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:
ever, all increases (i.e., those allowed by NF-3321.1(a) and F-1334) should always be subject to the limits in NF-3321.1(b). Material properties at temperature should be used to calculate the critical buckling strengths defined by NF-3321.1(b). As specified in F-1335, the allowable increase in tensile stress for bolts should not exceed the lesser value of 0.70 Su or Sy, at temperature, and the allowable increase in shear stress for bolts should not exceed the lesser value of 0.42 Su or 0.6 Sy, at temperature. 5 System mechanical loadings include all non-self-limiting loadings and the effects resulting from constraints of free-end displacements, but not the effects resulting from thermal or peak stresses generated within the component support. 6 Because component supports are deformation sensitive in the performance of their service requirements, satisfying these criteria does not ensure that their functional requirements will be fulfilled. Any deformation limits specified by the design specification may be controlling and should be satisfied. 7 Because the design of component supports is an integral part of the design of the system and the component, the designer should make sure that methods used for the analysis of the system, component, and component support are compatible. The designer of component supports should consider large deformations in the system or components. DG-1168, Page 7 If the increased service limit for stress range by NF-3321.1(a) is more than 2Sy or Su, its limit should be the lesser of two values, 2Sy or Su, unless a shakedown analysis justifies it. 4. The limits in Regulatory Positions 4a – 4d should apply to the design of component supports subjected to the combined loadings of system mechanical loadings5 associated with (1) either the ASME Code design condition or the normal or upset plant conditions, and (2) the vibratory motion of the OBE.5, 6 a. Component supports designed by using the linear-elastic-analysis method should not exceed