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:
dentified leakage exists for the throughwall flaws used in the deterministic fracture mechanics evaluation. Leak detection systems equivalent to Regulatory Guide 1.45 are required for the piping under evaluation inside the containment. The sensitivity and reliability of leakage detection systems used outside the containment must be demon strated to be equivalent to Regulatory Guide 1.45 systems. Methods that have been shown to be acceptable include local leak detection, for example, visual observation or instrumentation. Unless a detailed justification can be presented that accounts for the effects of these sources of uncertainties, a margin of 10 on the leakage prediction will be required for determining the leakage size flaw. 4. A systems evaluation of potential water hammer is made to assure that pipe rupture due to this mechanism is unlikely. Water hammer is a generic term including various unanticipated high frequency hydrodynamic events such as steam hammer and water slugging. To demonstrate that water hammer is not a significant contributor to pipe rupture, reliance on historical fre quency of water hammer events in specific piping systems coupled with a review of operating procedures and conditions may be used for this eval uation. Alternatively, design changes such as the use of J-tubes, vacuum breakers and jockey pumps coupled with improved operating procedures can be used to reduce concerns with water hammer. The reviewer establishes that any measures needed to abate water hammer frequency and magnitude will be effective for the life of the plant. 5. A review of creep and creep-fatigue is0 required. Operation below 7000F in ferritic steel piping and below 800 F in austenitic steel piping can satisfy concerns with creep. 3.6.3-3 6. The requirement that corrosion resistance of piping be demonstrated can rely on investigations of the frequency and degree of corrosion in the specific piping systems under review. Modification to operating condi tions (as ýor