Document: NUREG-0800
Document ID: 6b7eddf4-f7ce-4821-9f11-e37070221e57
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, STRUCTURES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1613/ML16133A418.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
igh frequency modes (i.e., f > ZPA frequency) should be included in the total dynamic solution using the guidance and methods described in RG 1.92, "Combining Modal Responses and Spatial Components in Seismic Response Analysis," Sections C.1.4 and C.1.5. (4) Consideration of maximum relative displacements among supports of seismic Category I systems and components. (5) Inclusion of such significant effects as piping interactions, externally-applied structural restraints, hydrodynamic (both mass and stiffness effects) loads, and nonlinear responses. (ii) Equivalent Static Load Method. An equivalent static load method is acceptable if: (1) There is justification that the system can be realistically represented by a simple model and the method produces conservative results in responses. Typical examples or published results for similar systems may be provided in support of the use of the simplified method. (2) The design and simplified analysis account for the relative motion between all points of support. (3) To obtain an equivalent static load of equipment or components that can be represented by a simple model, a factor of 1.5 is applied to the peak acceleration of the applicable floor response spectrum. A factor of less than 1.5 may be used where justified. In addition, for equipment that can be modeled adequately as a one-degree-of-freedom system, the use of a static load equivalent to the peak of the floor response spectra is acceptable. For piping supported at only two points, the use of a static load equivalent to the peak of the floor response spectra is also acceptable. B. Determination of Number of Earthquake Cycles. The number of earthquake cycles during one seismic event, the maximum number of cycles for which 3.9.2-17 Revision 4 – March 2017 applicable systems and components are designed, and the criteria and the applicant’s procedures to establish these parameters are reviewed by the staff in accordance with the guidance of SRP Section 3.7.3. C.