Document: NRC Regulatory Guide
Document ID: 111e064c-2d28-4647-872a-806b29019408
Document Type: regulatory_guide
Title: Design Limit and Loading Combinations for Seismic Category I Fluid System Components
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1229/ML12298A124.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.48
CFR Part: 
CFR Title: 

Content:
prinoary membrane and primary bending stresses. ASME Code Class 2 Vessels (Designed to Division 2 of Section VIII) Section III of the ASME Code allows Code Class 2 vessels to be designed in accordance with the rules of Division 2 to Section VIII of the ASME Code. Division 2 to Section VIII provides rules for design by analysis that are equivalent to those of Section III for Code Class I vessels. In addition, the quality level for Division 2 vessels is comparable to that for Code Class I vessels of Section III. Therefore, the design limits for the loading combinations delineated in regtilatory position 7. should be tile same as those for Code Class I vessels in regulatory position I. ASME Code Class 2 and 3 Piping NC-3600 of Section ill of the ASME Code land by reference ND-3600) provides design limits for piping under "Upset Conditions" and "Emergency Conditions" which are analogous to tile upset and emergency operating condition category design lilmits specified in NB-3600 for Code Class I piping. In utilizing these design limits'for assurance of pressure-retaining integrity, the "Upset Condition" limits should not be exceeded for the combination of loadings delineated in regulatory positions 8.a.(I), and 8.a.(2). and the "Emnergency Condition" limits should not be exceeded for the combination of loadings specified in regulatory position 8.b. However, only equation 9 of NC-3651 need he met for the loadings designated in regulatory position 8.a.(2) since thermal expansion effects of piping are not usually evaluated for these loadings. Non-Active ASME Code Class 2 and-3 Pumps Design limits were selected for Code Class 2 and 3 pumps in the absence of Section III of the ASME Code design rules for these components. These design limits relate to both primary membrane and primary bending stresses~and are derived on a basis that is comparable to the design limits for Code Class I components designed by analysis. One hundred ten percent of S and 120 percent of S (and the