Document: NUREG-0800
Document ID: b3748a15-3b80-4626-a0a5-eb9f270739ad
Document Type: srp
Title: DETERMINATION OF RUPTURE LOCATIONS AND DYNAMIC EFFECTS ASSOCIATED
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340555.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.2
CFR Part: 
CFR Title: 

Content:
ental conditions developed. (2) Through-wall leakage cracks should be postulated in fluid system piping designed to nonseismic standards as necessary to satisfy B.3.d of BTP ASB 3-1. 3.6.2-15 Rev. 1 - July 1981 d. Moderate-Energy Fluid Systems in Proximity to High-Energy Fluid Systems Cracks-need not be postulated in moderate-energy fluid system piping located in an area in which a break in high-energy fluid system piping is postulated, provided such cracks would not result in more limiting environmental conditions than the high-energy piping break. Where a postulated leakage crack in the moderate-energy fluid system piping results in more limiting environmental conditions than the break in proximate high-energy fluid system piping, the provisions of B.2.c should be applied. e. Fluid Systems Qualifying as High-Energy or Moderate-Energy Systems Through-wall leakage cracks instead of breaks may be postulated in the piping of those fluid systems that qualify as high-energy fluid systems for only short operational periods6 but qul1ify at moderate- energy fluid systems for the major operational period. 3. Type of Breaks and Leakage Cracks in Fluid System Piping a. Circumferential Pipe Breaks The following circumferential breaks should be postulated individually in high-energy fluid system piping at the locations specified in B.1 of this position: (1) Circumferential breaks should be postulated in fluid system piping and branch runs exceeding a nominal pipe size of inch, except where the maximum stress range3'4 exceeds the limits specified in B.1.c(1) and B.1.c(2) but the circumferential stress range is at least 1.5 times the axial stress range. Instrument lines, one inch and less nominal pipe or tubing size should meet the provisions of Regulatory Guide 1.11. (2) Where break locations are selected without the benefit of stress calculations, breaks should be postulated at the piping welds to each fitting, valve, or welded attachment. Alternatively, a single break location