Document: NRC Regulatory Guide
Document ID: 6ab6a5e8-47ac-40c0-8c91-837b4e6f0026
Document Type: regulatory_guide
Title: Physical Models for Design and Operation of Hydraulic Structures and Systems for Nuclear Power Plants + HISTORY – HISTORY 09/2014 – Periodic Review of Revision 2 – Reviewed with issues for future consideration 03/2009 – Periodic Review of Revision 1 – Revise 07/2008 – DG-1198 , Proposed Revision 2 (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0810/ML081080301.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.125
CFR Part: 
CFR Title: 

Content:
redicting the performance of safety-related hydraulic structures and systems for nuclear power plants. The methods of measuring, reporting, and evaluating the results of physical modeling have evolved and improved over the past 30 years. Revision 1 of Regulatory Guide 1.125 does not fully reflect current staff positions that have changed, based on the lessons learned and the operating experience gained since it was published. New guidance is needed to inform the licensees of current staff-approved detail and documentation of data and studies that an applicant should include in the PSAR or FSAR, as required, to support the use of physical hydraulic model testing for predicting the performance of hydraulic structures and systems for nuclear power plants. 2. Objective The objective of this regulatory action is to provide the licensees and applicants with current guidance on the detail and documentation of data and studies that should be included with the PSAR or FSAR, as required, to support the use of physical hydraulic model testing for predicting the performance of hydraulic structures and systems for nuclear power plants. 3. Alternative Approaches The NRC staff considered the following alternative approaches: • Do not revise Regulatory Guide 1.125. • Update Regulatory Guide 1.125. 3.1 Alternative 1: Do Not Revise Regulatory Guide 1.125 Under this alternative, the NRC would not revise this guidance, and the original version of this regulatory guide would continue to be the available guidance. This alternative is considered the baseline or “no action” alternative and, as such, involves no value/impact considerations. However, this alternative would not address inefficiencies in preparing and reviewing applications. DG-1198, Page 6 3.2 Alternative 2: Update the Regulatory Guide 1.125 Under this alternative, the NRC would update Regulatory Guide 1.125, taking into consideration the current risk-informed, performance-based approach to licensing and improved