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:
eactor internals. The forcing functions should account for the effects of transient flow conditions and the corresponding frequency content. Any potential amplification of a forcing function caused by self-excitation or lock-in of a flow instability with a structural or acoustic resonance should be clearly quantified (see RG 1.20, Revision 4, Section C.2.1.2.1 for more guidance on self-excited flow instabilities). Acoustic and mechanical forcing functions should also be described. The suitability of the approach used to define forcing functions should be assessed with expected bias errors and uncertainties of the selected approach. In addition to direct measurements in nuclear power plants, the following approaches may be used to formulate the forcing functions. (i) SMTs may be used to assess the susceptibility of plant components to FIV and fluid-structure interaction mechanisms as well as to help develop the forcing functions and/or establish amplification factors (sometimes called BUFs) between loads at higher plant power levels (see Section C.2.1.2.2 – Scale Model Testing of RG 1.20, Revision 4, for additional details). The use of SMT results in the vibration and stress analysis is acceptable where shown to be bounding. Geometric and dynamic similarity between SMT and full-scale plants needs to be established, with critical geometric details sufficiently modeled. Reynolds and Mach number effects need to be quantified, along with any differences in vibration damping and sound attenuation. Multiple tests are needed to establish uncertainties, and need to span a wide range of power and flow conditions to ensure worst-case conditions are measured, particularly when transient tests, such as blowdown testing, are conducted. Growth rates of resonance peaks should be measured over narrow frequency bands. Any SMT-based BUFs should be shown to be 3.9.2-22 Revision 4 – March 2017 bounding when compared to previously observed ratios from similar full- scale plants. When