Document: NUREG-0800
Document ID: 6d95bc89-e14a-4d87-bf91-1d1760c2aff8
Document Type: srp
Title: FOUNDATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1235/ML12353A388.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.8.5
CFR Part: 
CFR Title: 

Content:
ments. In addition, the documents listed in Subsection II.2 of SRP Section 3.8.1 are acceptable for the containment foundation. 3.8.5-8 Draft Revision 4 - December 2012 3. Loads and Load Combinations. The specified loads and load combinations used in the design of Seismic Category I foundations are acceptable if found to be in accordance with those combinations referenced in Subsection II.3 of SRP Section 3.8.1 for the containment foundation and with those combinations listed in Subsection II.3 of SRP Section 3.8.4 for all other Seismic Category I foundations. In addition to the load combinations referenced above, the combinations used to check against sliding and overturning attributable to earthquakes, winds, tornadoes and against flotation because of floods are acceptable if found to be in accordance with the following: A. D + H + E B. D + H + W C. D + H + E' D. D + H + Wt E. D + F' Where D, E, W, E', and Wt are as referenced in Subsection II.3 of SRP Section 3.8.4, where H is the lateral earth pressure, and F' is the buoyant force of the design-basis flood. Justification should be provided for including live loads or portions thereof in these combinations. As noted in Appendix S to 10 CFR Part 50, the operating-basis earthquake (OBE), designated as E above, is only associated with plant shutdown and inspection unless the applicant specifically selects it as a design input. If the OBE is set at one-third or less of the safe-shutdown earthquake (SSE) ground motion, an explicit response or design analysis is not required. If the OBE is set at a value greater than one-third of the SSE, an analysis and design must be performed to demonstrate that the Seismic Category I foundations remain functional and fall within applicable stress, strain, and deformation limits. SRP Section 3.7 provides additional guidance on OBE use. 4. Design and Analysis Procedures. The design and analysis procedures used for Seismic Category I foundations are acceptable if found to be in