Supplemental examination of alternative materials in a model steam generator: Volume 2, Correlation of Model 10 defects with eddy-current indications: Final report
The following report compares the nondestructive examination with the destructive metallographic examination of the tube bundle alternative materials, Model 10 steam generator. The model steam generator was fabricated using state-of-the-art tube processing (Alloys 600, 690 and 800) and corrosion resistant support alloys and designs. The model steam generator was operated for approximately one year with a secondary environment that was faulted with acidified simulated cooling tower water and sludge. The tube bundle was eddy current tested at the final inspection using multiple frequency differential and absolute mode probes and state-of-the-art eddy current equipment, including a computerized system for data analysis. Various frequency mixes were designed to suppress signals from deposits and to improve signal to noise ratios. Special tests were utilized to evaluate the Alloy 800 tubing. Eddy current data correlated favorably with results from the destructive examinations. Generally eddy current tests were most successful in detecting axial cracks, circumferential cracks, defects with depths greater than 10% throughwall and tube denting at trefoil supports. It was not possible to distinguish between cracks and deep wastage. Interpretation of the eddy current indications predicted corrosion damage deeper than that found metallographically for conservative depth estimates. Numerous false defect indications, with low signal to noise ratios, were produced by the presence of conductive deposits on the O.D. of the tubing. Absolute mode testing provided a reliable qualitative indication of tube corrosion despite the interference from the conductive deposits. 4 refs., 1 fig., 1 tab.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (USA); Combustion Engineering, Inc., Windsor, CT (USA). Nuclear Power Systems
- OSTI ID:
- 6423213
- Report Number(s):
- EPRI-NP-5928M-Vol.2; ON: TI89006844
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
220200* -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ALLOY-NI59CR30FE9
ALLOY-NI76CR15FE8
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
BOILERS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COOLING SYSTEMS
CORROSION
CORROSION RESISTANT ALLOYS
CRACKS
DESTRUCTIVE TESTING
DOCUMENT TYPES
EDDY CURRENT TESTING
ELECTROMAGNETIC TESTING
ENERGY SYSTEMS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INCONEL 600
INCONEL 690
INTERGRANULAR CORROSION
IRON ALLOYS
MATERIALS
MATERIALS TESTING
NIOBIUM ALLOYS
NONDESTRUCTIVE TESTING
OXYGEN COMPOUNDS
PROGRESS REPORT
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
SLUDGES
STEAM GENERATORS
STRESS CORROSION
SULFATES
SULFUR COMPOUNDS
TESTING
TITANIUM ADDITIONS
TITANIUM ALLOYS
TUBES
VAPOR GENERATORS