Document: NUREG-0800
Document ID: 92d817ac-3ce3-4cf7-8d1a-627e8242fbf2
Document Type: srp
Title: PLANT DESIGN FOR PROTECTION AGAINST POSTULATED PIPING FAILURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070312.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.1
CFR Part: 
CFR Title: 

Content:
lowing conditions will exist: (a) Both of the following piping system conditions are met: (1) the service temperature is less than 95 C (200 F); and 39 (2) the design pressure is 1900 kPa (275 psi) or less; or 40 (b) The piping is physically separated (or isolated) from structures, systems, or components important to safety by protective barriers, or restrained from whipping by plant design features, such as concrete encasement; or (c) Following a single break, the unrestrained pipe movement of either end of the ruptured pipe in any possible direction about a plastic hinge formed at the nearest pipe whip restraint cannot impact any structure, system, or component important to safety; or (d) The internal energy level associated with the whipping pipe can be demonstrated a* to be insufficient to impair the safety function of any structure, system or component to an unacceptable level. *FootnotesAlphabetical superscripts are collected at the end of this appendix. 41 2. Design basis break locations should be selected in accordance with the following pipe whip protection criteria: however, where pipes carrying high energy fluids are routed in the vicinity of structures and systems necessary for safe shutdown of the nuclear plant, DRAFT Rev. 3 - April 1996 3.6.1-20 supplemental protection of those structures and systems shall be provided to cope with the environmental effects (including the effects of jet impingement) of a single postulated open crack at the most adverse location(s) with regard to those essential structures and systems, the length of the crack being chosen not to exceed the critical crack size. The critical crack size is taken to be 1/2 the pipe diameter in length and 1/2 the wall thickness in width. The criteria used to determine the design basis piping break locations in the piping systems should be equivalent to the following: (a) ASME Section III Code Class I piping breaks should be postulated to occur at b the following locations in each piping run