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:
REVIEW RESPONSIBILITIES Primary - Materials Engineering Branch, NRR Secondary - Mechanical Engineering Branch, NRR I. APEAS OF REVIEW General Design CriteriDn 4 (GDC-4) of Appendix A to 10 CFR Part 50 allows the use of analyses reviewed and approved by the Commnission to eliminate from the design basis the dynamic effects of the pipe ruptures postulated in SRP Section 3.6.2. The staff reviews and approves each plant specific and fluid piping system specific submittal from licensees and applicants to eliminate these dynamic effects. Approval of these "leak-before-break" analyses by the staff permits the case-by-case removal of protective hardware such as pipe whip restraints and jet impingement barriers, the redesign of pipe connected components, their supports and their internals, and other related changes in operating plants. Likewise, requirements in plants under construction or to be designed in the future are similarly relaxed. The staff review assures that adequate consideration has been given to direct and indirect pipe failure mechanisms and other degradation sources which could challenge the integrity of piping. The staff review of direct pipe failure mechanisms comprises the following elements: 1. An evaluation over the entire life of the plant of the following: a. Water Hammer d. Corrosion b. Creep Damage e. Fatigue c. Erosion f. Environmental Conditions 2 A deterministic fracture mechanics and leak rate evaluation. The staff reviews the factors which contribute to the initial quality of the piping and the provisions adopted to maintain this quality. In addition, leak detection methods are examined to assure that adenuate detection margins exist for the postulated throughwall flaw used in the deterministic fracture mechan ics evaluation. March 1987 USNRC STANDARD REVIEW PLAN Standord review plans are prepared for the guidance of the Office of Nuclear Reactor Regulation staff responsible for the review of applications to construct and operate nuclear power