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:
reviewed along with their bias errors and uncertainties. For more details on NRC guidance to applicants, refer to RG 1.20, Revision 4, Section C.2. A. Structural, Hydraulic, and Acoustic Modeling. All analytic and numerical modeling procedures, models, and calculations are reviewed, including models of fluid hydraulic and acoustic behavior and their coupling to structural models. In particular, modes of vibration, structural damping, frequency response functions (FRFs), and the effects of variable or uncertain boundary conditions (when they affect structural vibration) should be assessed. (i) The resonance frequencies and mode shapes from simulations and measurements should be compared to establish the accuracy bounds of the models. (ii) Structural damping assumptions should be reviewed, and any use of greater than 1% damping should be assessed for adequacy. (iii) Simulated and measured (from modal or shaker testing) FRFs should be examined, along with resulting bias errors and uncertainties caused by differences between modeled and as-built conditions. For further details, refer to RG 1.20, Revision 4, Section C.2.1.1. B. Transient and steady-state flow-induced forcing functions. Forcing functions within the reactor vessel and the feedwater and steam systems are reviewed, including unsteady excitations induced by flow around the sampling probes in the feedwater piping and over the standoff pipes of safety valves and blind flanges in the main steam lines (MSLs). A list of typical forcing functions for reactor internals is provided in RG 1.20, Revision 4, Section C.2.1.2. The methods for specifying the forcing functions (e.g., analytic or numerical techniques such as computational fluid dynamics (CFD) models, test-analysis combination methods such as scale model testing (SMT), and response deduction methods) should be assessed. Any forcing function estimates caused by such adverse flow effects as flow instabilities over standoff pipe openings are reviewed to ensure