Document: NUREG-0800
Document ID: 22c713a3-851c-4195-8d52-e7a90bcbeed0
Document Type: srp
Title: LEAK-BEFORE-BREAK EVALUATION PROCEDURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600396.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.3
CFR Part: 
CFR Title: 

Content:
review addressed by this SRP section is discussed in the following paragraphs: 1. GDC 4 states that dynamic effects associated with postulated pipe ruptures in nuclear power units may be excluded from the design basis when analyses reviewed and approved by the Commission demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis for the piping. The staff approved LBB analyses allows licensees to remove existing pipe whip restraints and structures which are installed to protect safety systems from pipe jet impingement. Also, the approved analyses allows applicants the options of not installing pipe whip restraints and jet impingement structures. 2. Specific guidance regarding the piping systems that are qualified to be considered for the LBB application, fracture mechanics analyses of postulated pipe cracks, and leak detection system capability are provided to ensure that the probability of pipe rupture is extremely low. Meeting the requirements of GDC 4 provides assurance that LBB analyses approved by the staff will provide extremely low probability of piping rupture. III. REVIEW PROCEDURES The reviewer will select material from the procedures described below, as may be appropriate for a particular case. 3.6.3-5 Revision 1 - March 2007 These review procedures are based on the identified SRP acceptance criteria. For deviations from these acceptance criteria, the staff should review the applicant’s evaluation of how the proposed alternatives provide an acceptable method of complying with the relevant NRC requirements identified in Subsection II. The reviewer should verify the applicant’s or licensee’s LBB analysis with the following factors necessary for an acceptable LBB submittal. 1. The reviewer should verify that the licensee’s or applicant’s LBB evaluation uses design basis loads and is based on the as-built piping configuration, as opposed to the design configuration. Correct