Document: NRC Regulatory Guide
Document ID: cdc706d5-60ed-40a4-b55a-9771904107a7
Document Type: regulatory_guide
Title: Seismic Qualification of Electric and Mechanical Equipment for Nuclear Power Plants (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1809/ML18093A675.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.100
CFR Part: 
CFR Title: 

Content:
described in Regulatory Position C.1.2.1.i), in combination with other relevant static and dynamic loads, consistent with the design basis. f. The NRC staff does not find it acceptable to restrict the frequency range of testing up to 33 hertz. As identified in IEEE Std 344-2013, the frequency range should be consistent with the RRS of specific plant equipment. Different sections of this RG, ASME QME-1-2017, and IEEE Std 344-2013 refer to one-third-octave spacing for use with low-frequency excitation. For high-frequency sensitive equipment, the licensee or applicant should use an interval of one-sixth-octave spacing, extending up to the cutoff frequency shown in the RRS. g. For certain hard rock-based plants, the site-specific spectra might exceed the certified design spectra for active mechanical equipment in the high-frequency range. As a result of the high-frequency ground motion, the seismic input to SSCs might also contain high-frequency excitations. Most existing seismic qualification tests used input frequencies up to only 33 hertz. The licensee or applicant should justify its use of these DG-1328, Page 15 prior test results by demonstrating that the frequency content of the PSD of the test waveform is sufficient, in accordance with IEEE Std 344-2013, Annex B. h. If licensees or applicants plan new seismic qualification tests for active mechanical equipment in plants with high-frequency ground motion, the tests should demonstrate the adequacy of the frequency content and the stationarity of the frequency content of the synthesized input waveforms. The frequency content of the Fourier transform of the test waveform or the frequency content of the PSD of the test waveform should be compatible with the amplified portion of the RRS. IEEE Std 344-2013, Annex B, provides guidelines on frequency content and stationarity. i. For NPPs that do not require an evaluation of an OBE, active mechanical equipment that has been qualified by testing should be qualified with