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:
-sectional flow area upstream of the break location and downstream of the break location or is equal to a break area determined, by test data which defines the break geometry. Dynamic forces resulting from such breaks are assumed to cause lateral pipe movements in the direction normal to the pipe axis. ' ' Circumferential breaks are perpendicular to the pipe axis, and the break area is equivalent to the internal cross-sectional area of the ruptured pipe. Dynamic forces resulting from such breaks are assumed to separate the piping axially and cause whipping in any direction normal to the pipe axis. b. Following a single break, the unrestrained pipe movement of either end of the ruptured pipe in any. direction about a plastic hinge formed at the nearest pipe whip restraint cannot damage any structure, system, or component important to safety; 1 2 c. The energy' associated with the whipping pipe can be demonstrated to be insufficient to impair' 4 the safety function of any structure, system, or component important to safety to an unacceptable level; d. Both of the following piping system conditions are met: (1) the design temperature is 200°F or less, and (2) the design pressure is 275 psig or less. 1 2See 10 CFR Part 50 Appendix A, "General Design Criteria for Nuclear Power Plants." 1 3 The determination of this energy may take into account any line restrictions (e.g., flow limiter) between the pressure source and break location, and the effects of either single-ended or double-ended flow conditions, as applicable. 14 A whipping pipe should be considered as sufficient to rupture an impacted pipe of smaller nominal pipe size and lighter wall thickness. 1.46-4