Document: NUREG-0800
Document ID: e89cc26c-d19a-42b8-818a-fb598c05ccee
Document Type: srp
Title: PLANT DESIGN FOR PROTECTION AGAINST POSTULATED PIPING FAILURES IN FLUID
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340548.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.1
CFR Part: 
CFR Title: 

Content:
wn the reactor). In these cases, redundant design features that are separated or otherwise protected from postulated piping failures, or additional protec- tion, should be provided so that the effects of postulated piping failures are shown by the analyses and guidelines of Section B.3 to be acceptable. Additional protection may be provided by restraints and barriers or by designing or testing essential systems and components to withstand the effects associated with postulated piping failures. If a case should arise as a result of overriding engineering considerations, where adequate separation by physical distance or adequate separation by a combination of distance and barriers cannot be reasonably attained, and so justified to the staff, restraints may be used to assist in obtaining a finding of adequate separation by distance or barriers when designed as follows: (1) The use of a restraint should not affect the responses of the piping systems when subjected to the loads resulting from normal and upset plant and system operating conditions. (a) Care should be exercised to ensure that the system stresses due to normal and upset transients, thermal growth, and inertial effects and differential anchor motions associated with seismic events are not adversely affected by the restraints. (b) A program should be developed to ensure that the system stresses due to long term changes in the system and its supports and restraints, such as due to pipe relaxation and differential settling, will not be adversely affected by the restraints. (c) Details of the methods used to obtain these assurances should be submitted to the staff for review. (2) The restraint and its supporting structures should be designed so that they will not prevent the inservice inspection of any pipe welds. 2. Design Features a. Essential systems and components should be designed to meet the seismic design requirements of Regulatory Guide 1.29. b. Protective structures or compartments, fluid system piping