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:
otype” 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 thicknesses, welding and connections, boundary conditions, operational parameters (e.g., flow rates, temperature, and pressure), and operating experience. To classify reactor internals as a limited prototype, the applicant/licensee needs to demonstrate by test or analysis that the differences in arrangement, design, size, and operating conditions between the limited prototype reactor internals and the referenced valid prototype reactor internals have no significant effect on the excitation mechanisms and the vibratory response. If this determination cannot be justified, the NRC staff will classify the reactor internals as a prototype as described in this regulatory guide. 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 limited prototypes is delineated below in Section C.3. The applicability needs to be assessed and documented for all potential sources of vibratory excitation that are described below in Section C.2. The applicant or licensee may propose that a design previously classified as a “limited prototype” be reclassified as a “valid prototype” for reference in a new application after the limited prototype completes its CVAP and has adequate operating experience. The NRC staff will evaluate this proposal as part of the application. 1.3 Non-Prototype DG-1323, Page 10 A “non-prototype” is a reactor internal component that has substantially the same arrangement, design, size, and operating conditions as a “valid prototype.” Any nominal differences in arrangement, design, size, and operating conditions have been quantitatively shown (by test or analysis) to have no significant effect on the vibratory response and excitation