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:
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 frequency range of pump excitations (hydrodynamic and mechanical), its relation to resonance frequencies of reactor internals (mechanical and acoustic), and the possibility of resonance of internal components by the pump excitations need to be adequately addressed for the entire range of reactor operating conditions. Alternatively, the applicant/licensee may use other approaches than those listed above to formulate conservative bounding forcing functions. However, sufficient supporting justification should be provided to demonstrate that the selected approach is technically sound and realistically predicts the forcing function, or an upper bound of the forcing function. In addition, an assessment of bias errors and uncertainties should be provided. C. Acceptable methods of obtaining dynamic responses, margins of safety, and acceptance criteria for subsequent startup testing for vibration and stress predictions are as follows. Additional detail for each subtopic is available in RG 1.20, Revision 4, Section C.2.1.3. (i) Chosen locations for vibration and stress calculations should span all critical regions of the structure, along with locations where instrumentation will be installed for subsequent power ascension testing. Calculations should be conducted over multiple conditions where forcing function time histories are expanded and compressed to span the uncertainty range of simulated resonance frequencies. For each location, the frequency spectra, maximum response, the modal contribution to the total response (in case of cyclic or resonant behavior), and the response causing the maximum stress amplitude should be calculated. The choice of analysis approach (time or frequency domain) should be substantiated, confirming that conservative analysis results are obtained,