Document: NRC Regulatory Guide
Document ID: 99fe445b-c440-4921-ba8f-841c8f236046
Document Type: regulatory_guide
Title: Nuclear Power Plant Instrumentation for Earthquakes + HISTORY - HISTORY 09/2016 – DG-1332 , Proposed Revision 3 04/2015 – Periodic Review on Revision 2 – Revise 02/1995 – DG-1033, Third Proposed Revision 2 11/1992 – DG-1016, Second Proposed Revision 2 07/1981 – Draft MS 140-5 , First Proposed Revision 2 (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1610/ML16104A220.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.12
CFR Part: 
CFR Title: 

Content:
recorder, seismic trigger) may be assembled in a self-contained unit or may be separately located. Characteristics of an acceleration sensor, recorder and seismic trigger are defined below in sections 4.11-4.13. 4.11 Acceleration Sensors 4.11.1 Dynamic Range The dynamic range should be at least 300,000:1 zero to peak (not less than 110 decibel (dB)), or greater; for example, 0.000013g to 4.0g. 4.11.2 Frequency Range The frequency range should be from zero Hz to a minimum of 100 Hz or an equivalent frequency demonstrated to be adequate by computational techniques applied to the resultant accelerogram, except the one located in the free-field. The free-field acceleration sensor frequency range should be zero Hz to a minimum of 100 Hz. 4.11.3 Damping Sensors damping should be between 55 percent and 70 percent of critical. 4.11.4 Spurious Resonances No spurious resonances within the frequency range of zero Hz to 100 Hz. DG-1332, Page 11 4.11.5 Cross Axis Sensitivity Sensitivity to acceleration components orthogonal to the sensing axis should not exceed 0.01 g/g. 4.12 Recorder 4.12.1 Sample Rate (Recording Speed) The sample rate should be at least 250 samples per second (0.004 sec) in each of the three directions. 4.12.2 Bandwidth The bandwidth should be from zero Hz to a minimum of 100 Hz. 4.12.3 Dynamic Range The dynamic range should be 300,000:1 or greater (not less than 18-bit), and the instrumentation should be able to record 4.0g zero to peak. 4.12.4 Media The recorder should have archival capability. The data recording protocol should prevent overwriting of recorded earthquake files in the event memory is full. All earthquake records should be retained for the life of the plant. Information should be stored digitally on archival quality storage media. If the record is stored on computer memory, provisions should be made to transfer the record to a permanent medium during the processing phase to prevent accidental loss. The documentation and retention of all