Solid-State Sensor to Directly Replace Coils for Improved Eddy Current Testing (ECT)

Degradation of reactor components, heat exchangers, and piping systems in nuclear power plants subjected to heat, high pressure and corrosion has been estimated to cost the electric power industry $17.3 billion dollars annually. Eddy current testing is a widely practiced, and critically important nondestructive evaluation method used in power plants, yet it relies on decades-old sensor technology based on coils of wire that do not have the sensitivity or uniformity needed to reproducibly detect small, deeply buried defects. New, vastly superior, solid-state, eddy current sensors and monolithic sensor arrays that could directly replace the coil sensors now used in existing eddy current test systems are proposed. New solid-sensors will be developed and tested in collaboration with major eddy current test equipment users and manufacturers to result in sensors and sensors arrays that can directly replace the coil sensors now in use. The ability to detect incipient defects and monitor growth will provide data needed for prognostics and health monitoring. During Phase I, technical feasibility was proven by developing and fabricating prototype flexible sensors, flexible sensor arrays, and eddy current test electronics and software. Working with several large companies in the field, prototype equipment was evaluated in direct comparison with existing, coil type eddy current sensors and shown to offer higher sensitivity, better signal-to-noise ratio, in be capable of inspecting higher speed. The sensors were shown to be compatible with existing ECT equipment. In Phase II research and development will continue and include a number of large companies to prove that the new sensors, sensor probes and eddy current test technology offer superior performance and substantial cost savings for the inspection of key components in power plants. The technology will be developed to meet the standards and needs of industry, and commercialization will begin using company funds in the second year of Phase II. Commercial Applications and other Benefits: The sensors and sensor arrays will replace the coil sensors that have been used for decades to perform eddy current testing and provide far higher performance at approximately the same sensor cost. The new technology offers much higher signal-to-noise ratio and reproducibility than coil sensors, and will result in more definitive detection of defects, and the ability to detect smaller, more deeply buried defects. The sensors will be suitable for use in both existing eddy current test equipment and new eddy current test equipment making it available for all applications where eddy current test is used. Some of the major industries using eddy current testing include: electricity generation, aircraft inspection, transportation vehicle maintenance, oil drilling, and pipeline inspection.