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:
nomena experienced during an adequate period of operation, it may be proposed as a “valid prototype.” A valid prototype may be referenced in subsequent applications, as appropriate, subject to the restrictions and provisions defined below. The adequacy of operational experience needed to validate a prototype is assessed on a case-by-case basis, depending on the breadth and quality of the operational experience data. For example, to be proposed as a valid prototype, a BWR steam dryer will need to complete, as a minimum, the CVAP with no adverse inservice vibration phenomena and at least one inspection after a full operating cycle with the identification of no adverse indications. Reactor internals other than a BWR steam dryer will be evaluated on a case-by-case basis for justification as a valid prototype. For example, to be proposed as a valid prototype, natural circulation reactor internals (i.e., reactor internals in a natural circulation reactor) that will not undergo a preoperational test will need to complete the CVAP with no adverse inservice vibration phenomena and at least one inspection following initial startup testing with the identification of no adverse indications. See Section C.1.4 of this regulatory guide for special considerations for classifying reactor internals in multi-unit plants and standard reactor designs. An acceptable CVAP for prototype reactor internals is delineated below in Section C.2. The applicant should assess and document the applicability or non-applicability of all potential sources of vibratory excitation that are described below in Section C.2. 1.2 Limited Prototype A “limited prototype” is reactor internal component that is similar to a “prototype” reactor internal component but cannot be justified as a “non-prototype” reactor internal component. Differences between a limited prototype and a prototype might include, for example, scaling (similar shape but different size) or more than nominal changes to wall