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:
review of the piping layout and plant arrangement drawings should clearly show that the effects of postulated piping breaks at any location are isolated or are physically remote from essential systems and components.1 At the designer’s option, break locations as determined from 2A(iii) of this BTP may be assumed for this purpose. (ii) Fluid System Piping in Containment Penetration Areas. Breaks and cracks need not be postulated in those portions of piping from containment wall to and including the inboard or outboard isolation valves, provided that they meet the design criteria of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code), Section III, Subarticle NE-1120, and the following additional design criteria: (1) The following design stress and fatigue limits should not be exceeded: For ASME Code, Section III, Class 1 Piping (a) The maximum stress range between any two load sets (including the zero load set) should not exceed 2.4Sm and should be calculated2 by Eq. (10) in ASME Code, Section III, NB-3653. If the calculated maximum stress range of Eq. (10) exceeds 2.4Sm, the stress ranges calculated by both Eq. (12) and Eq. (13) 1 Essential systems and components are those necessary to shut down the reactor and mitigate the consequences of a postulated pipe rupture without offsite power. 2 The maximum stress range should be calculated for those loads and conditions for which Level A and Level B stress limits have been specified in the design specification (including the operating basis earthquake, if applicable). BTP 3-4-3 Draft Revision 3 – August 2015 in Paragraph ASME Code, Section III, NB-3653 should meet the limit of 2.4Sm. (b) The cumulative usage factor (CUF) should be less than 0.1. The CUF limit of 0.1 can be increased to 0.4 when the effects of environmental assisted fatigue (EAF) are considered in the piping design. (c) The maximum stress, as calculated by Eq. (9) in ASME Code, Section III, NB-3652 under the