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:
case-by-case basis depending on the breadth and quality of the available information. In their submission, applicants/licensees should address the considerations for selecting the mathematical models and computer software, the interpretation of analytical and numerical results and corresponding bias errors and uncertainties, the acceptance criteria, and the methods for verifying simulations by means of tests. Dynamic responses of reactor internals to self-excited flow oscillations should be estimated. The analysis should clearly identify whether each mechanism will be excited during the planned operating range of the power plant. Full dynamic analysis is requested for mechanisms expected to generate adverse flow effects, including estimation of vibration and stress amplitudes and in some cases frequency spectra at the critical locations and, in particular, where vibration sensors will be mounted on the reactor internals. RG 1.20, Revision 4, Section C.2.1.2 provides more guidance on self-excited flow instabilities. The dependence of the dynamic response on mechanical excitation forces like reactor recirculation pump frequencies and the flow path configuration should also be evaluated. Any frequency coincidence between the pump blade passing frequency and the natural frequencies of the internal structures should be identified and supplemented with bias error and uncertainty analysis. A. An acceptable summary of structural, hydraulic, and acoustic modeling consists of the following items. Additional detail is available in RG 1.20, Revision 4, Section C.2.1.1 (i) Simulated and measured (from modal or shaker testing) resonance frequencies and mode shapes should be examined to establish the appropriateness and accuracy of the analytic model(s). Simulated and measured mode shapes should be similar, and corresponding resonance frequencies should be used to establish the bounds of modeling accuracy over frequency. Subsequent response calculations should include forcing