Evaluation of crack pop-ins and the determining of their relevance to design considerations
- Oak Ridge National Lab., TN (United States)
The issue with regard to crack pop-ins is to determine if such events are significant to design considerations. The literature contains ample evidence of pop-in occurrences, but scant information is offered on how pop-ins should be handled as an issue for design problems. Because there are two types of cleavage crack origins, the problem was subdivided into two classes of materials, monolithic and weldments with brittle zones. The weldment situation can be analyzed as a crack-arrest toughness capability problem, following the recommendations of Sumpter et al. For monolithic materials, pop-ins are more dangerous, since they appear to be a part of the more commonly encountered full-cleavage K[sub jc] instability distributions. A recommendation is made on how to determine if pop-in events lie outside of the larger body of K[sub jc] instabilities. The evaluation procedure recommended by the American Society for Testing and Materials for pop-ins seems to dismiss the possibility that small crack jumps can be a safety-related issue. This work suggests that nearly all pop-in events, regardless of the magnitude of crack jump, are relevant to safety issues.
- Research Organization:
- Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering; Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USNRC; Nuclear Regulatory Commission, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6982915
- Report Number(s):
- NUREG/CR-5952; ORNL/TM-12247; ON: TI93008825
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
REACTOR COMPONENTS
FRACTURE PROPERTIES
REACTOR MATERIALS
CRACK PROPAGATION
CRACKS
EMBRITTLEMENT
STEELS
TENSILE PROPERTIES
WELDED JOINTS
ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MATERIALS
MECHANICAL PROPERTIES
220200* - Nuclear Reactor Technology- Components & Accessories
360103 - Metals & Alloys- Mechanical Properties