Document: NRC Regulatory Guide
Document ID: 1d715751-9321-4481-a46f-4ff802a5efe0
Document Type: regulatory_guide
Title: Service Limits and Loading Combinations for Class 1 Linear-Type Supports + HISTORY – HISTORY 10/2006 – DG-1168 , Proposed Revision 2
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063000449.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.124
CFR Part: 
CFR Title: 

Content:
, as defined above. System Mechanical Loadings. The static and dynamic loadings developed by the system operating parameters—including deadweight, pressure, and other external loadings—and effects resulting from constraints of free-end movements, but excluding effects resulting from thermal and peak stresses generated within the component support. Ultimate Tensile Strength. Material property based on the engineering stress-strain relationship. Critical Buckling Strength. The strength at which lateral displacements start to develop simultaneously with in-plane or axial deformation. 3 ASME Boiler and Pressure Vessel Code, Section III, Division I, 2001 Edition through the 2003 Addenda. 4 If the function of a component support is not required during a plant condition, satisfaction of the design limits of the support for that plant condition is not needed, provided excessive deflection or failure of the support will not result in the loss of function of any other safety-related system. DG-1168, Page 6 C. REGULATORY POSITION The construction of ASME Code3 Class 1 linear-type component supports, excluding snubbers, which this guide does not address, should follow the rules of Subsection NF of Section III as supplemented by the following stipulations:4 1. The classification of component supports should, as a minimum, be the same as that of the supported components. 2. The ASME Code Level A and B service limits for component supports designed by linear-elastic analysis, which are related to Sy, should meet the appropriate stress limits of Subsection NF of Section III of the ASME Code, but should not exceed the limit specified when the value of 5/6 Su is substituted for Sy. Examples are shown below in Regulatory Positions 2a, 2b, and 2c: a. The tensile stress limit Ft for a net section, as specified in NF-3322.1(a)(1) of Section III, should be the lesser of two values, 0.6Sy or 0.5Su, at temperature. For net sections at pinholes in eyebars, pin-connected plates, or