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:
ures or compartments needed to implement Section B.1 should be designed to seismic Category I requirements. The protective structures should be designed to withstand the effects of a postulated piping failure (i.e., pipe whip, jet impingement, pressurization of compartments, water spray, and flooding, as appropriate) in combination with loadings associated with the operating basis earthquake and safe shutdowndesign basis earthquake(s) within the respective design load 30 limits for structures. Piping restraints, if used, may be taken into account to limit effects of the postulated piping failure. (2) High energy fluid system piping restraints and protective measures should be designed such that a postulated break in one pipe cannot, in turn, lead to rupture of other nearby pipes or components if the secondary rupture could result in consequences that would be considered unacceptable for the initial postulated break. An unrestrained whipping pipe should be considered capable of rendering damage as defined in Subsection III.2. of SRP Section 3.6. c. Fluid system piping in containment penetration areas should be designed to meet the break exclusion provisions contained in item B.1.b of BTP EMEB 3-1. d. Piping classification as required by Regulatory Guide 1.26 should be maintained without change until beyond the outboard restraint. If the restraint is located at the isolation valve, a classification change at the valve interface is acceptable. 3. Analyses and Effects of Postulated Piping Failures a. To show that the plant arrangement and design features provide the necessary protection of essential systems and components, piping failures should be postulated in accordance with BTP EMEB 3-1, attached to SRP Section 3.6.2. In applying the provisions of BTP EMEB 3-1, each longitudinal or circumferential break in high energy fluid system piping or leakage crack in moderate energy fluid system piping should be considered separately as a single postulated initial event