Document: NRC Regulatory Guide
Document ID: 10f3c2aa-ada2-4132-8d49-7867458d81a7
Document Type: regulatory_guide
Title: Design Limits and Loading Combinations for Metal Primary Reactor Containment System Components + HISTORY - HISTORY 10/2006 – DG-1158 , Proposed Revision 1
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063000278.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.57
CFR Part: 
CFR Title: 

Content:
ill be designed to be capable of performing their containment function as long as required to prevent or mitigate the spread of radioactive material, and that they can withstand the effects of natural phenomena and other external events and maintain the plant in a safe condition. 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 regulatory guides is not required. The NRC issues regulatory guides in draft form to solicit public comment and involve the public in developing the agency’s regulatory positions. Draft regulatory guides have not received complete staff review and, therefore, they do not represent official NRC staff positions. This regulatory guide contains information collections, covered by the requirements of 10 CFR Part 50, that the Office of Management and Budget (OMB) has approved under OMB control number 3150-0011. 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. DG-1158, Page 3 B. DISCUSSION Background The American Society of Mechanical Engineers (ASME) publishes the “Rules for Construction of Nuclear Facility Components,” as Section III of the ASME B&PV Code.1 In that section, Division 1, Subsection NE sets forth the rules for Class MC components, which include metal containments and appurtenances, as well as metal portions of concrete containments that are not backed by concrete. (ASME B&PV Code Section III, Division 1, is hereinafter referred to as “the Code.”) However, the existing industry codes and standards are based on the current class of