Document: NUREG-0800
Document ID: d5452e7b-1e61-498b-9e3d-71073b3328ef
Document Type: srp
Title: LEAK-BEFORE-BREAK EVALUATION PROCEDURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0302/ML030280295.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.3
CFR Part: 
CFR Title: 

Content:
s it relates to the exclusion of dynamic effects of the pipe ruptures postulated in SRP Section 3.6.2. Analyses reviewed and approved by the staff must demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis •f the piping. The design basis for the piping means those conditions specified in the FSAR, as amended, and may include 10 CFR Part 50, applicable sections of the Standard Review Plan, Regulatory Guides, and industry standards such as the ASME Boiler and Pressure Vessel Code. A deterministic evaluation that demon strates sufficient margins against failure, and that includes verified design and fabrication in addition to an adequate inservice inspection program, can be assumed to satisfy the extremely low probability criterion. Leak-before-break should only be applied to ASME Code Class I and 2 piping or the equivalent. Applications to other high energy piping will be considered based on an evaluation of the proposed design and inservice inspection re quirements as compared to ASME Code Class 1 and 2 reouirements. Approval of the elimination of dynamic effects from postulated pipe ruptures is obtained individually for particular piping systems at specific nuclear power units. Leak-before-break cannot be applied to individual welded joints or other discrete locations. Leak-before-break is applicable only to an entire piping system or analyzable portion thereof. Analyzable portions are typically segments located between anchor points. When leak-before-break technology is applied, all potential pipe rupture locations are examined; the examination is not limited to those postulated pipe rupture locations determined from SRP Section 3.6.2. III. REVIEW PROCEDURES The reviewer verifies compliance with the following factors necessary for an acceptable submittal to utilize leak-before-break technology. 1. The leak-before-break evaluation uses design basis loads and is based on the as-built