Finite-length surface crack propagation in clad cylinders

Technical Report · Sun Nov 01 04:00:00 EST 1992

OSTI ID:10103897

Keeney-Walker, J; Merkle, J G; Iskander, S K; Dickson, T L ^[1]

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1. Oak Ridge National Lab., TN (United States)

Licensing issues within the nuclear industry dictate a need to investigate the effects of cladding on the extension of small finite-length cracks near the inside surface of a vessel. Limited experimental data and analyses indicate that cladding can inhibit the propagation of certain shallow flaws. This report describes an analytical study which was carried out to determine (1) the minimum flaw depth for crack initiation under PTS loading for semicircular surface flaws in a clad reactor pressure vessel and (2) the impact, in terms of the conditional probability of vessel failure, of using a semicircular surface flaw as the initial flaw. The analytical results indicate that, for initiation, a much deeper critical crack depth is required for the finite-length flaw than for the infinite-length flaw. Probabilistic analysis of selected PTS transients produced a substantial in the conditional probability of failure for a finite-length flaw model. It is recommended that a testing program be carried out utilizing clad cruciform and clad cylindrical test specimens. The completed experimental and analytical research will provide a basis for introducing a refined treatment of surface flaw initial geometry into PT`S fracture analysis procedures. This report is designated HSST Report 129.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering; Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 10103897
• Report Number(s): NUREG/CR--5915; ORNL/TM--12166; ON: TI93003171
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200
220900
36 MATERIALS SCIENCE
360103
CLADDING
COMPONENTS AND ACCESSORIES
CRACK PROPAGATION
CRACKS
FAILURES
FINITE ELEMENT METHOD
FRACTURE MECHANICS
MECHANICAL PROPERTIES
NUCLEAR POWER PLANTS
O CODES
PRESSURE VESSELS
PRESSURIZATION
PROBABILITY
REACTOR MATERIALS
REACTOR SAFETY
THERMAL SHOCK
TRANSIENTS