Document: NUREG-0800
Document ID: 7c104096-d040-463a-a94b-a0af08ab3478
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, STRUCTURES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0702/ML070230008.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
from the test and confirmation by additional testing to substantiate the effectiveness of the corrective action. 2. For seismic system analysis review, the following review procedures are implemented. A. Seismic Analysis Methods. For all Category I systems, components, equipment, and their supports (including supports for conduit and cable trays and ventilation ducts), the applicable methods of seismic analysis (response spectra, time history, equivalent static load) are reviewed for whether the techniques are in accordance with the acceptance criteria in subsection II.2.A of this SRP section. Common industry practice is to assume rigid and fixed attachments between the seismic subsystems (i.e., equipment and piping) and the supporting seismic systems (i.e., structures). This assumption allows neglect of the influence of the anchorage system stiffness on the dynamic response. In some cases, particularly for heavy equipment, this assumption potentially can cause under-estimation of seismic loadings. For new applications, the reviewer should verify whether appropriate assumptions have been made in the seismic analyses as to the stiffness of the seismic subsystem anchorage. B. Determination of Number of Earthquake Cycles. The number of earthquake cycles during one seismic event, the maximum number of cycles for which applicable systems and components are designed, and the applicant’s criteria and procedures to establish these parameters are reviewed by the staff in accordance with the guidance in SRP Section 3.7.3. C. Basis for Selection of Frequencies. As applicable, criteria or procedures to separate fundamental frequencies of components and equipment from the forcing frequencies of the support structure are reviewed for compliance with the acceptance criteria of subsection II.2.C of this SRP section. 3.9.2-27 Revision 3 - March 2007 D. Three Components of Earthquake Motion. The procedures by which the three components of earthquake motion are considered in the