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:
he exceptions of those portions of piping identified in 2.A(ii), leakage cracks should be postulated as follows: (1) For ASME Code, Section III, Class 1 piping, at axial locations where the calculated stress range7 by Eq. (10) in NB-3653 exceeds 1.2Sm. (2) For ASME Code, Section III, Class 2 and 3 or nonsafety-class (not ASME Class 1, 2, or 3) piping, at axial locations where the calculated stress8 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. 6 Note that, in addition, breaks in nonseismic (i.e., non-Category I) piping should be taken into account as described in Section II.2.k, “Interaction of Other Piping with Category I Piping,” of SRP Section 3.9.2. 7 See Footnote 2. 8 See Footnote 2. BTP 3-4-7 Draft Revision 3 – August 2015 2. 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 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