Document: NRC Regulatory Guide
Document ID: 2e29f931-cdf2-4faa-a9e4-5d7cb237e57f
Document Type: regulatory_guide
Title: Service Limits and Loading Combinations for Class 1 Plate-and-Shell-Type Component Supports + HISTORY – HISTORY 10/2006 – DG-1169 , Proposed Revision 2
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063000484.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.130
CFR Part: 
CFR Title: 

Content:
ies with the size of the bolt. For this reason, the increases permitted by NF-3221.2 and F-1332 of Section III do not directly apply to bolts and bolted connections. For bolts, allowable increases for Service Levels B, C, and D are specified in NF-3225. Design by Load Rating NF-3280 specifies load ratings for Service Level A, B, and C limits. F-1332.7 specifies the load rating for the Service Level D limit. Design by Experimental Stress Analysis Although II-1430 in Appendix II to Section III defines the test collapse load for the experimental- stress-analysis method, it does not delineate the method’s design limits or various operating condition categories. The interim method described in this guide remedies this deficiency. Large Deformations The design of component supports is an integral part of the design of a system and its components. A complete and consistent design is possible only when the interaction between the system, component, and component support is properly considered. When all three are evaluated on an elastic basis, the interaction is usually valid because individual deformations are small. However, if the design process uses plastic-analysis methods, large deformations may occur that would result in substantially different stress distributions. DG-1169, Page 4 For the evaluation of Level D service limits, Appendix F to Section III permits the use of plastic-analysis methods in certain acceptable combinations for all three elements. The selection of these acceptable combinations assumes that component supports are more deformation sensitive (i.e., their deformation in general will have a large effect on the stress distribution in the system and its components). Because large deformations always affect stress distribution, care should be exercised even when using the plastic-analysis method in the methodology combination approved in Appendix F. This is especially important for identifying buckling or instability problems when the change of