Refinement and evaluation of crack-opening-area analyses for circumferential through-wall cracks in pipes

Technical Report · Fri Mar 31 23:00:00 EST 1995

DOI:https://doi.org/10.2172/46620· OSTI ID:46620

Rahman, S; Brust, F; Ghadiali, N; Krishnaswamy, P; Wilkowski, G ^[1]; Choi, Y H ^[1]; Moberg, F; Brickstad, B ^[1]

---

1. Battelle, Columbus, OH (United States)

Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet impingement shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. These leak rates depend on the crack-opening area of a through-wall crack in the pipe. In addition to LBB analyses, which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section 11. This study was requested by the NRC to review, evaluate, and refine current analytical models for crack-opening-area analyses of pipes with circumferential through-wall cracks. Twenty-five pipe experiments were analyzed to determine the accuracy of the predictive models. Several practical aspects of crack-opening such as; crack-face pressure, off-center cracks, restraint of pressure-induced bending, cracks in thickness transition regions, weld residual stresses, crack-morphology models, and thermal-hydraulic analysis, were also investigated. 140 refs., 105 figs., 41 tabs.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering Technology; Battelle, Columbus, OH (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: FG02-90ER14135
• OSTI ID: 46620
• Report Number(s): NUREG/CR--6300; BMI--2184; ON: TI95010503
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
COMPARATIVE EVALUATIONS
COMPUTER CODES
CRACK PROPAGATION
CRACKS
ELASTICITY
EXPERIMENTAL DATA
FRACTURE MECHANICS
HYDRAULICS
LEAKS
LOSS OF COOLANT
MATHEMATICAL MODELS
MORPHOLOGY
NUCLEAR POWER PLANTS
PIPES
PLASTICITY
PRESSURE DEPENDENCE
RESTRAINTS
SENSITIVITY ANALYSIS
THERMAL ANALYSIS