Condition Monitoring of Live Cables in Nuclear Power Plants

No method currently exists for detecting intermittent faults in nuclear power plant cable circuits, which include circuit components, connectors, and end devices. Conventional techniques can locate hard faults, such as open or short circuits, but not the intermittent faults that occur occasionally. Furthermore, conventional testing techniques require circuits to be removed from service, disconnected, and de-energized, fundamentally altering the electrical properties which are being evaluated. These intermittent faults can result in signal spiking of process measurements, invariably leading to false alarms and plant trips which increase costs and reduce power production. Furthermore, these faults have a negative impact on plant safety and reliability. During the proposed Phase I project, AMS will recreate cable circuits in its laboratory facilities and examine coupling methods for signal injection onto energized circuits. Additionally, several established cable diagnostic methods currently used in disconnected cable circuits will be applied to live cables in order to determine effective testing techniques. AMS will investigate appropriate practices to ensure that plant equipment is isolated during the live test through the use of capacitors, buffers, and filters. The results of the laboratory research will be used to determine appropriate testing procedures for on-site testing of nuclear power plants and other industrial facilities in order to detect intermittent faults that cannot be found today. The knowledge gained in Phase I will be put to practice by development of an online monitoring system for detection of intermittent faults in nuclear power plant cables. Successful commercialization of this product will result in improved understanding of electrical degradation and cable conditioning monitoring. This will result in safer, more reliable, and more efficient electricity generation from nuclear power plants. The benefits of this research will extend to other industries, such as commercial aviation, in which fault detection of critical circuits is essential to passenger safety.