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:
Act This regulatory guide contains information collection requirements covered by 10 CFR Parts 50 and 52 that the Office of Management and Budget (OMB) approved under OMB control number 3150- 0011 and 3150-0151, respectively. The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number. DG-1323, Page 3 B. DISCUSSION Reason for Revision This revision of RG 1.20 (Revision 4) expands the guidance related to flow-induced vibration (FIV), acoustic resonance (AR), acoustic-induced vibration (AIV), and mechanical-induced vibration (MIV) for BWRs and pressurized water reactors (PWRs). This revision also expands the scope to include small modular reactor (SMR) nuclear power plants, including guidance for the control rod drive system (CRDS) and control rod drive mechanisms (CRDMs) which might be contained in an integral reactor vessel. The expanded guidance in Revision 4 is based in part on lessons learned from the review of recent applications, including both new plant applications and EPU applications. In addition, Revision 4 re- defines and clarifies the prototype, limited prototype, and non-prototype classifications of reactor internal configurations. Background Nuclear power plant operation can lead to adverse flow induced and mechanically induced vibrations and resonances in plant systems and their components. Some plant components, such as the steam dryer in a BWR nuclear power plant, perform no safety function, but must retain their structural integrity to avoid the generation of loose parts that might impair the capability of other plant equipment to perform safety functions. A CVAP is necessary to limit potential adverse flow effects at BWR and PWR nuclear power plants, including SMRs, during design, construction, and operation, including situations when power uprates or major plant modifications are proposed. This