Phased Array UT Technology for Nuclear Pipe Inspection

Phased array UT technologles have been applied to improve pipe inspection speed and reliability. Recent results on similar and dissimilar metal welds show clear, accurate, and fast results. Phased array ultrasound has been developed and commercialized already for high-value, inspections such as turbines and boiling water reactor (BWR) core shrouds. This paper describes how the benefits of phased array technology are being extended for application to piping examinations, including the detection and length sizing of intergranular stress corrosion cracking (IGSCC) in austenitic and dissimilar metal welds. The costs associated with pipe inspections contain factors related to the duration and reliability of inspections. The phased array improvements in flaw detectability, sizing accuracy, and speed, will lower the cost and increase the reliability of piping examinations by reducing qualification costs, radiation exposure, re-scans, and repairs. EPRI is encouraging the deployment of phased array pipe inspection technology by coordinating the technique development with several vendors so that when the technique is qualified, the vendor(s) will be ready to deliver it. This approach has already worked well for other phased array applications. As more vendors develop phased array capabilities, the deployment task becomes easier. To encourage the use of this technology, EPRI has developed and qualified through the Performance Demonstration Initiative (PDI) an automated phased array procedure for piping weld inspection.