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:
equipment class during and after an earthquake. c. The NRC staff concurs with the limitations specified in IEEE Std 344-2013, Section 10.4.2, for the use of earthquake or test experience data for the seismic qualification of certain active electrical components that might inadvertently change state or chatter during an earthquake and thus might not consistently perform their intended safety functions during or after an earthquake (e.g., certain types of relays, contactors, circuit breakers, switches, sensors, microprocessor-based components, and potentiometers). A seismic test might be needed to confirm that a component is not sensitive to high-frequency ground motion, if applicable. d. If the licensee or applicant proposes to use test experience data for seismic qualification in accordance with IEEE Std 344-2013, Clause 10.3, it should submit, for staff review DG-1328, Page 11 and approval, the details of the test experience database, including applicable implementation procedures, to ensure the structural integrity and functionality of the in-scope electrical equipment. Test experience with older electrical components is generally not applicable for the qualification of the new generation of digital instrumentation and control electrical components due to significant differences in component design. Supporting documentation for equipment identified in the database should confirm that such equipment will remain functional during and after the equivalent effect of five postulated occurrences of an operating-basis earthquake (OBE) and one SSE (or the alternative described in Regulatory Position C.1.1.1.h), in combination with other relevant static and dynamic loads, consistent with the design basis for the facility. e. The NRC staff does not find it acceptable to simply restrict the frequency range of testing up to 33 hertz. The tested frequency range should be consistent with the RRS of the specific plant equipment. Different sections of this RG and IEEE Std