Document: NUREG-0800
Document ID: e8ae4ac1-29ed-46b1-b4c2-19c7f632e815
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, COMPONENTS, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070336.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
ethod produces conservative results in terms of responses. Typical examples or published results for similar systems may be submitted in support of the use of the simplified method. (b) The design and associated simplified analysis account for the relative motion between all points of support. 3.9.2-9 DRAFT Rev. 3 - April 1996 (c) To obtain an equivalent static load of equipment or component which 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 if adequate justification is provided. In addition, for equipment which 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 During the plant life at least one safe shutdown earthquake (SSE) and five operating basis earthquakes (OBE) should be assumed. The number of cycles per earthquake should be obtained from the synthetic time history (with a minimum duration of 10 seconds) used for the system analysis, or a minimum of 10 maximum stress cycles per earthquake may be assumed (extract from SRP Section 3.7.3, subsection II.2).The number of earthquake cycles during one seismic event, the maximum number of cycles for which applicable systems and components are designed, and the criteria and procedures used by the applicant to establish these parameters are reviewed by the staff in accordance with the guidance in SRP Section 3.7.3.28 c. Basis for Selection of Frequencies To avoid resonance, the fundamental frequencies of components and equipment should preferably be selected to be less than 1/2 or more than twice the dominant frequencies of the support structure. Use of equipment frequencies within this range is acceptable if