Document: NUREG-0800
Document ID: c6f58bab-ddce-42eb-a3ef-02dd3da952fc
Document Type: srp
Title: Revision 3 – December 2016
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1608/ML16085A315.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3
CFR Part: 
CFR Title: 

Content:
t, 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. BTP 3-4-7 Revision 3 –December 2016 bases for environmental qualification of electrical and mechanical equipment both inside and outside the containment. (iv) The designer should identify each piping run it considered in order to postulate the break locations pursuant to 2.A(iii) above. In complex systems such as those containing arrangements of headers and parallel piping running between headers, the designer should identify and include all such piping within a designated run in order to postulate the number of breaks pursuant to these criteria. (v) With the 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. 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