Document: NRC Regulatory Guide
Document ID: 10f3c2aa-ada2-4132-8d49-7867458d81a7
Document Type: regulatory_guide
Title: Design Limits and Loading Combinations for Metal Primary Reactor Containment System Components + HISTORY - HISTORY 10/2006 – DG-1158 , Proposed Revision 1
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063000278.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.57
CFR Part: 
CFR Title: 

Content:
y I structures4 should be designed to withstand the following loads and loading combinations within the specified design limits. 1.1 Loads D -------Dead loads. L -------Live loads, including all loads resulting from platform flexibility and deformation, as well as crane loading, if applicable. Pt -------Test pressure. Tt-------Test temperature. To ------Thermal effects and loads during startup, normal operating, or shutdown conditions, based on the most critical transient or steady-state condition. Ro ------Pipe reactions during startup, normal operating, or shutdown conditions based on the most critical transient or steady-state condition. Po-------External pressure loads resulting from pressure variation either inside or outside containment. E -------Loads generated by the operating-basis earthquake including sloshing effects, if applicable. E’ ------Loads generated by the SSE, including sloshing effects. Pa-------Pressure load generated by the postulated pipe break accident, pool swell, and subsequent hydrodynamic loads.5 Ta-------Thermal loads under thermal conditions generated by the postulated pipe break accident, including To , pool swell, and subsequent hydrodynamic reaction loads.5 Ra ------Pipe reactions under thermal conditions generated by the postulated pipe break accident, including Ro, pool swell, and subsequent hydrodynamic reaction loads.5 4 Components of primary reactor containment systems are Seismic Category I for seismic design purposes in accordance with Regulatory Guide 1.29, “Seismic Design Classification.” Seismic Category I SSCs are designed to remain functional if the SSE occurs. 5 For load combinations 1.2.3.1(5), 1.2.3.3(3), and 1.2.3.4(2), a small or intermediate pipe break is postulated. For all other load combinations involving a loss of coolant accident (LOCA), the design-basis LOCA is postulated. DG-1158, Page 6 Ps-------All pressure loads that are caused by the actuation of safety relief valve (SRV) discharge, including pool