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:
asis depending on the breadth and quality of previously submitted information for similar SSCs. For example, the steam dryer in one BWR unit may be classified as a “prototype” and the steam dryers in the other on-site BWR units may be classified as “limited prototype” where justified. The applicant or licensee may demonstrate that a BWR steam dryer classified as a “limited prototype” in a reactor unit at a multi-unit plant performs in a manner consistent with the steam dryer in the unit classified as a “prototype” by using a reduced amount of instrumentation on the “limited prototype” steam dryer or, where justified, using MSL instrumentation rather than on- dryer instrumentation for the “limited prototype” steam dryer. Using MSL instrumentation for monitoring limited prototypes is acceptable when (a) prototype benchmarking shows a high margin of safety in the dryer alternating stresses, and (b) prototype MSL measurements do not reveal anomalies in data quality that would add significant uncertainty in monitoring the dryer. See section C.2.2.1 for more guidance. For reactor internals other than BWR steam dryers, the non-dryer reactor internals in one reactor unit may be classified as a “prototype” and the non-dryer reactor internals in the other reactor units may be classified as either “limited prototype” or “non-prototype” where justified. One example is that natural circulation reactor internals in one unit may be classified as a “prototype” and those reactor internals in the other units may be classified as “limited prototype” before the “prototype” reactor internals are inspected following initial startup testing. The natural circulation reactor internals in the other units may be classified as a “non-prototype” after the inspection of the “prototype” reactor internals following initial startup testing. The applicant/licensee should follow the applicable guidance in this regulatory guide for