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:
o be included in the application related to a non- prototype, and meet the criteria in this regulatory guide. DG-1323, Page 39 The vibration and stress analysis for the non-prototype, which includes a summary of the anticipated structural and hydraulic response and test acceptance criteria, should be updated to account for any nominal differences that might exist between the valid prototype and the non- prototype reactor internals. The vibration and stress analysis update related to any nominal differences needs to be conducted in a manner consistent with the general guidelines delineated in this regulatory guide for prototype reactor internals. As noted above, the applicant or licensee should be aware that minor design or operating changes from the valid prototype might substantially increase the vibration and alternating stresses, not only for the components with modified design, but also for other components that might appear unrelated to the design modifications. As an example, a small increase in the length of the SRV standpipes can trigger acoustic resonance in the MSLs and thereby substantially increase the alternating loading on the steam dryer of BWRs. Change in RRP speed is another example, where the VPF may shift to align with a resonance. If these issues exist, the applicant or licensee should address them in the CVAP. 4.2 Vibration Measurement Program The vibration measurement program for non-prototype reactor internals justified by a valid prototype may be reduced if an inspection program for the non-prototype reactor internals is implemented. For example, where reactor internals other than steam dryers are justified as “non- prototype,” the vibration measurement program may be omitted where the inspection program is implemented. If a vibration measurement program is proposed in lieu of an inspection program for non- prototype reactor internals, the vibration measurement program needs to have sufficient and appropriate instrumentation to verify