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:
eased 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 loadings resulting from a postulated piping failure beyond these portions of piping, should not exceed 2.25Sm and 1.8Sy, except that following a failure outside containment, the pipe between the outboard isolation valve and the first restraint may be permitted higher stresses provided that a plastic hinge is not formed and operability of the valves with such stresses is ensured in accordance with the criteria specified in SRP Section 3.9.3. Primary loads considered in Eq. (9) include those that are deflection-limited by whip restraints. For ASME Code, Section III, Class 2 Piping (d) The maximum stress ranges as calculated by the sum of Eqs. (9) and (10) in Paragraph NC-3653, ASME Code, Section III, considering those loads and conditions thereof for which level A and level B stress limits have been specified in the system’s design specification (i.e., sustained loads, occasional loads, and thermal expansion), including an OBE event (if applicable), should not exceed 0.8(1.8 Sh + SA). The Sh and SA are allowable stresses at maximum (hot) temperature and allowable stress range for thermal expansion, respectively, as defined in Article NC-3600 of the ASME Code, Section III. (e) The maximum stress, as calculated by ASME Code, Section III, NC-3653, paragraph Eq. (9) under the loadings resulting from a postulated piping failure of fluid system piping beyond these portions of piping, should not exceed 2.25Sh and 1.8Sy. Primary loads include those which are deflection-limited by whip restraints. The exceptions permitted in Subsection (c) above may also be applied, provided that when the piping between the outboard isolation valve and the restraint is constructed in accordance with the Power Piping Code ANSI B31.1, the piping should either be of seamless construction with full