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:
he alternative described in Regulatory Position C.1.1.1.h for plants that are not required to evaluate an OBE. b. Clause 10.2.3.3 (Earthquake Experience Data—Reference Equipment Class Functionality) Licensees or applicants should submit detailed information on the justification used to demonstrate the reference equipment class functionality during and after an earthquake. c. Clause 10.2.4 (Earthquake Experience Data—Qualification of Candidate Equipment) Licensees or applicants should ensure that in-structure response spectra used as the RRS for the qualification of candidate equipment are in accordance with the design basis. They should justify the use of an RRS that is less conservative than that described in the design basis. d. Clause 10.3.2 (Test Experience Data—Test Experience Spectra) (1) Use of the frequency-by-frequency mean of the successful TRS may be inadequate to define test experience spectra (TES). Therefore, the NRC takes exception to the existing second sentence in the first paragraph of Clause 10.3.2. Instead, the NRC finds the following statement acceptable: The TES shall be the frequency-by-frequency mean of the response spectra from successful tests without malfunction. When using test experience data, both the mean and the standard deviation of the data leading to the TES curve should be provided for review and approval. (2) The second paragraph of Clause 10.3.2 is inappropriate; instead, the NRC staff’s position is stated in Regulatory Position C.1.1.1.h. e. Clause 10.3.3 (Test Experience Data—Characterization of Reference Equipment Class) DG-1328, Page 13 This clause specifies that the significant natural frequencies of the reference equipment class should lie within approximately a one-third octave spacing. That will not provide an adequate range of significant natural frequencies in the high-frequency range of the reference equipment in a class. A one-sixth-octave spacing should be used instead of a one-third-octave spacing. f.