Document: NUREG-0800
Document ID: 645cc743-c9e4-428c-b05d-ead2517eb3fa
Document Type: srp
Title: DETERMINATION OF RUPTURE LOCATIONS AND DYNAMIC EFFECTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070315.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.2
CFR Part: 
CFR Title: 

Content:
(later).51 In the ABWR and System 80+ design certification FSERs the Staff accepted an exemption to 10 CFR 100 Appendix A that the design of all safety-related SSCs consider OBE loads. In SECY 93-087 (Reference 4) the staff recommended that the Commission approve the approach to eliminate the OBE from the design of SSCs. Furthermore, the Staff concluded that no replacement earthquake loading should be used to establish the postulated pipe rupture and leakage crack locations once the OBE is eliminated from the design and that the criteria for postulating pipe ruptures and leakage cracks in high- and moderate-energy piping systems be based on factors attributed only to normal and operational transients. However, for establishing pipe breaks and leakage cracks due to fatigue effects, the Staff concluded that calculation of the cumulative usage factor should continue to include seismic cyclic effects.52 B. BRANCH TECHNICAL POSITION 1. High-Energy Fluid Systems Piping a. 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 Branch Technical Position (BTP) ASBSPLB 3-1, a review 53 of the piping layout and plant arrangement drawings should clearly show the effects of postulated piping breaks at any location are isolated or physically Systems and components required to shut down the reactor and mitigate the consequences 1 of a postulated pipe rupture without offsite power. For those loads and conditions in which Level A and Level B stress limits have been 2 specified in the design specification (including the operating basis earthquake). DRAFT Rev. 2 - April 1996 3.6.2-14 remote from essential systems and components. At the designer's option, break 1 locations as determined from B.1.c of this position may be assumed for this purpose. b. Fluid System Piping in Containment Penetration Areas Breaks and cracks need not be postulated in those portions of piping from