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Title: Development of the monitoring system to detect the piping thickness reduction

Conference ·
OSTI ID:22030092
; ; ;  [1]
  1. Dept. of Nuclear Engineering, Seoul National Univ., 56-1, Shinlim-dong, Kwanak-ku, Seoul (Korea, Republic of)

As nuclear piping becomes aging, secondary piping which was considered safe, undergo thickness reduction problem these days. After some accidents caused by Flow Accelerated Corrosion (FAC), guidelines and recommendations for the thinned pipe management were issued, and thus need for monitoring increases. Through thinned pipe management program, monitoring activities based on the various analyses and the case study of other plants also increases. As the monitoring points increase, time needs to cover the recommended inspection area becomes increasing, while the time given to inspect the piping during overhaul becomes shortened. Existing Ultrasonic Technique (UT) can cover small area in a given time. Moreover, it cannot be applied to a complex geometry piping or a certain location like welded part. In this paper, we suggested Switching Direct Current Potential Drop (S-DCPD) method by which we can narrow down the FAC-susceptible area. To apply DCPD, we developed both resistance model and Finite Element Method (FEM) model to predict the DCPD feasibility. We tested elbow specimen to compare DCPD monitoring results with UT results to identify consistency. For the validation test, we designed simulation loop. To determine the text condition, we analyzed environmental parameters and introduced applicable wearing rate model. To obtain the model parameters, we developed electrodes and analyzed velocity profile in the test loop using CFX code. Based on the prediction model and prototype testing results, we are planning to perform validation test to identify applicability of S-DCPD in the NPP environment. Validation text plan will be described as a future work. (authors)

Research Organization:
American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
OSTI ID:
22030092
Resource Relation:
Conference: NPIC and HMIT 2006: 5. International Topical Meeting on Nuclear Plant Instrumentation Controls, and Human Machine Interface Technology, Albuquerque, NM (United States), 12-16 Nov 2006; Other Information: Country of input: France; 4 refs.; Related Information: In: Proceedings of the 5. International Topical Meeting on Nuclear Plant Instrumentation Controls, and Human Machine Interface Technology| 1430 p.
Country of Publication:
United States
Language:
English