Evaluation of cracking in steam generator feedwater piping in pressurized water reactor plants

Conference · Fri May 01 00:00:00 EDT 1981

OSTI ID:6275006

Goldberg, A; Streit, R D

Cracking in feedwater piping was detected near the inlet to steam generators in 15 pressurized water reactor plants. Sections with cracks from nine plants are examined with the objective of identifying the cracking mechanism and assessing various factors that might contribute to this cracking. Using transmission electron microscopy, fatigue striations are observed on replicas of cleaned crack surfaces. Calculations based on the observed striation spacings gave a cyclic stress value of 150 MPa (22 ksi) for one of the major cracks. The direction of crack propagation was invariably related to the piping surface and not to the piping axis. These two factors are consistent with the proposed concept of thermally induced, cyclic, tensile surface stresses and it is concluded that the overriding factor in the cracking problem was the presence of such undocumented cyclic loads.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6275006
• Report Number(s): UCRL-84168; CONF-811011-1; ON: DE81021834; TRN: 81-015969
• Resource Relation: Conference: 7. inter-american conference on materials technology, Mexico City, Mexico, Oct 1981
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
PIPES
CRACKS
FRACTURE PROPERTIES
TENSILE PROPERTIES
PWR TYPE REACTORS
STEAM SYSTEMS
STEELS
FEEDWATER
STRESSES
ALLOYS
ENERGY SYSTEMS
HYDROGEN COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
OXYGEN COMPOUNDS
REACTORS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
210200* - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
360103 - Metals & Alloys- Mechanical Properties