Document: NRC Regulatory Guide
Document ID: a4944d20-ef6e-480b-a45d-14425bedd2e5
Document Type: regulatory_guide
Title: ASME Code Cases Not Approved for Use (Rev. 8)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2219/ML22196A065.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.193
CFR Part: 
CFR Title: 

Content:
e NRC has not yet endorsed Section III, Division 3. Thus, it would not be appropriate to approve an Code Case that is an alternative to the provisions in Section III, Division 3. 11/2/04 1/11/21 N-717 Requirements for Construction of Storage Containments for Spent Nuclear Fuel and High Level Radioactive Waste and Material, Section III, Division 3 The NRC has not yet endorsed Section III, Division 3. Therefore, it would not be appropriate to approve an Code Case that is an alternative to the provisions in Section III, Division 3. 5/4/04 Annulled 1/4/08 N-721 Alternative Rules for Linear Piping Supports, Section III, Division 1 Code Case N-721 allows the use of ANSI/AISC N690L-03, “Load and Resistance Factor Design (LRFD) Specification for Safety-Related Steel Structures for Nuclear Facilities.” ANSI/AISC N690L-03 provides an alternative method of design to that given in ANSI/AISC N690-1994, “Specification for the Design, Fabrication, and Erection of Safety-Related Steel Structures for Nuclear Facilities,” including Supplement No. 2, which is based on Allowable Stress Design (ASD) specification. The LRFD method is a probabilistic method developed to provide uniform practice in the design of steel structures for nuclear facilities. The LRFD method uses many factors, including one factor per resistance, and one factor for each of the different load types, whereas the ASD method uses one factor of safety. The ASD method is a deterministic and normally 9/9/08 DG-1408, Page 27 CODE CASE NUMBER TABLE 4 ANNULLED OR SUPERSEDED UNACCEPTABLE SECTION III CODE CASE ANNULLMENT / REVISION DATE conservative method and has been approved by the NRC for use in the design of new reactors. The LRFD method continues to undergo development. Code Case N-721 was developed based on N690L-03 which has subsequently been superseded by N690L-06. Thus, the Code Case is not up-to-date. In addition, questions regarding uncertainty remain with regard to the probabilistic treatment of loads