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:
e Section C.2.1.2.4 of RG 1.20, Revision 4, for additional details). Other force inference methods estimate directly the maximum strains and vibrations in a structure. Force inference methods, whether used on dryers or other reactor internals, should be benchmarked on plants and systems similar to the plant being designed or licensed. All uncertainties and bias errors resulting from the methodology benchmarking need to be established. The selection of sensor locations and the use of reliable methods to filter extraneous noise from sensor signals need to be addressed. The geometric and mesh size adequacy of any acoustic models used to compute the pressures acting on a structural surface need to be demonstrated, and the acoustic parameters used (such as the speed of sound, reflection coefficient and sound attenuation) need to be substantiated. The geometric and mesh size adequacy of any structural model used to infer structural vibration and strain also needs to be demonstrated, and any modeling parameters used need to be substantiated. Simulated modes of vibration and resonance frequencies need to be demonstrated to be similar to those in the actual structure, and any significant differences accounted for with bias correction. (iv) Analysis of AIV and MIV involves knowledge of the RRP forcing functions. These include several tonal forces at multiples of pump drive frequency, 3.9.2-23 Revision 4 – March 2017 and those induced by electromagnetic oscillations within motor cores, by imbalance and misalignment, and by hydrodynamic forces at multiples of impeller VPFs (see Section C.2.1.2.5 of RG 1.20, Revision 4, for additional details). The method used to determine the forcing functions of individual pumps needs to be substantiated. For reactors with several pumps, the effect of various scenarios of pump operation modes (including number, arrangement and phase) together with the possibility of local amplification and beat of pump tones needs to be addressed. The