Document: NRC Regulatory Guide
Document ID: ad61f8a3-1cce-4446-9542-dcdda55c1ec6
Document Type: regulatory_guide
Title: Comprehensive Vibration Assessment Program for Reactor Internals During Preoperational and Initial Startup Testing + HISTORY - HISTORY 07/2015 – DG-1323 , Proposed Revision 4 03/2013 – Periodic Review of Revision 3 – No Issues Identified 11/2006 – DG-1163 , Proposed Revision 3 (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1508/ML15083A390.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.20
CFR Part: 
CFR Title: 

Content:
nes for the vibration measurement program delineated in Section C.2.2 of this regulatory guide for prototype reactor internals. DG-1323, Page 38 If the measured responses are found to be significantly higher than the anticipated responses for specific components (i.e., above acceptance limits), those components should be removed from the reactor vessel and visually examined, if feasible. Components for which removal is not feasible will need to be examined in situ using appropriate inspection equipment. The interior of the reactor vessel needs to be visually checked for loose parts and foreign material. In addition, the cause for the higher responses needs to be identified and adequately resolved by re-evaluating the vibration analysis and/or the measurement program. If further evaluation identifies a fundamental difference in response between the referenced valid prototype and the limited prototype, then it is necessary to implement a CVAP for prototype reactor internals. Classification as a limited prototype is no longer valid. For an applicant or licensee planning to use remote monitoring measurements to qualify a limited prototype, the bias errors and uncertainties of the instrumentation, measurements, and measurement system need to be factored into the acceptance criteria. For example, when planning to use limits on MSL pressure fluctuations measured by strain gage arrays to qualify the alternating stress state of a BWR steam dryer, the expected variability and bias of the measurements need to be quantified and compared to those made on the valid prototype. Use of a limited number of sensors on the steam dryer may provide an acceptable means to assess the variability of the vibration measurement procedure. Instrumentation and data acquisition for the limited prototype should be similar to that used in the prototype plant. However, when the results of various measurements are being compared, whether they are obtained from different plants or from different power