Document: NUREG-0800
Document ID: a4232dd4-7548-4c1c-9a51-16dc766f1087
Document Type: srp
Title: Revision 2 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0708/ML070800008.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3
CFR Part: 
CFR Title: 

Content:
where the calculated stress2 by the sum of Eqs. (9) and (10) in NC/ND-3653 exceeds 0.4 times the sum of the stress limits given in NC/ND-3653. (3) Nonsafety-class piping that has not been evaluated to obtain stress information should have leakage cracks postulated at axial locations that produce the most severe environmental effects. BTP 3-4-7 Revision 2 - March 2007 B. Moderate-Energy Fluid System Piping (i) Fluid Systems Separated from Essential Systems and Components. For the purpose of satisfying the separation provisions of plant arrangement as specified in B.1.a of BTP 3-3, a review of the piping layout and plant arrangement drawings should clearly show that the effects of through-wall leakage cracks at any location in piping designed to seismic and nonseismic standards are isolated or physically remote from essential systems and components. (ii) Fluid System Piping in Containment Penetration Areas. Leakage cracks need not be postulated in those portions of piping from containment wall to and including the inboard or outboard isolation valves, provided 1) they meet the criteria of the ASME Code, Section III, NE-1120, and 2) the stresses calculated2 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 exempted by 2.B(ii) or 2.B(iv), (b) For ASME Code, Section III, Class 1 piping, where the stress range calculated2 by Eq. (10) in NB-3653 is less than 1.2 S(m), and (c) For ASME Code, Section III, Class 2 or 3 and nonsafety-class piping, where the stresses calculated2 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 exempted by (1) above, should be postulated