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:
omponents. 2. The critical buckling strength should always limit the service limits for component supports designed by linear-elastic analysis. The calculation of critical buckling strength should use material at temperature properties. Critical buckling stresses for Service Level A, B, C, and D limits should be maintained in accordance with NF-3522, NF-3622, and F-1332.5 for loadings combined according to Regulatory Position 3 (below). Service limits related to critical buckling strength should not increase unless the ASME Code specifically allows such an increase. 3. For component supports subjected to the combined loadings of (1) the vibratory motion of the OBE and (2) system mechanical loadings associated with either the ASME Code design 4 condition or normal or upset plant conditions, the design approach should be as follows: 5, 6 a. Component supports designed by the linear-elastic-analysis method should not exceed (1) the service limits of NF-3522 and NF-3622 for design loadings and level A and B service limits and (2) Regulatory Position 2 (above). b. Component supports designed by the load-rating method should not exceed the load rating for Level A or B limits of NF-3280 of Section III. c. Component supports designed by the experimental-stress-analysis method should not exceed the test collapse load determined by II-1430 of Section III divided by 1.7. 4. The design of component supports subjected to the system mechanical loadings associated with 4 the emergency plant condition should adhere to the following design limits, except when the normal function of the supported system is to prevent or mitigate the consequences of events associated with the emergency plant condition (Regulatory Position 6 then applies):5,6 DG-1169, Page 7 a. Component supports designed by the linear-elastic-analysis method should not exceed the service limits of NF-3522 and NF-3622 of Section III and Regulatory Position 2. b. Component supports designed by the load-rating method