In an attempt to attain “Zero Fuel Leaks by 2010”, EPRI is embarking on a multi-disciplinary approach to NDE of fuel rods. This involves fast screening technique based on guided wave to evaluate and discriminate presence of flaws from deposits and geometry variations on individual rods by allowing access to top ends of loaded fuel rods while they are still in the fuel bundle assembly. Once the degraded fuel rod is identified, it will be removed from the fuel bundle for further testing. One of the quantification NDE methods for flaw location, OD/ID flaw discrimination, and estimation of percent wall losses is eddy current.

This paper describes the current state-of-the-art eddy current array probe used to detect, discriminate, and size identified fuel rod degradations. Present emphasis is on testing removed dry fuel rods at a hot cell facility. To perform this evaluation, EPRI has assembled an eddy current hardware/software system that can drive a 32-element OD array probe in a transmit-receive mode to allow simultaneous detection of both OD and ID initiating axial, circumferential, and off-axis flaws. To evaluate the capabilities and limitations of the fabricated array probe, a number of machined and electro-discharge machined (EDM) notches were made out of Zircoloy 4 fuel rod materials. Current capabilities of the fabricated array probe to detect and characterize various flaw sizes of known orientations and flaw depths are presented.