Crack stability analysis of low alloy steel primary coolant pipe

Conference · Tue Apr 01 04:00:00 EST 1997

OSTI ID:489297

Tanaka, T; Kameyama, M ^[1]; Urabe, Y ^[2]

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1. Kansai Electric Power Company, Osaka (Japan)
2. Mitsubishi Heavy Industries, Ltd., Takasago (Japan); and others

At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel than for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering Technology; Electricite de France (EDF), 69 - Villeurbanne (France); Battelle, Columbus, OH (United States)
• OSTI ID: 489297
• Report Number(s): NUREG/CP--0155; CONF-9510432--; ON: TI97004806
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
CRACK PROPAGATION
FATIGUE
FRACTURE MECHANICS
HEAT TREATMENTS
LEAKS
LOW ALLOY STEELS
PIPES
PRIMARY COOLANT CIRCUITS
PWR TYPE REACTORS
TENSILE PROPERTIES