A Capacitive Sensor for Nuclear Power Plant Cable
Publication: Publication Date: 1 October 2016
A capacitive sensor was designed and tested for
the purpose of monitoring nuclear power plant
(NPP) cable degradation. The sensor was designed
as two copper interdigital electrodes printed on a
polymer substrate. Two types of NPP industriallyrelevant
cable jacket materials, ethylene propylene
rubber (EPR) and cross-linked polyolefin (XLPO),
were studied in this research. Accelerated thermal
aging was conducted on EPR and XLPO jacket
materials by heating them for various durations up
to 15 weeks (2520 h), at 408 K (135 °C). Thermal
analysis of aged samples reveals degradation of
both cable jackets by the decrease of polymer
weight and crystalline regions. Scanning electron
microscopy and energy dispersive spectrometry
identified the dispersion and constituents of
inorganic additives in the jacket materials. A large
decrease of elongation at break (EAB) of aged
samples as a function of increasing aging duration,
observed by tensile testing, provided an effective
benchmark against which to evaluate the effectiveness
of the capacitive sensor. The capacitance of
the sensor in contact with the samples was
measured and correlated with EAB as a function of
aging time. Values of sensor capacitance measured
at 1 kHz correlated well (correlation magnitude
~0.85) with EAB of the tested materials.
- Arvia, E., R.T. Sheldon, and N. Bowler, “A Capacitive Test Method for Cable Insulation Degradation Assessment,” Annual Conference on Electrical Insulation and Dielectric Phenomena, Des Moines, Iowa, 19–22 October 2014.
- Bowler, N., and S. Liu, “Aging Mechanisms and Monitoring of Cable Insulation Polymers,” International Journal of Prognostics and Health Management, Vol. 6, No. 29, 2015.
- Burke, S.K., and L.R.F. Rose, “Eddy-current NDI of Cracks in Thin Plates,” Journal of Physics D: Applied Physics, Vol. 20, No. 6, 1987, pp. 797–800.
- Chen, T., and N. Bowler, “A Capacitive Probe for Quantitative Nondestructive Evaluation of Wiring Insulation,” NDT&E International, Vol. 52, November 2012, pp. 9–15.
- Chen, T., and N. Bowler, “Analysis of a Concentric Coplanar Capacitive Sensor for Nondestructive Evaluation of Multi-layered Dielectric Structures,” IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 17, No. 4, 2010, pp. 1307–1318.
- Chen, T., and N. Bowler, “Design of Interdigital Spiral and Concentric Capacitive Sensors for Materials Evaluation,” Review of Progress in Quantitative Nondestructive Evaluation, Vol. 1511, January 2013, pp. 1593–1600.
- EPRI, “Initial Acceptance Criteria Concepts and Data for Assessing Longevity of Low-voltage Cable Insulations and Jackets,” Technical Report 1008211, Electric Power Research Institute, 2005.
- EPRI, “Low-voltage Environmentally-qualified Cable License Renewal Industry Report; Revision 1,” Technical Report 103841, Electric Power Research Institute, 1994.
- Forney, D.M., and D.E. Chimenti, “Nondestructive Evaluation: Coming of Age,” Encyclopedia Britannica 1986 Yearbook of Science and the Future, Britannica, Chicago, Illinois, 1985, pp. 86–105.
- Gillen, K.T., and R. Bernstein, “Review of Nuclear Power Plant Safety Cable Aging Studies with Recommendations for Improved Approaches and for Future Work,” Report 201-7266, Sandia National Laboratories, 2010.
- Hsu, Y.T., K.S. Chang-Liao, T.K. Wang, and C.T. Kuo, “Correlation between Mechanical and Electrical Properties for Assessing the Degradation of Ethylene Propylene Rubber Cables Used in Nuclear Power Plants,” Polymer Degradation and Stability, Vol. 92, No. 7, 2007, pp. 1297–1303.
- Li, X.B.B., S.D. Larson, A.S. Zyuzin, and A.V. Mamishev, “Design Principles for Multi-channel Fringing Electric Field Sensors,” IEEE Sensors Journal, Vol. 6, No. 2, 2006, pp. 434–440.
- Nikolajevic, S.V., “The Behavior of Water in XLPE and EPR Cables and Its Influence on the Electric Characteristics of Insulation,” IEEE Transactions on Power Delivery, Vol. 14, No. 1, 1999, pp. 39–45.
- Sheldon, R.T., and N. Bowler, “Dielectrometry Sensors for Nondestructive Testing of Glass-fiber Polymer-matrix Composites,” Materials Evaluation, Vol. 72, No. 11, 2014, pp. 1421–1428.
- White, G., R. Bernstein, and K.T. Gillen, “Current and Ongoing Cable Aging Research to Support Life Extension Decisions,” Transactions of the American Nuclear Society, Vol. 107, 2012, pp. 438–440.
99 Page Views
0 PDF Downloads
0 Facebook Shares