Recent Accomplishment in Ultrasonic Health Monitoring for Nuclear Power Plants
Today's NPPs follow prescriptive requirements for maintenance and inspection of components, structures, and systems. While many of these requirements are derived from several decades of operational experience, they nonetheless do not take into consider ation the actual equipment conditions in determining the need for maintenance and operational adjustments. Continuous condition monitoring in current nuclear power plants is limited to sensor technologies that must be applied externally to already exi sting components and systems. Online continuous condition monitoring using non-destructive or non-intrusive testing, such as ultrasonic testing, radiography, infrared thermograph, and motor current signature analysis, have been popular in NPPs for over a decade. But advanced monitoring technologies, including the use of fusion sensors, laser and laser-ultrasonic sensors, and fiber optic sensors, that have been used in chemical and coal plants, have had no or limited application in the NPP industry.