Fracture assessment of Savannah River Reactor carbon steel piping. Revision 1
- Westinghouse Savannah River Co., Aiken, SC (United States)
- Westinghouse Electric Corp., Pittsburgh, PA (United States)
The Savannah River Site (SRS) production reactors have been in operation since the mid-1950`s. One postulated failure mechanism for the reactor piping is brittle fracture of the original A285 and A53 carbon steel piping. Material testing of archival piping determined (1) the static and dynamic tensile properties; (2) Charpy impact toughness; and (3) the static and dynamic compact tension fracture toughness properties. The nil-ductility transition temperature (NDTT), determined by Charpy impact test, is above the minimum operating temperature for some of the piping materials. A fracture assessment was performed to demonstrate that potential flaws are stable under upset loading conditions and minimum operating temperatures. A review of potential degradation mechanisms and plant operating history identified weld defects as the most likely crack initiation site for brittle fracture. Piping weld defects, as characterized by radiographic and metallographic examination, and low fracture toughness material properties were postulated at high stress locations in the piping. Normal operating loads, upset loads, and residual stresses were assumed to act on the postulated flaws. Calculated allowable flaw lengths exceed the size of observed weld defects, indicating adequate margins of safety against brittle fracture. Thus, a detailed fracture assessment was able to demonstrate that the piping systems will not fail by brittle fracture, even though the NDTT for some of the piping is above the minimum system operating temperature.
- Research Organization:
- Westinghouse Savannah River Co., Aiken, SC (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC09-89SR18035
- OSTI ID:
- 10152879
- Report Number(s):
- WSRC-MS-91-268-Rev.1; CONF-920631-40-Rev.1; ON: DE92015328
- Resource Relation:
- Conference: American Society of Mechanical Engineers (ASME) pressure vessels and piping conference,New Orleans, LA (United States),21-25 Jun 1992; Other Information: PBD: [1991]
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
REACTOR COOLING SYSTEMS
MATERIALS TESTING
SPECIAL PRODUCTION REACTORS
CARBON STEELS
MECHANICAL PROPERTIES
PIPES
CHARPY TEST
TENSILE PROPERTIES
FRACTURE PROPERTIES
WELDED JOINTS
DEFECTS
STRESSES
REACTOR SAFETY
HEAT TRANSFER
HYDRAULICS
220900
220600
360103
RESEARCH
TEST
TRAINING
PRODUCTION
IRRADIATION
MATERIALS TESTING REACTORS