Document: NUREG-0800
Document ID: 7c104096-d040-463a-a94b-a0af08ab3478
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, STRUCTURES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0702/ML070230008.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
certainties of the selected approach. In addition to direct measurements in nuclear power plants, the following approaches may be used to formulate the forcing functions. (1) Scale Model Tests (SMTs): If SMTs are used to develop forcing functions, the following areas should be considered. 3.9.2-17 Revision 3 - March 2007 (a) The scale model should be dynamically similar to the prototype. The dynamic similarity should cover all fluid, structural (such as piping dimensions and elbow locations), and acoustic parameters relevant to the phenomenon considered. If some distortions in the dimension-less parameters of the scale model should be made, the applicants/licensees should show that these distortions are conservative. As an example, sound attenuation in scale models is normally substantially higher than that of the prototype due to viscous heat conduction and other losses higher in small-size models tested at low pressures, leading to the requirement that the scale model size and its test pressure be sufficiently large to ensure the re-production of such specific flow phenomena as flow-induced vibration and acoustic resonance present in the prototype. (b) The effects of structural damping and sound attenuation (in the test medium) on the loading function measured in the scale model should be considered carefully. Any non-conservative deviations in these parameters from those of the prototype reactor should be corrected when the loading function is scaled to that of a full-size reactor pressure vessel (RPV). (c) The conservative simulation of boundary conditions in the scale model. (d) Whether the size of the scale model is sufficiently large to allow investigation of small relevant details in geometry (e.g., branch line openings). (e) Validation of the SMT results by measurements in nuclear power plants. (2) CFD: If CFD simulations are used to develop unsteady forcing functions, the following areas should be considered. (a) Include acoustic/vibration coupling to