized codes and standards are used, they shall be identified and evaluated to determine their applicability, adequacy, and sufficiency and shall be supplemented or modified as necessary to assure a quality product in keeping with the required safety function. A quality assurance program shall be established and implemented in order to provide adequate assurance that these SSCs will satisfactorily perform their safety functions. GDC 2, “Design Bases for Protection Against Natural Phenomena,” requires that SSCs important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions. The design bases for these SSCs shall reflect: (1) appropriate consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated, DG-1275, Page 2 (2) appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena, and (3) the