Document: NUREG-0800
Document ID: 383561fc-b739-42a6-b54f-40bbc4b47d03
Document Type: srp
Title: SEISMIC INSTRUMENTATION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070322.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.4
CFR Part: 
CFR Title: 

Content:
he time history records from the free field triaxial sensor are used as input ground motion for the reactor building dynamic model, including soil where applicable. Amplified response spectra are then calculated at the locations of the other sensors in the reactor building for comparison and correlation with the response spectra directly measured. Structural responses and amplified response spectra are calculated using the free field time history records with the dynamic model for comparison with the original design and analysis parameters. This comparison permits evaluation of seismic effects on structures and equipment and forms the basis for remodeling, detailed analyses, and physical inspection. 5. InserviceInstrument Surveillance12 Each of the seismic instruments shall be demonstrated operable by the performance of the channel check, channel calibration, and channel functional test operations at the intervals specified in Table 3.7.4-2. Technical Rationale:13 The technical rationale for application of the above acceptance criteria to seismic instrumentation is discussed in the following paragraphs. 1. 10 CFR 50.55a requires, in relevant part, that structures, systems and components (SSC) important to safety be tested and inspected to quality standards commensurate with the 3.7.4-5 DRAFT Rev. 2 - April 1996 importance of the safety function to be performed. Seismic instrumentation is installed to alert the plant operator when a significant seismic event has occurred and to record information critical to evaluation of earthquake effects on plant structures and equipment. Seismic instrumentation is inspected and tested on a periodic basis to assure that it will function as designed. Performing periodic testing to meet 10 CFR 50.55a ensures, in the event of a significant seismic event, that the plant operators are provided with information to assess the need to shut down the reactor and that recorded data are available to allow engineering evaluation of the safety