NDT System for Metal Components in Concrete Structures

Keeping aging nuclear power plants in operation is crucial to the energy requirements of the United States. Monitoring and maintaining the strength and durability of concrete structures in power plants is essential for their ongoing safety and longevity. RMD is developing solidstate eddy current sensor technology with superior sensitivity, signaltonoise ratio, depth of interrogation, and spatial resolution to perform nondestructive evaluation (NDE) of concrete structures. The sensors will allow plant operators to improve the longterm operation and performance of nuclear power plants and ensure safety and reliability. The sensors developed in this program will offer superior performance to stateoftheart commercial devices and will have general utility in the NDE market. How this Problem is Being Addressed: RMD has shown that its new solidstate AMR sensors for eddy current test (ECT) and NDE outperform current commercial NDE technologies. RMD will work with its industrial partners to capitalize on the unique ability to detect deeply buried, defects and develop this technology into a commercial product. Phase I Results: Using both theoretical modeling and experimentation, RMD has developed new sensors, electronics and software that have the capability to provide superior, high reliability NDE. The probes will be compatible with existing NDE instruments. Phase I demonstrated that the new sensors can detect defects in metal reinforcement rods beneath the surface, similar to the rods and posttensioning tendons used in today’s concrete structures, and that the approach offers significant advantages including high sensitivity, good spatial resolution, extended depth capability, and the potential for less complex and more costeffective sensors for ECT and NDE. Phase II Plans: The Phase II program will complete the research and development of RMD’s novel NDT technology for inspecting nuclear power plant infrastructure. RMD will continue the theoretical modelling to optimize the AMR sensor design and system configuration in order to provide better capabilities than the technology that is currently available for detecting defects in components encased in concrete. RMD will further develop specialized data collection and analysis algorithms, design and build electronic circuitry, and develop a 2D mechanical scanning system. The end result will be a selfcontained prototype that can be demonstrated in the field. Commercial Applications: The solidstate ECT probes will be more sensitive, have higher signaltonoise ratio, scan faster, and provide more reliable detection of smaller defects than existing technologies. The proposed sensor arrays will be compatible with existing ECT equipment, ensuring rapid acceptance in the marketplace. The markets we will target include power generation, highway infrastructure and transportation, oil drilling, utility pipes and natural gas pipelines. Keywords: NDE, nondestructive evaluation, ECT, eddy current test, reinforced concrete structures, sensor array, AMR