Document: NUREG-0800
Document ID: 6b7eddf4-f7ce-4821-9f11-e37070221e57
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, STRUCTURES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1613/ML16133A418.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
cy spectra, should be below acceptance limits. These acceptance limits are based on analysis results and allowable material fatigue limits. If not, rebenchmarking and reanalysis should be conducted to confirm structural integrity, and if necessary update acceptance limits. In cases where on-structure vibration and/or strain are measured, pressure data may be considered supplementary and do not need specific acceptance limits. (ii) Estimates, via data extrapolation, of anticipated vibration, strain, and pressure levels at subsequent power levels should be made, and compared to acceptance limits. If violations of limits are projected, reanalysis should be conducted to confirm structural integrity at higher power levels. Any flow-excited resonance phenomenon should be extrapolated conservatively based on narrow frequency band growth over increasing reactor power levels. Linear or quadratic extrapolation is generally non-conservative for flow-excited resonance. Extrapolation of pressures is not needed if those data are supplemental to on-structure vibration and/or strain. (iii) Final data analysis, comparisons to simulations and limits, and benchmarking, should be submitted in a final report to the staff. Any differences between as-built and as-designed structures should be clearly described. Final margins of safety should be submitted, and shown to be greater than 1.0. C. Special guidance for BWR steam dryers. Monitoring to evaluate potential adverse flow effects on reactor internal components should include the steam dryer. The instrumentation directly mounted on the steam dryer should include pressure sensors, strain gages, and accelerometers. If necessary, the MSLs also should be instrumented to collect data to determine steam pressure fluctuations in MSLs and identify the presence of flow-excited acoustic resonances. These pressure pulsations are used in some inverse analysis 3.9.2-28 Revision 4 – March 2017 methods to define the dryer loading function, the dryer