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:
sed to develop the forcing functions. For further details, refer to RG 1.20, Revision 4, Section C.2.1.2. C. Results of vibration and stress calculations. The calculated vibration and stress levels of reactor internal structures are reviewed with their safety margins and acceptance criteria. The procedures for combining the vibration and stress response models (Item 3.A above) with the forcing functions (Item 3.B above) to compute overall vibration and stress response are also reviewed. The results for structures and components with a history of failures from adverse flow effects (such as steam dryers excited by flow instabilities over the openings of valve standoff pipes) are evaluated in greater detail. In particular, the following items are reviewed: (i) Chosen locations for vibration and stress calculations, and any locations where instrumentation will be installed for subsequent power ascension testing; along with the choice of analysis approach (time or frequency domain) and the acceptability of damping modeling (such as the Rayleigh damping method used for time domain calculations). (ii) Benchmarking of analysis methodologies, particularly end-to-end benchmarking using previous testing on valid prototypes. (iii) Stress convergence and high-cycle fatigue evaluation, particularly structural model development, application of dynamic loads to the structural model, and fatigue analysis of two-sided fillet welds. (iv) Vibration and stress limits and their justification. For further details, refer to RG 1.20, Revision 4, Section C.2.1.3. 3.9.2-9 Revision 4 – March 2017 D. Preoperational and Initial Testing Analysis. Calculated structural and hydroacoustic responses for preoperational and initial startup testing conditions as well as for normal operation are reviewed. Any adjustments to the calculated response during the inspections, tests, analyses, and acceptance criteria (ITAAC) process to address differences between as-designed and as-built conditions are also