Document: NUREG-0800
Document ID: 0e333e1a-276a-43f1-b2ab-fdf1009c6f92
Document Type: srp
Title: Draft Revision 3 – August 2015
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1422/ML14227A646.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3
CFR Part: 
CFR Title: 

Content:
stresses calculated9 by the sum of Eqs. (9) and (10) in ASME Code, Section III, NC- 3653 do not exceed 0.4 times the sum of the stress limits given in NC-3653. (iii) Fluid Systems in Areas Other Than Containment Penetration. (1) Leakage cracks should be postulated in piping located adjacent to structures, systems, or components important to safety, except: (a) Where excluded by 2.B(ii) or 2.B(iv), (b) For ASME Code, Section III, Class 1 piping, where the stress range calculated10 by Eq. (10) in NB-3653 is less than 1.2Sm, and (c) For ASME Code, Section III, Class 2 or 3 and nonsafety-class piping, where the stresses calculated11 by the sum of Eqs. (9) and (10) in NC/HD-3653 are less than 0.4 times the sum of the stress limits given in NC/ND-3653. (2) Leakage cracks, unless the piping system is excluded by 2.B(iii)(1), should be postulated at axial and circumferential locations that result in the most severe environmental consequences. (3) Leakage cracks should be postulated in fluid system piping designed to nonseismic standards as necessary to satisfy B.3.d of BTP 3-3. (iv) Moderate-Energy Fluid Systems in Proximity to High-Energy Fluid Systems. Leakage 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 leakage 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 2.B(iii) should be applied. 9 See Footnote 2. 10 See Footnote 2. 11 See Footnote 2. BTP 3-4-8 Draft Revision 3 – August 2015 (v) 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12 that qualify as high-energy fluid