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:
973 to describe design limits and loading combinations for metal primary reactor containment system components that the NRC staff considered acceptable for use in nuclear power plants to prevent undue risk to the health and safety of the public. Reasons to revise the existing regulatory guide include (1) making it consistent with other similar regulatory guides, (2) including interim or current staff positions regarding new or advanced reactors, (3) reducing unnecessary conservatism, and (4) updating in accordance with the ASME Boiler & Pressure Vessel Code and removing some of the exceptions that the staff had previously taken from the1971 edition and addenda (because more recent editions have included those exceptions). Therefore, revision of this regulatory guidance is necessary to reflect current conditions. 2. Objective The objective of this regulatory action is to update the NRC’s guidance with respect to design limits and loading combinations for metal containments. This will give applicants and licensees the opportunity to take advantage of the Code requirements and current staff positions, which should lead to increased regulatory effectiveness by avoiding unnecessary conservatism that offers little or no safety benefit. 3. Alternative Approaches The NRC staff considered the following alternative approaches to the problem of outdated guidance regarding metal containments: (1) Do not revise Regulatory Guide 1.57. (2) Update Regulatory Guide 1.57. 3.1 Alternative 1: Do Not Revise Regulatory Guide 1.57 Under this alternative, the NRC would not revise this guidance, and licensees would continue to use the 1973 version of this regulatory guide. This alternative is considered the baseline or “no action” alternative and, as such, involves no value/impact considerations. DG-1158, Page 11 3.2 Alternative 2: Update Regulatory Guide 1.57 Under this alternative, the NRC would update Regulatory Guide 1.57 with the updated Code requirements and current staff