Document: NUREG-0800
Document ID: 10bc45c3-8e70-44ed-a57b-2dd08d4ef847
Document Type: srp
Title: SEISMIC SUBSYSTEM ANALYSIS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070640313.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.3
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ria that are necessary and sufficient to provide reasonable assurance that, if the inspections, tests, and analyses are performed and the acceptance criteria met, the facility has been constructed and will operate in conformity with the combined license, the provisions of the Atomic Energy Act, and the NRC's regulations. SRP Acceptance Criteria Specific SRP acceptance criteria acceptable to meet the relevant requirements of the NRC’s regulations identified above are as follows for the review described in this SRP section. The SRP is not a substitute for the NRC’s regulations, and compliance with it is not required. However, an applicant is required to identify differences between the design features, analytical techniques, and procedural measures proposed for its facility and the SRP acceptance criteria and evaluate how the proposed alternatives to the SRP acceptance criteria provide acceptable methods of compliance with the NRC regulations. 1. Seismic Analysis Methods. The acceptance criteria provided in SRP Section 3.7.2, subsection II.1, are applicable. 2. Determination of Number of Earthquake Cycles. During the plant life at least one safe shutdown earthquake (SSE) and five operating basis earthquakes (OBEs), if applicable, should be assumed. The number of cycles per earthquake should be obtained from the time history used for the system analysis, or a minimum of 10 maximum stress cycles per earthquake may be assumed. When the OBE is defined as less than one-third the SSE (and therefore the OBE does not need to be considered in design), there may be certain structural elements which still need to be evaluated for fatigue due to the OBE induced stress cycles. In these instances, the guidance for determining the number of earthquake cycles for use in fatigue calculations should be the same as the guidance provided in SRM for SECY-93-087 dated July 21, 1993 for piping systems. The number of earthquake cycles to consider are two SSE events with 10 maximum stress