Document: NRC Regulatory Guide
Document ID: 7da9830f-b2a1-484a-82ce-5b0a588c4fce
Document Type: regulatory_guide
Title: Protection Against Pipe Whip Inside Containment
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1229/ML12298A123.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.46
CFR Part: 
CFR Title: 

Content:
May 1973 U.S. ATOMIC ENERGY COMMISSION REGULAT'RY DIRECTORATE OF REGULATORY STANDARDS GU911 REGULATORY GUIDE 1.46 PROTECTION AGAINST PIPE WHIP INSIDE CONTAINMENT A. INTRODUCTION General Design Criteron 4, "Environmental and Missile Design Bases," of Appendix A to 10 CFR Part 50, "General Design Criteria for Nuclear Power Plants," requires, in part, that structures, systems, and components important to safety be appropriately protected against dynamic effects that may result from -equipment failures, including the effects of pipe whipping. This guide describes an acceptable basis for selecting the design locations and orientations of postulated breaks in fluid system piping within the reactor containment and for determining the measures that should be taken for restraint against pipe whipping that may result from such breaks. This guide applies to light-water-cooled reactors. The Advisory Committee on Reactor Safeguards has been consulted concerning this guide and has concurred in the regulatory position. B. DISCUSSION The design procedures for fluid piping systems as contained in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,' Section III, apply only to the assurance of pressure-retkding integrity. If a piping failure (i.e., a break or rupture resulting in a loss of pressure-retaining integrity) is postulated, the Section III design procedures do not provide for prnfoteinn noainst dynamic effects (e.g., plastic hinge formation and pipe whipping) of that part of the piping system which remains intact. The Atomic Energy Commission has developed an acceptable basis for selecting the locations and orientations of piping breaks to be used for determining appropriate measures for the protection of structures, systems, and components important to safety that are within the reactor containment. This basis is directly related to the design limits and piping procedures contained in Section 'Hereinafter, referred to as "ASME Code" III of