Development of remote field eddy current technique for in-service inspection of ferromagnetic steam generator tubes

Remote field eddy current (RFEC) technique uses separate exciter and receiver coils and low-excitation frequencies for non-destructive evaluation (NDE) of metallic tubes from tube-side. In this technique, induced voltage in a receiver coil placed at 2 to 3 tube diameters away from the exciter coil is measured. For in-service inspection of ferromagnetic steam generator (SG) tubes (~23 m long, 17.2 mm dia and 2.3 mm thickness) of fast breeder reactors, a comprehensive RFEC technology has been successfully developed and field-tested.